National Library of Energy BETA

Sample records for gas flow patterns

  1. Flow Patterns, Void Fraction and Pressure Drop in Gas-Liquid Two

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    and simultaneous transportation of oil and natural gas from remote extraction locations to the processing units#12;Chapter 4 Flow Patterns, Void Fraction and Pressure Drop in Gas-Liquid Two Phase Flow in gas-liquid two phase flow. The flow structure of different flow patterns observed in gas-liquid two

  2. Flow pattern and pressure drop of vertical upward gas-liquid flow in sinusoidal wavy channels

    SciTech Connect (OSTI)

    Nilpueng, Kitti [Department of Mechanical Engineering, South East Asia University, Bangkok 10160 (Thailand); Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

    2006-06-15

    Flow patterns and pressure drop of upward liquid single-phase flow and air-water two-phase flow in sinusoidal wavy channels are experimentally studied. The test section is formed by a sinusoidal wavy wall of 1.00 m length with a wave length of 67.20mm, an amplitude of 5.76mm. Different phase shifts between the side walls of the wavy channel of 0{sup o}, 90{sup o} and 180{sup o} are investigated. The flow phenomena, which are bubbly flow, slug flow, churn flow, and dispersed bubbly flow are observed and recorded by high-speed camera. When the phase shifts are increased, the onset of the transition from the bubbly flow to the churn flow shifts to a higher value of superficial air velocity, and the regions of the slug flow and the churn flow are smaller. In other words, the regions of the bubbly flow and the dispersed bubbly flow are larger as the phase shift increases. The slug flow pattern is only found in the test sections with phase shifts of 0{sup o} and 90{sup o}. Recirculating gas bubbles are always found in the troughs of the corrugations. The recirculating is higher when the phase shifts are larger. The relationship between the two-phase multipliers calculated from the measured pressure drops, and the Martinelli parameter is compared with the Lockhart-Martinelli correlation. The correlation in the case of turbulent-turbulent condition is shown to fit the data very well for the phase shift of 0{sup o} but shows greater deviation when the phase shifts are higher. (author)

  3. Solid oxide fuel cell having compound cross flow gas patterns

    DOE Patents [OSTI]

    Fraioli, Anthony V. (Hawthorn Woods, IL)

    1985-01-01

    A core construction for a fuel cell is disclosed having both parallel and cross flow passageways for the fuel and the oxidant gases. Each core passageway is defined by electrolyte and interconnect walls. Each electrolyte wall consists of cathode and anode materials sandwiching an electrolyte material. Each interconnect wall is formed as a sheet of inert support material having therein spaced small plugs of interconnect material, where cathode and anode materials are formed as layers on opposite sides of each sheet and are electrically connected together by the interconnect material plugs. Each interconnect wall in a wavy shape is connected along spaced generally parallel line-like contact areas between corresponding spaced pairs of generally parallel electrolyte walls, operable to define one tier of generally parallel flow passageways for the fuel and oxidant gases. Alternate tiers are arranged to have the passageways disposed normal to one another. Solid mechanical connection of the interconnect walls of adjacent tiers to the opposite sides of the common electrolyte wall therebetween is only at spaced point-like contact areas, 90 where the previously mentioned line-like contact areas cross one another.

  4. Solid oxide fuel cell having compound cross flow gas patterns

    DOE Patents [OSTI]

    Fraioli, A.V.

    1983-10-12

    A core construction for a fuel cell is disclosed having both parallel and cross flow passageways for the fuel and the oxidant gases. Each core passageway is defined by electrolyte and interconnect walls. Each electrolyte wall consists of cathode and anode materials sandwiching an electrolyte material. Each interconnect wall is formed as a sheet of inert support material having therein spaced small plugs of interconnect material, where cathode and anode materials are formed as layers on opposite sides of each sheet and are electrically connected together by the interconnect material plugs. Each interconnect wall in a wavy shape is connected along spaced generally parallel line-like contact areas between corresponding spaced pairs of generally parallel electrolyte walls, operable to define one tier of generally parallel flow passageways for the fuel and oxidant gases. Alternate tiers are arranged to have the passageways disposed normal to one another. Solid mechanical connection of the interconnect walls of adjacent tiers to the opposite sides of the common electrolyte wall therebetween is only at spaced point-like contact areas, 90 where the previously mentioned line-like contact areas cross one another.

  5. Modelling flow pattern transitions for steady upward gas-liquid flow in vertical tubes. [Bubble, slug, churn and dispersed-annular; also existence regions and transitions

    SciTech Connect (OSTI)

    Taitel, Y. (Tel-Aviv Univ., Israel); Bornea, D.; Dukler, A.E.

    1980-05-01

    Models for predicting flow patterns in steady upward gas-liquid flow in vertical tubes (such as production-well tubing) delineate the transition boundaries between each of the four basic flow patterns for gas-liquid flow in vertical tubes: bubble, slug, churn, and dispersed-annular. Model results suggest that churn flow is the development region for the slug pattern and that bubble flow can exist in small pipes only at high liquid rates, where turbulent dispersion forces are high. Each transition depends on the flow-rate pair, fluid properties, and pipe size, but the nature of the dependence is different for each transition because of differing control mechanisms. The theoretical predictions are in reasonably good agreement with a variety of published flow maps based on experimental data.

  6. Flow pattern, pressure drop and void fraction of two-phase gas-liquid flow in an inclined narrow annular channel

    SciTech Connect (OSTI)

    Wongwises, Somchai; Pipathattakul, Manop [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

    2006-03-01

    Two-phase flow pattern, pressure drop and void fraction in horizontal and inclined upward air-water two-phase flow in a mini-gap annular channel are experimentally studied. A concentric annular test section at the length of 880mm with an outer diameter of 12.5mm and inner diameter of 8mm is used in the experiments. The flow phenomena, which are plug flow, slug flow, annular flow, annular/slug flow, bubbly/plug flow, bubbly/slug-plug flow, churn flow, dispersed bubbly flow and slug/bubbly flow, are observed and recorded by high-speed camera. A slug flow pattern is found only in the horizontal channel while slug/bubbly flow patterns are observed only in inclined channels. When the inclination angle is increased, the onset of transition from the plug flow region to the slug flow region (for the horizontal channel) and from the plug flow region to slug/bubbly flow region (for inclined channels) shift to a lower value of superficial air velocity. Small shifts are found for the transition line between the dispersed bubbly flow and the bubbly/plug flow, the bubbly/plug flow and the bubbly/slug-plug flow, and the bubbly/plug flow and the plug flow. The rest of the transition lines shift to a higher value of superficial air velocity. Considering the effect of flow pattern on the pressure drop in the horizontal tube at low liquid velocity, the occurrence of slug flow stops the rise of pressure drop for a short while, before rising again after the air velocity has increased. However, the pressure does not rise abruptly in the tubes with {theta}=30{sup o} and 60{sup o} when the slug/bubbly flow occurs. At low gas and liquid velocity, the pressure drop increases, when the inclination angles changes from horizontal to 30{sup o} and 60{sup o}. Void fraction increases with increasing gas velocity and decreases with increasing liquid velocity. After increasing the inclination angle from horizontal to {theta}=30{sup o} and 60{sup o}, the void fraction appears to be similar, with a decreasing trend when the inclination angle increases. (author)

  7. Flow patterns in vertical two-phase flow

    SciTech Connect (OSTI)

    McQuillan, K.W.; Whalley, P.B.

    1985-03-01

    This paper is concerned with the flow patterns which occur in upwards gas-liquid two-phase flow in vertical tubes. The basic flow patterns are described and the use of flow patter maps is discussed. The transition between plug flow and churn flow is modelled under the assumption that flooding of the falling liquid film limits the stability of plug flow. The resulting equation is combined with other flow pattern transition equations to produce theoretical flow pattern maps, which are then tested against experimental flow pattern data. Encouraging agreement is obtained.

  8. Modeling gas flow in PEMFC channels: Part I e Flow pattern transitions and pressure drop in a simulated ex situ channel

    E-Print Network [OSTI]

    Kandlikar, Satish

    . Heat exchangers, refrigeration systems, and mini-tube condensers have adopted minichannels for two-phase flow in the gas channels of a proton exchange membrane fuel cell (PEMFC) is studied with an ex situ and horizontal orientations with two GDLs, e Baseline (Mitsubishi Rayon Co. MRC 105 with 5 wt.% PTFE and coated

  9. Magnetically stimulated fluid flow patterns

    SciTech Connect (OSTI)

    Martin, Jim; Solis, Kyle

    2014-03-06

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  10. Magnetically stimulated fluid flow patterns

    ScienceCinema (OSTI)

    Martin, Jim; Solis, Kyle

    2014-08-06

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  11. New patterns in high-speed granular flows

    E-Print Network [OSTI]

    Nicolas Brodu; Renaud Delannay; Alexandre Valance; Patrick Richard

    2015-03-04

    We report on new patterns in high-speed flows of granular materials obtained by means of extensive numerical simulations. These patterns emerge from the destabilization of unidirectional flows upon increase of mass holdup and inclination angle, and are characterized by complex internal structures including secondary flows, heterogeneous particle volume fraction, symmetry breaking and dynamically maintained order. In particular, we evidenced steady and fully developed "supported" flows, which consist of a dense core surrounded by a highly energetic granular gas. Interestingly, despite their overall diversity, these regimes are shown to obey a scaling law for the mass flow rate as a function of the mass holdup. This unique set of 3D flow regimes raises new challenges for extending the scope of current granular rheological models.

  12. EFM units monitor gas flow

    SciTech Connect (OSTI)

    Not Available

    1994-02-01

    This paper describes the radio-controlled pipeline monitoring system established by Transcontinental Gas Pipe Line Corp. which was designed to equip all its natural gas purchasing metering facilities with electronic flow measurement computers. The paper describes the actual radio equipment used and the features and reliability of the equipment.

  13. Anisotropic collective flow of a Lorentz gas

    E-Print Network [OSTI]

    Nicolas Borghini; Clement Gombeaud

    2011-06-30

    Analytical results for the anisotropic collective flow of a Lorentz gas of massless particles scattering on fixed centres are presented.

  14. Energy Policy Act Transportation Study: Interim Report on Natural Gas Flows and Rates

    Reports and Publications (EIA)

    1995-01-01

    This report, summarized data and studies that could be used to address the impact of legislative and regulatory actions on natural gas transportation rates and flow patterns.

  15. Laser cross-flow gas system

    DOE Patents [OSTI]

    Duncan, D.B.

    1992-11-24

    A method and laser apparatus are disclosed which provide for a cross-flow of gas near one end of a laser discharge tube. The cross-flow of gas causes a concentration gradient which affects diffusion of contaminants in the discharge tube towards the cross-flow of the gas, which contaminants are then withdrawn from the discharge tube. 1 figure.

  16. Two-Phase Flow Patterns in a Four by Four Rod Bundle

    SciTech Connect (OSTI)

    Yoshitaka Mizutani; Shigeo Hosokawa; Akio Tomiyama [Kobe University, Kobe (Japan)

    2006-07-01

    Air-water two-phase flow patterns in a four by four square lattice rod bundle consisting of an acrylic channel box of 68 mm in width and transparent rods of 12 mm in diameter were observed by utilizing a high speed video camera, FEP (fluorinated ethylene propylene) tubes for rods, and a fiber-scope inserted in a rod. The FEP possesses the same refractive index as water, and thereby, whole flow patterns in the bundle and local flow patterns in subchannels were successfully visualized with little optical distortion. The ranges of liquid and gas volume fluxes, and , in the present experiments were 0.1 < < 2.0 m/s and 0.04 < < 8.85 m/s, which covered typical two-phase flow patterns appearing in a fuel bundle of a boiling water nuclear reactor. As a result, the following conclusions were obtained: (1) the region of slug flow in the - flow pattern diagram is so narrow that it can be regarded as a boundary between bubbly and churn flows, (2) the boundary between bubbly and churn flows is close to the boundary between bubbly and slug flows of the Mishima and Ishii's flow pattern transition model, and (3) the boundary between churn and annular flows is well predicted by the Mishima and Ishii's model. (authors)

  17. Identification of two-phase flow patterns by a single void fraction sensor

    SciTech Connect (OSTI)

    Wang, Y.W.; King, C.H.; Pei, B.S.

    1988-10-01

    A wide range of combinations of gas and liquid flow rates that form various flow patterns are investigated. By analyzing the signal spectra detected by a single sensor using light techniques, the criteria for identifying two-phase flow patterns are proposed. By applying these criteria with only one parameter, the high-frequency contribution fraction (HFCF), the reasonable identifying performance is 76% when churn flow is counted and 88% when churn flow is not counted. When ..cap alpha..-bar is added as an auxiliary to HFCF, the identifying performance can be increased to 83 and 96%, depending on whether churn flow is counted. Both parameters can be acquired by signals from a single void fraction sensor. The criteria are expected to apply to other void fraction measurable systems for identifying two-phase flow patterns.

  18. Microgravity flow pattern identification using void fraction signals 

    E-Print Network [OSTI]

    Valota, Luca

    2005-08-29

    Knowledge of the two-phase flow state is fundamental for two-phase flow system design and operation. In traditional two-phase flow studies, the flow regime refers to the physical location of the gas and liquid in a conduit. Flow configuration...

  19. A study of grout flow pattern analysis

    SciTech Connect (OSTI)

    Lee, S. Y. [Savannah River National Lab., Aiken, SC (United States); Hyun, S. [Mercer Univ., Macon, GA (United States)

    2013-01-10

    A new disposal unit, designated as Salt Disposal Unit no. 6 (SDU6), is being designed for support of site accelerated closure goals and salt nuclear waste projections identified in the new Liquid Waste System plan. The unit is cylindrical disposal vault of 380 ft diameter and 43 ft in height, and it has about 30 million gallons of capacity. Primary objective was to develop the computational model and to perform the evaluations for the flow patterns of grout material in SDU6 as function of elevation of grout discharge port, and slurry rheology. A Bingham plastic model was basically used to represent the grout flow behavior. A two-phase modeling approach was taken to achieve the objective. This approach assumes that the air-grout interface determines the shape of the accumulation mound. The results of this study were used to develop the design guidelines for the discharge ports of the Saltstone feed materials in the SDU6 facility. The focusing areas of the modeling study are to estimate the domain size of the grout materials radially spread on the facility floor under the baseline modeling conditions, to perform the sensitivity analysis with respect to the baseline design and operating conditions such as elevation of discharge port, discharge pipe diameter, and grout properties, and to determine the changes in grout density as it is related to grout drop height. An axi-symmetric two-phase modeling method was used for computational efficiency. Based on the nominal design and operating conditions, a transient computational approach was taken to compute flow fields mainly driven by pumping inertia and natural gravity. Detailed solution methodology and analysis results are discussed here.

  20. Sandia Energy - Magnetically Stimulated Flow Patterns Offer Strategy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Magnetically Stimulated Flow Patterns Offer Strategy for Heat-Transfer Problems Home Office of Science Capabilities News News & Events Research & Capabilities Materials Science...

  1. Estimating Major and Minor Natural Fracture Patterns in Gas

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Estimating Major and Minor Natural Fracture Patterns in Gas Shales Using Production Data Razi Identification of infill drilling locations has been challenging with mixed results in gas shales. Natural fractures are the main source of permeability in gas shales. Natural fracture patterns in shale has a random

  2. Experimental and theoretical studies of isothermal upward gas-liquid flows in vertical tubes

    SciTech Connect (OSTI)

    Fernandes, R.C.

    1981-01-01

    In two-phase flow technolgy, two important problems exist which must be solved as a function of the various physical and system parameters associated with the phenomenon, and which stand as prerequisites for proper modelling of two-phase processes: Prediction of the flow pattern under existing operating conditions and prediction of the holdup for each given flow pattern. Modelling studies of steady isothermal upward gas-liquid flows in vertical pipes, at low pressures, were undertaken. Experimental data on liquid holdup over a wide range of flow rates were taken for all observed flow patterns-bubbly, slug, churn, and annular - by means of a specially designed Quick-Closing Valves System. This technique also allowed the detection of a unique phenomenon occurring in the form of fast-flowing slugs of gas-liquid mixture, in both the churn and annular flow patterns, which was called the lump phenomenon. The lump holdup was measured and a qualitative theory regarding the nature, formation and propagation of these structures was proposed. A photographic method was applied to the slug flow pattern in order to determine both the rise velocity and length of Taylor bubbles and liquid slugs characteristic of this flow regime. Assisted by the measured data, flow pattern-based physical models were developed for predicting holdup of bubbly flows and the detailed structure of slug flows. The latter was accomplished by means of a fairly complete analysis which enabled the prediction of several variables of interest such as void fractions, velocities, film thicknesses and the length ratio between Taylor bubbles and liquid slugs. The average holdup for churn flow was predicted by directly applying the slug flow model to that flow pattern. A simplified framework for calculating the holdup in annular flows was also proposed. The comparison between theory and experiment showed that for bubbly, slug and churn flows the predicted results are in good agreement with the data.

  3. Flow pattern, void fraction and pressure drop of two-phase air-water flow in a horizontal circular micro-channel

    SciTech Connect (OSTI)

    Saisorn, Sira [Energy Division, The Joint Graduate School of Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand); Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Laboratory (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

    2008-01-15

    Adiabatic two-phase air-water flow characteristics, including the two-phase flow pattern as well as the void fraction and two-phase frictional pressure drop, in a circular micro-channel are experimentally studied. A fused silica channel, 320 mm long, with an inside diameter of 0.53 mm is used as the test section. The test runs are done at superficial velocity of gas and liquid ranging between 0.37-16 and 0.005-3.04 m/s, respectively. The flow pattern map is developed from the observed flow patterns i.e. slug flow, throat-annular flow, churn flow and annular-rivulet flow. The flow pattern map is compared with those of other researchers obtained from different working fluids. The present single-phase experiments also show that there are no significant differences in the data from the use of air or nitrogen gas, and water or de-ionized water. The void fraction data obtained by image analysis tends to correspond with the homogeneous flow model. The two-phase pressure drops are also used to calculate the frictional multiplier. The multiplier data show a dependence on flow pattern as well as mass flux. A new correlation of two-phase frictional multiplier is also proposed for practical application. (author)

  4. Hydrodynamic Flow Patterns and Synchronization of Beating Cilia Andrej Vilfan*

    E-Print Network [OSTI]

    Jülicher, Frank

    Hydrodynamic Flow Patterns and Synchronization of Beating Cilia Andrej Vilfan* J. Stefan Institute 2006) We calculate the hydrodynamic flow field generated far from a cilium which is attached to a surface and beats periodically. In the case of two beating cilia, hydrodynamic interactions can lead

  5. NIST Measurement Services: Natural Gas Flow Calibration Service (NGFCS)

    E-Print Network [OSTI]

    NIST Measurement Services: Natural Gas Flow Calibration Service (NGFCS) NIST Special Publication of Standards and Technology #12;i Table of Contents for the Natural Gas Flowmeter Calibration Service (NGFCS;1 Abstract This document describes NIST's high pressure natural gas flow calibration service (NGFCS). Flow

  6. Modification of plasma flows with gas puff in the scrape-off layer of ADITYA tokamak

    SciTech Connect (OSTI)

    Sangwan, Deepak; Jha, Ratneshwar; Brotankova, Jana; Gopalkrishna, M. V. [Institute for Plasma Research, Gandhinagar 382428 (India)] [Institute for Plasma Research, Gandhinagar 382428 (India)

    2013-06-15

    The parallel Mach numbers are measured at three locations in the scrape-off layer (SOL) plasma of ADITYA tokamak by using Mach probes. The flow pattern is constructed from these measurements and the modification of flow pattern is observed by introducing a small puff of working gas. In the normal discharge, there is an indication of shell structure in the SOL plasma flows, which is removed during the gas puff. The plasma parameters, particle flux and Reynolds stress are also measured in the normal discharge and in the discharge with gas puff. It is observed that Reynolds stress and Mach number are coupled in the near SOL region and decoupled in the far SOL region. The coupling in the near SOL region gets washed away during the gas puff.

  7. Gas Flowmeter Calibrations with the Working Gas Flow Standard NIST Special Publication 250-80

    E-Print Network [OSTI]

    Gas Flowmeter Calibrations with the Working Gas Flow Standard NIST Special Publication 250-80 John of Standards and Technology U. S. Department of Commerce #12;ii Table of Contents Gas Flowmeter Calibrations with the Working Gas Flow Standard .......................... i Abstract

  8. Affinity patterning of biomaterials using plasma gas discharge

    E-Print Network [OSTI]

    Goessl, A; Hoffman, A S; Jung, L

    1996-01-01

    Patterned surfaces were prepared by combination of gas discharge and photolitographic processes. First a protein-repellent surface was prepared by glow discharge deposition of tri- and tetraglyme vapor on poly (ethylene terephtalate) surface, then on top of it fluorocarbon was deposited on selected domains by photolithography. Cell attachment was shown to be dependent of the surface hydrophilicity.

  9. Oil and Gas CDT Coupled flow of water and gas

    E-Print Network [OSTI]

    Henderson, Gideon

    , and experimental `toolbox' grounded in fluid mechanics and geomechanics, and specializing in multiphase flow

  10. Gas–Liquid Flow and Mass Transfer in an Advanced-Flow Reactor

    E-Print Network [OSTI]

    Kulkarni, Amol A.

    Hydrodynamics and mass transfer of gas–liquid flow are explored under ambient conditions in an Advanced-Flow Reactor (AFR), an emerging commercial system designed for continuous manufacture. Carbon dioxide/water is the ...

  11. Large scale structures in gas-liquid mixture flows

    SciTech Connect (OSTI)

    Davis, M.R.; Fungtamasan, B.

    1984-12-01

    Relatively slow variations in mixture void fraction in gas-liquid mixture flows are indicated by low pass filter averaging. The slow void fluctuations are found to have a regular characteristic frequency or scale in the churn flow regime or near the boundary with the dispersed bubble flow regime. These regular disturbances develop inherently in a vertical pipe flow in strength and in size and are not due to the method of flow mixing. There was no evidence of distinctive gas slugs in the flow, and the structures were identified as large clouds of bubbles which moved faster than the average velocity, growing in size and strength as they moved with the flow. The magnitude of the voidage fluctuations in the churn flow regime was on average 57% of the value for a slug flow. The large scale bubble clouds convect coherently over relatively long distances a up to 1.45 times the mean mixture flow velocity at a gas volume flow fraction of 0.4. In the bubbl flow regime, the slow voidage variations were more random in scale and were only approx. 10% of the slug flow (maximum possible) value. However, even in the bubble flow regime, the disturbances convected coherently over relatively long distances at a velocity of approx. 1.1 time the mean mixture velocity.

  12. Multiphase imaging of gas flow in a nanoporous material usingremote detection NMR

    SciTech Connect (OSTI)

    Harel, Elad; Granwehr, Josef; Seeley, Juliette A.; Pines, Alex

    2005-10-03

    Pore structure and connectivity determine how microstructured materials perform in applications such as catalysis, fluid storage and transport, filtering, or as reactors. We report a model study on silica aerogel using a recently introduced time-of-flight (TOF) magnetic resonance imaging technique to characterize the flow field and elucidate the effects of heterogeneities in the pore structure on gas flow and dispersion with Xe-129 as the gas-phase sensor. The observed chemical shift allows the separate visualization of unrestricted xenon and xenon confined in the pores of the aerogel. The asymmetrical nature of the dispersion pattern alludes to the existence of a stationary and a flow regime in the aerogel. An exchange time constant is determined to characterize the gas transfer between them. As a general methodology, this technique provides new insights into the dynamics of flow in porous media where multiple phases or chemical species may be present.

  13. OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS

    SciTech Connect (OSTI)

    Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto

    2001-09-04

    It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.

  14. Rotational-translational relaxation effects in diatomic-gas flows

    E-Print Network [OSTI]

    Riabov, Vladimir V.

    Rotational-translational relaxation effects in diatomic-gas flows V.V. Riabov Department the nonequilibrium gas dynamic equations from the first prin- ciples of the kinetic theory of gases was studied exchange ratio was analyzed in [2], [3], [4], [5] for polyatomic gas mixtures. In the present study

  15. Using multi-layer models to forecast gas flow rates in tight gas reservoirs 

    E-Print Network [OSTI]

    Jerez Vera, Sergio Armando

    2007-04-25

    USING MULTI-LAYER MODELS TO FORECAST GAS FLOW RATES IN TIGHT GAS RESERVOIRS A Thesis by SERGIO ARMANDO JEREZ VERA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2006 Major Subject: Petroleum Engineering USING MULTI-LAYER MODELS TO FORECAST GAS FLOW RATES IN TIGHT GAS RESERVOIRS A Thesis by SERGIO ARMANDO JEREZ VERA Submitted...

  16. Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

    E-Print Network [OSTI]

    Marchese, Francis

    Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

  17. DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS

    SciTech Connect (OSTI)

    X. Wang; X. Sun; H. Zhao

    2011-09-01

    In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do not exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in which flow regime transition occurs.

  18. Studies of vertical annular gas-liquid flows

    SciTech Connect (OSTI)

    Zabaras, G.J.

    1985-01-01

    Three types of vertical flowing films were studied. These are the free falling film, the falling film in the presence of countercurrent gas flow, and the upward moving film due to concurrent flow of gas. An experimental program was performed based on a new electrochemical method for the dynamic measurement of the magnitude and the direction of the wall shear stress, and on a conductance wire probe for the simultaneous measurement of the film thickness. Pressure drop was measured over a short distance with a differential pressure transducer. The data obtained for the free falling film reveal a strong length effect on the wavy-film structure. The measured variation of the wall shear stress along a wave suggests that a mixing vortex exists in the wave front followed by the development of a hydrodynamic boundary layer in the wave back. Analysis of the data taken with counter current flow of gas shows that even at the flooding condition, the film flow is controlled by downward wave motion. Measured wall shear stress was found to be upward directed and decreasing in magnitude with increasing gas rate. Analyses of the upward film flow data in a variety of ways suggest that, at low gas rates, the motion of the interface is controlled by a process of switching between possible steady states of the system. This condition is usually designated as churn flow but bridging of the liquid across the pipe as associated with churning does not occur.

  19. Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows

    SciTech Connect (OSTI)

    Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

    2014-04-11

    Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

  20. Pattern of shallow ground water flow at Mount Princeton Hot Springs...

    Open Energy Info (EERE)

    Pattern of shallow ground water flow at Mount Princeton Hot Springs, Colorado, using geoelectrical methods Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  1. Flammable gas interlock spoolpiece flow response test plan and procedure

    SciTech Connect (OSTI)

    Schneider, T.C., Fluor Daniel Hanford

    1997-02-13

    The purpose of this test plan and procedure is to test the Whittaker electrochemical cell and the Sierra Monitor Corp. flammable gas monitors in a simulated field flow configuration. The sensors are used on the Rotary Mode Core Sampling (RMCS) Flammable Gas Interlock (FGI), to detect flammable gases, including hydrogen and teminate the core sampling activity at a predetermined concentration level.

  2. Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability

    SciTech Connect (OSTI)

    Kim, Jihoon; Moridis, George

    2014-12-01

    We investigate coupled flow and geomechanics in gas production from extremely low permeability reservoirs such as tight and shale gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every time step. We consider gas reservoirs with the vertical and horizontal primary fractures, employing the single and dynamic double porosity (dual continuum) models. We modify the multiple porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that production of gas causes redistribution of the effective stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which in turn causes a change in distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, high Biot's coefficient, low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double porosity model is used, we observe a faster evolution of the enhanced permeability areas than that obtained from the single porosity model, mainly due to a higher permeability of the fractures in the double porosity model. These complicated physics for stress sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and thus tightly coupled flow and geomechanical models are highly recommended to accurately describe the reservoir behavior during gas production in tight and shale gas reservoirs and to smartly design production scenarios.

  3. System for controlling the flow of gas into and out of a gas laser

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA); Uhlich, Dennis M. (Livermore, CA); Benett, William J. (Livermore, CA); Ault, Earl R. (Dublin, CA)

    1994-01-01

    A modularized system for controlling the gas pressure within a copper vapor or like laser is described herein. This system includes a gas input assembly which serves to direct gas into the laser in a controlled manner in response to the pressure therein for maintaining the laser pressure at a particular value, for example 40 torr. The system also includes a gas output assembly including a vacuum pump and a capillary tube arrangement which operates within both a viscous flow region and a molecular flow region for drawing gas out of the laser in a controlled manner.

  4. Optimal Control of Transient Flow in Natural Gas Networks

    E-Print Network [OSTI]

    Zlotnik, Anatoly; Backhaus, Scott

    2015-01-01

    We outline a new control system model for the distributed dynamics of compressible gas flow through large-scale pipeline networks with time-varying injections, withdrawals, and control actions of compressors and regulators. The gas dynamics PDE equations over the pipelines, together with boundary conditions at junctions, are reduced using lumped elements to a sparse nonlinear ODE system expressed in vector-matrix form using graph theoretic notation. This system, which we call the reduced network flow (RNF) model, is a consistent discretization of the PDE equations for gas flow. The RNF forms the dynamic constraints for optimal control problems for pipeline systems with known time-varying withdrawals and injections and gas pressure limits throughout the network. The objectives include economic transient compression (ETC) and minimum load shedding (MLS), which involve minimizing compression costs or, if that is infeasible, minimizing the unfulfilled deliveries, respectively. These continuous functional optimiza...

  5. Rarefied gas flow in a rectangular enclosure induced by non-isothermal walls

    SciTech Connect (OSTI)

    Vargas, Manuel; Tatsios, Giorgos; Valougeorgis, Dimitris; Stefanov, Stefan

    2014-05-15

    The flow of a rarefied gas in a rectangular enclosure due to the non-isothermal walls with no synergetic contributions from external force fields is investigated. The top and bottom walls are maintained at constant but different temperatures and along the lateral walls a linear temperature profile is assumed. Modeling is based on the direct numerical solution of the Shakhov kinetic equation and the Direct Simulation Monte Carlo (DSMC) method. Solving the problem both deterministically and stochastically allows a systematic comparison and verification of the results as well as the exploitation of the numerical advantages of each approach in the investigation of the involved flow and heat transfer phenomena. The thermally induced flow is simulated in terms of three dimensionless parameters characterizing the problem, namely, the reference Knudsen number, the temperature ratio of the bottom over the top plates, and the enclosure aspect ratio. Their effect on the flow configuration and bulk quantities is thoroughly examined. Along the side walls, the gas flows at small Knudsen numbers from cold-to-hot, while as the Knudsen number is increased the gas flows from hot-to-cold and the thermally induced flow configuration becomes more complex. These flow patterns with the hot-to-cold flow to be extended to the whole length of the non-isothermal side walls may exist even at small temperature differences and then, they are enhanced as the temperature difference between the top and bottom plates is increased. The cavity aspect ratio also influences this flow configuration and the hot-to-cold flow is becoming more dominant as the depth compared to the width of the cavity is increased. To further analyze the flow patterns a novel solution decomposition into ballistic and collision parts is introduced. This is achieved by accordingly modifying the indexing process of the typical DSMC algorithm. The contribution of each part of the solution is separately examined and a physical interpretation of the flow configuration, including the hot-to-cold flow close to the side walls, in the whole range of the Knudsen number is provided.

  6. Turbine exhaust diffuser with region of reduced flow area and outer boundary gas flow

    DOE Patents [OSTI]

    Orosa, John

    2014-03-11

    An exhaust diffuser system and method for a turbine engine. The outer boundary may include a region in which the outer boundary extends radially inwardly toward the hub structure and may direct at least a portion of an exhaust flow in the diffuser toward the hub structure. At least one gas jet is provided including a jet exit located on the outer boundary. The jet exit may discharge a flow of gas downstream substantially parallel to an inner surface of the outer boundary to direct a portion of the exhaust flow in the diffuser toward the outer boundary to effect a radially outward flow of at least a portion of the exhaust gas flow toward the outer boundary to balance an aerodynamic load between the outer and inner boundaries.

  7. Gas flow driven by thermal creep in dusty plasma T. M. Flanagan and J. Goree

    E-Print Network [OSTI]

    Goree, John

    Gas flow driven by thermal creep in dusty plasma T. M. Flanagan and J. Goree Department of Physics 2009 Thermal creep flow TCF is a flow of gas driven by a temperature gradient along a solid boundary to the bulk gas, causing the bulk gas to flow, thereby stirring the suspension of dust particles. This result

  8. Computational Study of Turbulent Laminar Patterns in Couette Flow Dwight Barkley*

    E-Print Network [OSTI]

    Barkley, Dwight

    Computational Study of Turbulent Laminar Patterns in Couette Flow Dwight Barkley* Mathematics, 91403 Orsay, France (Received 29 March 2004; published 7 January 2005) Turbulent-laminar patterns near--undergoes a discontinuous transition from laminar flow to turbulence as the Reynolds number is increased. Because of its

  9. Gas mass transfer for stratified flows

    SciTech Connect (OSTI)

    Duffey, R.B.; Hughes, E.D.

    1995-06-01

    We analyzed gas absorption and release in water bodies using existing surface renewal theory. We show a new relation between turbulent momentum and mass transfer from gas to water, including the effects of waves and wave roughness, by evaluating the equilibrium integral turbulent dissipation due to energy transfer to the water from the wind. Using Kolmogoroff turbulence arguments the gas transfer velocity, or mass transfer coefficient, is then naturally and straightforwardly obtained as a non-linear function of the wind speed drag coefficient and the square root of the molecular diffusion coefficient. In dimensionless form, the theory predicts the turbulent Sherwood number to be Sh{sub t} = (2/{radical}{pi})Sc{sup 1/2}, where Sh{sub t} is based on an integral dissipation length scale in the air. The theory confirms the observed nonlinear variation of the mass transfer coefficient as a function of the wind speed; gives the correct transition with turbulence-centered models for smooth surfaces at low speeds; and predicts experimental data from both laboratory and environmental measurements within the data scatter. The differences between the available laboratory and field data measurements are due to the large differences in the drag coefficient between wind tunnels and oceans. The results also imply that the effect of direct aeration due to bubble entrainment at wave breaking is no more than a 20% increase in the mass transfer for the highest speeds. The theory has importance to mass transfer in both the geo-physical and chemical engineering literature.

  10. Gas mass transfer for stratified flows

    SciTech Connect (OSTI)

    Duffey, R.B.; Hughes, E.D.

    1995-07-01

    We analyzed gas absorption and release in water bodies using existing surface renewal theory. We show a new relation between turbulent momentum and mass transfer from gas to water, including the effects of waves and wave roughness, by evaluating the equilibrum integral turbulent dissipation due to energy transfer to the water from the wind. Using Kolmogoroff turbulence arguments the gas transfer velocity, or mass transfer coefficient, is then naturally and straightforwardly obtained as a non-linear function of the wind speed drag coefficient and the square root of the molecular diffusion coefficient. In dimensionless form, the theory predicts the turbulent Sherwood number to be Sh{sub t} = (2/{radical}{pi}) Sc{sup 1/2}, where Sh{sub t} is based on an integral dissipation length scale in the air. The theory confirms the observed nonlinear variation of the mass transfer coefficient as a function of the wind speed; gives the correct transition with turbulence-centered models for smooth surfaces at low speeds; and predicts experimental data from both laboratory and environmental measurements within the data scatter. The differences between the available laboratory and field data measurements are due to the large differences in the drag coefficient between wind tunnels and oceans. The results also imply that the effect of direct aeration due to bubble entrainment at wave breaking is no more than a 20% increase in the mass transfer for the highest speeds. The theory has importance to mass transfer in both the geophysical and chemical engineering literature.

  11. Pressure drop and void fraction in intermittent inclined gas-liquid pipe flow

    SciTech Connect (OSTI)

    Aboba, B.D.

    1990-01-01

    The mechanistic approach to gas-liquid flow has been gaining in popularity over the last decade. However currently no models exist to predict pressure drop and void fraction in steeply inclined intermittent Flow. In this work, a model has been developed for prediction of pressure drop and void fraction in intermittent flow at all inclination angles, and verified for angles between {minus}9{degree} and +90{degree}. This model is also suitable for predicting pressure drop and void fraction within the bubble and churn flow regimes. Pressure drop and void fraction predictions are compared with published experimental data on inclined intermittent gas-liquid flow, and agreement is found to be very good. While accurate estimeates of pressure drop and void fraction require accurate flow regime predictions, no comprehensive evaluation of inclined flow pattern prediction methods is currently available. This work compares the theories advanced by workers at the University of Houston and Tel-Aviv University, the University of Cincinnati and Drexel University, and the University of Tulsa against a wide range of experimental data. Alternative schemes are proposed for the dispersed bubble. distorted bubble, elongated bubble-slug, churn, and annular transitions.

  12. Microfluidic gas flow profiling using remote detection NMR

    SciTech Connect (OSTI)

    Hilty, Christian; McDonnell, Erin; Granwehr, Josef; Pierce,Kimberly; Han, Song-I Han; Pines, Alexander

    2005-05-06

    Miniaturized fluid handling devices have recently attracted considerable interest in many areas of science1. Such microfluidic chips perform a variety of functions, ranging from analysis of biological macromolecules2,3 to catalysis of reactions and sensing in the gas phase4,5. To enable precise fluid handling, accurate knowledge of the flow properties within these devices is important. Due to low Reynolds numbers, laminar flow is usually assumed. However, either by design or unintentionally, the flow characteristic in small channels is often altered, for example by surface interactions, viscous and diffusional effects, or electrical potentials. Therefore, its prediction is not always straight-forward6-8. Currently, most microfluidic flow measurements rely on optical detection of markers9,10, requiring the injection of tracers and transparent devices. Here, we show profiles of microfluidic gas flow in capillaries and chip devices obtained by NMR in the remote detection modality11,12. Through the transient measurement of dispersion13, NMR is well adaptable for non-invasive, yet sensitive determination of the flow field and provides a novel and potentially more powerful tool to profile flow in capillaries and miniaturized flow devices.

  13. CFD evaluation of pipeline gas stratification at low fluid flow due to temperature effects 

    E-Print Network [OSTI]

    Brar, Pardeep Singh

    2005-02-17

    It has been found through experiments at Southwest Research Institute that temperature differences between the gas and wall of the pipe through which the gas is flowing can greatly influence the gas flow in the pipe line ...

  14. Classification of Two-Phase Flow Patterns by Ultrasonic Sensing

    E-Print Network [OSTI]

    Ray, Asok

    in addition to several other factors such as the bulk flow rate, fluid properties, and flow boundary of their departure from the single-phase liquid as bubbly, capillary (also called cap-bubbly), slug, churn, annular

  15. Recognising Visual Patterns to Communicate Gas Turbine Time-Series Data

    E-Print Network [OSTI]

    Reiter, Ehud

    Recognising Visual Patterns to Communicate Gas Turbine Time-Series Data Jin Yu, Jim Hunter, Ehud analogue channels are sampled once per second and archived by the Tiger system for monitoring gas turbines that it is very important to identify such patterns in any attempt at summarisation. In the gas turbine domain

  16. Gas flows, star formation and galaxy evolution

    E-Print Network [OSTI]

    John E. Beckman; Emilio Casuso; Almudena Zurita; Monica Relaño

    2004-05-31

    In the first part of this article we show how observations of the chemical evolution of the Galaxy: G- and K-dwarf numbers as functions of metallicity, and abundances of the light elements, D, Li, Be and B, in both stars and the interstellar medium (ISM), lead to the conclusion that metal poor HI gas has been accreting to the Galactic disc during the whole of its lifetime, and is accreting today at a measurable rate, ~2 Msun per year across the full disc. Estimates of the local star formation rate (SFR) using methods based on stellar activity, support this picture. The best fits to all these data are for models where the accretion rate is constant, or slowly rising with epoch. We explain here how this conclusion, for a galaxy in a small bound group, is not in conflict with graphs such as the Madau plot, which show that the universal SFR has declined steadily from z=1 to the present day. We also show that a model in which disc galaxies in general evolve by accreting major clouds of low metallicity gas from their surroundings can explain many observations, notably that the SFR for whole galaxies tends to show obvious variability, and fractionally more for early than for late types, and yields lower dark to baryonic matter ratios for large disc galaxies than for dwarfs. In the second part of the article we use NGC 1530 as a template object, showing from Fabry-Perot observations of its Halpha emission how strong shear in this strongly barred galaxy acts to inhibit star formation, while compression acts to stimulate it.

  17. Energy policy act transportation study: Interim report on natural gas flows and rates

    SciTech Connect (OSTI)

    1995-11-17

    This report, Energy Policy Act Transportation Study: Interim Report on Natural Gas Flows and Rates, is the second in a series mandated by Title XIII, Section 1340, ``Establishment of Data Base and Study of Transportation Rates,`` of the Energy Policy Act of 1992 (P.L. 102--486). The first report Energy Policy Act Transportation Study: Availability of Data and Studies, was submitted to Congress in October 1993; it summarized data and studies that could be used to address the impact of legislative and regulatory actions on natural gas transportation rates and flow patterns. The current report presents an interim analysis of natural gas transportation rates and distribution patterns for the period from 1988 through 1994. A third and final report addressing the transportation rates and flows through 1997 is due to Congress in October 2000. This analysis relies on currently available data; no new data collection effort was undertaken. The need for the collection of additional data on transportation rates will be further addressed after this report, in consultation with the Congress, industry representatives, and in other public forums.

  18. Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas

    E-Print Network [OSTI]

    Oldenburg, C.M.

    2013-01-01

    for estimates of the oil and gas flow rate from the Macondoteam and carried out oil and gas flow simulations using theoil-gas system. The flow of oil and gas was simulated using

  19. Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas

    E-Print Network [OSTI]

    Oldenburg, C.M.

    2013-01-01

    for estimates of the oil and gas flow rate from the Macondooil-gas system. The flow of oil and gas was simulated usingmaximal flow rates of oil and gas. With the conceptual model

  20. Modeling non-annular flow in gas condensate wells

    SciTech Connect (OSTI)

    Garber, J.D.; Varanasi, N.R.S. [Univ. of Southwestern Louisiana, Lafayette, LA (United States). Corrosion Research Center

    1997-09-01

    As gas condensate wells mature they begin producing less gas and more formation water. At this point the wells will likely begin to experience non-annular flow. A model has been developed which fully describes slug flow, and a criterion has been established to locate the slug-churn hydrodynamic transition in the non-annular region. The model has been verified using laboratory generated data. It has been applied to several wells being produced in the Gulf of Mexico to indicate whether they are in slug or churn flow. The information generated has been useful in providing a method for calculating the residence time of the liquids inside the tubing and the pressure drop per 100 feet of tubing.

  1. Coupling of a two phase gas liquid compositional 3D Darcy flow with a 1D compositional free gas

    E-Print Network [OSTI]

    Ribot, Magali

    Coupling of a two phase gas liquid compositional 3D Darcy flow with a 1D compositional free gas. Masson1 , L. Trenty2 , Y. Zhang1 Coupling of a two phase gas liquid compositional 3D Darcy flow #12 analysis K, Brenner1 , R. Masson1 , L. Trenty2 , Y. Zhang1 Coupling of a two phase gas liquid compositional

  2. Parametric study of flow patterns behind the standing accretion shock wave for core-collapse supernovae

    SciTech Connect (OSTI)

    Iwakami, Wakana; Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Yamada, Shoichi, E-mail: wakana@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2014-05-10

    In this study, we conduct three-dimensional hydrodynamic simulations systematically to investigate the flow patterns behind the accretion shock waves that are commonly formed in the post-bounce phase of core-collapse supernovae. Adding small perturbations to spherically symmetric, steady, shocked accretion flows, we compute the subsequent evolutions to find what flow pattern emerges as a consequence of hydrodynamical instabilities such as convection and standing accretion shock instability for different neutrino luminosities and mass accretion rates. Depending on these two controlling parameters, various flow patterns are indeed realized. We classify them into three basic patterns and two intermediate ones; the former includes sloshing motion (SL), spiral motion (SP), and multiple buoyant bubble formation (BB); the latter consists of spiral motion with buoyant-bubble formation (SPB) and spiral motion with pulsationally changing rotational velocities (SPP). Although the post-shock flow is highly chaotic, there is a clear trend in the pattern realization. The sloshing and spiral motions tend to be dominant for high accretion rates and low neutrino luminosities, and multiple buoyant bubbles prevail for low accretion rates and high neutrino luminosities. It is interesting that the dominant pattern is not always identical between the semi-nonlinear and nonlinear phases near the critical luminosity; the intermediate cases are realized in the latter case. Running several simulations with different random perturbations, we confirm that the realization of flow pattern is robust in most cases.

  3. Fiber-optic interferometric sensor for gas flow measurements

    SciTech Connect (OSTI)

    Kaminski, W.R. ); Griffin, J.W.; Bates, J.M. )

    1991-12-01

    This paper presents the results of an investigation to determine the feasibility of a novel approach to measuring gas flow in a pipe. An optical fiber is stretched across a pipe and serves as a sensor which is based upon the well-established principle of vortex shedding of a cylinder in cross-flow. The resulting time varying optical signal produces a frequency component proportional to the average velocity in the pipe which is in turn proportional to volumetric flow. A Mach-Zehnder interferometer is used to enhance the accuracy of the vortex shedding frequency signal. The analytical and experimental effort discussed herein shows that the concept is feasible and holds promise for a sensitive and accurate flow measuring technique.

  4. Enhanced thermal and gas flow performance in a three-way catalytic...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    thermal and gas flow performance in a three-way catalytic converter through use of insulation within the ceramic monolith Enhanced thermal and gas flow performance in a three-way...

  5. Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow

    E-Print Network [OSTI]

    Braun, Paul

    Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow Hyung as narrow as 5 m was created by controlling these parameters. The chemical gradient by laminar co validates the numerical procedures established in this study. Flow of multiple laminar streams of reactive

  6. Mass flow rate measurements in gas-liquid flows by means of a venturi or orifice plate coupled to a void fraction sensor

    SciTech Connect (OSTI)

    Oliveira, Jorge Luiz Goes; Passos, Julio Cesar [Departamento de Engenharia Mecanica-LEPTEN/Boiling-UFSC, Campus Universitario, Trindade, 88.040-900 Florianopolis-SC (Brazil); Verschaeren, Ruud; Geld, Cees van der [Eindhoven University of Technology, Faculty of Mechanical Engineering, W-hoog 2.135, P.O. Box 513, 5600 MB, Eindhoven (Netherlands)

    2009-01-15

    Two-phase flow measurements were carried out using a resistive void fraction meter coupled to a venturi or orifice plate. The measurement system used to estimate the liquid and gas mass flow rates was evaluated using an air-water experimental facility. Experiments included upward vertical and horizontal flow, annular, bubbly, churn and slug patterns, void fraction ranging from 2% to 85%, water flow rate up to 4000 kg/h, air flow rate up to 50 kg/h, and quality up to almost 10%. The fractional root mean square (RMS) deviation of the two-phase mass flow rate in upward vertical flow through a venturi plate is 6.8% using the correlation of Chisholm (D. Chisholm, Pressure gradients during the flow of incompressible two-phase mixtures through pipes, venturis and orifice plates, British Chemical Engineering 12 (9) (1967) 454-457). For the orifice plate, the RMS deviation of the vertical flow is 5.5% using the correlation of Zhang et al. (H.J. Zhang, W.T. Yue, Z.Y. Huang, Investigation of oil-air two-phase mass flow rate measurement using venturi and void fraction sensor, Journal of Zhejiang University Science 6A (6) (2005) 601-606). The results show that the flow direction has no significant influence on the meters in relation to the pressure drop in the experimental operation range. Quality and slip ratio analyses were also performed. The results show a mean slip ratio lower than 1.1, when bubbly and slug flow patterns are encountered for mean void fractions lower than 70%. (author)

  7. A Lattice Boltzmann study of flow along patterned surfaces and through channels with alternating slip length

    E-Print Network [OSTI]

    Nayaz Khalid Ahmed; Martin Hecht

    2009-11-09

    In microfluidics, varying wetting properties, expressed in terms of the local slip length, can be used to influence the flow of a liquid through a device. We study flow past surfaces on which the slip length is modulated in stripes. We find that the effective slip length for such a flow can be expressed as a function of the individual slip lengths on the stripes. The angle dependence of the effective slip is in excellent agreement with a recent theory describing the slip length as a tensorial quantity. This tensorial nature allows to induce a transverse flow, which can be used in micro mixers to drive a vortex. In our simulations of a flow through a square channel with patterned surfaces we see a homogeneous rotation about the direction of the flow. We investigate the influence of patterns of cosine shaped varying local slip on the flow field depending on the orientation of the pattern and find the largest effective slip length for periods of stripes parallel to the flow direction.

  8. Analysis of Developing Gas/liquid Two-Phase Flows

    SciTech Connect (OSTI)

    Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal; Donna Post Guillen; Matthias Beyer; Dirk Lucas

    2010-06-01

    The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made in simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.

  9. MOUNTAIN-VALLEY AND KATABATIC FLOW IN BOULDER Find mountain valley circulation patterns that indicate mountain-valley flow, e.g.,

    E-Print Network [OSTI]

    MOUNTAIN-VALLEY AND KATABATIC FLOW IN BOULDER TASK: Find mountain valley circulation patterns that indicate mountain-valley flow, e.g., in the Boulder Canyon or katabatic flow between the mountain ranges and the lower terrains around Denver and Colorado. MOTIVATION: Mountain-valley flow is a common well understood

  10. Acoustic cross-correlation flowmeter for solid-gas flow

    DOE Patents [OSTI]

    Sheen, S.H.; Raptis, A.C.

    1984-05-14

    Apparatus for measuring particle velocity in a solid-gas flow within a pipe includes: first and second transmitting transducers for transmitting first and second ultrasonic signals into the pipe at first and second locations, respectively, along the pipe; an acoustic decoupler, positioned between said first and second transmitting transducers, for acoustically isolating said first and second signals from one another; first and second detecting transducers for detecting said first and second signals and for generating first and second detected signals; and means for cross-correlating said first and second output signals.

  11. Lattice gas automata for flow and transport in geochemical systems

    SciTech Connect (OSTI)

    Janecky, D.R.; Chen, S.; Dawson, S.; Eggert, K.C.; Travis, B.J.

    1992-05-01

    Lattice gas automata models are described, which couple solute transport with chemical reactions at mineral surfaces within pore networks. Diffusion in a box calculations are illustrated, which compare directly with Fickian diffusion. Chemical reactions at solid surfaces, including precipitation/dissolution, sorption, and catalytic reaction, can be examined with the model because hydrodynamic transport, solute diffusion and mineral surface processes are all treated explicitly. The simplicity and flexibility of the approach provides the ability to study the interrelationship between fluid flow and chemical reactions in porous materials, at a level of complexity that has not previously been computationally possible.

  12. Lattice gas automata for flow and transport in geochemical systems

    SciTech Connect (OSTI)

    Janecky, D.R.; Chen, S.; Dawson, S.; Eggert, K.C.; Travis, B.J.

    1992-01-01

    Lattice gas automata models are described, which couple solute transport with chemical reactions at mineral surfaces within pore networks. Diffusion in a box calculations are illustrated, which compare directly with Fickian diffusion. Chemical reactions at solid surfaces, including precipitation/dissolution, sorption, and catalytic reaction, can be examined with the model because hydrodynamic transport, solute diffusion and mineral surface processes are all treated explicitly. The simplicity and flexibility of the approach provides the ability to study the interrelationship between fluid flow and chemical reactions in porous materials, at a level of complexity that has not previously been computationally possible.

  13. Measurement of Flow Phenomena in a Lower Plenum Model of a Prismatic Gas-Cooled Reactor

    SciTech Connect (OSTI)

    Hugh M. McIlroy, Jr.; Donald M. McEligot; Robert J. Pink

    2008-05-01

    Mean-velocity-field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. The data were obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered for assessing computational fluid dynamics (CFD) software. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. This paper reviews the experimental apparatus and procedures, presents a sample of the data set, and reviews the INL Standard Problem. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid so that optical techniques may be employed for the measurements. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages in and around objects to be obtained without locating intrusive transducers that will disturb the flow field and without distortion of the optical paths. An advantage of the INL system is its large size, leading to improved spatial and temporal resolution compared to similar facilities at smaller scales. A three-dimensional (3-D) Particle Image Velocimetry (PIV) system was used to collect the data. Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. Uncertainty analysis and a discussion of the standard problem are included. The measurements reveal undeveloped, non-uniform, turbulent flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and presentations that describe the component flows at specific regions in the model. Information on inlet conditions are also presented.

  14. Flammable gas interlock spoolpiece flow response test report

    SciTech Connect (OSTI)

    Schneider, T.C., Fluor Daniel Hanford

    1997-03-24

    The purpose of this test report is to document the testing performed under the guidance of HNF-SD-WM-TC-073, {ital Flammable Gas Interlock Spoolpiece Flow Response Test Plan and Procedure}. This testing was performed for Lockheed Martin Hanford Characterization Projects Operations (CPO) in support of Rotary Mode Core Sampling jointly by SGN Eurisys Services Corporation and Numatec Hanford Company. The testing was conducted in the 305 building Engineering Testing Laboratory (ETL). NHC provides the engineering and technical support for the 305 ETL. The key personnel identified for the performance of this task are as follows: Test responsible engineering manager, C. E. Hanson; Flammable Gas Interlock Design Authority, G. P. Janicek; 305 ETL responsible manager, N. J. Schliebe; Cognizant RMCS exhauster engineer, E. J. Waldo/J. D. Robinson; Cognizant 305 ETL engineer, K. S. Witwer; Test director, T. C. Schneider. Other support personnel were supplied, as necessary, from 305/306 ETL. The testing, on the flammable Gas Interlock (FGI) system spoolpiece required to support Rotary Mode Core Sampling (RMCS) of single shell flammable gas watch list tanks, took place between 2-13-97 and 2-25-97.

  15. The static and dynamic characteristics of divergent tapered-bore hole-pattern gas seals 

    E-Print Network [OSTI]

    Carter, Jeremy John

    2001-01-01

    Experimental data is presented for three hole-pattern annular gas seals with differing diverging tapers machined in them. The holes are approximately 3.12 mm (.123 in) deep on average with a hole area to surface area ratio ...

  16. Gas flow to a barometric pumping well in a multilayer unsaturated Kehua You,1

    E-Print Network [OSTI]

    Zhan, Hongbin

    Gas flow to a barometric pumping well in a multilayer unsaturated zone Kehua You,1 Hongbin Zhan,1. [1] When an open well is installed in an unsaturated zone, gas can flow between the subsurface and the well depending on the gas pressure gradient near the well. This well is called a barometric pumping

  17. Use of exhaust gas as sweep flow to enhance air separation membrane performance

    DOE Patents [OSTI]

    Dutart, Charles H. (Washington, IL); Choi, Cathy Y. (Morton, IL)

    2003-01-01

    An intake air separation system for an internal combustion engine is provided with purge gas or sweep flow on the permeate side of separation membranes in the air separation device. Exhaust gas from the engine is used as a purge gas flow, to increase oxygen flux in the separation device without increasing the nitrogen flux.

  18. Wastewater treatment and flow patterns in an onsite subsurface flow constructed wetland 

    E-Print Network [OSTI]

    Stecher, Matthew C

    2001-01-01

    Subsurface flow constructed wetlands (SFCWs) are becoming increasingly common as a secondary treatment of onsite domestic wastewater. Even though SFCWs are being used widely, sufficient data has not been collected to determine how parameters...

  19. ARTICLE IN PRESS 1 Inferring flow types from dye patterns in macroporous soils

    E-Print Network [OSTI]

    Weiler, Markus

    2003; accepted 29 August 2003 6 Abstract 7 In this study, we exploit dye patterns to identify flow, and we think the concepts will have broad 18 application in soil science and infiltration research to compare the infiltration regimes of soils. 19 D 2003 Published by Elsevier B.V. 20 21 Keywords: Dye

  20. Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma

    SciTech Connect (OSTI)

    Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)] [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

    2014-04-15

    We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n{sub plu}, which is estimated from the current and the drift velocity, and the gas flow velocity v{sub gas} is examined. It is found that the dependence of the density on the gas flow velocity has relations of n{sub plu} ? log(v{sub gas}). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity.

  1. Microscale gas flow: A comparison of Grad's 13 moment equations and other continuum approaches

    E-Print Network [OSTI]

    Victoria, University of

    and chemical sensors, and fuel cells. The gas and fluid flows in devices of this size exhibit behavior that can) is not negligible compared to the characteristic length scale. The rarefaction of a fluid flow is also seen aircraft. Currently, when one looks to model fluid flow and heat transfer in a rarefied flow there are two

  2. Laminar-turbulent patterning in wall-bounded shear flows: a Galerkin model

    E-Print Network [OSTI]

    Seshasayanan, K

    2015-01-01

    On its way to turbulence, plane Couette flow - the flow between counter-translating parallel plates - displays a puzzling steady oblique laminar-turbulent pattern. We approach this problem via Galerkin modelling of the Navier-Stokes equations. The wall-normal dependence of the hydrodynamic field is treated by means of expansions on functional bases fitting the boundary conditions exactly. This yields a set of partial differential equations for the spatiotemporal dynamics in the plane of the flow. Truncating this set beyond lowest nontrivial order is numerically shown to produce the expected pattern, therefore improving over what was obtained at cruder effective wall-normal resolution. Perspectives opened by the approach are discussed.

  3. The lattice Boltzmann method for isothermal micro-gaseous flow and its application in shale gas flow: a review

    E-Print Network [OSTI]

    Wang, Junjian; Kang, Qinjun; Rahman, Sheik S

    2015-01-01

    The lattice Boltzmann method (LBM) has experienced tremendous advances and been well accepted as a popular method of simulation of various fluid flow mechanisms on pore scale in tight formations. With the introduction of an effective relaxation time and slip boundary conditions, the LBM has been successfully extended to solve micro-gaseous related transport and phenomena. As gas flow in shale matrix is mostly in the slip flow and transition flow regimes, given the difficulties of experimental techniques to determine extremely low permeability, it appears that the computational methods especially the LBM can be an attractive choice for simulation of these micro-gaseous flows. In this paper an extensive overview on a number of relaxation time and boundary conditions used in LBM-like models for micro-gaseous flow are carried out and their advantages and disadvantages are discussed. Furthermore, potential application of the LBM in flow simulation in shale gas reservoirs on pore scale and representative elementary...

  4. A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation

    SciTech Connect (OSTI)

    Dr. Adam London

    2008-06-20

    The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.

  5. A simple model of gas flow in a porous powder compact

    SciTech Connect (OSTI)

    Shugard, Andrew D.; Robinson, David B.

    2014-04-01

    This report describes a simple model for ideal gas flow from a vessel through a bed of porous material into another vessel. It assumes constant temperature and uniform porosity. Transport is treated as a combination of viscous and molecular flow, with no inertial contribution (low Reynolds number). This model can be used to fit data to obtain permeability values, determine flow rates, understand the relative contributions of viscous and molecular flow, and verify volume calibrations. It draws upon the Dusty Gas Model and other detailed studies of gas flow through porous media.

  6. Study of gas flow dynamics in porous and granular media with laser-polarized ¹²?Xe NMR

    E-Print Network [OSTI]

    Wang, Ruopeng, 1972-

    2005-01-01

    This thesis presents Nuclear Magnetic Resonance (NMR) studies of gas flow dynamics in porous and granular media by using laser-polarized ¹²?Xe . Two different physical processes, the gas transport in porous rock cores and ...

  7. Fractal flow patterns in hydrophobic microfluidic pore networks: experimental modeling of two-phase flow in porous electrodes

    E-Print Network [OSTI]

    Berejnov, Viatcheslav; Sinton, David; Djilali, Ned

    2009-01-01

    Experimental two-phase invasion percolation flow patterns were observed in hydrophobic micro-porous networks designed to model fuel cell specific porous media. In order to mimic the operational conditions encountered in the porous electrodes of polymer electrolyte membrane fuel cells (PEMFCs), micro-porous networks were fabricated with corresponding microchannel size distributions. The inlet channels were invaded homogeneously with flow rates corresponding to fuel cell current densities of 1.0 to 0.1 A/cm2 (Ca 10e-7-10e-8). A variety of fractal breakthrough patterns were observed and analyzed to quantify flooding density and geometrical diversity in terms of the total saturation, St, local saturations, s, and fractal dimension, D. It was found that St increases monotonically during the invasion process until the breakthrough point is reached, and s profiles indicate the dynamic distribution of the liquid phase during the process. Fractal analysis confirmed that the experiments fall within the flow regime of i...

  8. Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

    E-Print Network [OSTI]

    Schmidt, Patrick; Lucquiaud, Mathieu; Valluri, Prashant

    2015-01-01

    We consider the genesis and dynamics of interfacial instability in gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of three main flow parameters (density contrast between liquid and gas, film thickness, pressure drop applied to drive the gas stream) on the interfacial dynamics. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable internal mode for low density contrast. The same linear stability approach provides a quantitative prediction for the onset of (partial) liquid flow reversal in terms of the gas and liquid flow rates. ...

  9. Flow Integrating Section for a Gas Turbine Engine in Which Turbine Blades are Cooled by Full Compressor Flow

    SciTech Connect (OSTI)

    Steward, W. Gene

    1999-11-14

    Routing of full compressor flow through hollow turbine blades achieves unusually effective blade cooling and allows a significant increase in turbine inlet gas temperature and, hence, engine efficiency. The invention, ''flow integrating section'' alleviates the turbine dissipation of kinetic energy of air jets leaving the hollow blades as they enter the compressor diffuser.

  10. A CFD study of gas-solid jet in a CFB riser flow

    SciTech Connect (OSTI)

    Li, Tingwen; Guenther, Chris

    2012-03-01

    Three-dimensional high-resolution numerical simulations of a gas–solid jet in a high-density riser flow were conducted. The impact of gas–solid injection on the riser flow hydrodynamics was investigated with respect to voidage, tracer mass fractions, and solids velocity distribution. The behaviors of a gas–solid jet in the riser crossflow were studied through the unsteady numerical simulations. Substantial separation of the jetting gas and solids in the riser crossflow was observed. Mixing of the injected gas and solids with the riser flow was investigated and backmixing of gas and solids was evaluated. In the current numerical study, both the overall hydrodynamics of riser flow and the characteristics of gas–solid jet were reasonably predicted compared with the experimental measurements made at NETL.

  11. Bubble Size Control to Improve Oxygen-Based Bleaching: Characterization of Flow Regimes in Pulp-Water-Gas Three-Phase Flows

    SciTech Connect (OSTI)

    S.M. Ghiaasiaan and Seppo Karrila

    2006-03-20

    Flow characteristics of fibrous paper pulp-water-air slurries were investigated in a vertical circular column 1.8 m long, with 5.08 cm diameter. Flow structures, gas holdup (void fraction), and the geometric and population characteristics of gas bubbles were experimentally investigated, using visual observation, Gamma-ray densitometry, and flash X-ray photography. Five distinct flow regimes could be visually identified: dispersed bubbly, layered bubbly, plug, churn-turbulent, and slug. Flow regime maps were constructed, and the regime transition lines were found to be sensitive to consistency. The feasibility of using artificial neural networks (ANNs) for the identification of the flow regimes, using the statistical characteristics of pressure fluctuations measured by a single pressure sensor, was demonstrated. Local pressure fluctuations at a station were recorded with a minimally-intrusive transducer. Three-layer, feed-forward ANNs were designed that could identify the four major flow patterns (bubbly, plug, churn, and slug) well. The feasibility of a transportable artificial neural network (ANN) - based technique for the classification of flow regimes was also examined. Local pressures were recorded at three different locations using three independent but similar transducers. An ANN was designed, trained and successfully tested for the classification of the flow regimes using one of the normalized pressure signals (from Sensor 1). The ANN trained and tested for Sensor 1 predicted the flow regimes reasonably well when applied directly to the other two sensors, indicating a good deal of transportability. An ANN-based method was also developed, whereby the power spectrum density characteristics of other sensors were adjusted before they were used as input to the ANN that was based on Sensor 1 alone. The method improved the predictions. The gas-liquid interfacial surface area concentration was also measured in the study. The gas absorption technique was applied, using CO2 as the transferred species and sodium hydroxide as the alkaline agent in water. Statistical analysis was performed to identify the parametric dependencies. The experimental data were empirically correlated.

  12. Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

    SciTech Connect (OSTI)

    Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu; Timothy J. O'hern; Steven Trujillo; Michael R. Prairie

    2005-06-04

    Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemical industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at various planes. Together, these two techniques can provide the needed local solids flow dynamic information for the same setup under identical operating conditions, and the data obtained can be used as a benchmark for development, and refinement of the appropriate riser models. For the above reasons these two techniques were implemented in this study on a fully developed section of the riser. To derive the global mixing information in the riser, accurate solids RTD is needed and was obtained by monitoring the entry and exit of a single radioactive tracer. Other global parameters such as Cycle Time Distribution (CTD), overall solids holdup in the riser, solids recycle percentage at the bottom section of the riser were evaluated from different solids travel time distributions. Besides, to measure accurately and in-situ the overall solids mass flux, a novel method was applied.

  13. Analytical model for transient gas flow in nuclear fuel rods. [PWR; BWR

    SciTech Connect (OSTI)

    Rowe, D.S.; Oehlberg, R.N.

    1981-08-01

    An analytical model for calculating gas flow and pressure inside a nuclear fuel rod is presented. Such a model is required to calculate the pressure loading of cladding during ballooning that could occur for postulated reactor accidents. The mathematical model uses a porous media (permeability) concept to define the resistance to gas flow along the fuel rod. 7 refs.

  14. Interplay of discharge and gas flow in atmospheric pressure plasma jets Nan Jiang,1

    E-Print Network [OSTI]

    Zexian, Cao

    Interplay of discharge and gas flow in atmospheric pressure plasma jets Nan Jiang,1 JingLong Yang,2 2011) Interplay of discharge and gas flow in the atmospheric pressure plasma jets generated with three jets at smaller applied voltages. Larger applied voltage implies an elongated plasma jet only

  15. Investigation of flow modifying tools for the continuous unloading of wet-gas wells 

    E-Print Network [OSTI]

    Ali, Ahsan Jawaid

    2003-01-01

    patented vortex flow modifier to lift liquids from low rate (stripper) gas wells. Vortex Flow LLC has developed a flow modifying tool using the patented EcoVeyor technology developed by EcoTech. This technology has been used successfully for almost a...

  16. Kinematic flow patterns in slow deformation of a dense granular material

    E-Print Network [OSTI]

    Koushik Viswanathan; Anirban Mahato; Tejas G. Murthy; Tomasz Koziara; Srinivasan Chandrasekar

    2015-07-19

    The kinematic flow pattern in slow deformation of a model dense granular medium is studied at high resolution using \\emph{in situ} imaging, coupled with particle tracking. The deformation configuration is indentation by a flat punch under macroscopic plane-strain conditions. Using a general analysis method, velocity gradients and deformation fields are obtained from the disordered grain arrangement, enabling flow characteristics to be quantified. The key observations are the formation of a stagnation zone, as in dilute granular flow past obstacles; occurrence of vortices in the flow immediately underneath the punch; and formation of distinct shear bands adjoining the stagnation zone. The transient and steady state stagnation zone geometry, as well as the strength of the vortices and strain rates in the shear bands, are obtained from the experimental data. All of these results are well-reproduced in exact-scale Non-Smooth Contact Dynamics (NSCD) simulations. Full 3D numerical particle positions from the simulations allow extraction of flow features that are extremely difficult to obtain from experiments. Three examples of these, namely material free surface evolution, deformation of a grain column below the punch and resolution of velocities inside the primary shear band, are highlighted. The variety of flow features observed in this model problem also illustrates the difficulty involved in formulating a complete micromechanical analytical description of the deformation.

  17. High temperature ultrasonic gas flow sensor based on lead free piezoelectric material

    E-Print Network [OSTI]

    Krsmanovic, Dalibor

    2011-11-08

    ], and it is selected as the material of choice, having good abrasion resistance, desirable anti-corrosion properties and is cost effective for present application. This thesis begins with a broad literature review of current gas flow measurement technologies... are satisfied by flow meters with multiple ultrasonic measurement paths, typically supplied as a spool piece and used in custody transfer applications such as natural gas pipelines. With respect to flow metering in general, a substantial and key body of work...

  18. Rapid granular flows on a rough incline: phase diagram, gas transition, and effects of air drag

    E-Print Network [OSTI]

    Tamas Borzsonyi; Robert E. Ecke

    2006-11-16

    We report experiments on the overall phase diagram of granular flows on an incline with emphasis on high inclination angles where the mean layer velocity approaches the terminal velocity of a single particle free falling in air. The granular flow was characterized by measurements of the surface velocity, the average layer height, and the mean density of the layer as functions of the hopper opening, the plane inclination angle and the downstream distance x of the flow. At high inclination angles the flow does not reach an x-invariant steady state over the length of the inclined plane. For low volume flow rates, a transition was detected between dense and very dilute (gas) flow regimes. We show using a vacuum flow channel that air did not qualitatively change the phase diagram and did not quantitatively modify mean flow velocities of the granular layer except for small changes in the very dilute gas-like phase.

  19. Experimental on two sensors combination used in horizontal pipe gas-water two-phase flow

    SciTech Connect (OSTI)

    Wu, Hao; Dong, Feng

    2014-04-11

    Gas-water two phase flow phenomenon widely exists in production and living and the measurement of it is meaningful. A new type of long-waist cone flow sensor has been designed to measure two-phase mass flow rate. Six rings structure of conductance probe is used to measure volume fraction and axial velocity. The calibration of them have been made. Two sensors have been combined in horizontal pipeline experiment to measure two-phase flow mass flow rate. Several model of gas-water two-phase flow has been discussed. The calculation errors of total mass flow rate measurement is less than 5% based on the revised homogeneous flow model.

  20. THEORY OF THREE-PHASE FLOW APPLIED TO WATER-ALTERNATING-GAS ENHANCED OIL RECOVERY

    E-Print Network [OSTI]

    THEORY OF THREE-PHASE FLOW APPLIED TO WATER-ALTERNATING-GAS ENHANCED OIL RECOVERY D. MARCHESIN is the key to this improvement. 1. Introduction In secondary oil recovery, water or gas is injected in three-phase ow in a porous medium, we consider the idealized ow of water, oil, and gas

  1. Pipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Casavant and David J. Beebe*

    E-Print Network [OSTI]

    Beebe, David J.

    destination for loaded fluid and balances the pressure applied to each branch for laminar flow patterningPipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Laminar flow patterning (LFP) is a characteristic method of microfluidic systems that allows two (or more

  2. World pipeline construction patterns shifting away from big North American gas lines

    SciTech Connect (OSTI)

    Koen, A.D.; True, W.R.

    1992-02-10

    The pattern of world pipeline construction has begun to shift away from large diameter gas lines in North America. Total miles of gas pipelines planned this year and beyond have registered big increases in Europe and Asia- Pacific regions, more than offsetting decreased mileage of planned U.S. and Canadian gas projects. World products pipeline construction planned in 1992 and beyond shows the largest year to year gain, paced by projects in Latin America. Those are among highlights of this article. Many projects only under study or unlikely to be built are excluded from final mileage tallies.

  3. Modeling the patterned two-dimensional electron gas: Electrostatics John H. Davies and Ivan A. Larkin

    E-Print Network [OSTI]

    Davies, John H.

    Modeling the patterned two-dimensional electron gas: Electrostatics John H. Davies and Ivan A. V. Sukhorukov Institute of Problems of Microelectronics Technology, Academy of Science of Russia, Chernogolovka, Moscow district, Russia, 142432 (Dated: February 21, 2005) Abstract We present analytical

  4. Identification of two-phase flow patterns in a nuclear reactor by high-frequency contribution fraction

    SciTech Connect (OSTI)

    Wang, Y.W.; Pei, B.S. (National Tsing Hua Univ., Hsinchu (Taiwan). Dept. of Nuclear Engineering); King, C.H.; Lee, S.C. (Institute of Nuclear Energy Research, Lung-Tan (Taiwan))

    1990-02-01

    A method based on noise analysis techniques that can be applied to the identification of two-phase flow patterns in nuclear reactors is proposed. The identifying criterion, the high-frequency contribution fraction (HFCF), offers new potential to the in-core recognition of two-phase flow patterns. By analyzing 76 sets of signals acquired from a research nuclear reactor where two-phase flow patterns are generated in an in-core air/water loop, the typical signal, autocorrelogram, and spectrum of each flow pattern are demonstrated and evaluated. The identification success rate is 87 or 93%, depending on whether churn flow is counted. A method to improve the identification rate is also presented. This study demonstrates that the fluctuation characteristics above 10 Hz are induced by two-phase flow itself and are independent of the driving source; thus, it is adequate to apply the HFCF to the identification of two-phase flow patters. This study shows that it is possible to identify two-phase flow patterns by HFCF values.

  5. Heat flow and seismicity patterns in the vicinity of the eastern Snake River Plain, Idaho

    SciTech Connect (OSTI)

    Blackwell, D.D. Kelley, S.A.; Steele, J.L. (Southern Methodist Univ., Dallas, TX (United States). Dept. of Geological Sciences)

    1993-04-01

    New heat flow data and thermal modeling are used to calculate crustal temperatures in and adjacent to the eastern Snake River Plain (SRP). The estimated crustal temperature are then used to investigate the relationship between crustal strength and the observed parabolic pattern of seismicity around the SRP. Heat flow below the SRP aquifer in deep wells on the Idaho National Engineering Laboratory (INEL) site near the northern margin of the SRP is 107 [plus minus] 15 mWm[sup [minus]2]. Heat flow values from deep wells on both the northern and southern margins of the eastern SRP average 100 [plus minus] 15 mWm[sup [minus]2]. 2-D finite-difference thermal models were developed to fit seismic and heat flow data in the vicinity of the SRP. The models have a shallow silicic magma chamber that is as wide as the SRP. The silicic chamber is underlain by mafic heat sources in the middle to lower crust and in the upper mantle. The heat flow data are best fit by models with deep heat sources that are wider than the SRP. These results are consistent with the presence of young basaltic centers that have been observed outside the SRP. The temperature from the authors thermal models were used to calculate strength envelopes for the crust in the SRP/Basin and Range region. The weakest part of the crust is along the edge of the Basin and Range, where it is heated by the SRP; thus the boundary to the two provinces may be a zone of weak coupling. Their modeling indicates that it is difficult to explain the earthquake pattern in the vicinity of the SRP as a thermomechanical effect related to the passage of the Yellowstone hot spot.

  6. Manufacturability of lab on chip devices : reagent-filled reservoirs bonding process and its effect on reagents flow pattern

    E-Print Network [OSTI]

    Saber, Aabed (Aabed Saud)

    2013-01-01

    In its lab-on-a-chip product, Daktari Diagnostics utilizes "reagent-filled reservoirs" as a means of storing and delivering the liquid reagent. During the clinical trials of the product, undesired reagent flow patterns ...

  7. Common Patterns of Energy Flow and Biomass Distribution on Weighted Food Webs

    E-Print Network [OSTI]

    Zhang, Jiang

    2012-01-01

    Weights of edges and nodes on food webs which are available from the empirical data hide much information about energy flows and biomass distributions in ecosystem. We define a set of variables related to weights for each species $i$, including the throughflow $T_i$, the total biomass $X_i$, and the dissipated flow $D_i$ (output to the environment) to uncover the following common patterns in 19 empirical weighted food webs: (1) DGBD distributions (Discrete version of a Generalized Beta Distribution), a kind of deformed Zipf's law, of energy flow and storage biomass; (2) The allometric scaling law $T_i\\propto X_i^{\\alpha}$, which can be viewed as the counterpart of the Kleiber's 3/4 law at the population level; (3) The dissipation law $D_i\\propto T_i^{\\beta}$; and (4) The gravity law, including univariate version $f_{ij}\\propto (T_iT_j)^{\\gamma}$ and bivariate approvement $f_{ij}\\propto T_i^{\\gamma_1}T_j^{\\gamma_2}$. These patterns are very common and significant in all collected webs, as a result, some remark...

  8. Influence of the gas-flow Reynolds number on a plasma column in a glass tube

    SciTech Connect (OSTI)

    Jin, Dong Jun; Uhm, Han S.; Cho, Guangsup [Department of Electronic and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul 139-701 (Korea, Republic of)] [Department of Electronic and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul 139-701 (Korea, Republic of)

    2013-08-15

    Atmospheric-plasma generation inside a glass tube is influenced by gas stream behavior as described by the Reynolds number (Rn). In experiments with He, Ne, and Ar, the plasma column length increases with an increase in the gas flow rate under laminar flow characterized by Rn < 2000. The length of the plasma column decreases as the flow rate increases in the transition region of 2000 < Rn < 4000. For a turbulent flow beyond Rn > 4000, the length of the plasma column is short in front of the electrode, eventually leading to a shutdown.

  9. Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways

    SciTech Connect (OSTI)

    Minard, Kevin R.; Kuprat, Andrew P.; Kabilan, Senthil; Jacob, Rick E.; Einstein, Daniel R.; Carson, James P.; Corley, Richard A.

    2012-08-01

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  10. Stress-induced patterns in ion-irradiated Silicon: a model based on anisotropic plastic flow

    E-Print Network [OSTI]

    Scott A. Norris

    2012-07-24

    We present a model for the effect of stress on thin amorphous films that develop atop ion-irradiated silicon, based on the mechanism of ion-induced anisotropic plastic flow. Using only parameters directly measured or known to high accuracy, the model exhibits remarkably good agreement with the wavelengths of experimentally-observed patterns, and agrees qualitatively with limited data on ripple propagation speed. The predictions of the model are discussed in the context of other mechanisms recently theorized to explain the wavelengths, including extensive comparison with an alternate model of stress.

  11. Ion transport membrane module and vessel system with directed internal gas flow

    DOE Patents [OSTI]

    Holmes, Michael Jerome (Thompson, ND); Ohrn, Theodore R. (Alliance, OH); Chen, Christopher Ming-Poh (Allentown, PA)

    2010-02-09

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

  12. Induced-charge electro-osmosis around metal and Janus spheres in water: Patterns of flow and breaking symmetries

    E-Print Network [OSTI]

    Chenhui Peng; Israel Lazo; Sergij V. Shiyanovskii; Oleg D. Lavrentovich

    2014-11-06

    We establish experimentally the flow patterns of induced-charge electro-osmosis (ICEO) around immobilized metallic spheres in aqueous electrolyte. The AC field modifies local electrolyte concentration and causes quadrupolar flows with inward velocities being smaller than the outward ones. At high fields, the flow becomes irregular, with vortices smaller than the size of the sphere. Janus metallo-dielectric spheres create dipolar flows and pump the fluid from the dielectric toward the metallic part. The experimentally determined far-field flows decay with the distance as r-3.

  13. Macro-to-microchannel transition in two-phase flow: Part 1 - Two-phase flow patterns and film thickness measurements

    SciTech Connect (OSTI)

    Ong, C.L.; Thome, J.R. [Ecole Polytechnique Federale de Lausanne, EPFL-STI-IGM-LTCM, Station 9, CH-1015 Lausanne (Switzerland)

    2011-01-15

    The classification of macroscale, mesoscale and microscale channels with respect to two-phase processes is still an open question. The main objective of this study focuses on investigating the macro-to-microscale transition during flow boiling in small scale channels of three different sizes with three different refrigerants over a range of saturation conditions to investigate the effects of channel confinement on two-phase flow patterns and liquid film stratification in a single circular horizontal channel (Part 2 covers the flow boiling heat transfer and critical heat flux). This paper presents the experimental two-phase flow pattern transition data together with a top/bottom liquid film thickness comparison for refrigerants R134a, R236fa and R245fa during flow boiling in small channels of 1.03, 2.20 and 3.04 mm diameter. Based on this work, an improved flow pattern map has been proposed by determining the flow patterns transitions existing under different conditions including the transition to macroscale slug/plug flow at a confinement number of Co {approx} 0.3-0.4. From the top/bottom liquid film thickness comparison results, it was observed that the gravity forces are fully suppressed and overcome by the surface tension and shear forces when the confinement number approaches 1, Co {approx} 1. Thus, as a new approximate rule, the lower threshold of macroscale flow is Co = 0.3-0.4 while the upper threshold of symmetric microscale flow is Co {approx} 1 with a transition (or mesoscale) region in-between. (author)

  14. Effect of Cooling Flow on the Operation of a Hot Rotor-Gas Foil Bearing System 

    E-Print Network [OSTI]

    Ryu, Keun

    2012-02-14

    Gas foil bearings (GFBs) operating at high temperature rely on thermal management procedures that supply needed cooling flow streams to keep the bearing and rotor from overheating. Poor thermal management not only makes ...

  15. A Novel Approach For the Simulation of Multiple Flow Mechanisms and Porosities in Shale Gas Reservoirs 

    E-Print Network [OSTI]

    Yan, Bicheng

    2013-07-15

    The state of the art of modeling fluid flow in shale gas reservoirs is dominated by dual porosity models that divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control...

  16. Performance Analysis of an Annular Diffuser Under the Influence of a Gas Turbine Stage Exit Flow

    E-Print Network [OSTI]

    Blanco, Rafael Rodriguez

    2013-12-31

    In this investigation the performance of a gas turbine exhaust diffuser subject to the outlet flow conditions of a turbine stage is evaluated. Towards that goal, a fully three-dimensional computational analysis has been performed where several...

  17. A phenomenological model for rarefied gas flows in thin film slider bearings 

    E-Print Network [OSTI]

    Bahukudumbi, Pradipkumar

    2002-01-01

    We analyze rarefied gas flows in lubricating films that form between the read/write head and rotating recording medium in computer hard drives. A modified slip-corrected Reynolds lubrication equation is derived for arbitrary Knudsen numbers using...

  18. The impact of gravity segregation on multiphase non-Darcy flow in hydraulically fractured gas wells 

    E-Print Network [OSTI]

    Dickins, Mark Ian

    2008-10-10

    ON MULTIPHASE NON-DARCY FLOW IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by MARK DICKINS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 2008 Major Subject: Petroleum Engineering THE IMPACT OF GRAVITY SEGREGATION ON MULTIPHASE NON-DARCY FLOW IN HYDRAULICALLY FRACTURED GAS WELLS A Thesis by MARK DICKINS Submitted to the Office of Graduate Studies of Texas...

  19. Effects of aspect ratios on internal flow patterns of an inclined closed two-phase thermosyphon at normal operating condition

    SciTech Connect (OSTI)

    Terdtoon, P.; Chailungkar, M. [Chiang Mai Univ. (Thailand). Dept. of Mechanical Engineering; Shiraishi, M. [MITI, Tsukuba, Ibaraki (Japan). Mechanical Engineering Lab.

    1998-10-01

    A visual study of internal flow patterns inside an inclined closed two-phase thermosyphon at normal operating conditions for several aspect ratios has been conducted. The article describes the details of the flow patterns varying with inclination angles and aspect ratios. A thermosyphon with a diameter of 11.1 mm was used. R123 was selected as the working fluid, with a vapor temperature of 30 C and a filling ratio of 80%. Observation of the flow phenomena was conducted at selected inclination angles of 90{degree}, 30{degree}, and 5{degree} from the horizontal axis, with aspect ratios of 30, 10, and 5. Flow phenomena were recorded with a standard video camera and a still camera, and the corresponding heat transfer rate was also monitored. It was observed that the basic internal flow patterns could be classified according to the aspect ratios as follows: At an aspect ratio of 10 and higher, the internal flow changed from annular and churn flow at the vertical position to a stratified slug flow in the inclined position, and there was an improvement in heat transfer rates between the vertical and the inclined positions. However, in the case of an aspect ratio less than 10, tilting the thermosyphon from vertical did not result in changing the internal bubbly flow. It was observed that the improvement in heat transfer rates in this case was likely to be higher than in the previous case.

  20. Modelling Shale Gas Flow Using the Concept of Dynamic Apparent Permeability 

    E-Print Network [OSTI]

    Farid, Syed Munib Ullah

    2015-05-12

    The basic idea behind this research is to propose a work flow to model gas flow in numerical simulators, which would take into consideration all the complexities of the multiple porosity systems that exist in shale matrix and the different dynamics...

  1. Surface chemistry of bulk nanocrystalline pure iron and electrochemistry study in gas-flow physiological saline

    E-Print Network [OSTI]

    Zheng, Yufeng

    Surface chemistry of bulk nanocrystalline pure iron and electrochemistry study in gas greatly than that of MC-Fe. A further comparative study of corrosion and electrochemistry per- formance of bulk nanocrystalline pure iron and electrochemistry study in gas-flow physiological saline. J Biomed

  2. GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS

    E-Print Network [OSTI]

    Johansen, Tor Arne

    1 GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS MSc. Hans, NTNU, Trondheim, Norway Abstract A mathematical program for finding the optimal oil production rates in an oil production system is developed. Each well may be manipulated by injecting lift gas and adjusting

  3. Suitability of Drift-Flux Models, Void-Fraction Evolution, and 3-D Flow Pattern Visualization During Stationary and Transient Flashing Flow in a Vertical Pipe

    SciTech Connect (OSTI)

    Manera, Annalisa [Delft University of Technology (Netherlands); Prasser, Horst-Michael [Forschungszentrum Rossendorf (Germany); Hagen, Tim H.J.J. van der [Delft University of Technology (Netherlands)

    2005-10-15

    An assessment of void-fraction correlations and drift-flux models applied to stationary and transient flashing flows in a vertical pipe has been performed. Experiments have been carried out on a steam/water loop that can be operated both in forced- and natural-circulation conditions to provide data for the assessment. The GE-Ramp and Dix models are found to give very good predictions both for forced- and natural-circulation flow conditions, in the whole range of measured void fractions.Advanced instrumentation, namely, wire-mesh sensors, has been used to obtain a detailed picture of the void-fraction development in the system. On the basis of experimental data, a three-dimensional visualization of the transient flow pattern during flashing was achieved. A transition of the flow pattern between bubbly and slug/churn regimes was found.

  4. The Gas Flow from the Gas Attenuator to the Beam Line

    SciTech Connect (OSTI)

    Ryutov, D.D.

    2010-12-03

    The gas leak from the gas attenuator to the main beam line of the Linac Coherent Light Source has been evaluated, with the effect of the Knudsen molecular beam included. It has been found that the gas leak from the gas attenuator of the present design, with nitrogen as a working gas, does not exceed 10{sup -5} torr x l/s even at the highest pressure in the main attenuation cell (20 torr).

  5. An investigation of two-phase gas-liquid slug flow

    SciTech Connect (OSTI)

    Mao, Z.

    1988-01-01

    Both experimental and numerical approaches were used in this study to explore the hydrodynamics of slug flow and its transition to the churn flow pattern. Extensive experimental data were taken using conductance wires, an electrochemical probe and a phase detection probe to simultaneously provide the axial void fraction distribution in the liquid slug, the axial profile of wall shear stress, the shape of the Taylor bubble, and the length and velocity of liquid slugs and Taylor bubbles. Data were collected for single Taylor bubbles rising in stagnant and flowing liquid as well as for continuous slug flow. A numerical method was developed for computing the flow field in the liquid slug and the falling film around a Taylor bubble. The field is first computed with a designated rise velocity and shape profile. Then the shape is adjusted to satisfy a constant pressure conditions at the free surface. It is shown that from an infinity of possible solutions the physically realistic Taylor bubble must have a rise velocity which creases a spherical nose in the vicinity of the vertex. The combination of experimental measurements and the numerical simulations reveal the details of slug flow and suggest that a circulating eddy exists at the top of a liquid slug. In contrast to conventional belief, churn flow is found to be better perceived as an extension of slug flow, instead of a distinct flow pattern. Numerical simulations for the flow around a single Taylor bubble give results in good agreement with the measured shape and the rise velocity of the bubble in both stagnant and flowing liquid for both turbulent and laminar flow. Similar computations for a train of bubbles show qualitative agreement with experiment.

  6. WETTABILITY ALTERATION OF POROUS MEDIA TO GAS-WETTING FOR IMPROVING PRODUCTIVITY AND INJECTIVITY IN GAS-LIQUID FLOWS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2003-12-01

    Wettability alteration to intermediate gas-wetting in porous media by treatment with FC-759, a fluoropolymer polymer, has been studied experimentally. Berea sandstone was used as the main rock sample in our work and its wettability before and after chemical treatment was studied at various temperatures from 25 to 93 C. We also studied recovery performance for both gas/oil and oil/water systems for Berea sandstone before and after wettability alteration by chemical treatment. Our experimental study shows that chemical treatment with FC-759 can result in: (1) wettability alteration from strong liquid-wetting to stable intermediate gas-wetting at room temperature and at elevated temperatures; (2) neutral wetting for gas, oil, and water phases in two-phase flow; (3) significant increase in oil mobility for gas/oil system; and (4) improved recovery behavior for both gas/oil and oil/water systems. This work reveals a potential for field application for improved gas-well deliverability and well injectivity by altering the rock wettability around wellbore in gas condensate reservoirs from strong liquid-wetting to intermediate gas-wetting.

  7. VOLUME 84, NUMBER 15 P H Y S I C A L R E V I E W L E T T E R S 10 APRIL 2000 Patterning Electro-osmotic Flow with Patterned Surface Charge

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    VOLUME 84, NUMBER 15 P H Y S I C A L R E V I E W L E T T E R S 10 APRIL 2000 Patterning Electro-osmotic the measurement of electro-osmotic flows (EOF) in microchannels with surface charge patterned on the 200 mm scale driven flow [electro-osmotic flow (EOF)] is an al- ternative to pressure driven flow in microchannels

  8. Canada Mexico Figure 11. Flow of natural gas exports, 2014

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979Coal4Cubic Feet) Gas Wells (Million Cubic Feet)Cubic8

  9. The heat recovery steam generator (HRSG) is a key component of Combined Cycle Power Plants (CCPP). The exhaust (flue gas) from the CCPP gas turbine flows through the HRSG -this gas typically contains a high

    E-Print Network [OSTI]

    The heat recovery steam generator (HRSG) is a key component of Combined Cycle Power Plants (CCPP). The exhaust (flue gas) from the CCPP gas turbine flows through the HRSG - this gas typically contains a high

  10. Modifications to a two-control-volume, frequency dependent, transfer-function analysis of hole-pattern gas annular seals 

    E-Print Network [OSTI]

    Shin, Yoon Shik

    2007-04-25

    A rotordynamic analysis of hole-pattern gas annular seals using a two-control-volume model, Ha and Childs and frequency dependent transfer-function model, Kleynhans and Childs is modified with four features. The energy ...

  11. Couette flow regimes with heat transfer in rarefied gas

    SciTech Connect (OSTI)

    Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)

    2013-06-15

    Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.

  12. Application of convolution theory for solving non-linear flow problems: gas flow systems 

    E-Print Network [OSTI]

    Mireles, Thomas Joseph

    1995-01-01

    The accurate description of fluid flow through porous media using physically representative analytical or numerical models greatly improves an engineer's ability to correctly analyze and predict the flowrate and pressure performance in a reservoir...

  13. DEVELOPMENT AND VALIDATION OF A MULTIFIELD MODEL OF CHURN-TURBULENT GAS/LIQUID FLOWS

    SciTech Connect (OSTI)

    Elena A. Tselishcheva; Steven P. Antal; Michael Z. Podowski; Donna Post Guillen

    2009-07-01

    The accuracy of numerical predictions for gas/liquid two-phase flows using Computational Multiphase Fluid Dynamics (CMFD) methods strongly depends on the formulation of models governing the interaction between the continuous liquid field and bubbles of different sizes. The purpose of this paper is to develop, test and validate a multifield model of adiabatic gas/liquid flows at intermediate gas concentrations (e.g., churn-turbulent flow regime), in which multiple-size bubbles are divided into a specified number of groups, each representing a prescribed range of sizes. The proposed modeling concept uses transport equations for the continuous liquid field and for each bubble field. The overall model has been implemented in the NPHASE-CMFD computer code. The results of NPHASE-CMFD simulations have been validated against the experimental data from the TOPFLOW test facility. Also, a parametric analysis on the effect of various modeling assumptions has been performed.

  14. Time-resolved gas temperatures in the oscillating turbulent flow of a pulse combustor tail pipe

    SciTech Connect (OSTI)

    Dec, J.E. (Michigan Univ., Ann Arbor, MI (USA)); Keller, J.O. (Sandia National Labs., Livermore, CA (USA). Combustion Research Faclity)

    1990-06-01

    This paper reports the cyclic behavior of the gas temperature in the oscillating turbulent flow in a pulse combustor tail pipe studied using two-line atomic fluorescence. In this flow, the oscillations result from an acoustic resonance, and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Spatially resolved temperature measurements were made to within 400 {mu}m of the wall, providing cycle-resolved profiles of the temperature and the random temperature fluctuations. The combustor-cycle phase relationships among the gas temperature, random-temperature-fluctuation intensity, velocity, and combustion chamber pressure, are compared.

  15. Method For Enhanced Gas Monitoring In High Density Flow Streams

    DOE Patents [OSTI]

    Von Drasek, William A. (Oak Forest, IL); Mulderink, Kenneth A. (Countryside, IL); Marin, Ovidiu (Lisle, IL)

    2005-09-13

    A method for conducting laser absorption measurements in high temperature process streams having high levels of particulate matter is disclosed. An impinger is positioned substantially parallel to a laser beam propagation path and at upstream position relative to the laser beam. Beam shielding pipes shield the beam from the surrounding environment. Measurement is conducted only in the gap between the two shielding pipes where the beam propagates through the process gas. The impinger facilitates reduced particle presence in the measurement beam, resulting in improved SNR (signal-to-noise) and improved sensitivity and dynamic range of the measurement.

  16. EIA - Natural Gas Pipeline Network - Expansion Process Flow Diagram

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979Coal4Cubic43,728Configuration AquiferDevelopment &

  17. EIA - Natural Gas Pipeline Network - Transportation Process & Flow

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1 Table272/SPipeline Utilization

  18. Analysis of Breathing Air Flow Patterns in Thermal Imaging Department of Computer Science

    E-Print Network [OSTI]

    biometric. I. INTRODUCTION Many respiratory diseases like sleep apnea syndrome and bronchial asthma of pathophysiolog- ical causes, pattern analysis reveals that individual breathing patterns are not random [3

  19. Evaluation of flow patterns and elongated bubble characteristics during the flow boiling of halocarbon refrigerants in a micro-scale channel

    SciTech Connect (OSTI)

    Arcanjo, Alexandre Alves; Tibirica, Cristiano Bigonha; Ribatski, Gherhardt [Department of Mechanical Engineering, Escola de Engenharia de Sao Carlos (EESC), University of Sao Paulo (USP), Av. Trabalhador SanCarlense 400, Centro, Sao Carlos, SP (Brazil)

    2010-09-15

    In the present study, quasi-diabatic two-phase flow pattern visualizations and measurements of elongated bubble velocity, frequency and length were performed. The tests were run for R134a and R245fa evaporating in a stainless steel tube with diameter of 2.32 mm, mass velocities ranging from 50 to 600 kg/m{sup 2} s and saturation temperatures of 22 C, 31 C and 41 C. The tube was heated by applying a direct DC current to its surface. Images from a high-speed video-camera (8000 frames/s) obtained through a transparent tube just downstream the heated sections were used to identify the following flow patterns: bubbly, elongated bubbles, churn and annular flows. The visualized flow patterns were compared against the predictions provided by Barnea et al. (1983), Felcar et al. (2007), Revellin and Thome (2007) and Ong and Thome (2009). From this comparison, it was found that the methods proposed by Felcar et al. (2007) and Ong and Thome (2009) predicted relatively well the present database. Additionally, elongated bubble velocities, frequencies and lengths were determined based on the analysis of high-speed videos. Results suggested that the elongated bubble velocity depends on mass velocity, vapor quality and saturation temperature. The bubble velocity increases with increasing mass velocity and vapor quality and decreases with increasing saturation temperature. Additionally, bubble velocity was correlated as linear functions of the two-phase superficial velocity. (author)

  20. Practical application of large eddy simulation to film cooling flow analysis on gas turbine airfoils

    SciTech Connect (OSTI)

    Takata, T.; Takeishi, K.; Kawata, Y.; Tsuge, A.

    1999-07-01

    Large eddy simulation (LES) using body-fitted coordinates is applied to solve film cooling flow on turbine blades. The turbulent model was tuned using the experimental flow field and adiabatic film cooling effectiveness measurements for a single row of holes on a flat plate surface. The results show the interaction between the main stream boundary layer and injected film cooling air generates kidney and horseshoe shaped vortices. Comparison of the temperature distribution between experimental results and present analysis has been conducted. The non-dimensional temperature distribution at x/d = 1 is dome style and quantitatively agrees with experimental results. LES was also applied to solve film cooling on a turbine airfoil. If LES was applied to solve whole flow field domain large CPU time would make the solution impractical. LES, using body-fitted coordinates, is applied to solve the non-isotropic film cooling flow near the turbine blade. The cascade flow domain, with a pitch equal to one film cooling hole spacing, is solved using {kappa}-{epsilon} model. By using such a hybrid numerical method, CPU time is reduced and numerical accuracy is insured. The analytical results show the interaction between the flow blowing through film cooling holes and mainstream on the suction and pressure surfaces of the turbine airfoil. They also show the fundamental structure of the film cooling air flow is governed by arch internal secondary flow and horseshoe vortices which have a similar structure to film cooling air flow blowing through a cooling hole on a flat plate. In the flow field, the effect of turbulent structure on curvature (relaminarization) and flow pattern, involving the interaction between main flow and the cooling jet, are clearly shown. Film cooling effectiveness on the blade surface is predicted from the results of the thermal field calculation and is compared with the test result.

  1. Energy Efficient Thermal Management for Natural Gas Engine Aftertreatment via Active Flow Control

    SciTech Connect (OSTI)

    David K. Irick; Ke Nguyen; Vitacheslav Naoumov; Doug Ferguson

    2006-04-01

    The project is focused on the development of an energy efficient aftertreatment system capable of reducing NOx and methane by 90% from lean-burn natural gas engines by applying active exhaust flow control. Compared to conventional passive flow-through reactors, the proposed scheme cuts supplemental energy by 50%-70%. The system consists of a Lean NOx Trap (LNT) system and an oxidation catalyst. Through alternating flow control, a major amount of engine exhaust flows through a large portion of the LNT system in the absorption mode, while a small amount of exhaust goes through a small portion of the LNT system in the regeneration or desulfurization mode. By periodically reversing the exhaust gas flow through the oxidation catalyst, a higher temperature profile is maintained in the catalyst bed resulting in greater efficiency of the oxidation catalyst at lower exhaust temperatures. The project involves conceptual design, theoretical analysis, computer simulation, prototype fabrication, and empirical studies. This report details the progress during the first twelve months of the project. The primary activities have been to develop the bench flow reactor system, develop the computer simulation and modeling of the reverse-flow oxidation catalyst, install the engine into the test cell, and begin design of the LNT system.

  2. Influence of hydrogen patterning gas on electric and magnetic properties of perpendicular magnetic tunnel junctions

    SciTech Connect (OSTI)

    Jeong, J. H.; Endoh, T.; Kim, Y.; Kim, W. K.; Park, S. O.

    2014-05-07

    To identify the degradation mechanism in magnetic tunnel junctions (MTJs) using hydrogen, the properties of the MTJs were measured by applying an additional hydrogen etch process and a hydrogen plasma process to the patterned MTJs. In these studies, an additional 50?s hydrogen etch process caused the magnetoresistance (MR) to decrease from 103% to 14.7% and the resistance (R) to increase from 6.5?k? to 39?k?. Moreover, an additional 500?s hydrogen plasma process decreased the MR from 103% to 74% and increased R from 6.5?k? to 13.9?k?. These results show that MTJs can be damaged by the hydrogen plasma process as well as by the hydrogen etch process, as the atomic bonds in MgO may break and react with the exposed hydrogen gas. Compounds such as MgO hydrate very easily. We also calculated the damaged layer width (DLW) of the patterned MTJs after the hydrogen etching and plasma processes, to evaluate the downscaling limitations of spin-transfer-torque magnetic random-access memory (STT-MRAM) devices. With these calculations, the maximum DLWs at each side of the MTJ, generated by the etching and plasma processes, were 23.8?nm and 12.8?nm, respectively. This result validates that the hydrogen-based MTJ patterning processes cannot be used exclusively in STT-MRAMs beyond 20?nm.

  3. Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows

    SciTech Connect (OSTI)

    Sankaran Sundaresan

    2010-02-14

    Gas-particle flows in fluidized beds and riser reactors are inherently unstable, and they manifest fluctuations over a wide range of length and time scales. Two-fluid models for such flows reveal unstable modes whose length scale is as small as ten particle diameters. Yet, because of limited computational resources, gas-particle flows in large fluidized beds are invariably simulated by solving discretized versions of the two-fluid model equations over a coarse spatial grid. Such coarse-grid simulations do not resolve the small-scale spatial structures which are known to affect the macroscale flow structures both qualitatively and quantitatively. Thus there is a need to develop filtered two-fluid models which are suitable for coarse-grid simulations and capturing the effect of the small-scale structures through closures in terms of the filtered variables. The overall objective of the project is to develop validated closures for filtered two-fluid models for gas-particle flows, with the transport gasifier as a primary, motivating example. In this project, highly resolved three-dimensional simulations of a kinetic theory based two-fluid model for gas-particle flows have been performed and the statistical information on structures in the 100-1000 particle diameters length scale has been extracted. Based on these results, closures for filtered two-fluid models have been constructed. The filtered model equations and closures have been validated against experimental data and the results obtained in highly resolved simulations of gas-particle flows. The proposed project enables more accurate simulations of not only the transport gasifier, but also many other non-reacting and reacting gas-particle flows in a variety of chemical reactors. The results of this study are in the form of closures which can readily be incorporated into existing multi-phase flow codes such as MFIX (www.mfix.org). Therefore, the benefits of this study can be realized quickly. The training provided by this project has prepared a PhD student to enter research and development careers in DOE laboratories or chemicals/energy-related industries.

  4. Sparger Effects on Gas Volume Fraction Distributions in Vertical Bubble-Column Flows as Measured by Gamma-Densitometry Tomography

    SciTech Connect (OSTI)

    GEORGE,DARIN L.; SHOLLENBERGER,KIM ANN; TORCZYNSKI,JOHN R.

    2000-01-18

    Gamma-densitometry tomography is applied to study the effect of sparger hole geometry, gas flow rate, column pressure, and phase properties on gas volume fraction profiles in bubble columns. Tests are conducted in a column 0.48 m in diameter, using air and mineral oil, superficial gas velocities ranging from 5 to 30 cm s{sup -1}, and absolute column pressures from 103 to 517 kPa. Reconstructed gas volume fraction profiles from two sparger geometries are presented. The development length of the gas volume fraction profile is found to increase with gas flow rate and column pressure. Increases in gas flow rate increase the local gas volume fraction preferentially on the column axis, whereas increases in column pressure produce a uniform rise in gas volume fraction across the column. A comparison of results from the two spargers indicates a significant change in development length with the number and size of sparger holes.

  5. Numerical simulation of gas flow through unsaturated fractured rock at Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Cooper, C.A.

    1990-01-01

    Numerical analysis is used to identify the physical phenomena associated with barometrically driven gas (air and water vapor) flow through unsaturated fractured rock at Yucca Mountain, Nevada. Results from simple finite difference simulations indicate that for a fractured rock scenario, the maximum velocity of air out of an uncased 10 cm borehole is 0.002 m s{sub {minus}1}. An equivalent porous medium (EPM) model was incorporated into a multiphase, multicomponent simulator to test more complex conceptual models. Results indicate that for a typical June day, a diurnal pressure wave propagates about 160 m into the surrounding Tiva Canyon hydrogeologic unit. Dry air that enters the formation evaporates water around the borehole which reduces capillary pressure. Multiphase countercurrent flow develops in the vicinity of the hole; the gas phase flows into the formation while the liquid phase flows toward the borehole. The effect occurs within 0.5 m of the borehole. The amount of water vapor leaving the formation during 1 day is 900 cm{sup 3}. This is less than 0.1% of the total recharge into the formation, suggesting that the barometric effect may be insignificant in drying the unsaturated zone. However, gas phase velocities out of the borehole (3 m s{sup {minus}1}), indicating that observed flow rates from wells along the east flank of Yucca Mountain were able to be simulated with a barometric model.

  6. UK Oil and Gas Collaborative Doctoral Training Centre (2014 start) Project Title: Coupled flow of water and gas during hydraulic fracture in shale (EARTH-15-CM1)

    E-Print Network [OSTI]

    Henderson, Gideon

    UK Oil and Gas Collaborative Doctoral Training Centre (2014 start) Project Title: Coupled flow of water and gas during hydraulic fracture in shale (EARTH-15-CM1) Host institution: University of Oxford Cartwright Project description: Recovery of natural gas from mudstone (shale) formations has triggered

  7. Pore-scale mechanisms of gas flow in tight sand reservoirs

    SciTech Connect (OSTI)

    Silin, D.; Kneafsey, T.J.; Ajo-Franklin, J.B.; Nico, P.

    2010-11-30

    Tight gas sands are unconventional hydrocarbon energy resource storing large volume of natural gas. Microscopy and 3D imaging of reservoir samples at different scales and resolutions provide insights into the coaredo not significantly smaller in size than conventional sandstones, the extremely dense grain packing makes the pore space tortuous, and the porosity is small. In some cases the inter-granular void space is presented by micron-scale slits, whose geometry requires imaging at submicron resolutions. Maximal Inscribed Spheres computations simulate different scenarios of capillary-equilibrium two-phase fluid displacement. For tight sands, the simulations predict an unusually low wetting fluid saturation threshold, at which the non-wetting phase becomes disconnected. Flow simulations in combination with Maximal Inscribed Spheres computations evaluate relative permeability curves. The computations show that at the threshold saturation, when the nonwetting fluid becomes disconnected, the flow of both fluids is practically blocked. The nonwetting phase is immobile due to the disconnectedness, while the permeability to the wetting phase remains essentially equal to zero due to the pore space geometry. This observation explains the Permeability Jail, which was defined earlier by others. The gas is trapped by capillarity, and the brine is immobile due to the dynamic effects. At the same time, in drainage, simulations predict that the mobility of at least one of the fluids is greater than zero at all saturations. A pore-scale model of gas condensate dropout predicts the rate to be proportional to the scalar product of the fluid velocity and pressure gradient. The narrowest constriction in the flow path is subject to the highest rate of condensation. The pore-scale model naturally upscales to the Panfilov's Darcy-scale model, which implies that the condensate dropout rate is proportional to the pressure gradient squared. Pressure gradient is the greatest near the matrix-fracture interface. The distinctive two-phase flow properties of tight sand imply that a small amount of gas condensate can seriously affect the recovery rate by blocking gas flow. Dry gas injection, pressure maintenance, or heating can help to preserve the mobility of gas phase. A small amount of water can increase the mobility of gas condensate.

  8. WETTABILITY ALTERATION OF POROUS MEDIA TO GAS-WETTING FOR IMPROVING PRODUCTIVITY AND INJECTIVITY IN GAS-LIQUID FLOWS

    SciTech Connect (OSTI)

    Abbas Firoozabadi

    2002-10-21

    The authors have performed a number of imbibition tests with the treated and untreated cores in nC{sub 10}, nC{sub 14}, and nC{sub 16} and a natural gas condensate liquid. Imbibition tests for nC{sub 14} and nC{sub 16} were also carried out at elevated temperatures of 100 C and 140 C. An experimental polymer synthesized for the purpose of this project was used in core treatment. Imbibition results are very promising and imply liquid condensate mobility enhancement in the treated core. They also performed flow tests to quantify the increase in well deliverability and to simulate flow under realistic field conditions. In the past we have performed extensive testing of wettability alteration in intermediate gas wetting for polymer FC759 at temperatures of 24 C and 90 C. The results were promising for the purpose of gas well deliverability improvement in gas condensate wells. We used FC759 to lower the surface energy of various rocks. The model fluids nC{sub 10}, and nC{sub 14} were used to represent condensate liquid, and air was used as the gas phase. A new (L-16349) polymer, which has been recently synthesized for the purpose of the project, was used in the work to be presented here. L-16349 is a water-soluble fluorochemical polymer, with low order, neutral PH and very low volatile organic compound (VOC < 9.1 g/l). It is light yellow in appearance and density in 25% solution is 1.1 g/cc. Polymer L-16349 is very safe from environmental considerations and it is economical for our purpose. In this work, in addition to nC{sub 10}, and nC{sub 14}, we used two other liquids nC{sub 16}, and a liquid condensate in order to study the effect of wettability alteration with a broader range of fluids.

  9. Turbine exhaust diffuser with a gas jet producing a coanda effect flow control

    DOE Patents [OSTI]

    Orosa, John; Montgomery, Matthew

    2014-02-11

    An exhaust diffuser system and method for a turbine engine includes an inner boundary and an outer boundary with a flow path defined therebetween. The inner boundary is defined at least in part by a hub structure that has an upstream end and a downstream end. The outer boundary may include a region in which the outer boundary extends radially inward toward the hub structure and may direct at least a portion of an exhaust flow in the diffuser toward the hub structure. The hub structure includes at least one jet exit located on the hub structure adjacent to the upstream end of the tail cone. The jet exit discharges a flow of gas substantially tangential to an outer surface of the tail cone to produce a Coanda effect and direct a portion of the exhaust flow in the diffuser toward the inner boundary.

  10. A TECHNOLOGY ASSESSMENT AND FEASIBILITY EVALUATION OF NATURAL GAS ENERGY FLOW MEASUREMENT ALTERNATIVES

    SciTech Connect (OSTI)

    Kendricks A. Behring II; Eric Kelner; Ali Minachi; Cecil R. Sparks; Thomas B. Morrow; Steven J. Svedeman

    1999-01-01

    Deregulation and open access in the natural gas pipeline industry has changed the gas business environment towards greater reliance on local energy flow rate measurement. What was once a large, stable, and well-defined source of natural gas is now a composite from many small suppliers with greatly varying gas compositions. Unfortunately, the traditional approach to energy flow measurement [using a gas chromatograph (GC) for composition assay in conjunction with a flow meter] is only cost effective for large capacity supplies (typically greater than 1 to 30 million scfd). A less costly approach will encourage more widespread use of energy measurement technology. In turn, the US will benefit from tighter gas inventory control, more efficient pipeline and industrial plant operations, and ultimately lower costs to the consumer. An assessment of the state and direction of technology for natural gas energy flow rate measurement is presented. The alternative technologies were ranked according to their potential to dramatically reduce capital and operating and maintenance (O and M) costs, while improving reliability and accuracy. The top-ranked technologies take an unconventional inference approach to the energy measurement problem. Because of that approach, they will not satisfy the fundamental need for composition assay, but have great potential to reduce industry reliance on the GC. Technological feasibility of the inference approach was demonstrated through the successful development of data correlations that relate energy measurement properties (molecular weight, mass-based heating value, standard density, molar ideal gross heating value, standard volumetric heating value, density, and volume-based heating value) to three inferential properties: standard sound speed, carbon dioxide concentration, and nitrogen concentration (temperature and pressure are also required for the last two). The key advantage of this approach is that inexpensive on-line sensors may be used to measure the inferential variables, which can then be applied (through the data correlations) to convert existing flow meters (ultrasonic, orifice, turbine, rotary, Coriolis, diaphragm, etc.) for on-line energy measurement. The practical issues for field development were evaluated using two transducers extracted from a $100 ultrasonic domestic gas meter, and a $400 infrared sensor.

  11. Medium effects on the relaxation of dissipative flows in a hot pion gas

    E-Print Network [OSTI]

    Sukanya Mitra; Utsab Gangopadhyaya; Sourav Sarkar

    2015-05-27

    The relaxation times over which dissipative fluxes restore their steady state values have been evaluated for a pion gas using the 14-moment method. The effect of the medium has been implemented through a temperature dependent pi-pi cross-section in the collision integral which is obtained by including one-loop self-energies in the propagators of the exchanged rho and sigma mesons. To account for chemical freeze out in heavy ion collisions, a temperature dependent pion chemical potential has been introduced in the distribution function. The temperature dependence of the relaxation times for shear and bulk viscous flows as well as the heat flow is significantly affected.

  12. Medium effects on the relaxation of dissipative flows in a hot pion gas

    E-Print Network [OSTI]

    Mitra, Sukanya; Sarkar, Sourav

    2015-01-01

    The relaxation times over which dissipative fluxes restore their steady state values have been evaluated for a pion gas using the 14-moment method. The effect of the medium has been implemented through a temperature dependent pi-pi cross-section in the collision integral which is obtained by including one-loop self-energies in the propagators of the exchanged rho and sigma mesons. To account for chemical freeze out in heavy ion collisions, a temperature dependent pion chemical potential has been introduced in the distribution function. The temperature dependence of the relaxation times for shear and bulk viscous flows as well as the heat flow is significantly affected.

  13. Numerical Simulation of Rarefied-Gas Flows about a Rotating Cylinder

    E-Print Network [OSTI]

    Riabov, Vladimir V.

    -Gas Flows, Aerodynamic Coefficients. PACS: 47.11.Mn, 47.27 ek, 47.32 Ef, 47.45 n, 47.85 Gj. NOMENCLATURE Cx. The lift and drag coefficients Cy,FM and Cx,FM , respectively, can be calculated using the formulae [6]: Cy,FM = Cy (0) + Cy (W), Cy (W) = ( /2) t W (1) Cx,FM = Cx (0) + Cx (W), Cx (W) = 0 (2) where the parameter

  14. Numerical simulation of flow and heat transfer of internal cooling passage in gas turbine blade 

    E-Print Network [OSTI]

    Su, Guoguang

    2007-04-25

    for efficient energy utilization; one of the most powerful means of achieving higher efficiency in industrial gas turbine engines is to raise the turbine inlet temperature (TIT). Sophisticated cooling techniques must be employed to cool the components... for momentum, energy, and turbulence quantities are solved in curvilinear, body-fitted coordinates using the finite-analytic method. 2.1 The Governing Equation and Chimera Method For unsteady incompressible flow, the continuty equation and momentum...

  15. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Trehu, Anne; Kannberg, Peter

    2011-06-30

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m2). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that ~50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a "toe-thrust" ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those ~70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the KG basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m2. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basin is at the low end of glob

  16. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Anne Trehu; Peter Kannberg

    2011-06-30

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m{sup 2}). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that {approx}50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a 'toe-thrust' ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those {approx}70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the K-G basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m{sup 2}. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basi

  17. Analyzing flow patterns in unsaturated fractured rock of Yucca Mountain using an integrated modeling approach

    E-Print Network [OSTI]

    Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson, Gudmundur S.

    2008-01-01

    temperature profiles or geothermal gradients within the UZthe UZ by ambient geothermal gradients. Any large increasein net heat flow or geothermal gradients, such that model

  18. Dynamic and spectroscopic characteristics of atmospheric gliding arc in gas-liquid two-phase flow

    SciTech Connect (OSTI)

    Tu, X.; Yu, L.; Yan, J. H.; Cen, K. F.; Cheron, B. G.

    2009-11-15

    In this study, an atmospheric alternating-current gliding arc device in gas-liquid two-phase flow has been developed for the purpose of waste water degradation. The dynamic behavior of the gas-liquid gliding arc is investigated through the oscillations of electrical signals, while the spatial evolution of the arc column is analyzed by high speed photography. Different arc breakdown regimes are reported, and the restrike mode is identified as the typical fluctuation characteristic of the hybrid gliding arc in air-water mixture. Optical emission spectroscopy is employed to investigate the active species generated in the gas-liquid plasma. The axial evolution of the OH (309 nm) intensity is determined, while the rotational and vibrational temperatures of the OH are obtained by a comparison between the experimental and simulated spectra. The significant discrepancy between the rotational and translational temperatures has also been discussed.

  19. Idaho National Laboratory Experimental Program to Measure the Flow Phenomena in a Scaled Model of a Prismatic Gas-Cooled Reactor Lower Plenum for Validation of CFD Codes

    SciTech Connect (OSTI)

    Hugh M. McIlroy Jr.; Donald M. McEligot; Robert J. Pink

    2008-09-01

    The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a prismatic gas-cooled reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A description of the scaling analysis, experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples of the data sets that have been obtained are included. Samples of the data set that will be presented include mean-velocity-field and turbulence data in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid. The benefit of the MIR technique is that it permits high-quality measurements to be obtained without locating intrusive transducers that disturb the flow field and without distortion of the optical paths. An advantage of the INL MIR system is its large size which allows improved spatial and temporal resolution compared to similar facilities at smaller scales. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. The measurements reveal developing, non-uniform flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and charts that describe the component flows at specific regions in the model. Information on inlet velocity profiles is also presented.

  20. The Impacts of Alternative Patterns of Urbanization on Greenhouse Gas Emissions in an Agricultural County

    E-Print Network [OSTI]

    Wheeler, Stephen

    2013-01-01

    Jackson. 2013. “Use of Local Green- house Gas Inventories toMTP/SCS Appendix E-7: Green- house Gas Regional Inventory

  1. Optimal fracture treatment design for dry gas wells maximizes well performance in the presence of non-Darcy flow effects 

    E-Print Network [OSTI]

    Lopez Hernandez, Henry De Jesus

    2004-11-15

    This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, ...

  2. The RealGas and RealGasH2O Options of the TOUGH+ Code for the Simulation of Coupled Fluid and Heat Flow in Tight/Shale Gas Systems

    SciTech Connect (OSTI)

    Moridis, George; Freeman, Craig

    2013-09-30

    We developed two new EOS additions to the TOUGH+ family of codes, the RealGasH2O and RealGas . The RealGasH2O EOS option describes the non-isothermal two-phase flow of water and a real gas mixture in gas reservoirs, with a particular focus in ultra-tight (such as tight-sand and shale gas) reservoirs. The gas mixture is treated as either a single-pseudo-component having a fixed composition, or as a multicomponent system composed of up to 9 individual real gases. The RealGas option has the same general capabilities, but does not include water, thus describing a single-phase, dry-gas system. In addition to the standard capabilities of all members of the TOUGH+ family of codes (fully-implicit, compositional simulators using both structured and unstructured grids), the capabilities of the two codes include: coupled flow and thermal effects in porous and/or fractured media, real gas behavior, inertial (Klinkenberg) effects, full micro-flow treatment, Darcy and non-Darcy flow through the matrix and fractures of fractured media, single- and multi-component gas sorption onto the grains of the porous media following several isotherm options, discrete and fracture representation, complex matrix-fracture relationships, and porosity-permeability dependence on pressure changes. The two options allow the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in problems of geologic storage of greenhouse gas mixtures, and of geothermal reservoirs with multi-component condensable (H2O and CH4) and non-condensable gas mixtures. The codes are verified against available analytical and semi-analytical solutions. Their capabilities are demonstrated in a series of problems of increasing complexity, ranging from isothermal flow in simpler 1D and 2D conventional gas reservoirs, to non-isothermal gas flow in 3D fractured shale gas reservoirs involving 4 types of fractures, micro-flow, non-Darcy flow and gas composition changes during production.

  3. Rotordynamic evaluation of frequency dependent impedances of hole-pattern gas damper seals 

    E-Print Network [OSTI]

    Holt, Christopher George

    2000-01-01

    Two hole-pattern seals are compared with one smooth bore seal. The two hole-pattern seals have cell depths of 2.03 mm and 3.18 mm with a cell diameter of 1.59 mm. The hole area density factor for both hole-pattern seals is 43%. The L/D ratio...

  4. An efficient particle Fokker–Planck algorithm for rarefied gas flows

    SciTech Connect (OSTI)

    Gorji, M. Hossein; Jenny, Patrick

    2014-04-01

    This paper is devoted to the algorithmic improvement and careful analysis of the Fokker–Planck kinetic model derived by Jenny et al. [1] and Gorji et al. [2]. The motivation behind the Fokker–Planck based particle methods is to gain efficiency in low Knudsen rarefied gas flow simulations, where conventional direct simulation Monte Carlo (DSMC) becomes expensive. This can be achieved due to the fact that the resulting model equations are continuous stochastic differential equations in velocity space. Accordingly, the computational particles evolve along independent stochastic paths and thus no collision needs to be calculated. Therefore the computational cost of the solution algorithm becomes independent of the Knudsen number. In the present study, different computational improvements were persuaded in order to augment the method, including an accurate time integration scheme, local time stepping and noise reduction. For assessment of the performance, gas flow around a cylinder and lid driven cavity flow were studied. Convergence rates, accuracy and computational costs were compared with respect to DSMC for a range of Knudsen numbers (from hydrodynamic regime up to above one). In all the considered cases, the model together with the proposed scheme give rise to very efficient yet accurate solution algorithms.

  5. ACCRETION OF GAS ONTO GAP-OPENING PLANETS AND CIRCUMPLANETARY FLOW STRUCTURE IN MAGNETIZED TURBULENT DISKS

    SciTech Connect (OSTI)

    Uribe, A. L. [University of Chicago, Chicago, IL 60637 (United States); Klahr, H.; Henning, Th., E-mail: uribe@oddjob.uchicago.edu [Max-Planck-Institut fuer Astronomie, Heidelberg (Germany)

    2013-06-01

    We have performed three-dimensional magnetohydrodynamical simulations of stellar accretion disks, using the PLUTO code, and studied the accretion of gas onto a Jupiter-mass planet and the structure of the circumplanetary gas flow after opening a gap in the disk. We compare our results with simulations of laminar, yet viscous disks with different levels of an {alpha}-type viscosity. In all cases, we find that the accretion flow across the surface of the Hill sphere of the planet is not spherically or azimuthally symmetric, and is predominantly restricted to the mid-plane region of the disk. Even in the turbulent case, we find no significant vertical flow of mass into the Hill sphere. The outer parts of the circumplanetary disk are shown to rotate significantly below Keplerian speed, independent of viscosity, while the circumplanetary disk density (therefore the angular momentum) increases with viscosity. For a simulation of a magnetized turbulent disk, where the global averaged alpha stress is {alpha}{sub MHD} = 10{sup -3}, we find the accretion rate onto the planet to be M-dot {approx}2 Multiplication-Sign 10{sup -6}M{sub J} yr{sup -1} for a gap surface density of 12 g cm{sup -2}. This is about a third of the accretion rate obtained in a laminar viscous simulation with equivalent {alpha} parameter.

  6. Modeling hot gas flow in the low-luminosity active galactic nucleus of NGC 3115

    SciTech Connect (OSTI)

    Shcherbakov, Roman V.; Reynolds, Christopher S.; Wong, Ka-Wah; Irwin, Jimmy A.

    2014-02-20

    Based on the dynamical black hole (BH) mass estimates, NGC 3115 hosts the closest billion solar mass BH. Deep studies of the center revealed a very underluminous active galactic nucleus (AGN) immersed in an old massive nuclear star cluster. Recent 1 Ms Chandra X-ray visionary project observations of the NGC 3115 nucleus resolved hot tenuous gas, which fuels the AGN. In this paper we connect the processes in the nuclear star cluster with the feeding of the supermassive BH. We model the hot gas flow sustained by the injection of matter and energy from the stars and supernova explosions. We incorporate electron heat conduction as the small-scale feedback mechanism, the gravitational pull of the stellar mass, cooling, and Coulomb collisions. Fitting simulated X-ray emission to the spatially and spectrally resolved observed data, we find the best-fitting solutions with ?{sup 2}/dof = 1.00 for dof = 236 both with and without conduction. The radial modeling favors a low BH mass <1.3 × 10{sup 9} M {sub ?}. The best-fitting supernova rate and the best-fitting mass injection rate are consistent with their expected values. The stagnation point is at r {sub st} ? 1'', so that most of the gas, including the gas at a Bondi radius r{sub B} = 2''-4'', outflows from the region. We put an upper limit on the accretion rate at 2 × 10{sup –3} M {sub ?} yr{sup –1}. We find a shallow density profile n?r {sup –?} with ? ? 1 over a large dynamic range. This density profile is determined in the feeding region 0.''5-10'' as an interplay of four processes and effects: (1) the radius-dependent mass injection, (2) the effect of the galactic gravitational potential, (3) the accretion flow onset at r ? 1'', and (4) the outflow at r ? 1''. The gas temperature is close to the virial temperature T{sub v} at any radius.

  7. Determination of the permeability of carbon aerogels by gas flow measurements

    SciTech Connect (OSTI)

    Kong, F.M.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W.

    1992-04-01

    Carbon aerogels are synthesized via the polycondensation of resorcinol and formaldehyde, followed by supercritical drying and pyrolysis at 1050{degree}C in nitrogen. Because of their interconnected porosity, ultrafine cell structure and high surface area, carbon aerogels have many potential applications, such as in supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, we calculated the permeability of carbon aerogels from equations based upon Darcy's law. Our measurements show that carbon aerogels have apparent permeabilities on the order of 10{sup {minus}12}to 10{sup {minus}10} cm{sup 2} for densities ranging from 0.44 to 0.05 g/cm{sup 3}. Like their mechanical properties, the permeability of carbon aerogels follows a power law relationship with density and average pore size. Such findings help us to estimate the average pore sizes of carbon aerogels once their densities are known. This paper reveals the relationships among permeability, pore size and density in carbon aerogels.

  8. Determination of the permeability of carbon aerogels by gas flow measurements

    SciTech Connect (OSTI)

    Kong, F.M.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W.

    1992-04-01

    Carbon aerogels are synthesized via the polycondensation of resorcinol and formaldehyde, followed by supercritical drying and pyrolysis at 1050{degree}C in nitrogen. Because of their interconnected porosity, ultrafine cell structure and high surface area, carbon aerogels have many potential applications, such as in supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, we calculated the permeability of carbon aerogels from equations based upon Darcy`s law. Our measurements show that carbon aerogels have apparent permeabilities on the order of 10{sup {minus}12}to 10{sup {minus}10} cm{sup 2} for densities ranging from 0.44 to 0.05 g/cm{sup 3}. Like their mechanical properties, the permeability of carbon aerogels follows a power law relationship with density and average pore size. Such findings help us to estimate the average pore sizes of carbon aerogels once their densities are known. This paper reveals the relationships among permeability, pore size and density in carbon aerogels.

  9. CFD Simulation of 3D Flow field in a Gas Centrifuge

    SciTech Connect (OSTI)

    Dongjun Jiang; Shi Zeng

    2006-07-01

    A CFD method was used to study the whole flow field in a gas centrifuge. In this paper, the VSM (Vector Splitting Method) of the FVM (Finite Volume Method) was used to solve the 3D Navier-Stokes equations. An implicit second-order upwind scheme was adopted. The numerical simulation was successfully performed on a parallel cluster computer and a convergence result was obtained. The simulation shows that: in the withdrawal chamber, a strong detached shock wave is formed in front of the scoop; as the radial position increases, the shock becomes stronger and the distance to scoop front surface is smaller. An oblique shock forms in the clearance between the scoop and the centrifuge wall; behind the shock-wave, the radially-inward motion of gas is induced because of the imbalance of the pressure gradient and the centrifugal force. In the separation chamber, a countercurrent is introduced. This indicates that CFD method can be used to study the complex three-dimensional flow field of gas centrifuges. (authors)

  10. Controlling fuel and diluent gas flow for a diesel engine operating in the fuel rich low-temperature-combustion mode

    E-Print Network [OSTI]

    Lopez, David M

    2007-01-01

    The flow of a diluent gas supplied to a motoring engine was controlled at a diluent to air mass flow ratios of 10%, 30%, 50%, and 70%. This arrangement was a significant set up for running the engine in the Low-Temperature ...

  11. Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Timothy R. Kline, Walter F. Paxton, Yang Wang, Darrell Velegol,*, Thomas E. Mallouk,* and

    E-Print Network [OSTI]

    Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Formation Timothy R. Kline of the driving forces for developing micro/nanofluidics. Engineering fluid flows at this scale remains a "fuel" can be converted locally at a catalyst surface, possibly eliminating external pumps or power

  12. The use of temperature and the isotopes of O, H, C, and noble gases to determine the pattern and spatial extent of groundwater flow

    E-Print Network [OSTI]

    Manga, Michael

    and spatial extent of groundwater flow E.R. Jamesa , M. Mangaa,*, T.P. Roseb , G.B. Hudsonb a Department springs in the central Oregon Cascades are used to understand the pattern of groundwater flow. Standard at the springs to determine whether groundwater circulates to shallow or deep depths in the subsurface

  13. Mathematical Simulation of the Gas-Particles Reaction Flows in Incineration of Metal-Containing Waste

    SciTech Connect (OSTI)

    Ojovan, M. I.; Klimov, V. L.; Karlina, O. K.

    2002-02-26

    A ''quasi-equilibrium'' approach for thermodynamic calculation of chemical composition and properties of metal-containing fuel combustion products has been developed and used as a part of the mathematical model of heterogeneous reacting flow which carry burning and/or evaporating particles. By using of this approach, the applicable mathematical model has been devised, which allows defining the change in chemical composition and thermal characteristics of combustion products along the incineration chamber. As an example, the simulation results of the reacting flow of magnesium-sodium nitrate-organic mixture are presented. The simulation results on the gas phase temperature in the flow of combustion products are in good agreement with those obtained experimentally. The proposed method of ''quasi-equilibrium'' thermodynamic calculation and mathematical model provide a real possibility for performing of numerical experiments on the basis of mathematical simulation of nonequilibrium flows of combustion products. Numerical experiments help correctly to estimate the work characteristics in the process of treatment devices design saving time and costs.

  14. A gas kinetic scheme for the Baer-Nunziato two-phase flow model

    SciTech Connect (OSTI)

    Pan, Liang, E-mail: panliangjlu@sina.com [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China) [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); The Graduate School of China Academy of Engineering Physics, Beijing 100088 (China); Zhao, Guiping, E-mail: zhaogp@nsfc.gov.cn [National Natural Science Foundation of China, Beijing 100085 (China)] [National Natural Science Foundation of China, Beijing 100085 (China); Tian, Baolin, E-mail: tian_baolin@iapcm.ac.cn [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China) [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Wang, Shuanghu, E-mail: wang_shuanghu@iapcm.ac.cn [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China) [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2012-09-15

    Numerical methods for the Baer-Nunziato (BN) two-phase flow model have attracted much attention in recent years. In this paper, we present a new gas kinetic scheme for the BN two-phase flow model containing non-conservative terms in the framework of finite volume method. In the view of microscopic aspect, a generalized Bhatnagar-Gross-Krook (BGK) model which matches with the BN model is constructed. Based on the integral solution of the generalized BGK model, we construct the distribution functions at the cell interface. Then numerical fluxes can be obtained by taking moments of the distribution functions, and non-conservative terms are explicitly introduced into the construction of numerical fluxes. In this method, not only the complex iterative process of exact solutions is avoided, but also the non-conservative terms included in the equation can be handled well.

  15. Characterization of the reactive flow field dynamics in a gas turbine injector using high frequency PIV

    E-Print Network [OSTI]

    Barbosa, Séverine; Ducruix, Sébastien

    2008-01-01

    The present work details the analysis of the aerodynamics of an experimental swirl stabilized burner representative of gas turbine combustors. This analysis is carried out using High Frequency PIV (HFPIV) measurements in a reactive situation. While this information is usually available at a rather low rate, temporally resolved PIV measurements are necessary to better understand highly turbulent swirled flows, which are unsteady by nature. Thanks to recent technical improvements, a PIV system working at 12 kHz has been developed to study this experimental combustor flow field. Statistical quantities of the burner are first obtained and analyzed, and the measurement quality is checked, then a temporal analysis of the velocity field is carried out, indicating that large coherent structures periodically appear in the combustion chamber. The frequency of these structures is very close to the quarter wave mode of the chamber, giving a possible explanation for combustion instability coupling.

  16. Efficient boron-carbon-nitrogen nanotube formation via combined laser-gas flow levitation

    DOE Patents [OSTI]

    Whitney, R Roy; Jordan, Kevin; Smith, Michael W

    2015-03-24

    A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z. The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z.

  17. Efficient boron nitride nanotube formation via combined laser-gas flow levitation

    DOE Patents [OSTI]

    Whitney, R. Roy; Jordan, Kevin; Smith, Michael

    2014-03-18

    A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z. The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z.

  18. Reprocessing of radiation by multi-phase gas in Low Luminosity Accretion Flows

    E-Print Network [OSTI]

    A. Celotti; M. J. Rees

    1998-07-24

    We discuss the role that magnetic fields in low luminosity accretion flows can play in creating and maintaining a multi-phase medium, and show that small magnetically-confined clouds or filaments of dense cold gas can dramatically reprocess the `primary' radiation from tori. In particular, radio emission would be suppressed by free-free absorption, and an extra (weak) component would appear at optical wavelengths. This is expected to be a common process in various environments in the central regions of Active Galaxies, such as broad line regions, accretion disk coronae and jets.

  19. Interfacial Friction in Gas-Liquid Annular Flow: Analogies to Full and Transition Roughness

    SciTech Connect (OSTI)

    Bauer, R.C.; Beus, S.G.; Fore, L.B.

    1999-03-01

    New film thickness and pressure gradient data were obtained in a 5.08 by 101.6 mm duct for nitrogen and water in annular flow. Pressures of 3.4 and 17 atm and temperatures of 38 and 93 C were used to vary the gas density and liquid viscosity. These data are used to compute interfacial shear stresses and interfacial friction factors for comparison with several accepted literature correlations. These comparisons are reasonable for small values of the relative film thickness. However, the new data cover conditions not approached by the data used to construct those correlations. By combining the current data with the results of two other comprehensive modern experimental studies, a new correlation for the interfacial friction factor has been developed. This correlation adds elements of transition roughness to Wallis' fully-rough analogy to better predict interfacial friction factors over a wide range of gas Reynolds numbers and liquid film thicknesses.

  20. DEVELOPMENT OF A LOW COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

    SciTech Connect (OSTI)

    E. Kelner; D. George; T. Morrow; T. Owen; M. Nored; R. Burkey; A. Minachi

    2005-05-01

    In 1998, Southwest Research Institute began a multi-year project to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype energy meter in 2002-2003 included: (1) refinement of the algorithm used to infer properties of the natural gas stream, such as heating value; (2) evaluation of potential sensing technologies for nitrogen content, improvements in carbon dioxide measurements, and improvements in ultrasonic measurement technology and signal processing for improved speed of sound measurements; (3) design, fabrication and testing of a new prototype energy meter module incorporating these algorithm and sensor refinements; and (4) laboratory and field performance tests of the original and modified energy meter modules. Field tests of the original energy meter module have provided results in close agreement with an onsite gas chromatograph. The original algorithm has also been tested at a field site as a stand-alone application using measurements from in situ instruments, and has demonstrated its usefulness as a diagnostic tool. The algorithm has been revised to use measurement technologies existing in the module to measure the gas stream at multiple states and infer nitrogen content. The instrumentation module has also been modified to incorporate recent improvements in CO{sub 2} and sound speed sensing technology. Laboratory testing of the upgraded module has identified additional testing needed to attain the target accuracy in sound speed measurements and heating value.

  1. Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns

    SciTech Connect (OSTI)

    Carlson, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States); Kruizenga, A. [Sandia National Laboratory (United States); Anderson, M.; Corradini, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2012-07-01

    Closed-loop Brayton cycles using supercritical carbon dioxide (SCO{sub 2}) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO{sub 2} Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO{sub 2} Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO{sub 2} flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

  2. Pore-scale mechanisms of gas flow in tight sand reservoirs

    E-Print Network [OSTI]

    Silin, D.

    2011-01-01

    production increased. Unconventional gas resources accountedwellbores. ” Unconventional gas resources traditionallysand is an unconventional natural gas resource. According to

  3. 3D Modeling of One and Two Component Gas Flow in Fibrous Microstructures in Fuel Cells by Using the Lattice-Boltzmann Method

    E-Print Network [OSTI]

    Schmidt, Volker

    In fuel cells, a homogeneous distribution of gas flow is desirable for optimal performance. The gas3D Modeling of One and Two Component Gas Flow in Fibrous Microstructures in Fuel Cells by Using: Fuel Cells, 52425 Jülich, Germany b Institute of Stochastics, Ulm University, 89069 Ulm, Germany

  4. Numerical modeling of carrier gas flow in atomic layer deposition vacuum reactor: A comparative study of lattice Boltzmann models

    SciTech Connect (OSTI)

    Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)

    2014-01-15

    This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice Bhatnagar–Gross–Krook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.

  5. Two phase partially miscible flow and transport modeling in porous media: application to gas migration in a nuclear waste repository

    E-Print Network [OSTI]

    Bourgeat, Alain; Smaï, Farid

    2008-01-01

    We derive a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological repository for radioactive waste. This model includes capillary effects and the gas high diffusivity. Moreover, it is written in variables (total hydrogen mass density and liquid pressure) chosen in order to be consistent with gas appearance or disappearance. We discuss the well possedness of this model and give some computational evidences of its adequacy to simulate gas generation in a water saturated repository.

  6. Two phase partially miscible flow and transport modeling in porous media: application to gas migration in a nuclear waste repository

    E-Print Network [OSTI]

    Alain Bourgeat; Mladen Jurak; Farid Smaï

    2008-02-29

    We derive a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological repository for radioactive waste. This model includes capillary effects and the gas high diffusivity. Moreover, it is written in variables (total hydrogen mass density and liquid pressure) chosen in order to be consistent with gas appearance or disappearance. We discuss the well possedness of this model and give some computational evidences of its adequacy to simulate gas generation in a water saturated repository.

  7. Test versus predictions for rotordynamic coefficients and leakage rates of hole-pattern gas seals at two clearances in choked and unchoked conditions 

    E-Print Network [OSTI]

    Wade, Jonathan Leigh

    2004-09-30

    This thesis documents the results of high pressure testing of hole-pattern annular gas seals conducted at the Texas A&M University's Turbomachinery Laboratory. The testing conditions were aimed at determining the test seals ...

  8. DESIGN AND DEVELOPMENT OF GAS-LIQUID CYLINDRICAL CYCLONE COMPACT SEPARATORS FOR THREE-PHASE FLOW

    SciTech Connect (OSTI)

    Dr. Ram S. Mohan; Dr. Ovadia Shoham

    2003-06-25

    The U.S. Department of Energy (DOE) has awarded a five-year (1997-2002) grant (Mohan and Shoham, DE-FG26-97BC15024, 1997) to The University of Tulsa, to develop compact multiphase separation components for 3-phase flow. The research activities of this project have been conducted through cost sharing by the member companies of the Tulsa University Separation Technology Projects (TUSTP) research consortium and the Oklahoma Center for the Advancement of Science and Technology (OCAST). As part of this project, several individual compact separation components have been developed for onshore and offshore applications. These include gas-liquid cylindrical cyclones (GLCC{copyright}), liquid-liquid cylindrical cyclones (LLCC{copyright}), and the gas-liquid-liquid cylindrical cyclones (GLLCC{copyright}). A detailed study has also been completed for the liquid-liquid hydrocyclones (LLHC). Appropriate control strategies have been developed for proper operation of the GLCC{copyright} and LLCC{copyright}. Testing of GLCC{copyright} at high pressure and real crude conditions for field applications is also completed. Limited studies have been conducted on flow conditioning devices to be used upstream of the compact separators for performance improvement. This report presents a brief overview of the activities and tasks accomplished during the 5-year project period, October 1, 1997-March 31, 2003 (including the no-cost extended period of 6 months). An executive summary is presented initially followed by the tasks of the 5-year budget periods. Then, detailed description of the experimental and modeling investigations are presented. Subsequently, the technical and scientific results of the activities of this project period are presented with some discussions. The findings of this investigation are summarized in the ''Conclusions'' section, followed by relevant references. The publications resulting from this study in the form of MS Theses, Ph.D. Dissertation, Journal Papers and Conference Presentations are provided at the end of this report.

  9. Pore-scale mechanisms of gas flow in tight sand reservoirs

    E-Print Network [OSTI]

    Silin, D.

    2011-01-01

    adjacent fractures. Natural gas composition consists mostlyNatural gas is called wet or dry depending on how large is the lique?able portion of gas composition.

  10. Pore-scale mechanisms of gas flow in tight sand reservoirs

    E-Print Network [OSTI]

    Silin, D.

    2011-01-01

    include tight gas sands, gas shales, and coal-bed methane.Figure 3. Although the gas-shale production grows at a

  11. The atomization of a liquid jet by a high speed cross-flowing gas has many applications such as gas turbines and augmentors. The mechanisms by which the liquid jet initially breaks up, however, are not

    E-Print Network [OSTI]

    The atomization of a liquid jet by a high speed cross-flowing gas has many applications such as gas turbines and augmentors. The mechanisms by which the liquid jet initially breaks up, however, are not well

  12. Flow Visualization and Measurements of the Mixing Evolution of a Shock-Accelerated Gas Curtain

    SciTech Connect (OSTI)

    Prestridge, K.; Vorobieff, P.V.; Rightley, P.M.; Benjamin, R.F

    1999-07-19

    We describe a highly-detailed experimental characterization of the impulsively driven Rayleigh-Taylor instability, called the Richtmyer-Meshkov instability. This instability is produced by flowing a diffuse, vertical curtain of heavy gas (SF{sub 6}) into the test section of an air-filled horizontally oriented shock tube. The instability evolves after the passage of a Mach 1.2 shock past the curtain, and the development of the curtain is visualized by seeding the SF{sub 6} with small (d{approximately}0.5 and micro;m) glycol droplets using a modified theatrical fog generator. Because the event lasts only 1 ms and the initial conditions vary from test to test, rapid and complete data acquisition is required in order to characterize the initial and dynamic conditions for each experimental shot. Through the use of a custom-built pulsed Nd: YAG laser, we are able to image the flowfield at seven different times. We acquire a double-pulsed image of the flow with the use of a second pulsed Nd:YAG, which is used to determine the instantaneous velocity field using Particle Image Velocimetry (PIV). During a single experiment, high resolution images of the initial conditions and dynamic conditions are acquired using three CCD cameras. Issues of the fidelity of the flow seeding technique and the reliability of the PIV technique will be addressed. We have successfully provided interesting data through analysis of the images alone, and we are hoping that PIV information will be able to add further physical insight to the evolution of the RM instability and the transition to turbulence.

  13. COARSE-GRID SIMULATION OF REACTING AND NON-REACTING GAS-PARTICLE FLOWS

    SciTech Connect (OSTI)

    Sankaran Sundaresan

    2004-03-01

    The principal goal of this project, funded under the ''DOE Vision 21 Virtual Demonstration Initiative'' is virtual demonstration of circulating fluidized bed performance. We had proposed a ''virtual demonstration tool'', which is based on the open-domain CFD code MFIX. The principal challenge funded through this grant is to devise and implement in this CFD code sound physical models for the rheological characteristics of the gas-particle mixtures. Within the past year, which was the third year of the project, we have made the following specific advances. (a) We have completed a study of the impact of sub-grid models of different levels of detail on the results obtained in coarse-grid simulations of gas-particle flow. (b) We have also completed a study of a model problem to understand the effect of wall friction, which was proved in our earlier work to be very important for stable operation of standpipes in a circulating fluidized bed circuit. These are described in a greater detail in this report.

  14. Design and Development of Gas-Liquid Cylindrical Cyclone Compact Separators for Three-Phase Flow

    SciTech Connect (OSTI)

    Mohan, R.S.; Shoham, O.

    2001-01-10

    The objective of this five-year project (October 1997--September 2002) was to expand the current research activities of Tulsa University Separation Technology Projects (TUSTP) to multiphase oil/water/gas separation. This project was executed in two phases. Phase I (1997--2000) focused on the investigations of the complex multiphase hydrodynamic flow behavior in a three-phase Gas-Liquid Cylindrical Cyclone (GLCC) Separator. The activities of this phase included the development of a mechanistic model, a computational fluid dynamics (CFD) simulator, and detailed experimentation on the three-phase GLCC. The experimental and CFD simulation results will be suitably integrated with the mechanistic model. In Phase II (2000--2002), the developed GLCC separator will be tested under high pressure and real crude conditions. This is crucial for validating the GLCC design for field application and facilitating easy and rapid technology deployment. Design criteria for industrial applications will be developed based on these results and will be incorporated into the mechanistic model by TUSTP.

  15. Design and Development of Gas-Liquid Cylindrical Cyclone Compact Separators for Three-Phase Flow

    SciTech Connect (OSTI)

    Mohan, R.S.; Shoham, O.

    2001-01-18

    The objective of this five-year project (October 1997 - September 2002) was to expand the current research activities of Tulsa University Separation Technology Projects (TUSTP) to multiphase oil/water/gas separation. This project was executed in two phases. Phase I (1997 - 2000) focused on the investigations of the complex multiphase hydrodynamic flow behavior in a three-phase Gas-Liquid Cylindrical Cyclone (GLCC) Separator. The activities of this phase included the development of a mechanistic model, a computational fluid dynamics (CFD) simulator, and detailed experimentation on the three-phase GLCC. The experimental and CFD simulation results will be suitably integrated with the mechanistic model. In Phase II (2000 - 2002), the developed GLCC separator will be tested under high pressure and real crude conditions. This is crucial for validating the GLCC design for field application and facilitating easy and rapid technology deployment. Design criteria for industrial applications will be developed based on these results and will be incorporated into the mechanistic model by TUSTP.

  16. A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge

    SciTech Connect (OSTI)

    de Stadler, M; Chand, K

    2007-11-12

    Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are presented.

  17. GAS-PARTICLE FLOW IN THE ENTRY REGION OF A CURVED PIPE

    E-Print Network [OSTI]

    Yeung, Woon-Shing

    2011-01-01

    =Equilibrium Fluid Dynamics-«Laminar Flow ?ver a Flat Plate.fluid is assumed to be incompressible and the flow nonseparating and laminar.

  18. characterization and visualization of two-phase flow properties of gas diffusion layers used in a PEM fuel cell

    E-Print Network [OSTI]

    Gao, Yan

    2011-04-26

    Due to the low-temperature operation of Polymer Electrolyte Membrane fuel cell (PEMFC), liquid water can build up in either flow channels or gas diffusion layers (GDL). Better understanding of the effect of two-phase transport properties on liquid...

  19. A coupled model for ring dynamics, gas flow, and oil flow through the ring grooves in IC engines

    E-Print Network [OSTI]

    Jia, Ke, S. M. Massachusetts Institute of Technology

    2009-01-01

    Oil flows through ring/groove interface play a critical role in oil transport among different regions the piston ring pack of internal combustion engines. This thesis work is intended to improve the understanding and ...

  20. The Tremaine-Weinberg method for pattern speeds using H-alpha emission from ionized gas

    E-Print Network [OSTI]

    John E. Beckman; Kambiz Fathi; Núria Piñol; Silvia Toonen; Olivier Hernandez; Claude Carignan

    2008-01-18

    The Fabry-Perot interferometer FaNTOmM was used at the 3.6m Canada France Hawaii Telescope and the 1.6m Mont Megantic Telescope to obtain data cubes in H-alpha of 9 nearby spiral galaxies from which maps in integrated intensity, velocity, and velocity dispersion were derived. We then applied the Tremaine-Weinberg method, in which the pattern speed can be deduced from its velocity field, by finding the integrated value of the mean velocity along a slit parallel to the major axis weighted by the intensity and divided by the weighted mean distance of the velocity points from the tangent point measured along the slit. The measured variables can be used either to make separate calculations of the pattern speed and derive a mean, or in a plot of one against the other for all the points on all slits, from which a best fit value can be derived. Linear fits were found for all the galaxies in the sample. For two galaxies a clearly separate inner pattern speed with a higher value, was also identified and measured.

  1. The Tremaine-Weinberg method for pattern speeds using H-alpha emission from ionized gas

    E-Print Network [OSTI]

    Beckman, John E; Piñol, Núria; Toonen, Silvia; Hernandez, Olivier; Carignan, Claude

    2007-01-01

    The Fabry-Perot interferometer FaNTOmM was used at the 3.6m Canada France Hawaii Telescope and the 1.6m Mont Megantic Telescope to obtain data cubes in H-alpha of 9 nearby spiral galaxies from which maps in integrated intensity, velocity, and velocity dispersion were derived. We then applied the Tremaine-Weinberg method, in which the pattern speed can be deduced from its velocity field, by finding the integrated value of the mean velocity along a slit parallel to the major axis weighted by the intensity and divided by the weighted mean distance of the velocity points from the tangent point measured along the slit. The measured variables can be used either to make separate calculations of the pattern speed and derive a mean, or in a plot of one against the other for all the points on all slits, from which a best fit value can be derived. Linear fits were found for all the galaxies in the sample. For two galaxies a clearly separate inner pattern speed with a higher value, was also identified and measured.

  2. Radially-Inflowing Molecular Gas in NGC 1275 Deposited by a X-ray Cooling Flow in the Perseus Cluster

    E-Print Network [OSTI]

    Jeremy Lim; YiPing Ao; Dinh-V-Trung

    2007-12-18

    We have imaged in CO(2-1) the molecular gas in NGC 1275 (Perseus A), the cD galaxy at the center of the Perseus Cluster, at a spatial resolution of $\\sim$1 kpc over a central region of radius $\\sim$ 10 kpc. Per A is known to contain $\\sim$1.3x10$^{10}$ M$_\\odot$ of molecular gas, which has been proposed to be captured from mergers with or ram-pressure stripping of gas-rich galaxies, or accreted from a X-ray cooling flow. The molecular gas detected in our image has a total mass of $\\sim$4x10$^9$ M$_\\odot$, and for the first time can be seen to be concentrated in three radial filaments with lengths ranging from at least 1.1-2.4 kpc all lying in the east-west directions spanning the center of the galaxy to radii of $\\sim$8 kpc. The eastern and outer western filaments exhibit larger blueshifted velocities with decreasing radii, whereas the inner western filament spans the systemic velocity of the galaxy. The molecular gas shows no signature of orbital motion, and is therefore unlikely to have been captured from gas-rich galaxies. Instead, we are able to reproduce the observed kinematics of the two outer filaments as free-fall in the gravitational potential of Per A, as would be expected if they originate from a X-ray cooling flow. Indeed, all three filaments lie between two prominent X-ray cavities carved out by radio jets from Per A, and closely resembles the spatial distribution of the coolest X-ray gas in the cluster core. The inferred mass-deposition rate into the two outermost filaments alone is roughly 75 M$_odot$ yr$^{-1}$. This cooling flow can provide a nearly continuous supply of molecular gas to fuel the active nucleus in Per A.

  3. Burden distribution control for maintaining the central gas flow at No. 1 blast furnace in Pohang Works

    SciTech Connect (OSTI)

    Jung, S.K.; Lee, Y.J.; Suh, Y.K.; Ahn, T.J.; Kim, S.M. [Pohang Iron and Steel Co. Ltd. (Korea, Republic of). Technical Research Labs.

    1995-12-01

    The causes for temperature lowering at the upper shaft center in Pohang No. 1 blast furnace were investigated. The test operation with charging notch change in the actual blast furnace and with a 1/12 scale model to Pohang No. 1 blast furnace were carried out in order to improve central gas flow in the shaft. Finally, rebuilding of the lower bunker interior was performed using the results of model experiments. It was confirmed that the main reason for the gas temperature lowering at the upper shaft center was the smaller particle size at center than the wall according to the discharging characteristics of center feed bunker with stone box. The central gas flow could be secured through modifying the stone box in the bunker.

  4. INTERNAL FORCED iquid or gas flow through pipes or ducts is commonly used in heating and

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    to flow by a fan or pump through a flow section that is sufficiently long to accomplish the desired heat Transitional Flow in Tubes* An important design problem in industrial heat exchangers arises when flow inside or ducts is commonly used in heating and cooling applications. The fluid in such applications is forced

  5. Experimental damage-gas flow correlations for cyclically loaded reinforced concrete walls

    E-Print Network [OSTI]

    Soppe, Travis E.

    2009-01-01

    will be on cracked concrete permeability and flow rates.Concrete Permeability..Concrete Permeability

  6. DESIGN AND DEVELOPMENT OF GAS-LIQUID CYLINDRICAL CYCLONE COMPACT SEPARATORS FOR THREE-PHASE FLOW

    SciTech Connect (OSTI)

    Dr. Ram S. Mohan; Dr. Ovadia Shoham

    2000-04-28

    The objective of this five-year project (October, 1997-September, 2002) is to expand the current research activities of Tulsa University Separation Technology Projects (TUSTP) to multiphase oil/water/gas separation. This project will be executed in two phases. Phase I (1997-2000) will focus on the investigations of the complex multiphase hydrodynamic flow behavior in a three-phase Gas-Liquid Cylindrical Cyclone (GLCC{copyright}) Separator. The activities of this phase will include the development of a mechanistic model, a computational fluid dynamics (CFD) simulator, and detailed experimentation on the three-phase GLCC{copyright}. The experimental and CFD simulation results will be suitably integrated with the mechanistic model. In Phase II (2000-2002), the developed GLCC{copyright} separator will be tested under high pressure and real crudes conditions. This is crucial for validating the GLCC{copyright} design for field application and facilitating easy and rapid technology deployment. Design criteria for industrial applications will be developed based on these results and will be incorporated into the mechanistic model by TUSTP. This report presents a brief overview of the activities and tasks accomplished during the first half year (October 1, 1999-March 31, 2000) of the budget period (October 1, 1999-September 30, 2000). The total tasks of the budget period are given initially, followed by the technical and scientific results achieved till date. The report concludes with a detailed description of the plans for the conduct of the project for the second half year (April 1, 2000-September 30, 2000) of the current budget period.

  7. IDAHO NATIONAL LABORATORY PROGRAM TO OBTAIN BENCHMARK DATA ON THE FLOW PHENOMENA IN A SCALED MODEL OF A PRISMATIC GAS-COOLED REACTOR LOWER PLENUM FOR THE VALIDATION OF CFD CODES

    SciTech Connect (OSTI)

    Hugh M. McIlroy Jr.; Donald M. McEligot; Robert J. Pink

    2008-09-01

    The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a typical prismatic gas-cooled (GCR) reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A detailed description of the model, scaling, the experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples of the data sets that have been obtained are included. Samples of the data set that are presented include mean-velocity-field and turbulence data in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic GCR design. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. The measurements reveal undeveloped, non-uniform flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and charts that describe the component flows at specific regions in the model. Information on inlet flow is also presented.

  8. FEMO, A FLOW AND ENRICHMENT MONITOR FOR VERIFYING COMPLIANCE WITH INTERNATIONAL SAFEGUARDS REQUIREMENTS AT A GAS CENTRIFUGE ENRICHMENT FACILITY

    SciTech Connect (OSTI)

    Gunning, John E; Laughter, Mark D; March-Leuba, Jose A

    2008-01-01

    A number of countries have received construction licenses or are contemplating the construction of large-capacity gas centrifuge enrichment plants (GCEPs). The capability to independently verify nuclear material flows is a key component of international safeguards approaches, and the IAEA does not currently have an approved method to continuously monitor the mass flow of 235U in uranium hexafluoride (UF6) gas streams. Oak Ridge National Laboratory is investigating the development of a flow and enrichment monitor, or FEMO, based on an existing blend-down monitoring system (BDMS). The BDMS was designed to continuously monitor both 235U mass flow and enrichment of UF6 streams at the low pressures similar to those which exists at GCEPs. BDMSs have been installed at three sites-the first unit has operated successfully in an unattended environment for approximately 10 years. To be acceptable to GCEP operators, it is essential that the instrument be installed and maintained without interrupting operations. A means to continuously verify flow as is proposed by FEMO will likely be needed to monitor safeguards at large-capacity plants. This will enable the safeguards effectiveness that currently exists at smaller plants to be maintained at the larger facilities and also has the potential to reduce labor costs associated with inspections at current and future plants. This paper describes the FEMO design requirements, operating capabilities, and development work required before field demonstration.

  9. Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks 

    E-Print Network [OSTI]

    Ogbechie, Joachim Nwabunwanne

    2012-02-14

    Fluid flow process in fractured reservoirs is controlled primarily by the connectivity of fractures. The presence of fractures in these reservoirs significantly affects the mechanism of fluid flow. They have led to problems in the reservoir which...

  10. Study of Flow Regimes in Multiply-Fractured Horizontal Wells in Tight Gas and Shale Gas Reservoir Systems 

    E-Print Network [OSTI]

    Freeman, Craig M.

    2010-07-14

    Various analytical, semi-analytical, and empirical models have been proposed to characterize rate and pressure behavior as a function of time in tight/shale gas systems featuring a horizontal well with multiple hydraulic fractures. Despite a small...

  11. Observer Design for Multiphase Flow in Vertical Pipes with Gas-Lift --Theory and

    E-Print Network [OSTI]

    Foss, Bjarne A.

    .M. Aamo, G.O. Eikrem, H.B. Siahaan, B.A. Foss Department of Engineering Cybernetics, Norwegian University of Science and Technology, 7491 Trondheim, Norway Abstract Unstable regimes occuring for multiphase flow the multiphase flow. Key words: Nonlinear observer design, Multiphase flow, Petroleum technology 1 Introduction

  12. Experimental investigation on impingement heat transfer of gas-solid suspension flow

    SciTech Connect (OSTI)

    Yokomine, Takenhiko; Shimizu, Akihiko

    1999-07-01

    This paper aims to demonstrate experimentally the heat transfer performance of dense gas-solid suspension impinging jet for diverter cooling of the fusion power reactor. Prior to the experimental study, a tentative goal of 20 kW/m{sup 2}K was set as the heat transfer coefficient based on the expected temperature level of both coolant and diverter plate materials. Figure A-1 summarizes the results of experiments, where H/D is non-dimensional space between nozzle exit and impingement plate. The ranges of examined nozzle Reynolds number Re{sub N} and thermal loading ratio {Gamma}{sub th} were 5.5 x 10{sup 4} {<=} Re{sub N} {<=} 2.4 x 10{sup 5} and 0 {<=} {Gamma}{sub th} {<=} 8.55, respectively. When the glassy-carbon (G-C) particles with 26{micro}m in diameter were used, the maximum heat transfer coefficient could not reach the target value because the solid flow rate was restricted by the crucial erosion damage of test plate and a strong vibration observed in the test line. On the other hand, in the case that the fine graphite particles (10{micro}m in diameter) were used, the maximum heat transfer coefficient of 20 kW/m{sup 2}K was obtained at relatively dilute condition of solid loading ratio, which is considered to be due to the additive production of turbulence by particles' wake. Furthermore, the following consideration can be obtained. (1) Changing the particle from hard glassy carbon to soft and fine graphite is effective not only for anti-erosion but also for heat transfer enhancement by increasing heat capacity. (2) Turbulence augmentation by particles is also important for heat transfer enhancement in addition to the increased heat capacity. However, increasing the solid loading is likely to lead to the saturation of heat transfer enhancement effect, on the contrary, to the attenuation of turbulence. (3) If soft and fine particle, like graphite of 10{micro}m diameter employed in present study, is used as suspended particle in coolant for anti-erosion, the cooling by the gas-solid suspension impinging jet will be able to correspond to the thermal heat flux on the diverter plate when the nozzle Reynolds number is 1.5 x 10{sup 5} and thermal loading ratio is only 3. Provided that fine particles is used, however, some additional difficulties may be occurred, such as handling of powder and thermophoresis adhesion on the heat transfer surface.

  13. Fast wire-mesh sensors for gas-liquid flows - Visualisation with up to 10 000 frames per second

    SciTech Connect (OSTI)

    Prasser, H.M.; Zschau, J. [Forschungszentrum Rossendorf e.V., P.O.Box 510119, D-01314 Dresden (Germany); Peters, D.; Pietzsch, G.; Taubert, W.; Trepte, M. [Teletronic Ingenieurbuero GmbH, Bautzner Landstrasse 45, D-01454 Grosserkmannsdorf (Germany)

    2002-07-01

    A wire-mesh sensor developed by the Forschungszentrum Rossendorf produces sequences of instantaneous gas fraction distributions in a cross section at a rate of up to 10 000 frames per second and a spatial resolution of about 2-3 mm. This sensor was applied to an upwards air-liquid flow in a vertical pipe of 51.2 mm diameter. After a brief introduction of the functioning of the sensor, the paper presents results obtained in a at vertical pipe operated with an air-water mixture. Two wire-mesh sensors with a measuring matrix of 24 x 24 points (resolution 2 mm) were placed in a small axial distance behind each other. They were used to study the flow structure in the transition region from bubble to slug flow at an imaging frequency of 2 500 Hz. The two available measuring planes allowed to obtain velocity profiles of the gaseous phase. A sensor with 16 x 16 points (resolution 3 mm) was applied to visualize the transition from bubbly via churn turbulent to annular flow with 10 000 frames per second. In the churn flow region, periodic plug-like structures were found. In the annular flow the sensor is able to resolve wispy structures. (authors)

  14. 2007 Estimated International Energy Flows

    SciTech Connect (OSTI)

    Smith, C A; Belles, R D; Simon, A J

    2011-03-10

    An energy flow chart or 'atlas' for 136 countries has been constructed from data maintained by the International Energy Agency (IEA) and estimates of energy use patterns for the year 2007. Approximately 490 exajoules (460 quadrillion BTU) of primary energy are used in aggregate by these countries each year. While the basic structure of the energy system is consistent from country to country, patterns of resource use and consumption vary. Energy can be visualized as it flows from resources (i.e. coal, petroleum, natural gas) through transformations such as electricity generation to end uses (i.e. residential, commercial, industrial, transportation). These flow patterns are visualized in this atlas of 136 country-level energy flow charts.

  15. Purged window apparatus. [On-line spectroscopic analysis of gas flow systems

    DOE Patents [OSTI]

    Ballard, E.O.

    1982-04-05

    A purged window apparatus is described which utilizes tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube thereby preventing backstreaming of flowing gases under investigation in a chamber to which a plurality of similar purged apparatus is attached with the consequent result that spectroscopic analyses can be undertaken for lengthy periods without the necessity of interrupting the flow for cleaning or replacing the windows due to contamination.

  16. A high sensitivity fiber optic macro-bend based gas flow rate transducer for low flow rates: Theory, working principle, and static calibration

    SciTech Connect (OSTI)

    Schena, Emiliano; Saccomandi, Paola; Silvestri, Sergio [Center for Integrated Research, Unit of Measurements and Biomedical Instrumentation, Universita Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Rome (Italy)

    2013-02-15

    A novel fiber optic macro-bend based gas flowmeter for low flow rates is presented. Theoretical analysis of the sensor working principle, design, and static calibration were performed. The measuring system consists of: an optical fiber, a light emitting diode (LED), a Quadrant position sensitive Detector (QD), and an analog electronic circuit for signal processing. The fiber tip undergoes a deflection in the flow, acting like a cantilever. The consequent displacement of light spot center is monitored by the QD generating four unbalanced photocurrents which are function of fiber tip position. The analog electronic circuit processes the photocurrents providing voltage signal proportional to light spot position. A circular target was placed on the fiber in order to increase the sensing surface. Sensor, tested in the measurement range up to 10 l min{sup -1}, shows a discrimination threshold of 2 l min{sup -1}, extremely low fluid dynamic resistance (0.17 Pa min l{sup -1}), and high sensitivity, also at low flow rates (i.e., 33 mV min l{sup -1} up to 4 l min{sup -1} and 98 mV min l{sup -1} from 4 l min{sup -1} up to 10 l min{sup -1}). Experimental results agree with the theoretical predictions. The high sensitivity, along with the reduced dimension and negligible pressure drop, makes the proposed transducer suitable for medical applications in neonatal ventilation.

  17. On projected NewtonKrylov solvers for instationary laminar reacting gas flows

    E-Print Network [OSTI]

    Vuik, Kees

    deposition (CVD) [8] and flows with combustion [19] requires the simultaneous solution of many strongly and considerations apply to laminar combustion as well. Assuming continuum flow, the mathematical model consists for advection, diffusion and reaction, equations (1) are very stiff. In that case, most commercial CFD codes

  18. Pore-scale mechanisms of gas flow in tight sand reservoirs

    E-Print Network [OSTI]

    Silin, D.

    2011-01-01

    a homoge- neous reservoir the condensate saturation will bewater saturation distribution in a tight gas sand reservoirreservoir, the accumulating condensate can become mobile after reaching a certain saturation

  19. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    E-Print Network [OSTI]

    Xu, T.

    2009-01-01

    Lying Repositories for Nuclear Waste, NAGRA Technical Reporthost rock formation for nuclear waste storage. EngineeringGas Generation in a Nuclear Waste Repository: Reactive

  20. Integrated use of burden profile probe and in-burden probe for gas flow control in the blast furnace

    SciTech Connect (OSTI)

    Bordemann, F.; Hartig, W.H. [AG der Dillinger Huettenweke, Dillingen (Germany); Grisse, H.J. [Dango and Dienenthal Siegen (Germany); Speranza, B.E. [Dango and Dienenthal, Inc., Highland, IN (United States)

    1995-12-01

    Gas flow in the blast furnace is one of the most important factors in controlling a furnace. It not only determines the production but also the fuel consumption and the campaign life. At Nos. 4 and 5 blast furnaces of ROGESA, probes are installed for detection of the burden profiles and of the gas flow distribution. For an optimum use of these probes a program system has been developed by ROGESA and Dango and Dienenthal. With this program system it is possible to analyze the operating condition of a blast furnace by means of a fuzzy logic analysis. In case of deviations from the defined desired condition, recommendations for corrective measures for the material distribution are made. Both furnaces are equipped with a bell-less top, a coal injection system, high-temperature hot blast stoves with heat recovery and a top gas pressure recovery turbine. Most of the time it is impossible to control all the required parameters. For this reason it is meaningful to measure the actual material distribution at the furnace top by means of a burden profile probe which permits quick and repeated measurements without any retroactive effects. The paper describes the instrumentation of the furnace, correlation of measuring methods, and a program system for analysis of measuring data.

  1. Influence of Atmospheric Pressure and Water Table Fluctuations on Gas Phase Flow and Transport of Volatile Organic Compounds (VOCs) in Unsaturated Zones 

    E-Print Network [OSTI]

    You, Kehua

    2013-04-19

    solution in a three-layered unsaturated zone in response to field atmospheric pressure fluctuations at the Hanford site in Richland, Washington... ................................................................................................. 92 4.3 Comparison of gas flow rate calculated by the ML solution with measured flow rates in a three-layered unsaturated zone in response to field atmospheric pressure variations at the Hanford site in Richland...

  2. The Implications and Flow Behavior of the Hydraulically Fractured Wells in Shale Gas Formation 

    E-Print Network [OSTI]

    Almarzooq, Anas Mohammadali S.

    2012-02-14

    Shale gas formations are known to have low permeability. This low permeability can be as low as 100 nano darcies. Without stimulating wells drilled in the shale gas formations, it is hard to produce them at an economic rate. One of the stimulating...

  3. Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs 

    E-Print Network [OSTI]

    Zapata Arango, Jose? Francisco

    2002-01-01

    more important. Modeling fluid flow in these systems must consider the dependence of relative permeability on both viscous and capillary forces. This research focuses on the evaluation of several recently proposed relative permeability models...

  4. Effects of non-Darcy flow on pressure buildup analysis of hydraulically fractured gas reservoirs 

    E-Print Network [OSTI]

    Alvarez Vera, Cesar

    2001-01-01

    Conventional well-testing techniques are commonly used to evaluate pressure transient tests of hydraulically fractured wells to estimate values such as formation permeability, fracture length, and fracture conductivity. When non-Darcy flow occurs...

  5. Numerical simulation of flow distribution for pebble bed high temperature gas cooled reactors 

    E-Print Network [OSTI]

    Yesilyurt, Gokhan

    2004-09-30

    to be investigated. No detailed complete calculations for this kind of reactor to address these local phenomena are available. This work is an attempt to bridge this gap by evaluating this effect. I.2 TURBULENCE MODEL SELECTION The simulation of these local... number of numerical studies on flows around spherical bodies, none of them use the necessary turbulence models that are required to simulate flow where strong separation exists. With the development of high performance computers built for applications...

  6. The development of a curb valve flow meter for gas theft detection

    E-Print Network [OSTI]

    Fitzgerald, Kevin Francis

    1984-01-01

    As the supply of natural gas continues to dwindle, and government decontrol of pricing progresses, the rising cost of this essential natural resource will drive more individuals to consider various forms of pilferage as a ...

  7. Comparison of Single, Double, and Triple Linear Flow Models for Shale Gas/Oil Reservoirs 

    E-Print Network [OSTI]

    Tivayanonda, Vartit

    2012-10-19

    There have been many attempts to use mathematical method in order to characterize shale gas/oil reservoirs with multi-transverse hydraulic fractures horizontal well. Many authors have tried to come up with a suitable and practical mathematical model...

  8. Design Calculations for Gas Flow & Diffusion Behavior in the large Diameter Container & Cask

    SciTech Connect (OSTI)

    PIEPHO, M.G.

    2003-10-21

    This report describes the calculations for the gas behavior in the void volumes or gas spaces of the sludge Large Diameter Container (LDC) and Cask. The objective is to prevent flammable gas conditions in the LDC and Cask gas spaces. This is achieved by the Active Inert Ventilation System (AIVS), which uses argon gas for dilution purposes. With AIVS, the oxygen content is kept below 5 vol% in the LDC, and the hydrogen content is kept below 4 vol% in the Cask before its purge at the KE Basin. After the Cask sweep-through purge with argon at the KE Basin, oxygen is kept below 5% in both the Cask and the LDC. The analysis here assumes that any oxygen generated in the sludge is consumed by the uranium and uranium dioxide (SNF-18133, ''Gas Behavior in Large Diameter Containers (LDCs) During and Following Loading with 105K East Sludge''). Thus, oxygen production from radiolysis is intentionally not included in this report, but hydrogen from radiolysis and from chemical reactions between uranium and water are considered, depending on the scenario being analyzed. The analysis starts immediately after the final decant at K Basin, when argon is assumed to be the only gas in the LDC gas space, except for the normal water vapor. The oxygen ingress is calculated during the disconnecting of the lines hoses from the LDC, during the time that air is surrounding the LDC with two NucFil-type filters in place after the disconnect, before the Cask is sealed, and, finally, during the sweep-through Cask purge. Dissolution of oxygen from water due to increasing sludge temperatures (mainly during hot transport to the T Plant) is also included.

  9. PARTICLE IMAGE VELOCIMETRY MEASUREMENTS IN A REPRESENTATIVE GAS-COOLED PRISMATIC REACTOR CORE MODEL: FLOW IN THE COOLANT CHANNELS AND INTERSTITIAL BYPASS GAPS

    SciTech Connect (OSTI)

    Thomas E. Conder; Richard Skifton; Ralph Budwig

    2012-11-01

    Core bypass flow is one of the key issues with the prismatic Gas Turbine-Modular Helium Reactor, and it refers to the coolant that navigates through the interstitial, non-cooling passages between the graphite fuel blocks instead of traveling through the designated coolant channels. To determine the bypass flow, a double scale representative model was manufactured and installed in the Matched Index-of-Refraction flow facility; after which, stereo Particle Image Velocimetry (PIV) was employed to measure the flow field within. PIV images were analyzed to produce vector maps, and flow rates were calculated by numerically integrating over the velocity field. It was found that the bypass flow varied between 6.9-15.8% for channel Reynolds numbers of 1,746 and 4,618. The results were compared to computational fluid dynamic (CFD) pre-test simulations. When compared to these pretest calculations, the CFD analysis appeared to under predict the flow through the gap.

  10. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Miura, H; Miura, Hitoshi; Nakamoto, Taishi

    2006-01-01

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded t...

  11. A Study of Three Dimensional Bubble Velocities at Co-current Gas-liquid Vertical Upward Bubbly Flows

    E-Print Network [OSTI]

    Kuntoro, Hadiyan Yusuf; Deendarlianto,

    2015-01-01

    Recently, experimental series of co-current gas-liquid upward bubbly flows in a 6 m-height and 54.8 mm i.d. vertical titanium pipe had been conducted at the TOPFLOW thermal hydraulic test facility, Helmholtz-Zentrum Dresden-Rossendorf, Germany. The experiments were initially performed to develop a high quality database of two-phase flows as well as to validate new CFD models. An ultrafast dual-layer electron beam X-ray tomography, named ROFEX, was used as measurement system with high spatial and temporal resolutions. The gathered cross sectional grey value image results from the tomography scanning were reconstructed, segmented and evaluated to acquire gas bubble parameters for instance bubble position, size and holdup. To assign the correct paired bubbles from both measurement layers, a bubble pair algorithm was implemented on the basis of the highest probability values of bubbles in position, volume and velocity. Hereinafter, the individual characteristics of bubbles were calculated include instantaneous th...

  12. Study of void fraction and mixing of immiscible liquids in a pool configuration by an upward gas flow

    SciTech Connect (OSTI)

    Casas, J.C.; Corradini, M.L. (Univ. of Wisconsin-Madison, Nuclear Engineering and Engineering Physics Dept., Madison, WI (US))

    1992-07-01

    In this paper, investigations are performed to study the mixing between immiscible liquids in a pool configuration due to an upward gas flow. A water-R113 system is sued in the bubbly/churn-turbulent regimes to determine the effects of the unagitated pool depth on layer mixing. The superficial gas velocity at which full mixing is attained is observed to increase with the pool depth, although it is concluded that this is a weak dependency. Mixing in the churn-turbulent regime is studied with Wood's metal-water and Wood's metal-silicone fluid (100 cS) as pairs of fluids. Additional past mixing data from six other fluids are also included in the data base. A criterion is proposed to determine if two liquids will entrain in bubbly or churn-turbulent flow. Correlations are derived that, for a set of given conditions, allow prediction of the mixing state (mixed or segregated) of a system. Because of the indirect method of measuring the mixed layer thickness, pool void fraction experiments are also performed. For the case of water and R113, the effect of unagitated pool depth on the void fraction is studied.

  13. Design Calculations for Gas Flow & Diffusion Behavior in the Large Diameter Container & Cask

    SciTech Connect (OSTI)

    PIEPHO, M.G.

    2003-11-06

    This report describes the calculations for the gas behavior in the void volumes or gas spaces of the sludge Large Diameter Container (LDC) and Cask. The objective is to prevent flammable gas conditions in the LDC and Cask gas spaces. This is achieved by the Active Inert Ventilation System (AIVS), which uses argon gas for dilution purposes. With AIVS, the oxygen content is kept below 4 to 5 vol% in the LDC, and the hydrogen content is kept below 4 vol% in the Cask before its purge at the KE Basin. After the Cask sweep-through purge with argon at the KE Basin, oxygen stays below 4 to 5% in the LDC until two LDC ports are opened at T Plant. The oxygen content stays below 4% in the Cask until the Cask lid is opened at T Plant. The analysis here assumes that any oxygen generated in the sludge is consumed by the uranium and uranium dioxide (SNF-18133, ''Gas Behavior in Large Diameter Containers (LDCs) During and Following Loading with 105K East Sludge''). Thus, oxygen production from radiolysis is not included in this report, but hydrogen from radiolysis and from chemical reactions between uranium and water are considered, depending on the scenario being analyzed. The analysis starts immediately after the final decant at K Basin, when argon is assumed to be the only gas in the LDC gas space, except for the normal water vapor. The oxygen ingress is calculated during the disconnecting of the lined hoses from the LDC, during the time that air is surrounding the LDC with two NucFil-type filters in place after the disconnect, before the Cask is sealed, and, finally, during the sweep-through Cask purge at the KE Basin. Dissolution of oxygen from water due to increasing sludge temperatures (mainly during hot transport to the T Plant) is also included. The analysis includes the gas behavior during the T-Plant operations, which include the venting after the LDC/Cask are received at T Plant, the Cask sweep-through purge, the LDC purge with forced argon delivery into the LDC with 1 open port, followed by the natural sweep-through purge with two open LDC ports.

  14. Application of Crunch-Flow Routines to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites

    SciTech Connect (OSTI)

    Torres, Marta

    2014-01-31

    In November 2012, Oregon State University initiated the project entitled: Application of Crunch-Flow routines to constrain present and past carbon fluxes at gas-hydrate bearing sites. Within this project we developed Crunch-Flow based modeling modules that include important biogeochemical processes that need to be considered in gas hydrate environments. Our modules were applied to quantify carbon cycling in present and past systems, using data collected during several DOE-supported drilling expeditions, which include the Cascadia margin in US, Ulleung Basin in South Korea, and several sites drilled offshore India on the Bay of Bengal and Andaman Sea. Specifically, we completed modeling efforts that: 1) Reproduce the compositional and isotopic profiles observed at the eight drilled sites in the Ulleung Basin that constrain and contrast the carbon cycling pathways at chimney (high methane flux) and non-chimney sites (low methane, advective systems); 2) Simulate the Ba record in the sediments to quantify the past dynamics of methane flux in the southern Hydrate Ridge, Cascadia margin; and 3) Provide quantitative estimates of the thickness of individual mass transport deposits (MTDs), time elapsed after the MTD event, rate of sulfate reduction in the MTD, and time required to reach a new steady state at several sites drilled in the Krishna-Godavari (K-G) Basin off India. In addition we developed a hybrid model scheme by coupling a home-made MATLAB code with CrunchFlow to address the methane transport and chloride enrichment at the Ulleung Basins chimney sites, and contributed the modeling component to a study focusing on pore-scale controls on gas hydrate distribution in sediments from the Andaman Sea. These efforts resulted in two manuscripts currently under review, and contributed the modeling component of another pare, also under review. Lessons learned from these efforts are the basis of a mini-workshop to be held at Oregon State University (Feb 2014) to instruct graduate students (OSU and UW) as well as DOE staff from the NETL lab in Albany on the use of Crunch Flow for geochemical applications.

  15. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Tulsa Fluid Flow

    2008-08-31

    The developments of fields in deep waters (5000 ft and more) is a common occurrence. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oil-and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of the hydrocarbon recovery from design to operation. The recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is very crucial to any multiphase separation technique that is employed either at topside, seabed or bottom-hole to know inlet conditions such as the flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. The overall objective was to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict the flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). The project was conducted in two periods. In Period 1 (four years), gas-oil-water flow in pipes were investigated to understand the fundamental physical mechanisms describing the interaction between the gas-oil-water phases under flowing conditions, and a unified model was developed utilizing a novel modeling approach. A gas-oil-water pipe flow database including field and laboratory data was formed in Period 2 (one year). The database was utilized in model performance demonstration. Period 1 primarily consisted of the development of a unified model and software to predict the gas-oil-water flow, and experimental studies of the gas-oil-water project, including flow behavior description and closure relation development for different flow conditions. Modeling studies were performed in two parts, Technology Assessment and Model Development and Enhancement. The results of the Technology assessment study indicated that the performance of the current state of the art two-phase flow models was poor especially for three-phase pipeline flow when compared with the existing data. As part of the model development and enhancement study, a new unified model for gas-oil-water three-phase pipe flow was developed. The new model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. An experimental program including three-phase gas-oil-water horizontal flow and two-phase horizontal and inclined oil-water flow testing was conducted utilizing a Tulsa University Fluid Flow Projects Three-phase Flow Facility. The experimental results were incorporated into the unified model as they became available, and model results were used to better focus and tailor the experimental study. Finally, during the Period 2, a new three-phase databank has been developed using the data generated during this project and additional data available in the literature. The unified model to predict the gas-oil-water three phase flow characteristics was tested by comparing the prediction results with the data. The results showed good agreements.

  16. Dissolution of carbon dioxide bubbles and microfluidic multiphase flows Ruopeng Sun and Thomas Cubaud*

    E-Print Network [OSTI]

    Cubaud, Thomas

    . Introduction Carbon dioxide gas is widespread in natural and industrial processes. At the small scale microfluidic flow pattern consists of elongated gas bubbles separated by liquid plugs. When the liquid wets-sections. The liquid gener- ally fills the corners and gas slugs are separated from the walls by thin liquid films.11

  17. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Hitoshi Miura; Taishi Nakamoto

    2006-11-09

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded to reproduce the fragmentation of droplets when the gas ram pressure is stronger than the effect of the surface tension. Finally, we compared the deformation of droplets in the shock-wave heating with the measured data of chondrules and suggested the importance of other effects to deform droplets, for example, the rotation of droplets. We believe that our new code is a very powerful tool to investigate the hydrodynamics of molten droplets in the framework of the shock-wave heating model and has many potentials to be applied to various problems.

  18. European Conference on the Mathematics of Oil Recovery --Freiberg, Germany, 3 -6 September 2002 We consider a model for immiscible three-phase (e.g., water, oil, and gas) flow in a porous

    E-Print Network [OSTI]

    New York at Stoney Brook, State University of

    2002 Abstract We consider a model for immiscible three-phase (e.g., water, oil, and gas) flow of three-phase (water-oil-gas) flow in a core sample of porous rock, taking into account hysteresis effects the effects of hysteresis on the Water-Alternating-Gas (WAG) oil-recovery process. In outline, the remainder

  19. RECTILINEAR VORTEX SHEETS OF INVISCID LIQUID-GAS TWO-PHASE FLOW: LINEAR STABILITY

    E-Print Network [OSTI]

    Wang, Dehua

    sediment transport, geysers, volcanic eruptions, clouds, rain in natural and climate system; mixture of oil and natural gas in extraction tubes of oil exploitation, oil transportation, steam generators, cooling systems- ology in chemical engineering, medical and genetic engineering, bioengineering, and so on. Multi

  20. Attenuation of hydrogen radicals traveling under flowing gas conditions through tubes of different materials

    E-Print Network [OSTI]

    George, Steven M.

    efficiently on the exposed thermocouple and the energy of formation of H2 heated the thermocouple. The second thermocouple was covered by glass and was heated primarily by the ambient gas. The dual thermocouple probe or on a catalytic surface in contact with a thermocouple. The recombination energy heats the thermo- couple

  1. Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs: W. Scott Phillips

    E-Print Network [OSTI]

    Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs: A Review W. Scott or production of fluids can induce microseismic events in hydrocarbon and geothermal reservoirs. By deploying Patterns in Reservoirs Key Words: induced microseismicity, geothermal, oil and gas, fluid flow, location

  2. Coupled flow and geomechanical analysis for gas production in the Prudhoe Bay Unit L-106 well Unit C gas hydrate deposit in Alaska

    E-Print Network [OSTI]

    Kim, J.

    2014-01-01

    way Coupled Fluid Flow and Geomechanics in Hydrate Deposits.for Coupled Flow and Geomechanics. Soc. Pet. Eng. J. 16(2):for coupled flow and geomechanics: Drained and undrained

  3. Measurements versus predictions for rotordynamic coefficients and leakage rates for a novel hole-pattern gas seal 

    E-Print Network [OSTI]

    Seifert, Brent Alan

    2007-04-25

    Results are presented for measured and predicted rotordynamic coefficients and leakage for hole-pattern seals with a hole depth that varies axially along the seal. Testing was done to discover how pressure ratio, inlet ...

  4. Effect of argon gas flow rate on properties of film electrodes prepared by thermal vacuum evaporation from synthesized Cu{sub 2}SnSe{sub 3} source

    SciTech Connect (OSTI)

    Sabli, Nordin; Talib, Zainal Abidin; Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Zainal, Zulkarnain [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Hilal, Hikmat S. [SSERL, Department of Chemistry An-Najah N. University, PO Box 7, Nablus, West Bank (Country Unknown); Fujii, Masatoshi [Department of Molecular Science, School of Medicine, Shimane University, Izumo, Shimane, 693-8501 (Japan)

    2014-03-05

    This work describes a new technique to enhance photoresponse of metal chalcogenide-based semiconductor film electrodes deposited by thermal vacuum evaporation under argon gas flow from synthesized Cu{sub 2}SnSe{sub 3} sources. SnSe formation with Cu-doped was obtained under higher argon gas flow rate (V{sub A} = 25 cm{sup 3}/min). Higher value of photoresponse was observed for films deposited under V{sub A} = 25 cm{sup 3}/min which was 9.1%. This finding indicates that Cu atoms inside the SnSe film were important to increase carrier concentrations that promote higher photoresponse.

  5. Investigation of Swirl Flows Applied to the Oil and Gas Industry 

    E-Print Network [OSTI]

    Ravuri Venkata Krish, Meher Surendra

    2010-01-16

    savings for topsides and subsea applications. Inlet cyclones, demisting cyclones, and 13 stand-alone monocyclones are being considered more often in the process design. The following are the advantages of swirl technology/swirlers are: 1. Low capital.... In the UK, a survey by the Department of Trade and Industry put the cost of erosion at around ?20 million/annum. Costs can be as high as ?500,000 for subsea replacements in the oil and gas industry. In extreme cases pipeline components are eroded away...

  6. 1 Forecasting Greenhouse Gas Emissions from Urban Regions: 2 Microsimulation of Land Use and Transport Patterns in Austin, Texas

    E-Print Network [OSTI]

    Kockelman, Kara M.

    use electricity, natural gas and other energy sources regularly52 for space conditioning and powering1 Forecasting Greenhouse Gas Emissions from Urban Regions: 2 Microsimulation of Land Use 2030 household energy 26 demands and GHG emissions estimates are compared under five different land use

  7. Development of a transonic front stage of an axial flow compressor for industrial gas turbines

    SciTech Connect (OSTI)

    Katoh, Y.; Ishii, H.; Tsuda, Y.; Yanagida, M. . Mechanical Engineering Research Lab.); Kashiwabara, Y. . Dept. of Mechanical Systems Engineering)

    1994-10-01

    This paper describes the aerodynamic blade design of a highly loaded three-stage compressor, which is a model compressor for the front stage of an industrial gas turbine. Test results are presented that confirm design performance. Some surge and rotating stall measurement results are also discussed. The first stator blade in this test compressor operates in the high subsonic range at the inlet. To reduce the pressure loss due to blade surface shock waves, a shock-free airfoil is designed to replace the first stator blade in an NACA-65 airfoil in a three-stage compressor. Comparison of the performance of both blades shows that the shock-free airfoil blade reduces pressure loss. This paper also presents some experimental results for MCA (multicircular arc) airfoils, which are used for first rotor blades.

  8. A Fast Network Flow Model is used in conjunction with Measurements of Filter Permeability to calculate the Performance of Hot Gas Filters

    SciTech Connect (OSTI)

    VanOsdol, J.G.; Chiang, T-K.

    2002-09-19

    Two different technologies that are being considered for generating electric power on a large scale by burning coal are Pressurized Fluid Bed Combustion (PFBC) systems and Integrated Gasification and Combined Cycle (IGCC) systems. Particulate emission regulations that have been proposed for future systems may require that these systems be fitted with large scale Hot Gas Clean-Up (HGCU) filtration systems that would remove the fine particulate matter from the hot gas streams that are generated by PFBC and IGCC systems. These hot gas filtration systems are geometrically and aerodynamically complex. They typically are constructed with large arrays of ceramic candle filter elements (CFE). The successful design of these systems require an accurate assessment of the rate at which mechanical energy of the gas flow is dissipated as it passes through the filter containment vessel and the individual candle filter elements that make up the system. Because the filtration medium is typically made of a porous ceramic material having open pore sizes that are much smaller than the dimensions of the containment vessel, the filtration medium is usually considered to be a permeable medium that follows Darcy's law. The permeability constant that is measured in the lab is considered to be a function of the filtration medium only and is usually assumed to apply equally to all the filters in the vessel as if the flow were divided evenly among all the filter elements. In general, the flow of gas through each individual CFE will depend not only on the geometrical characteristics of the filtration medium, but also on the local mean flows in the filter containment vessel that a particular filter element sees. The flow inside the CFE core, through the system manifolds, and inside the containment vessel itself will be coupled to the flow in the filter medium by various Reynolds number effects. For any given filter containment vessel, since the mean flows are different in different locations inside the vessel, the flow of gas through an individual CFE will adjust itself to accommodate the local mean flows that prevail in its general location. In some locations this adjustment will take place at High Reynolds numbers and in other locations this will occur at low Reynolds numbers. The analysis done here investigates the nature of this coupling.

  9. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Cem Sarica; Holden Zhang

    2006-05-31

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The basic continuity and momentum equations is established for each phase, and used for both flow pattern and flow behavior predictions. The required closure relationships are being developed, and will be verified with experimental results. Gas-oil-water experimental studies are currently underway for the horizontal pipes. Industry-driven consortia provide a cost-efficient vehicle for developing, transferring, and deploying new technologies into the private sector. The Tulsa University Fluid Flow Projects (TUFFP) is one of the earliest cooperative industry-university research consortia. TUFFP's mission is to conduct basic and applied multiphase flow research addressing the current and future needs of hydrocarbon production and transportation. TUFFP participants and The University of Tulsa are supporting this study through 55% cost sharing.

  10. Kinematics of Arp 270: gas flows, nuclear activity, and two regimes of star formation

    E-Print Network [OSTI]

    Zaragoza-Cardiel, J; Beckman, J E; Blasco-Herrera, J; García-Lorenzo, B; Camps, A; Gonzalez-Martin, O; Almeida, C Ramos; Loiseau, N; Gutiérrez, L

    2013-01-01

    We have observed the Arp 270 system (NGC 3395 & NGC 3396) in H{\\alpha} emission using the GH{\\alpha}FaS Fabry-Perot spectrometer on the 4.2m William Herschel Telescope (La Palma). In NGC 3396, which is edge-on to us, we detect gas inflow towards the centre, and also axially confined opposed outflows, characteristic of galactic superwinds, and we go on to examine the possibility that there is a shrouded AGN in the nucleus. The combination of surface brightness, velocity and velocity dispersion information enabled us to measure the radii, FWHM, and the masses of 108 HII regions in both galaxies. We find two distinct modes of physical behaviour, for high and lower luminosity regions. We note that the most luminous regions show especially high values for their velocity dispersions and hypothesize that these occur because the higher luminosity regions form from higher mass, gravitationally bound clouds while those at lower luminosity HII regions form within molecular clouds of lower mass, which are pressure co...

  11. Liquid water quantification in the cathode side gas channels of a proton exchange membrane fuel cell through two-phase flow

    E-Print Network [OSTI]

    Kandlikar, Satish

    t s Liquid water in the cathode side channels of PEM fuel cell is quantified. Algorithm developed in MATLABÒ electrolyte membrane fuel cell Two-phase flow visualization Gas channels Area coverage ratio Water quantification a b s t r a c t Water management is crucial to the performance of PEM fuel cells. Water

  12. Influence of Gas Flow Rate for Formation of Aligned Nanorods in ZnO Thin Films for Solar-Driven Hydrogen Production

    SciTech Connect (OSTI)

    Shet, S.; Chen, L.; Tang, H.; Nuggehalli, R.; Wang, H.; Yan, Y.; Turner, J.; Al-Jassim, M.

    2012-04-01

    ZnO thin films have been deposited in mixed Ar/N{sub 2} gas ambient at substrate temperature of 500 C by radiofrequency sputtering of ZnO targets. We find that an optimum N{sub 2}-to-Ar ratio in the deposition ambient promotes the formation of well-aligned nanorods. ZnO thin films grown in ambient with 25% N{sub 2} gas flow rate promoted nanorods aligned along c-axis and exhibit significantly enhanced photoelectrochemical (PEC) response, compared with ZnO thin films grown in an ambient with different N{sub 2}-to-Ar gas flow ratios. Our results suggest that chamber ambient is critical for the formation of aligned nanostructures, which offer potential advantages for improving the efficiency of PEC water splitting for H{sub 2} production.

  13. Point flow sensor study for electronic gas energy metering. Phase 1. Thermophysical and fluid-dynamic data. Final report, March 15, 1994-July 15, 1996

    SciTech Connect (OSTI)

    Bonne, U.; Vesovic, V.; Wakeham, W.A.

    1996-07-15

    The set published properties of gases constituting natural gas, at pressures up to 300 basr (4500 psi) ad for -40 less than or equal to T less than or equal to 250 deg C, is not accurate or consistent enough for members of hte gas industry, research groups, NGV-automotive engineers, and meter manufacturers to nondestructively calibrate existing, affordable, combustionless, on-line and in situ microsensors for their applications. Therefore, this study was set up to (1) establish a consistent set of thermophysical properties (thermal conductivity, viscosity, and isobaric heat capacity) of pure and mixed gas constituents of natural gases and (2) prove the validity and limitations of using one or more point sensors in suitable flow channels for the determination of total fluid flow.

  14. 1 Purdue Micro Pattern Gas Detector R&D Miyamoto, Shipsey, Guirl (undergrad), Kane (undergrad), May (undergrad)

    E-Print Network [OSTI]

    , a variety of commercial and custom electronics and diagnostics equipment. A heat-seal connector bonding ECE and the physics department to electron beam and atomic force microscopes for 3-D MPGD imaging used. The field of gas proportional wire counters was revolutionized by the introduction of micro-electronic

  15. An investigation of a model of the flow pattern transition mechanism in relation to the identification of annular flow of R134a in a vertical tube using various void fraction models and flow regime maps

    SciTech Connect (OSTI)

    Dalkilic, A.S. [Heat and Thermodynamics Division, Department of Mechanical Engineering, Yildiz Technical University, Yildiz, Besiktas, Istanbul 34349 (Turkey); Wongwises, S. [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

    2010-09-15

    In the present study, new experimental data are presented for literature on the prediction of film thickness and identification of flow regime during the co-current downward condensation in a vertical smooth copper tube having an inner diameter of 8.1 mm and a length of 500 mm. R134a and water are used as working fluids in the tube side and annular side of a double tube heat exchanger, respectively. Condensation experiments are done at mass fluxes of 300 and 515 kg m{sup -2} s{sup -1}. The condensing temperatures are between 40 and 50 C; heat fluxes are between 12.65 and 66.61 kW m{sup -2}. The average experimental heat transfer coefficient of the refrigerant HFC-134a is calculated by applying an energy balance based on the energy transferred from the test section. A mathematical model by Barnea et al. based on the momentum balance of liquid and vapor phases is used to determine the condensation film thickness of R134a. The comparative film thickness values are determined indirectly using relevant measured data together with various void fraction models and correlations reported in the open literature. The effects of heat flux, mass flux, and condensation temperature on the film thickness and condensation heat transfer coefficient are also discussed for the laminar and turbulent flow conditions. There is a good agreement between the film thickness results obtained from the theoretical model and those obtained from six of 35 void fraction models in the high mass flux region of R134a. In spite of their different valid conditions, six well-known flow regime maps from the literature are found to be predictive for the annular flow conditions in the test tube in spite of their different operating conditions. (author)

  16. Application of convolution and average pressure approximation for solving non-linear flow problems. constant pressure inner boundary condition for gas flow 

    E-Print Network [OSTI]

    Zhakupov, Mansur

    2006-08-16

    The accurate description of fluid flow through porous media allows an engineer to properly analyze past behavior and predict future reservoir performance. In particular, appropriate mathematical models which describe fluid ...

  17. HST-COS SPECTROSCOPY OF THE COOLING FLOW IN A1795—EVIDENCE FOR INEFFICIENT STAR FORMATION IN CONDENSING INTRACLUSTER GAS

    SciTech Connect (OSTI)

    McDonald, Michael; Ehlert, Steven; Roediger, Joel; Veilleux, Sylvain

    2014-08-20

    We present far-UV spectroscopy from the Cosmic Origins Spectrograph on the Hubble Space Telescope of a cool, star-forming filament in the core of A1795. These data, which span 1025 Å < ?{sub rest} < 1700 Å, allow for the simultaneous modeling of the young stellar populations and the intermediate-temperature (10{sup 5.5} K) gas in this filament, which is far removed (?30 kpc) from the direct influence of the central active galactic nucleus. Using a combination of UV absorption line indices and stellar population synthesis modeling, we find evidence for ongoing star formation, with the youngest stars having ages of 7.5{sub ?2.0}{sup +2.5} Myr and metallicities of 0.4{sub ?0.1}{sup +0.2} Z {sub ?}. The latter is consistent with the local metallicity of the intracluster medium. We detect the O VI ?1038 line, measuring a flux of f {sub O} {sub VI,} {sub 1038} = 4.0 ± 0.9 × 10{sup –17} erg s{sup –1} cm{sup –2}. The O VI ?1032 line is redshifted such that it is coincident with a strong Galactic H{sub 2} absorption feature, and is not detected. The measured O VI ?1038 flux corresponds to a cooling rate of 0.85 ± 0.2 (stat) ± 0.15 (sys) M {sub ?} yr{sup –1} at ?10{sup 5.5} K, assuming that the cooling proceeds isochorically, which is consistent with the classical X-ray luminosity-derived cooling rate in the same region. We measure a star formation rate of 0.11 ± 0.02 M {sub ?} yr{sup –1} from the UV continuum, suggesting that star formation is proceeding at 13{sub ?2}{sup +3}% efficiency in this filament. We propose that this inefficient star formation represents a significant contribution to the larger-scale cooling flow problem.

  18. Investigation of the Effect of Non-Darcy Flow and Multi-Phase Flow on the Productivity of Hydraulically Fractured Gas Wells 

    E-Print Network [OSTI]

    Alarbi, Nasraldin Abdulslam A.

    2011-10-21

    Hydraulic fracturing has recently been the completion of choice for most tight gas bearing formations. It has proven successful to produce these formations in a commercial manner. However, some considerations have to be taken into account to design...

  19. Study on multiphase flow and mixing in semidry flue gas desulfurization with a multifluid alkaline spray generator using particle image velocimetry

    SciTech Connect (OSTI)

    Zhou, Y.G.; Wang, D.F.; Zhang, M.C. [Shanghai Jiao Tong University, Shanghai (China)

    2009-06-15

    Particle image velocimetry (PIV) technique was used to measure the velocity fields of gas-droplet-solid multiphase flow in the experimental setup of a novel semidry flue gas desulfurization process with a multifluid alkaline spray generator. The flow structure, mixing characteristic, and interphase interaction of gas-droplet-solid multiphase flow were investigated both in the confined alkaline spray generator and in the duct bent pipe section. The results show that sorbent particles in the confined alkaline spray generator are entrained into the spray core zone by a high-speed spray jet and most of the sorbent particles can be effectively humidified by spray water fine droplets to form aqueous lime slurry droplets. Moreover, a minimum amount of air stream in the generator is necessary to achieve higher collision humidification efficiency between sorbent particles and spray water droplets and to prevent the possible deposition of fine droplets on the wall. The appropriate penetration length of the slurry droplets from the generator can make uniform mixing between the formed slurry droplets and main air stream in the duct bent pipe section, which is beneficial to improving sulfur dioxide removal efficiency and to preventing the deposition of droplets on the wall.

  20. Overall and average local heat transfer from a horizontal cylinder in a gas-fluidized bed with an opposing oscillatory flow

    SciTech Connect (OSTI)

    Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

    1996-12-31

    The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines fundamental aspects of heat transfer in this hybrid combustor by measuring the effect of an opposing oscillatory flow on the overall and time-averaged local heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Overall and time-averaged local heat flux measurements from the surface of a submerged horizontal cylinder show that heat transfer characteristics are significantly altered by an opposing oscillatory flow. Increases in overall heat transfer on the order of 12% were identified for operating conditions with low primary and secondary flow rates and low pulse frequencies. These enhancements were identified to be a consequence of significant localized enhancements. The fundamental trends and magnitude of the particle Nusselt number are effectively characterized by a modified form of the Strouhal number.

  1. CFD Analysis of Core Bypass Flow and Crossflow in the Prismatic Very High Temperature Gas-cooled Nuclear Reactor 

    E-Print Network [OSTI]

    Wang, Huhu 1985-

    2012-12-13

    effect. The bypass flow occurs when the coolant flow into gaps between fuel blocks. These gaps are formed as a result of carbon expansion and shrinkage induced by radiations and manufacturing and installation errors. Hot spots may appear in the core...

  2. Multiphase flow calculation software

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-04-15

    Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

  3. Development of the T+M coupled flow-geomechanical simulator to describe fracture propagation and coupled flow-thermal-geomechanical processes in tight/shale gas systems

    SciTech Connect (OSTI)

    Kim, Jihoon; Moridis, George

    2013-05-22

    We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturing operations, after which the domain description changes from single continuum to double or multiple continua in order to rigorously model both flow and geomechanics for fracture-rock matrix systems. The T+H simulator provides two-way coupling between fluid-heat flow and geomechanics, accounting for thermoporomechanics, treats nonlinear permeability and geomechanical moduli explicitly, and dynamically tracks changes in the fracture(s) and in the pore volume. We also fully accounts for leak-off in all directions during hydraulic fracturing. We first validate the T+M simulator, matching numerical solutions with the analytical solutions for poromechanical effects, static fractures, and fracture propagations. Then, from numerical simulation of various cases of the planar fracture propagation, shear failure can limit the vertical fracture propagation of tensile failure, because of leak-off into the reservoirs. Slow injection causes more leak-off, compared with fast injection, when the same amount of fluid is injected. Changes in initial total stress and contributions of shear effective stress to tensile failure can also affect formation of the fractured areas, and the geomechanical responses are still well-posed.

  4. Geological flows

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2008-11-19

    In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

  5. Flow regimes

    SciTech Connect (OSTI)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced.

  6. Elbow mass flow meter

    DOE Patents [OSTI]

    McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

    1994-01-01

    Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

  7. Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs W. Scott Phillips

    E-Print Network [OSTI]

    Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs W. Scott Phillips James T microseismic events in hydrocarbon and geothermal reservoirs. By deploying sensors downhole, data sets have Key Words: induced microseismicity, geothermal, oil and gas, fluid flow, location #12;2 Introduction

  8. Gas separating

    DOE Patents [OSTI]

    Gollan, Arye Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  9. Gas separating

    DOE Patents [OSTI]

    Gollan, Arye (Newton, MA)

    1988-01-01

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  10. The effect of temperature and gas flow on the physical vapour growth of mm-scale rubrene crystals for organic FETs

    E-Print Network [OSTI]

    A. R. Ullah; A. P. Micolich; J. W. Cochrane; A. R. Hamilton

    2007-11-12

    There has recently been significant interest in rubrene single-crystals grown using physical vapour transport techniques due to their application in high-mobility organic field-effect transistor (OFET) devices. Despite numerous studies of the electrical properties of such crystals, there has only been one study to date focussing on characterising and optimising the crystal growth as a function of the relevant growth parameters. Here we present a study of the dependence of the yield of useful crystals (defined as crystals with at least one dimension of order 1 mm) on the temperature and volume flow of carrier gas used in the physical vapour growth process.

  11. Preferential mode of gas invasion in sediments : grain-scale model of coupled multiphase fluid flow and sediment mechanics

    E-Print Network [OSTI]

    Jain, Antone Kumar

    2009-01-01

    We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on ...

  12. Numerical Simulation of Flow and Heat Transfer in Internal Multi-Pass Cooling Channel within Gas Turbine Blade 

    E-Print Network [OSTI]

    Chu, Hung-Chieh 1979-

    2012-11-16

    four-pass channel with two different inlet settings. The main flowing channel was rectangular channel (AR=2:1) with hydraulic diameter (Dh ) equals to 2/3 inch (16.9 mm). The first and fourth channel were set as different aspect ratio (AR=2:1; AR=1...

  13. Influence of the Pipe Diameter on the Structure of the Gas-Liquid Interface in a Vertical Two-Phase Pipe Flow

    SciTech Connect (OSTI)

    Prasser, H.-M.; Beyer, M.; Boettger, A.; Carl, H.; Lucas, D.; Schaffrath, A.; Schuetz, P.; Weiss, F.-P.; Zschau, J. [Forschungszentrum Rossendorf (Germany)

    2005-10-15

    Air-water two-phase flow tests in a large vertical pipe of 194.1-mm inner diameter (i.d.) are reported. Close to the outlet of a 9-m-tall test section, two wire-mesh sensors are installed that deliver instantaneous void fraction distributions over the entire cross section with a resolution of 3 mm and 2500 Hz used for fast-flow visualization. Void fraction profiles, gas velocity profiles, and bubble-size distributions were obtained. A comparison to a small pipe of 52.3-mm i.d. (DN50) revealed significant scaling effects. Here, the increase of the airflow rate leads to a transition from bubbly via slug to churn-turbulent flow. This is accompanied by an appearance of a second peak in the bubble-size distribution. A similar behavior was found in the large pipe; though the large bubbles have a significantly larger diameter at identical superficial velocities, the peak is less high but wider. These bubbles move more freely in the large pipe and show more deformations. The shapes of such large bubbles were characterized in three dimensions. They can be rather complicated and far from ideal Taylor bubbles. Also, the small bubble fraction tends to bigger sizes in the large pipe.

  14. Onset and Subsequent Transient Phenomena of Liquid Loading in Gas Wells: Experimental Investigation Using a Large Scale Flow Loop 

    E-Print Network [OSTI]

    Waltrich, Paulo

    2012-10-19

    . Thank to my friends from office 602 for their camaraderie and support. vii I also would like to thank the sponsors (namely Petrobras, RWE and Shell) of the Joint Industry Project on “Liquid Loading in the Operation of Gas Fields: Mechanisms...

  15. Analytical Investigation by Using the Two-fluid-model to Study the Interfacial Behavior of Air-water Horizontal Stratified Flow

    E-Print Network [OSTI]

    Kuntoro, Hadiyan Yusuf; Indarto,

    2015-01-01

    In the chemical, petroleum and nuclear industries, pipelines are often used to transport fluids from one process site to another one. The understanding of the fluids behavior inside the pipelines is the most important consideration for the engineers and scientists. From the previous studies, there are several two-phase flow patterns in horizontal pipe. One of them is stratified flow pattern, which is characterized by the liquid flowing along the bottom of the pipe and the gas moving above it cocurrently. Another flow patterns are slug and plug flow patterns. This kind of flow triggers the damage in pipelines, such as corrosion, abrasion, and blasting pipe. Therefore, slug and plug flow patterns are undesirable in pipelines, and the flow is maintained at the stratified flow condition for safety reason. In this paper, the analytical-based study on the experiment of the stratified flow pattern in a 26 mm i.d. horizontal pipe is presented. The experiment is performed to develop a high quality database of the stra...

  16. Flowing afterglow measurements of the density dependence of gas-phase ion-ion mutual neutralization reactions

    SciTech Connect (OSTI)

    Shuman, Nicholas S.; Viggiano, Albert A.; Johnsen, Rainer

    2013-05-28

    We have studied the dependence of several ion-ion mutual neutralization (MN) reactions on helium density in the range from 1.6 Multiplication-Sign 10{sup 16} to 1.5 Multiplication-Sign 10{sup 17} cm{sup -3} at 300 K, using the Variable Electron and Neutral Density Attachment Mass Spectrometry method. The rate coefficients of the reactions Ar{sup +}+ Br{sub 2}{sup -}, Ar{sup +}+ SF{sub 6}{sup -}, and Ar{sup +}+ C{sub 7}F{sub 14}{sup -} were found to be independent of gas density over the range studied, in disagreement with earlier observations that similar MN reactions are strongly enhanced at the same gas densities. The cause of the previous enhancement with density is traced to the use of 'orbital-motion-limit' theory to infer ion densities from the currents collected by ion-attracting Langmuir probes in a region where it is not applicable.

  17. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 95, NO. C10, PAGES 18,081-18,094,OCTOBER 15, 1990 Surface Patterns in Temperature, Flow, Phytoplankton Biomass, and Species

    E-Print Network [OSTI]

    Kurapov, Alexander

    km offshore were present in our study area. These features were bounded by the meandering coastal jet and offshore flows in relatively slow moving water, but entrainment of coastal water into the jet was apparent. INTRODUCTION analvses have shown that zooplankton biomass offshore in Satellite data has dramatically changed

  18. Elbow mass flow meter

    DOE Patents [OSTI]

    McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

    1994-08-16

    The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

  19. Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic Fracturing in Shale Gas Systems and Electromagnetic Geophysical Monitoring of Fluid Migration

    SciTech Connect (OSTI)

    Kim, Jihoon; Um, Evan; Moridis, George

    2014-12-01

    We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostly filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow-geomechanical simulator and are transformed via a rock-physics model into electrical conductivity models. It is shown that anomalous conductivity distribution in the resulting models is closely related to injected water saturation, but not closely related to newly created unsaturated fractures. Our numerical modeling experiments demonstrate that the crosswell EM method can be highly sensitive to conductivity changes that directly indicate the migration pathways of the injected fluid. Accordingly, the EM method can serve as an effective monitoring tool for distribution of injected fluids (i.e., migration pathways) during hydraulic fracturing operations

  20. Buoyancy-driven heat transfer and flow between a wetted heat source and an isothermal cube

    SciTech Connect (OSTI)

    Close, D.J.; Peck, M.K.; White, R.F.; Mahoney, K.J. )

    1991-05-01

    This paper describes flow visualization and heat transfer experiments conducted with a heat source inside an isothermal cube filled with a saturated or near-saturated gas/vapor mixture. The mixture was formed by vaporizing liquid from the surface of the heat source, and allowing it to condense on the surfaces of the cube, which was initially filled with a noncondensing gas. Visualization studies showed that for air and ethanol below 35C, and for air and water, the flow patterns were similar with the hot plume rising from the source. For air and ethanol above 35C the flow pattern reversed with the hot plume flowing downward. For temperatures spanning 35C, which is the zero buoyancy temperature for the ethanol/water azeotrope and air, no distinct pattern was observed. Using water, liquid droplets fell like rain throughout the cube. Using ethanol, a fog of droplets moved with the fluid flow. Heat transfer experiments were made with water and air, and conductances between plate and cube of around 580 W{center dot}m{sup {minus}2}{center dot}K{sup {minus}1} measured. Agreement between the similarity theory developed for saturated gas/vapor mixtures, and correlations for single component fluids only, was very good. Together with qualitative support from the visualization experiments, the theory developed in a earlier paper deriving a similarity relationship between single fluids and gas/vapor mixtures has been validated.

  1. The megasecond Chandra X-ray visionary project observation of NGC 3115: Witnessing the flow of hot gas within the Bondi radius

    SciTech Connect (OSTI)

    Wong, Ka-Wah; Irwin, Jimmy A.; Yukita, Mihoko; Million, Evan T.; Shcherbakov, Roman V.; Bregman, Joel N.

    2014-01-01

    Observational confirmation of hot accretion model predictions has been hindered by the challenge to resolve spatially the Bondi radii of black holes with X-ray telescopes. Here, we use the Megasecond Chandra X-ray Visionary Project observation of the NGC 3115 supermassive black hole to place the first direct observational constraints on the spatially and spectroscopically resolved structures of the X-ray emitting gas inside the Bondi radius of a black hole. We measured temperature and density profiles of the hot gas from a fraction out to tens of the Bondi radius (R{sub B} = 2.''4-4.''8 = 112-224 pc). The projected temperature jumps significantly from ?0.3 keV beyond 5'' to ?0.7 keV within ?4''-5'', but then abruptly drops back to ?0.3 keV within ?3''. This is contrary to the expectation that the temperature should rise toward the center for a radiatively inefficient accretion flow. A hotter thermal component of ?1 keV inside 3'' (?150 pc) is revealed using a two-component thermal model, with the cooler ?0.3 keV thermal component dominating the spectra. We argue that the softer emission comes from diffuse gas physically located within ?150 pc of the black hole. The density profile is broadly consistent with ??r {sup –1} within the Bondi radius for either the single temperature or the two-temperature model. The X-ray data alone with physical reasoning argue against the absence of a black hole, supporting that we are witnessing the onset of the gravitational influence of the supermassive black hole.

  2. NEWS & VIEWS PATTERN FORMATION

    E-Print Network [OSTI]

    Loss, Daniel

    no apologies for investing energy into problems of specific application to a particular process in nature, and having the curiosity to want to find out how they work. The general public, and especially children flow/surface growth system in a rarely explored region of parameter space for such pattern formation

  3. Study of Particle Rotation Effect in Gas-Solid Flows using Direct Numerical Simulation with a Lattice Boltzmann Method

    SciTech Connect (OSTI)

    Kwon, Kyung; Fan, Liang-Shih; Zhou, Qiang; Yang, Hui

    2014-09-30

    A new and efficient direct numerical method with second-order convergence accuracy was developed for fully resolved simulations of incompressible viscous flows laden with rigid particles. The method combines the state-of-the-art immersed boundary method (IBM), the multi-direct forcing method, and the lattice Boltzmann method (LBM). First, the multi-direct forcing method is adopted in the improved IBM to better approximate the no-slip/no-penetration (ns/np) condition on the surface of particles. Second, a slight retraction of the Lagrangian grid from the surface towards the interior of particles with a fraction of the Eulerian grid spacing helps increase the convergence accuracy of the method. An over-relaxation technique in the procedure of multi-direct forcing method and the classical fourth order Runge-Kutta scheme in the coupled fluid-particle interaction were applied. The use of the classical fourth order Runge-Kutta scheme helps the overall IB-LBM achieve the second order accuracy and provides more accurate predictions of the translational and rotational motion of particles. The preexistent code with the first-order convergence rate is updated so that the updated new code can resolve the translational and rotational motion of particles with the second-order convergence rate. The updated code has been validated with several benchmark applications. The efficiency of IBM and thus the efficiency of IB-LBM were improved by reducing the number of the Lagragian markers on particles by using a new formula for the number of Lagrangian markers on particle surfaces. The immersed boundary-lattice Boltzmann method (IBLBM) has been shown to predict correctly the angular velocity of a particle. Prior to examining drag force exerted on a cluster of particles, the updated IB-LBM code along with the new formula for the number of Lagrangian markers has been further validated by solving several theoretical problems. Moreover, the unsteadiness of the drag force is examined when a fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. The simulation results agree well with the theories for the short- and long-time behavior of the drag force. Flows through non-rotational and rotational spheres in simple cubic arrays and random arrays are simulated over the entire range of packing fractions, and both low and moderate particle Reynolds numbers to compare the simulated results with the literature results and develop a new drag force formula, a new lift force formula, and a new torque formula. Random arrays of solid particles in fluids are generated with Monte Carlo procedure and Zinchenko's method to avoid crystallization of solid particles over high solid volume fractions. A new drag force formula was developed with extensive simulated results to be closely applicable to real processes over the entire range of packing fractions and both low and moderate particle Reynolds numbers. The simulation results indicate that the drag force is barely affected by rotational Reynolds numbers. Drag force is basically unchanged as the angle of the rotating axis varies.

  4. Gas separating

    DOE Patents [OSTI]

    Gollan, A.Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  5. Gas separating

    DOE Patents [OSTI]

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  6. Recirculating rotary gas compressor

    DOE Patents [OSTI]

    Weinbrecht, John F. (601 Oakwood Loop, NE., Albuquerque, NM 87123)

    1992-01-01

    A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

  7. Recirculating rotary gas compressor

    DOE Patents [OSTI]

    Weinbrecht, J.F.

    1992-02-25

    A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

  8. 8. Yu. P. Golovachev and F. D. Popov, "Investigation of hypersonic flow of viscous gas past blunt cones with allowance for the real physicochemical processes," Fiz. Goreniya

    E-Print Network [OSTI]

    Prigozhin, Leonid

    flow velocity. i. Dispersion Model We consider laminar flow of a fluid in an infinite straight tube- sociating air of high temperatures," Phys. Fluids, 5, 380 (1962). SOLUTE DISPERSION IN A PULSATING FLOW L. B. In the present paper, the Taylor--Aris theory is extended to the case of laminar flows with periodically varying

  9. Predicting multiphase flow behavior in a deviated well

    SciTech Connect (OSTI)

    Hasan, A.R. (Univ. of North Dakota (US)); Kabir, C.S. (Schlumberger Well Services (US))

    1988-11-01

    In deviated wells of an offshore producing environment, flow of two- or three-phase mixtures is invariably encountered. While many investigators have studied vertical multiphase flow behavior, few studies, often entirely empirical, deal with deviated well systems. The main objective of this work is to present a model that predicts both flow regime and pressure gradient in a deviated wellbore. In the modeling of flow-pattern transition and void fraction, an approach similar to that for vertical flow is taken; i.e., four principal flow regimes are recognized: bubbly, slug, churn, and annular. The transition form bubbly to slug flow is found to be at a local void fraction of 0.25. This transition criterion in terms of gas and liquid superficial velocities is found to be significantly affected by the well deviation, particularly in highly deviated wells. The transitions from slug to churn flow and churn to annular flow occur at high fluid velocities and are unaffected by well deviation. The velocity-profile-distribution parameter for bubbly, slug, and churn flows is found to be unaffected by the well deviation angle. Similarly, the terminal rise velocity for small bubbles also appears to be insignificantly affected by the well deviation. In contrast, the ''Taylor'' bubble-rise velocity changes dramatically as deviation angle is increased. Thus, the characters of slug and churn flows in a deviated well differ from those in a vertical well. Data on gas void fraction were obtained both from a 5-in. (127-mm) circular pipe and from annular flow channels for deviation angles up to 32/sup 0/ from the vertical. The validity of the proposed model is demonstrated with these data and with laboratory data from other sources. Several field examples are presented to show the application of the model.

  10. SOLVING POWER-CONSTRAINED GAS TRANSPORTATION ...

    E-Print Network [OSTI]

    2014-11-27

    Nov 27, 2014 ... pressure and the mass flow at supply and demand nodes. Using mass flow ...... Modeling of Oil Product and Gas Pipeline Transportation. Wein-.

  11. Paper No. S7_Thu_A_46 6 International Conference on Multiphase Flow,

    E-Print Network [OSTI]

    Hidrovo, Carlos H.

    and flow parameters. Previous polymer electrolyte membrane (PEM) fuel cell flow regime studies have been pattern such as droplet/bubbly flow, annular film flow, and dynamic clogging plug flow in the fuel cell

  12. Foam patterns

    DOE Patents [OSTI]

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  13. Two-phase flow studies

    SciTech Connect (OSTI)

    Hanold, R.J.

    1983-12-01

    The two-phase flow program is directed at understanding the hydrodynamics of two-phase flows. The two-phase flow regime is characterized by a series of flow patterns that are designated as bubble, slug, churn, and annular flow. Churn flow has received very little scientific attention. This lack of attention cannot be justified because calculations predict that the churn flow pattern will exist over a substantial portion of the two-phase flow zone in producing geothermal wells. The University of Houston is experimentally investigating the dynamics of churn flow and is measuring the holdup over the full range of flow space for which churn flow exists. These experiments are being conducted in an air/water vertical two-phase flow loop. Brown University has constructed and is operating a unique two-phase flow research facility specifically designed to address flow problems of relevance to the geothermal industry. An important feature of the facility is that it is dedicated to two-phase flow of a single substance (including evaporation and condensation) as opposed to the case of a two-component two-phase flow. This facility can be operated with horizontal or vertical test sections of constant diameter or with step changes in diameter to simulate a geothermal well profile.

  14. Static gas expansion cooler

    DOE Patents [OSTI]

    Guzek, J.C.; Lujan, R.A.

    1984-01-01

    Disclosed is a cooler for television cameras and other temperature sensitive equipment. The cooler uses compressed gas ehich is accelerated to a high velocity by passing it through flow passageways having nozzle portions which expand the gas. This acceleration and expansion causes the gas to undergo a decrease in temperature thereby cooling the cooler body and adjacent temperature sensitive equipment.

  15. 9.11.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/44 3. Absorption, gas expansion and

    E-Print Network [OSTI]

    Zevenhoven, Ron

    (AR) processes 1: NH3 #12;9.11.2014Åbo Akademi Univ - Thermal and Flow Engineering Piispankatu 8 energy, solar energy, biogas fuel, etc. Absorption refrigeration involves absorption of refrigerant Akademi Univ - Thermal and Flow Engineering Piispankatu 8, 20500 Turku 7/44 A practical NH3/H2O AR system

  16. Development of New Geothermal Wellbore Holdup Correlations Using Flowing Well Data

    SciTech Connect (OSTI)

    Garg, S.K.; Pritchett, J.W.; Alexander, J.H.

    2004-03-01

    An ability to predict both the quantity of fluid that can be produced and its thermodynamic state (pressure, temperature, enthalpy, gas content, salinity, etc.) is essential for estimating the total usable energy of a geothermal resource. Numerical reservoir simulators can be utilized to calculate the thermodynamic state of the fluid at the underground feed-zone(s) at which the fluid enters the wellbore. The computation of the well-head fluid properties from a given underground state (or vice-versa) requires the use of a wellbore simulator. The fluid flow in the wellbore is not amenable to strict analytical treatment. Depending upon the relative amounts of gas and liquid, a variety of flow patterns can occur in the pipe. At small gas loadings, bubble flow takes place. An increase in gas flow rate can result in slug, churn or annular flow. Existing methods for treating two-phase flow in a wellbore require use of empirical correlations for action factor and for liquid hold-up.

  17. Low flow fume hood

    DOE Patents [OSTI]

    Bell, Geoffrey C. (Pleasant Hill, CA); Feustel, Helmut E. (Albany, CA); Dickerhoff, Darryl J. (Berkeley, CA)

    2002-01-01

    A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.

  18. Micromechanics of emergent patterns in plastic flows

    E-Print Network [OSTI]

    Grant, Martin

    , Bombay, Powai, Mumbai-400 076, India, 2 Physics Department, McGill University, 3600 rue University, Indian Institute of Technology, Bombay, Powai, Mumbai-400 076, India, 4 Product Research Group, Research

  19. Fischer-Tropsch synthesis from a low H/sub 2/:CO gas in a dry fluidized-bed system. Volume 3. Heat transfer between a supernatant gas and a flowing shallow fluidized bed of solids. Final technical report, October 1, 1986

    SciTech Connect (OSTI)

    Boyd, J.H.; Liu, Y.A.; Squires, A.M.

    1986-10-01

    Volume II describes the details of heat-transfer studies in a dry fluidized-bed system (called ''heat tray''), which has been proposed for heat recovery from hot gases and for heat management in exothermic reactions. In particular, this report presents the results of bench-scale and pilot-scale experimental studies which quantify heat transfer between a hot supernatant gas (S-gas) and a flowing shallow fluidized bed of solids. A fractional-factorial design of experiments has been performed on two heat-tray systems using three different solids. The results show that fine fluid cracking catalyst (FCC) particles out-perform larger alumina spheres as a fluidized solid. Heat transfer coefficients between the supernatant gas and the shallow fluidized bed approaches 440 W/m/sup 2/-K using FCC with a heat-exchange area of 0.124 m/sup 2/. Various S-gas inlet nozzle configurations have been studied, with a nozzle height equal to one-half of the static bed height (0.051 m) giving the best results. The study shows that short heat-tray lengths (< 0.8 m) are desirable and that S-gas redistributors are needed to compartmentalize the unit. An economic analysis shows that the proposed heat tray would be economically feasible for adaption as a boiler feedwater preheater in a small steam-generation facility, using boiler combustion gases as the S-gas. The payback time for the system would be as short as 1.9 years when used continuously. The heat transfer results from a supernatant gas to a flowing shallow fluidized bed represent the only data reported thus far, and have led to a better understanding of the heat management in the proposed ''heat-tray'' reactor for Fischer-Tropsch synthesis. 20 refs., 46 figs., 15 tabs.

  20. Mobile Monolith Polymer Elements For Flow Control In Microfluidic Systems

    DOE Patents [OSTI]

    Hasselbrink, Jr., Ernest F. (Saline, MI); Rehm, Jason E. (Alameda, CA); Shepodd, Timothy J. (Livermore, CA); Kirby, Brian J. (San Francisco, CA)

    2006-01-24

    A cast-in-place and lithographically shaped mobile, monolithic polymer element for fluid flow control in microfluidic devices and method of manufacture. Microfluid flow control devices, or microvalves that provide for control of fluid or ionic current flow can be made incorporating a cast-in-place, mobile monolithic polymer element, disposed within a microchannel, and driven by fluid pressure (either liquid or gas) against a retaining or sealing surface. The polymer elements are made by the application of lithographic methods to monomer mixtures formulated in such a way that the polymer will not bond to microchannel walls. The polymer elements can seal against pressures greater than 5000 psi, and have a response time on the order of milliseconds. By the use of energetic radiation it is possible to depolymerize selected regions of the polymer element to form shapes that cannot be produced by conventional lithographic patterning and would be impossible to machine.

  1. Mobile monolithic polymer elements for flow control in microfluidic devices

    DOE Patents [OSTI]

    Hasselbrink, Jr., Ernest F. (Saline, MI); Rehm, Jason E. (Alameda, CA); Shepodd, Timothy J. (Livermore, CA); Kirby, Brian J. (San Francisco, CA)

    2005-11-11

    A cast-in-place and lithographically shaped mobile, monolithic polymer element for fluid flow control in microfluidic devices and method of manufacture. Microfluid flow control devices, or microvalves that provide for control of fluid or ionic current flow can be made incorporating a cast-in-place, mobile monolithic polymer element, disposed within a microchannel, and driven by fluid pressure (either liquid or gas) against a retaining or sealing surface. The polymer elements are made by the application of lithographic methods to monomer mixtures formulated in such a way that the polymer will not bond to microchannel walls. The polymer elements can seal against pressures greater than 5000 psi, and have a response time on the order of milliseconds. By the use of energetic radiation it is possible to depolymerize selected regions of the polymer element to form shapes that cannot be produced by conventional lithographic patterning and would be impossible to machine.

  2. Mobile monolithic polymer elements for flow control in microfluidic devices

    DOE Patents [OSTI]

    Hasselbrink, Jr., Ernest F.; Rehm, Jason E.; Shepodd, Timothy J.

    2004-08-31

    A cast-in-place and lithographically shaped mobile, monolithic polymer element for fluid flow control in microfluidic devices and method of manufacture. Microfluid flow control devices, or microvalves that provide for control of fluid or ionic current flow can be made incorporating a cast-in-place, mobile monolithic polymer element, disposed within a microchannel, and driven by either fluid or gas pressure against a retaining or sealing surface. The polymer elements are made by the application of lithographic methods to monomer mixtures formulated in such a way that the polymer will not bond to microchannel walls. The polymer elements can seal against pressures greater than 5000 psi, and have a response time on the order of milliseconds. By the use of energetic radiation it is possible to depolymerize selected regions of the polymer element to form shapes that cannot be produced by conventional lithographic patterning and would be impossible to machine.

  3. Anisotropic flow

    E-Print Network [OSTI]

    S. A. Voloshin

    2002-11-20

    Recent experimental results on directed and elliptic flow, theoretical developments, and new techniques for anisotropic flow analysis are reviewed.

  4. Sauget Plant Flare Gas Reduction Project 

    E-Print Network [OSTI]

    Ratkowski, D. P.

    2007-01-01

    Empirical analysis of stack gas heating value allowed the Afton Chemical Corporation Sauget Plant to reduce natural gas flow to its process flares by about 50% while maintaining the EPA-required minimum heating value of the gas streams....

  5. A heat exchanger between forced flow helium gas at 14 to 18 K and liquid hydrogen at 20 K circulated by natural convection

    E-Print Network [OSTI]

    Green, M.A.; Ishimoto, S.; Lau, W.; Yang, S.

    2003-01-01

    GAS AT 14 TO 18 K AND LIQUID HYDROGEN AT 20 K CIRCULATED BYhas three 350-mm long liquid hydrogen absorbers to reduceis taken up by the liquid hydrogen in the absorber. The

  6. Fluid flow effects on electroplating

    SciTech Connect (OSTI)

    Kirkpatrick, J.R.

    1990-09-01

    The effects of fluid flow patterns on the electroplating of rotating cylindrically symmetric objects are examined. Ways are outlined for preventing undesirable spiral patterns on the plated surface. Estimates are given for the diffusion boundary later thickness for cylinders, disks, spheres, and cones. 16 refs., 7 figs., 1 tab.

  7. Interphase mass transfer in cocurrent vertical two-phase channel flows with non-Newtonian liquids

    SciTech Connect (OSTI)

    Luo, D.; Ghiaasiaan, S.M. [Georgia Inst. of Tech., Atlanta, GA (United States). G.W. Woodruff School of Mechanical Engineering] [Georgia Inst. of Tech., Atlanta, GA (United States). G.W. Woodruff School of Mechanical Engineering

    1997-01-01

    Flow patterns, gas hold-up, and volumetric liquid-side interphase mass transfer coefficients were experimentally studied using aqueous solutions of Polyacrylamide as the liquid phase, pure nitrogen as the gas phase, and oxygen as the transferred species. The channel entrance effects were eliminated by performing hydrodynamically-identical tests with two different test section lengths, and using the shorter test section results for quantification of entrance effects in the longer test section. Experimental data were obtained over a range of gas and liquid superficial velocities covering the bubbly, slug and churn flow regimes and were compared with data previously obtained with pure water and aqueous sucrose solutions. The effect of the liquid-phase rheological properties on channel hydrodynamic and mass transfer processes were examined.

  8. Module bay with directed flow

    SciTech Connect (OSTI)

    Torczynski, John R. (Albuquerque, NM)

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  9. DIFFERENTIAL EQUATIONS FOR FLOW IN RESERVOIRS By ...

    E-Print Network [OSTI]

    2008-08-23

    phases (water, oil, and gas) flow simultaneously, while mass transfer may take place ..... netic field theory and in hydrodynamics of incompressible fluids.

  10. Oil and Gas CDT Gas hydrate distribution on tectonically active continental

    E-Print Network [OSTI]

    Henderson, Gideon

    Oil and Gas CDT Gas hydrate distribution on tectonically active continental margins: Impact on gas. Gregory F. Moore, University of Hawaii (USA) http://www.soest.hawaii.edu/moore/ Key Words Gas Hydrates, Faults, Fluid Flow, gas prospectivity Overview Fig. 1. Research on gas hydrates is often undertaken

  11. Project Title Economic Modeling & Unconventional Gas Resource Appraisal Program Line Tough Gas

    E-Print Network [OSTI]

    Santos, Juan

    support to assess the economic viability of new tough gas plays (tight gas, shale gas, CBM). Project are illustrated using the US shale gas plays as case templates. Discounted cash flow models are applied1 Project Title Economic Modeling & Unconventional Gas Resource Appraisal Program Line Tough Gas

  12. Pumpkin Patterns

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996HowFOA Applicant Webinar PresentationMinutes of the

  13. Pumpkin Patterns

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy AEnergyPresidentialThis 3-D rendering of apump systems by applyingfluorescent

  14. Gas only nozzle

    DOE Patents [OSTI]

    Bechtel, William Theodore (15 Olde Coach Rd., Scotia, NY 12302); Fitts, David Orus (286 Sweetman Rd., Ballston Spa, NY 12020); DeLeonardo, Guy Wayne (60 St. Stephens La., Glenville, NY 12302)

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  15. Flow assurance and multiphase pumping 

    E-Print Network [OSTI]

    Nikhar, Hemant G.

    2009-05-15

    ????????????????????????????????????????. xvii NOMENCLATURE???????????????????????????????????????. xviii 1. INTRODUCTION??????????????????????????????????????? 1 2. LITERATURE REVIEW???????????????????????????????????.. 5 Deepwater Oilfields???????????????????????????????????.. 7 Flow...????????????????????????????????.. 71 Limited Energy Reservoirs and Deep Waters???????????????????? 71 5. SOLIDS FORMATION AND DEPOSITION??????????????????????????. 72 Gas Hydrates??????????????????????????????????????? 72 Field Problems??????????????????????????????????????. 74...

  16. Multiphase Flow and Cavern Abandonment in Salt

    SciTech Connect (OSTI)

    Ehgartner, Brian; Tidwell, Vince

    2001-02-13

    This report will explore the hypothesis that an underground cavity in gassy salt will eventually be gas filled as is observed on a small scale in some naturally occurring salt inclusions. First, a summary is presented on what is known about gas occurrences, flow mechanisms, and cavern behavior after abandonment. Then, background information is synthesized into theory on how gas can fill a cavern and simultaneously displace cavern fluids into the surrounding salt. Lastly, two-phase (gas and brine) flow visualization experiments are presented that demonstrate some of the associated flow mechanisms and support the theory and hypothesis that a cavity in salt can become gas filled after plugging and abandonment

  17. US energy flow, 1991

    SciTech Connect (OSTI)

    Borg, I.Y.; Briggs, C.K.

    1992-06-01

    Trends in energy consumption and assessment of energy sources are discussed. Specific topics discussed include: energy flow charts; comparison of energy use with 1990 and earlier years; supply and demand of fossil fuels (oils, natural gas, coal); electrical supply and demand; and nuclear power.

  18. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    SciTech Connect (OSTI)

    1995-02-17

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A.

  19. Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

    SciTech Connect (OSTI)

    McCulloch, R.W.; MacPherson, R.E.

    1983-03-01

    The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

  20. Network Flow Optimization under Uncertainty

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    , production, generation, transportation, trade, storage injections and withdrawals of coal, gas?) xij is flow along arc (i, j), from node i to node j cij is cost per unit of flow along (i, j Network model in words Minimize the cost of satisfying demands for electric energy By: imports, exports

  1. The transition from the annular to the slug flow regime in two-phase flow

    E-Print Network [OSTI]

    Haberstroh, Robert D.

    1964-01-01

    Experiments were conducted to determine the transition from annular to semiannular flow regimes for two-phase, gas-liquid upflow in vertical tubes. The influencesof liquid flow rate, tube diameter, liquid viscosity, surface ...

  2. Dynamic Optimization in Gas Pipeline Networks EWO MEETING, Spring 2012

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    , consumers and compressor stations Compressor Stations Processing Plants Customers 3 Suppliers: Continuous flow of gas into network. Customers: Chemical industries, Power plants, Residential/commercial heating: Flow demands must be satisfied at a contract pressure. Compressor Stations: Compression of gas

  3. Supersonic gas compressor

    DOE Patents [OSTI]

    Lawlor, Shawn P. (Bellevue, WA); Novaresi, Mark A. (San Diego, CA); Cornelius, Charles C. (Kirkland, WA)

    2007-11-13

    A gas compressor based on the use of a driven rotor having a compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which compresses inlet gas against a stationary sidewall. In using this method to compress inlet gas, the supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdyanamic flow path formed between the rim of the rotor, the strakes, and a stationary external housing. Part load efficiency is enhanced by the use of a pre-swirl compressor, and using a bypass stream to bleed a portion of the intermediate pressure gas after passing through the pre-swirl compressor back to the inlet of the pre-swirl compressor. Inlet guide vanes to the compression ramp enhance overall efficiency.

  4. TURBULENT-LAMINAR PATTERNS IN PLANE COUETTE Dwight Barkley

    E-Print Network [OSTI]

    Barkley, Dwight

    @limsi.fr Abstract Regular patterns of turbulent and laminar fluid motion arise in plane Couette flow near the lowest and is the kinematic viscosity of the fluid. See figure 1. For all val- ues of ¡£¢ , laminar Couette flow at an angle to the streamwise direction. Fluid flows exhibiting coexisting turbulent and laminar regions have

  5. Gas cleaning system and method

    DOE Patents [OSTI]

    Newby, Richard Allen

    2006-06-06

    A gas cleaning system for removing at least a portion of contaminants, such as halides, sulfur, particulates, mercury, and others, from a synthesis gas (syngas). The gas cleaning system may include one or more filter vessels coupled in series for removing halides, particulates, and sulfur from the syngas. The gas cleaning system may be operated by receiving gas at a first temperature and pressure and dropping the temperature of the syngas as the gas flows through the system. The gas cleaning system may be used for an application requiring clean syngas, such as, but not limited to, fuel cell power generation, IGCC power generation, and chemical synthesis.

  6. Convective cores in galactic cooling flows

    E-Print Network [OSTI]

    A. Kritsuk; T. Plewa; E. Mueller

    2001-05-02

    We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating mechanisms including Type Ia supernovae and sporadic nuclear activity of a central supermassive black hole. As a starting point for this research we use an equilibrium hydrostatic recycling model (Kritsuk 1996). We show that a compact cooling inflow develops, if the heating is slightly insufficient to counterbalance radiative cooling of the hot gas in the central few kiloparsecs. An excessive heating in the centre, instead, drives a convectively unstable outflow. We model the onset of the instability and a quasi-steady convective regime in the core of the galaxy in two-dimensions assuming axial symmetry. Provided the power of net energy supply in the core is not too high, the convection remains subsonic. The convective pattern is dominated by buoyancy driven large-scale mushroom-like structures. Unlike in the case of a cooling inflow, the X-ray surface brightness of an (on average) isentropic convective core does not display a sharp maximum at the centre. A hybrid model, which combines a subsonic peripheral cooling inflow with an inner convective core, appears to be stable. We also discuss observational implications of these results.

  7. Gas-controlled dynamic vacuum insulation with gas gate

    DOE Patents [OSTI]

    Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

    1994-06-07

    Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber.

  8. Gas-controlled dynamic vacuum insulation with gas gate

    DOE Patents [OSTI]

    Benson, D.K.; Potter, T.F.

    1994-06-07

    Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber. 25 figs.

  9. Pattern Alteration: Principles of Pattern Alteration 

    E-Print Network [OSTI]

    2006-02-09

    This publication gives instructions on taking body measurements, measuring and altering pattern pieces, and checking the altered fit....

  10. Convex Relaxations for Gas Expansion Planning

    E-Print Network [OSTI]

    2015-06-24

    to mechanical problems and shortages of gas fuel supplies, which drove wholesale power ...... Unsteady and transient flow of compressible fluids in pipelinesa.

  11. Generalized correlation for foam flow in tubes 

    E-Print Network [OSTI]

    Cotter, Carol Lynnette

    1996-01-01

    with respect to foam in the laminar flow region. A semi-automated system to collect pressure drop-flow rate data for gas in liquid foams was constructed in which foam is created by a foam generator and the pressure drop resulting from the foam flow is measured...

  12. Seismic Absorption and Modulus Measurements in Porous Rocks Under Fluid and Gas Flow-Physical and Chemical Effects: a Laboratory Study

    SciTech Connect (OSTI)

    Harmut Spetzler

    2005-11-28

    This paper describes the culmination of a research project in which we investigated the complex modulus change in partially fluid saturated porous rocks. The investigation started with simple flow experiments over ''clean'' and ''contaminated'' surfaces, progressed to moduli measurements on partially filled single cracks, to measurements in ''clean'' and ''contaminated'' porous rocks and finally to a feasibility study in the field. For the experiments with the simple geometries we were able to measure fundamental physical properties such as contact angles of the meniscus and time dependent forces required to get the meniscus moving and to keep it moving at various velocities. From the data thus gathered we were able to interpret the complex elastic moduli data we measured in the partially saturated single cracks. While the geometry in real rocks is too complex to make precise calculations we determined that we had indeed identified the mechanisms responsible for the changes in the moduli we had measured. Thus encouraged by the laboratory studies we embarked on a field experiment in the desert of Arizona. The field site allowed for controlled irrigation. Instrumentation for fluid sampling and water penetration were already in place. The porous loosely consolidated rocks at the site were not ideal for finding the effects of the attenuation mechanism we had identified in the lab, but for logistic and cost constraint reasons we chose to field test the idea at that site. Tiltmeters and seismometers were installed and operated nearly continuously for almost 3 years. The field was irrigated with water in the fall of 2003 and with water containing a biosurfactant in the fall of 2004. We have indications that the biosurfactant irrigation has had a notable effect on the tilt data.

  13. Production Trends of Shale Gas Wells 

    E-Print Network [OSTI]

    Khan, Waqar A.

    2010-01-14

    To obtain better well performance and improved production from shale gas reservoirs, it is important to understand the behavior of shale gas wells and to identify different flow regions in them over a period of time. It is also important...

  14. STUDIES OF MICROMORPHOLOGY AND CURRENT EFFICIENCY OF ZINC ELECTRODEPOSITED FROM FLOWING CHLORIDE ELECTROLYTES

    E-Print Network [OSTI]

    Mc Vay, L.

    2011-01-01

    J. , Flow distribution in the zinc chloride battery, JES,ensures a con- The flow patterns in this battery were stant,and products. flow As a result the battery is separate from

  15. Automated gas chromatography

    DOE Patents [OSTI]

    Mowry, Curtis D. (Albuquerque, NM); Blair, Dianna S. (Albuquerque, NM); Rodacy, Philip J. (Albuquerque, NM); Reber, Stephen D. (Corrales, NM)

    1999-01-01

    An apparatus and process for the continuous, near real-time monitoring of low-level concentrations of organic compounds in a liquid, and, more particularly, a water stream. A small liquid volume of flow from a liquid process stream containing organic compounds is diverted by an automated process to a heated vaporization capillary where the liquid volume is vaporized to a gas that flows to an automated gas chromatograph separation column to chromatographically separate the organic compounds. Organic compounds are detected and the information transmitted to a control system for use in process control. Concentrations of organic compounds less than one part per million are detected in less than one minute.

  16. Numerical simulation of electrokinetically driven micro flows 

    E-Print Network [OSTI]

    Hahm, Jungyoon

    2005-11-01

    are systematically studied. As a first application, flow and species transport control in a grooved micro-channel using local electrokinetic forces are studied. Locally applied electric fields, zeta potential patterned grooved surfaces, and geometry are manipulated...

  17. Temporary Pedestrian & Vehicular Traffic Flow Typical Conditions

    E-Print Network [OSTI]

    Kamat, Vineet R.

    Temporary Pedestrian & Vehicular Traffic Flow Typical Conditions Winter 2014 Ann Arbor - Medical://www.umaec.umich.edu/closures.html Roadway Closure Existing Traffic Pattern I0 400 800 1,200200 Feet Pedestrian Route Existing Building

  18. System for measuring multiphase flow using multiple pressure differentials

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-01-01

    An improved method and system for measuring a multi-phase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multi-phase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The system for determining the mass flow of the high void fraction fluid flow and the gas flow includes taking into account a pressure drop experienced by the gas phase due to work performed by the gas phase in accelerating the liquid phase.

  19. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalystes to Poisons form High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect (OSTI)

    Burton Davis; Gary Jacobs; Wenping Ma; Khalid Azzam; Janet ChakkamadathilMohandas; Wilson Shafer

    2009-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations.

  20. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect (OSTI)

    Burton Davis; Gary Jacobs; Wenping Ma; Dennis Sparks; Khalid Azzam; Janet Chakkamadathil Mohandas; Wilson Shafer; Venkat Ramana Rao Pendyala

    2011-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations. In the second and third years, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H{sub 2}S and NH{sub 3}. Cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts were also subjected to a number of the same compounds in order to evaluate their sensitivities at different concentration levels of added contaminant.

  1. Modeling joint patterns using combinations of mechanical and probabilistic concepts

    E-Print Network [OSTI]

    Locsin, Jean Louis Zuñiga, 1975-

    2005-01-01

    Rock fracture pattern description is important in civil engineering, engineering geology, and petroleum engineering. Deformability, strength, and stability of a rock mass as well as fluid flow through it are all influenced ...

  2. Flow chamber

    DOE Patents [OSTI]

    Morozov, Victor (Manassas, VA)

    2011-01-18

    A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

  3. Gas Hydrate Equilibrium Measurements for Multi-Component Gas Mixtures and Effect of Ionic Liquid Inhibitors 

    E-Print Network [OSTI]

    Othman, Enas Azhar

    2014-04-07

    -component gas mixtures whose compositions are typical of Qatari natural gases with initiatives aimed at helping producers minimize costs, optimize operations, and prevent interruption of gas flow in offshore drilling and production. In addition, it presents...

  4. Numerical Modeling of Fractured Shale-Gas and Tight-Gas Reservoirs Using Unstructured Grids 

    E-Print Network [OSTI]

    Olorode, Olufemi Morounfopefoluwa

    2012-02-14

    Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non...

  5. Two-phase flow interfacial drag for once through steam generators 

    E-Print Network [OSTI]

    Rais, Omar Tahar

    1990-01-01

    which determined in subroutine PHAINT. The term FIJ is determined for each junction from different models depending on what flow regimes are calculated for the volumes adjoining the junction. IV. 3 Introduction to Two Phase Flow Patterns When a... transfer rates, and other parameters of 25 interest will behave differently as the flow pattern changes. Various techniques are available for the study of two-phase flow patterns in heated and unheated channels. In a transparent channels at low...

  6. Flow conditioner for fuel injector for combustor and method for low-NO.sub.x combustor

    DOE Patents [OSTI]

    Dutta, Partha; Smith, Kenneth O.; Ritz, Frank J.

    2013-09-10

    An injector for a gas turbine combustor including a catalyst coated surface forming a passage for feed gas flow and a channel for oxidant gas flow establishing an axial gas flow through a flow conditioner disposed at least partially within an inner wall of the injector. The flow conditioner includes a length with an interior passage opening into upstream and downstream ends for passage of the axial gas flow. An interior diameter of the interior passage smoothly reduces and then increases from upstream to downstream ends.

  7. Can We Accurately Model Fluid Flow in Shale?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Can We Accurately Model Fluid Flow in Shale? Can We Accurately Model Fluid Flow in Shale? Print Thursday, 03 January 2013 00:00 Over 20 trillion cubic meters of natural gas are...

  8. Society of Petroleum Engineers Staggered In Time Coupling of Reservoir Flow Simulation and Geomechanical Defor-

    E-Print Network [OSTI]

    Minkoff, Susan E.

    ) the flow of oil, gas, and water fluid phases in the reservoir while the lat- ter has been specialized

  9. Stopping Cooling Flows with Jets

    E-Print Network [OSTI]

    Fabrizio Brighenti; William G. Mathews

    2006-01-24

    We describe 2D gasdynamical models of jets that carry mass as well as energy to the hot gas in galaxy clusters. These flows have many attractive attributes for solving the galaxy cluster cooling flow problem: Why the hot gas temperature and density profiles resemble cooling flows but show no spectral evidence of cooling to low temperatures. Using an approximate model for the cluster A1795, we show that mass-carrying jets can reduce the overall cooling rate to or below the low values implied by X-ray spectra. Biconical subrelativistic jets, described with several ad hoc parameters, are assumed to be activated when gas flows toward or cools near a central supermassive black hole. As the jets proceed out from the center they entrain more and more ambient gas. The jets lose internal pressure by expansion and are compressed by the ambient cluster gas, becoming rather difficult to observe. For a wide variety of initial jet parameters and several feedback scenarios the global cooling can be suppressed for many Gyrs while maintaining cluster temperature profiles similar to those observed. The intermittancy of the feedback generates multiple generations of X-ray cavities similar to those observed in the Perseus Cluster and elsewhere.

  10. Cross-flow electrochemical reactor cells, cross-flow reactors, and use of cross-flow reactors for oxidation reactions

    DOE Patents [OSTI]

    Balachandran, Uthamalingam (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Udovich, Carl A. (Joliet, IL)

    1994-01-01

    This invention discloses cross-flow electrochemical reactor cells containing oxygen permeable materials which have both electron conductivity and oxygen ion conductivity, cross-flow reactors, and electrochemical processes using cross-flow reactor cells having oxygen permeable monolithic cores to control and facilitate transport of oxygen from an oxygen-containing gas stream to oxidation reactions of organic compounds in another gas stream. These cross-flow electrochemical reactors comprise a hollow ceramic blade positioned across a gas stream flow or a stack of crossed hollow ceramic blades containing a channel or channels for flow of gas streams. Each channel has at least one channel wall disposed between a channel and a portion of an outer surface of the ceramic blade, or a common wall with adjacent blades in a stack comprising a gas-impervious mixed metal oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity. The invention includes reactors comprising first and second zones seprated by gas-impervious mixed metal oxide material material having electron conductivity and oxygen ion conductivity. Prefered gas-impervious materials comprise at least one mixed metal oxide having a perovskite structure or perovskite-like structure. The invention includes, also, oxidation processes controlled by using these electrochemical reactors, and these reactions do not require an external source of electrical potential or any external electric circuit for oxidation to proceed.

  11. Quantitative tomographic measurements of opaque multiphase flows

    SciTech Connect (OSTI)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O'HERN,TIMOTHY J.; CECCIO,STEVEN L.

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  12. Gas only nozzle fuel tip

    DOE Patents [OSTI]

    Bechtel, William Theodore (Scotia, NY); Fitts, David Orus (Ballston Spa, NY); DeLeonardo, Guy Wayne (Glenville, NY)

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  13. Strong solutions of the compressible nematic liquid crystal flow

    E-Print Network [OSTI]

    2011-04-29

    Apr 29, 2011 ... nematic liquid crystal flows in a domain ? ? R3. We first prove the local ... natural compatibility condition. The initial density .... gas dynamics).

  14. GAS FLOW THROUGH POROUS BARRiERS

    E-Print Network [OSTI]

    Jacobson, N.S.

    2011-01-01

    reached. The equilibrium constant for S03 = S02 + PSO isK PO PSO log K = 8,8557 - 54~5.5 ~ 1,21572 log T.one has a known inlet or PSO - 2KPso in + 4KPso PSO ln -

  15. Turbulent flow of gas in fractures 

    E-Print Network [OSTI]

    Koh, Wong In

    1974-01-01

    his sincere appreciation to Dr. W, D. Yon Gonten, Chairman of the author's graduate committee, for his kind and helpful guidanoe and sugges- tion, to Dr. R. A. Norse and to Dr. C . ED Gates for serving on his graduate oommittee. The author... of this study by paying full scholarship from the Petroleum Educational Fund in the Ninistry of Commeroe and Industry. He expresses his appreoiation to Dr C . K. Hong, Head of the department of Mineral and Petroleum Engineering in Seoul National University...

  16. Can We Accurately Model Fluid Flow in Shale?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2013 00:00 Over 20 trillion cubic meters of natural gas are trapped in shale, but many shale oil and gas producers still use models of underground fluid flow that date back to...

  17. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect (OSTI)

    Burtron Davis; Gary Jacobs; Wenping Ma; Khalid Azzam; Dennis Sparks; Wilson Shafer

    2010-09-30

    The successful adaptation of conventional cobalt and iron-based Fischer-Tropsch synthesis catalysts for use in converting biomass-derived syngas hinges in part on understanding their susceptibility to byproducts produced during the biomass gasification process. With the possibility that oil production will peak in the near future, and due to concerns in maintaining energy security, the conversion of biomass-derived syngas and syngas derived from coal/biomass blends to Fischer-Tropsch synthesis products to liquid fuels may provide a sustainable path forward, especially considering if carbon sequestration can be successfully demonstrated. However, one current drawback is that it is unknown whether conventional catalysts based on iron and cobalt will be suitable without proper development because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using an entrained-flow oxygen-blown gasifier) than solely from coal, other byproducts may be present in higher concentrations. The current project examines the impact of a number of potential byproducts of concern from the gasification of biomass process, including compounds containing alkali chemicals like the chlorides of sodium and potassium. In the second year, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H{sub 2}S and NH{sub 3}. Cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts were also subjected to a number of the same compounds in order to evaluate their sensitivities.

  18. Motivational Design Patterns

    E-Print Network [OSTI]

    Lewis, Chris

    2013-01-01

    1.5 Motivational design patterns . . . 1.5.1 Gameful3.2.3 Motivational design pattern definition . . . .3.2.42011). Gamification by Design: Im- plementing Game Mechanics

  19. Emerging Energy-Efficiency and Greenhouse Gas Mitigation Technologies for the Pulp and Paper Industry

    E-Print Network [OSTI]

    Kong, Lingbo

    2014-01-01

    economics of black liquor gasifier/gas turbine cogenerationblack liquor and biomass gasifier/gas turbine technology".entrained flow booster gasifier in New Bern, North Carolina;

  20. Method and apparatus for dispensing compressed natural gas and liquified natural gas to natural gas powered vehicles

    DOE Patents [OSTI]

    Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.

    2005-05-31

    A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.

  1. Multiphase flow in fractured porous media

    SciTech Connect (OSTI)

    Firoozabadi, A.

    1995-02-01

    The major goal of this research project was to improve the understanding of the gas-oil two-phase flow in fractured porous media. In addition, miscible displacement was studied to evaluate its promise for enhanced recovery.

  2. Approved Module Information for ME1F20, 2014/5 Module Title/Name: Gas Engineering Principles Module Code: ME1F20

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    , Flow measurement, Coal Bed Methane, Natural Gas Phase Behaviour, Natural Gas Properties, Chemical and calculate the solutions of problems associated with Natural Gas flow and transmission Learn properties and Physical Properties, Gas Specific Gravity, Ideal and Real Gas Laws, Gas Formation Volume Factor, Gas

  3. Microfluidics Formation of Bubbles in a Multisection Flow-Focusing

    E-Print Network [OSTI]

    Prentiss, Mara

    Microfluidics Formation of Bubbles in a Multisection Flow-Focusing Junction Michinao Hashimoto the stable formation of trains of mono-, bi-, and tri-disperse bubbles in microfluidic flow- focusing (FF-assembly through the patterns of flow created by the bubbles. 1.1 Bubbles and Droplets in Microfluidics

  4. GEOLOGIC NOTE A simple model of gas

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    GEOLOGIC NOTE A simple model of gas production from hydrofractured horizontal wells in shales Tad Patzek, Frank Male, and Michael Marder ABSTRACT Assessing the production potential of shale gas can a nonlinear initial boundary value problem for transient flow of real gas that may sorb on the rock and solve

  5. Deliverability on the interstate natural gas pipeline system

    SciTech Connect (OSTI)

    1998-05-01

    Deliverability on the Interstate Natural Gas Pipeline System examines the capability of the national pipeline grid to transport natural gas to various US markets. The report quantifies the capacity levels and utilization rates of major interstate pipeline companies in 1996 and the changes since 1990, as well as changes in markets and end-use consumption patterns. It also discusses the effects of proposed capacity expansions on capacity levels. The report consists of five chapters, several appendices, and a glossary. Chapter 1 discusses some of the operational and regulatory features of the US interstate pipeline system and how they affect overall system design, system utilization, and capacity expansions. Chapter 2 looks at how the exploration, development, and production of natural gas within North America is linked to the national pipeline grid. Chapter 3 examines the capability of the interstate natural gas pipeline network to link production areas to market areas, on the basis of capacity and usage levels along 10 corridors. The chapter also examines capacity expansions that have occurred since 1990 along each corridor and the potential impact of proposed new capacity. Chapter 4 discusses the last step in the transportation chain, that is, deliverability to the ultimate end user. Flow patterns into and out of each market region are discussed, as well as the movement of natural gas between States in each region. Chapter 5 examines how shippers reserve interstate pipeline capacity in the current transportation marketplace and how pipeline companies are handling the secondary market for short-term unused capacity. Four appendices provide supporting data and additional detail on the methodology used to estimate capacity. 32 figs., 15 tabs.

  6. Quantitative supersonic flow visualization by hydraulic analogy 

    E-Print Network [OSTI]

    Rani, Sarma Laxminarasimha

    1998-01-01

    The hydraulic analogy, which forms the basis for the phics. current investigation, can be used to study supersonic gas flows with great ease by means of a water table. As a result of the analogy, water heights in free surface water flow correspond...

  7. Gas-cooled nuclear reactor

    DOE Patents [OSTI]

    Peinado, Charles O. (La Jolla, CA); Koutz, Stanley L. (San Diego, CA)

    1985-01-01

    A gas-cooled nuclear reactor includes a central core located in the lower portion of a prestressed concrete reactor vessel. Primary coolant gas flows upward through the core and into four overlying heat-exchangers wherein stream is generated. During normal operation, the return flow of coolant is between the core and the vessel sidewall to a pair of motor-driven circulators located at about the bottom of the concrete pressure vessel. The circulators repressurize the gas coolant and return it back to the core through passageways in the underlying core structure. If during emergency conditions the primary circulators are no longer functioning, the decay heat is effectively removed from the core by means of natural convection circulation. The hot gas rising through the core exits the top of the shroud of the heat-exchangers and flows radially outward to the sidewall of the concrete pressure vessel. A metal liner covers the entire inside concrete surfaces of the concrete pressure vessel, and cooling tubes are welded to the exterior or concrete side of the metal liner. The gas coolant is in direct contact with the interior surface of the metal liner and transfers its heat through the metal liner to the liquid coolant flowing through the cooling tubes. The cooler gas is more dense and creates a downward convection flow in the region between the core and the sidewall until it reaches the bottom of the concrete pressure vessel when it flows radially inward and up into the core for another pass. Water is forced to flow through the cooling tubes to absorb heat from the core at a sufficient rate to remove enough of the decay heat created in the core to prevent overheating of the core or the vessel.

  8. Gas turbine combustor transition

    DOE Patents [OSTI]

    Coslow, Billy Joe (Winter Park, FL); Whidden, Graydon Lane (Great Blue, CT)

    1999-01-01

    A method of converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit.

  9. Gas turbine combustor transition

    DOE Patents [OSTI]

    Coslow, B.J.; Whidden, G.L.

    1999-05-25

    A method is described for converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit. 7 figs.

  10. Efficient numerical methods for the instationary solution of laminar reacting gas

    E-Print Network [OSTI]

    Vuik, Kees

    Efficient numerical methods for the instationary solution of laminar reacting gas flow problems Universiteit Delft Efficient numerical methods for the instationary solution of laminar reacting gas flow of laminar reacting gas flow problems Sander van Veldhuizen Production processes of high-purity, high

  11. SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW

    E-Print Network [OSTI]

    First industrial scale CO2 injection project: Sleipner gas field (North Sea). ... The Black-Oil formulation of two-phase flow in porous media ... Attenuation adn dispersion in the periodic gas-water case is in perfect agreement with that predicted by ...

  12. Automated gas chromatography

    DOE Patents [OSTI]

    Mowry, C.D.; Blair, D.S.; Rodacy, P.J.; Reber, S.D.

    1999-07-13

    An apparatus and process for the continuous, near real-time monitoring of low-level concentrations of organic compounds in a liquid, and, more particularly, a water stream. A small liquid volume of flow from a liquid process stream containing organic compounds is diverted by an automated process to a heated vaporization capillary where the liquid volume is vaporized to a gas that flows to an automated gas chromatograph separation column to chromatographically separate the organic compounds. Organic compounds are detected and the information transmitted to a control system for use in process control. Concentrations of organic compounds less than one part per million are detected in less than one minute. 7 figs.

  13. Rarefied gas dynamics and its applications to vacuum technology F. Sharipov

    E-Print Network [OSTI]

    Sharipov, Felix

    . A methodology for modelling the Holweck pump is described. An extensive list of publications on these topics of gas dynamics (Poiseuille flow, Couette flow, heat transfer between two plates, flow past a sphere, etc, but no numerical calculation of rarefied gas flows could be realized at that time. In 1954 the so-called model

  14. Experimental characterisation of bubbly flow using MRI

    E-Print Network [OSTI]

    Tayler, Alexander B.

    2011-11-08

    and industry. Known as gas-liquid flows, these systems occur in situations as diverse as the bow wave of a ship to the cooling system in a nuclear power plant. The structure of a gas-liquid flow depends upon the relative flow-rates of the two phases, and... . [3] Deckwer, W.D., 1985. Bubble column reactors. Wiley, Chichester. [4] Jacobsen, H.A., 2008. Chemical reactor modeling. Springer-Verlag, Berlin. [5] Saxena, S.C., Patel, D., Smith, D.N. and Ruether, J.A., 1988. An assessment of experimental...

  15. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, J.A.

    1997-07-01

    A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

  16. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA)

    1997-01-01

    A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

  17. COMPARISON OF VARIOUS FORMULATIONS OF THREEPHASE FLOW IN POROUS MEDIA

    E-Print Network [OSTI]

    , oil, and gas) flow in porous media, including phase, global, and pseudo­global pressure three­phase (e.g., water, oil, and gas) flow in porous media. We show that, under a so­called total­global pressure and two saturations without any assumption. However, it turns out that the phase and pseudo

  18. Flow cytometer

    DOE Patents [OSTI]

    Van den Engh, G.

    1995-11-07

    A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.

  19. Evaluation of wall boundary condition parameters for gas-solids...

    Office of Scientific and Technical Information (OSTI)

    predictions of various gas-solids fluidized beds. Several models for the granular flow wall boundary condition are available in the open literature for numerical modeling of...

  20. Notice of Weekly Natural Gas Storage Report Changes

    Weekly Natural Gas Storage Report (EIA)

    The Energy Information Administration (EIA) is changing the Weekly Natural Gas Storage Report (WNGSR) for the following: The table will now include a column for implied flow...

  1. Gas Sampling At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    respect to the caldera, to understand variations in gas compositions that occured during drilling and flow testing of the Valles scientific wells, and to compare Valles gases with...

  2. Inductively coupled plasma torch with laminar flow cooling

    DOE Patents [OSTI]

    Rayson, Gary D. (Las Cruces, NM); Shen, Yang (Las Cruces, NM)

    1991-04-30

    An improved inductively coupled gas plasma torch. The torch includes inner and outer quartz sleeves and tubular insert snugly fitted between the sleeves. The insert includes outwardly opening longitudinal channels. Gas flowing through the channels of the insert emerges in a laminar flow along the inside surface of the outer sleeve, in the zone of plasma heating. The laminar flow cools the outer sleeve and enables the torch to operate at lower electrical power and gas consumption levels additionally, the laminar flow reduces noise levels in spectroscopic measurements of the gaseous plasma.

  3. Development of a Compressed Hydrogen Gas

    E-Print Network [OSTI]

    ,321,775 (Gas Manifold, Nov 2001) NGV versions safety certified to FMVSS # 304 and undergoing long · Design » T700 carbon fiber overwrap with high interspersed winding pattern with design FOS of 2.45 » NGV

  4. Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow and Inclined Wellbore Conditions

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    and the enhancement is clearly demonstrated. The developed VMP is applied to wellbore hydraulic problems. It addresses three-phase (oil, water, and gas) flow in wellbores. This tool applies to a variety of wells, including vertical wells and those with various degrees of inclination. Introduction Concurrent flow of oil and gas

  5. Turbine blade tip flow discouragers

    DOE Patents [OSTI]

    Bunker, Ronald Scott (Niskayuna, NY)

    2000-01-01

    A turbine assembly comprises a plurality of rotating blade portions in a spaced relation with a stationery shroud. The rotating blade portions comprise a root section, a tip portion and an airfoil. The tip portion has a pressure side wall and a suction side wall. A number of flow discouragers are disposed on the blade tip portion. In one embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned generally parallel to the direction of rotation. In an alternative embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned at an angle in the range between about 0.degree. to about 60.degree. with respect to a reference axis aligned generally parallel to the direction of rotation. The flow discouragers increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the blade tip portion so as to improve overall turbine efficiency.

  6. Predicting multiphase flow behavior in a deviated well

    SciTech Connect (OSTI)

    Hasan, A.R.; Kabir, C.S.

    1986-01-01

    In deviated wells of an offshore producing environment, flow of two- or three - phase mixtures are invariably encountered. While large number of investigators have studied vertical multiphase flow behavior, there are few studies, often entirely empirical, that deal with deviated well systems. The main objective of this work is to present a model that predicts both flow regime and pressure gradient in a deviated wellbore. In modeling flow pattern transition and void fraction, an approach similar to that for vertical flow is taken; that is, four principal flow regimes are recognized - bubbly, slug, churn and annular.

  7. EXPERIMENTS OF RISER SLUG FLOW USING TOPSIDE MEASUREMENTS: PART I

    E-Print Network [OSTI]

    Skogestad, Sigurd

    flow in pipelines is of great concern in the offshore oil and gas industry, and a lot of time due to varying flow rates and pressure in the system. This usually happens in the end of the life cycle of a well, when flow rates are lower than the system was designed for. The rate and pressure

  8. Understanding mechanisms of flow instability leads to improved control of

    E-Print Network [OSTI]

    California at Los Angeles, University of

    ? CO2 absorption at the turbulent free-surface deformed by the shear wind, by means of direct numerical solution procedure for a coupled gas-liquid flow Wind flow Free surface contour - wind-driven calculation ? #12;Coherent Structures in Wind-driven Turbulent Free Surface Flow Water Wind 10-1 100 10-7 10-6 10 -5

  9. Co-flow planar SOFC fuel cell stack

    DOE Patents [OSTI]

    Chung, Brandon W.; Pham, Ai Quoc; Glass, Robert S.

    2004-11-30

    A co-flow planar solid oxide fuel cell stack with an integral, internal manifold and a casing/holder to separately seal the cell. This construction improves sealing and gas flow, and provides for easy manifolding of cell stacks. In addition, the stack construction has the potential for an improved durability and operation with an additional increase in cell efficiency. The co-flow arrangement can be effectively utilized in other electrochemical systems requiring gas-proof separation of gases.

  10. Investigation of two-phase flow phenomena associated with corrosion in an SF/HLW repository in Opalinus Clay, Switzerland

    SciTech Connect (OSTI)

    Senger, R.; Marschall, P.; Finsterle, S.

    2008-08-04

    Gas generation from corrosion of the waste canisters and gas accumulation in the backfilled emplacement tunnels is a key issue in the assessment of long-term radiological safety of the proposed repository for spent fuel and high-level waste (SF/HLW) sited in the Opalinus Clay formation of Northern Switzerland. Previous modeling studies indicated a significant pressure buildup in the backfilled emplacement tunnels for those sensitivity runs, where corrosion rates were high and the permeability of the Opalinus Clay was very low. As an extension to those studies, a refined process model of the canister corrosion phenomena has been developed, which accounts not only for the gas generation but also for the water consumption associated with the chemical reaction of corrosion of steel under anaerobic conditions. The simulations with the new process model indicate, that with increasing corrosion rates and decreasing host-rock permeability, pressure buildup increased, as expected. However, the simulations taking into account water consumption show that the pressure buildup is reduced compared to the simulation considering only gas generation. The pressure reduction is enhanced for lower permeability of the Opalinus Clay and for higher corrosion rates, which correspond to higher gas generations rates and higher water consumption rates. Moreover, the simulated two-phase flow patterns in the engineered barrier system (EBS) and surrounding Opalinus Clay show important differences at late time of the gas production phase as the generated gas continues to migrate outward into the surrounding host rock. For the case without water consumption, the water flow indicates overall downward flow due to a change in the overall density of the gas-fluid mixture from that based on the initially prescribed hydrostatic pressure gradient. For the case with water consumption, water flow converges toward the waste canister at a rate corresponding to the water consumption rate associated with the corrosion reaction. The water flow toward the canister is maintained even for very low permeabilities of the Opalinus clay, sustaining the anaerobic corrosion of the steel canister.

  11. TANK MIXING STUDY WITH FLOW RECIRCULATION

    SciTech Connect (OSTI)

    Lee, S.

    2014-06-25

    The primary objective of this work is to quantify the mixing time when two miscible fluids are mixed by one recirculation pump and to evaluate adequacy of 2.5 hours of pump recirculation to be considered well mixed in SRS tanks, JT-71/72. The work scope described here consists of two modeling analyses. They are the steady state flow pattern analysis during pump recirculation operation of the tank liquid and transient species transport calculations based on the initial steady state flow patterns. The modeling calculations for the mixing time are performed by using the 99% homogeneity criterion for the entire domain of the tank contents.

  12. Gas Mask 

    E-Print Network [OSTI]

    Unknown

    2011-09-05

    The gas industry fostered more efficient energy utilization long before the idea of energy conservation became fashionable. It became apparent in the late '60's that misguided Federal Legislation was discouraging necessary search for new gas...

  13. Combustion synthesis continuous flow reactor

    DOE Patents [OSTI]

    Maupin, G.D.; Chick, L.A.; Kurosky, R.P.

    1998-01-06

    The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor. 10 figs.

  14. Understanding order flow

    E-Print Network [OSTI]

    Evans, MDD; Lyons, Richard K.

    2006-01-01

    Understanding Order Flow October 2005 Martin D. D. Evans 1Rate Fundamentals and Order Flow, typescript, Georgetown2005), Customer Order Flow and Exchange Rate Movements: Is

  15. Gas cooled traction drive inverter

    DOE Patents [OSTI]

    Chinthavali, Madhu Sudhan

    2013-10-08

    The present invention provides a modular circuit card configuration for distributing heat among a plurality of circuit cards. Each circuit card includes a housing adapted to dissipate heat in response to gas flow over the housing. In one aspect, a gas-cooled inverter includes a plurality of inverter circuit cards, and a plurality of circuit card housings, each of which encloses one of the plurality of inverter cards.

  16. Method of lift-off patterning thin films in situ employing phase change resists

    DOE Patents [OSTI]

    Bahlke, Matthias Erhard; Baldo, Marc A; Mendoza, Hiroshi Antonio

    2014-09-23

    Method for making a patterned thin film of an organic semiconductor. The method includes condensing a resist gas into a solid film onto a substrate cooled to a temperature below the condensation point of the resist gas. The condensed solid film is heated selectively with a patterned stamp to cause local direct sublimation from solid to vapor of selected portions of the solid film thereby creating a patterned resist film. An organic semiconductor film is coated on the patterned resist film and the patterned resist film is heated to cause it to sublime away and to lift off because of the phase change.

  17. Pattern Alteration: Large Abdomen 

    E-Print Network [OSTI]

    2006-08-04

    A large abdomen causes the hemline on a skirt to hike in front and pulls the side seam forward. This publication gives instructions on altering patterns for a basic skirt and pants....

  18. Visualizing flow patterns in coupled geomechanical simulation using streamlines 

    E-Print Network [OSTI]

    Parihar, Prannay

    2009-05-15

    and reservoir issues. The log-based geomechanics models used to evaluate sand production and pressure dependent pore volume compressibility have aided in reducing project risks and increasing project life. In-situ stress depletion is one of the main reasons... field. The results are also applicable for other geomechanical activities in the field like well design, water injection, hydraulic fracturing and design of waterflood. Generic studies, involving coupled geomechanical, thermal and fluid modeling have...

  19. Sandia Energy - Magnetically Stimulated Flow Patterns Offer Strategy for

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-Throughput Analysis ofSampleLignin-Feasting Microbe Holds PromiseHeat-Transfer

  20. Pipeline Politics: Natural Gas in Eurasia 

    E-Print Network [OSTI]

    Landrum, William W.; Llewellyn, Benjamin B.; Limesand, Craig M.; Miller, Dante J.; Morris, James P.; Nowell, Kathleen S.; Sherman, Charlotte L.

    2010-01-01

    Eurasia is a major source of oil and natural gas, and events in the region have a great potential to destabilize global security patterns. Supplies of natural gas and oil from Eurasia are vital for the functioning of European economies, and also...

  1. Radiative Flow in a Luminous Disk

    E-Print Network [OSTI]

    Jun Fukue

    2006-01-07

    Radiatively-driven flow in a luminous disk is examined in the subrelativistic regime of $(v/c)^1$, taking account of radiation transfer. The flow is assumed to be vertical, and the gravity and gas pressure are ignored. When internal heating is dropped, for a given optical depth and radiation pressure at the flow base (disk ``inside''), where the flow speed is zero, the flow is analytically solved under the appropriate boundary condition at the flow top (disk ``surface''), where the optical depth is zero. The loaded mass and terminal speed of the flow are both determined by the initial conditions; the mass-loss rate increases as the initial radiation pressure increases, while the flow terminal speed increases as the initial radiation pressure and the loaded mass decrease. In particular, when heating is ignored, the radiative flux $F$ is constant, and the radiation pressure $P_0$ at the flow base with optical depth $\\tau_0$ is bound in the range of $2/3 flow terminal speed becomes zero, while, in the limit of $cP_0/F = 2/3$, the loaded mass becomes zero and the terminal speed approaches $(3/8)c$, which is the terminal speed above the luminous flat disk under an approximation of the order of $(v/c)^1$. We also examine the case where heating exists, and find that the flow properties are qualitatively similar to the case without heating.

  2. Method and apparatus for controlling the flow rate of mercury in a flow system

    SciTech Connect (OSTI)

    Grossman, M.W.; Speer, R.

    1991-01-01

    This patent describes a process for increasing the mercury flow rate {ital Q{sub Hg}} to a photochemical mercury enrichment process. It comprises: utilizing an entrainment system having a temperature regulated pool of mercury, a bubbler or sparger system, and a carrier gas for entraining mercury vapor; passing the carrier gas over a pool of mercury maintained at a first temperature, T{sub 1} wherein the carrier gas entrains mercury vapor; and passing the mercury vapor entrained carrier gas to a second temperature zone, maintained at a temperature T{sub 2}, such that T{sub 2} is less than T{sub 1}, in which the entrained mercury vapor is condensed, thereby producing a saturated Hg conditioning the carrier gas; and passing the saturated Hg carrier gas to the photochemical enrichment reactor, yielding a high flow rate {ital Q{sub Hg}}.

  3. Method and apparatus for controlling the flow rate of mercury in a flow system

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)

    1991-01-01

    A method for increasing the mercury flow rate to a photochemical mercury enrichment utilizing an entrainment system comprises the steps of passing a carrier gas over a pool of mercury maintained at a first temperature T1, wherein the carrier gas entrains mercury vapor; passing said mercury vapor entrained carrier gas to a second temperature zone T2 having temperature less than T1 to condense said entrained mercury vapor, thereby producing a saturated Hg condition in the carrier gas; and passing said saturated Hg carrier gas to said photochemical enrichment reactor.

  4. Regeneration of an aqueous solution from an acid gas absorption process by matrix stripping

    DOE Patents [OSTI]

    Rochelle, Gary T. (Austin, TX); Oyenekan, Babatunde A. (Katy, TX)

    2011-03-08

    Carbon dioxide and other acid gases are removed from gaseous streams using aqueous absorption and stripping processes. By replacing the conventional stripper used to regenerate the aqueous solvent and capture the acid gas with a matrix stripping configuration, less energy is consumed. The matrix stripping configuration uses two or more reboiled strippers at different pressures. The rich feed from the absorption equipment is split among the strippers, and partially regenerated solvent from the highest pressure stripper flows to the middle of sequentially lower pressure strippers in a "matrix" pattern. By selecting certain parameters of the matrix stripping configuration such that the total energy required by the strippers to achieve a desired percentage of acid gas removal from the gaseous stream is minimized, further energy savings can be realized.

  5. Dynamics of precipitation pattern formation at geothermal hot springs

    E-Print Network [OSTI]

    Nigel Goldenfeld; Pak Yuen Chan; John Veysey

    2006-05-26

    We formulate and model the dynamics of spatial patterns arising during the precipitation of calcium carbonate from a supersaturated shallow water flow. The model describes the formation of travertine deposits at geothermal hot springs and rimstone dams of calcite in caves. We find explicit solutions for travertine domes at low flow rates, identify the linear instabilities which generate dam and pond formation on sloped substrates, and present simulations of statistical landscape evolution.

  6. Energy flow structuring in the focused field

    E-Print Network [OSTI]

    Chen, Hao

    2015-01-01

    We propose an iterative method of energy flow shaping in the focal region with the amplitude, phase and polarization modulation of incident light. By using an iterative optimization based on the diffraction calculation with help of the fast Fourier transform, we can tailor the polarization and phase structure in the focal plane. By appropriate design of the polarization and phase gradients, arbitrary energy flow including spin and orbital parts can be designed and tailored independently. The capability of energy flow structuring is demonstrated by the measurement of the Stokes parameters and self-interference pattern. This provides a novel method to control the vectorial feature of the focal volume.

  7. A moving horizon solution to the gas pipeline optimization problem

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    discharge pressures and supplier flow rates for Parameters Forecast of future demand loads for i i i ti describing flow of gas through a pipe. Optimization scope ­ Compression energy for the supplier to be minimized, while satisfying gas demands, contract pressures and physical constraints. Moving Horizon

  8. Accretion, radial flows and abundance gradients in spiral galaxies

    E-Print Network [OSTI]

    Pezzulli, Gabriele

    2015-01-01

    The metal-poor gas continuously accreting onto the discs of spiral galaxies is unlikely to arrive from the intergalactic medium (IGM) with exactly the same rotation velocity as the galaxy itself and even a small angular momentum mismatch inevitably drives radial gas flows within the disc, with significant consequences to galaxy evolution. Here we provide some general analytic tools to compute accretion profiles, radial gas flows and abundance gradients in spiral galaxies as a function of the angular momentum of accreting material. We generalize existing solutions for the decomposition of the gas flows, required to reproduce the structural properties of galaxy discs, into direct accretion from the IGM and a radial mass flux within the disc. We then solve the equation of metallicity evolution in the presence of radial gas flows with a novel method, based on characteristic lines, which greatly reduces the numerical demand on the computation and sheds light on the crucial role of boundary conditions on the abunda...

  9. Impact of Impulse Stops on Pedestrian Flow

    E-Print Network [OSTI]

    Kwak, Jaeyoung; Luttinen, Tapio; Kosonen, Iisakki

    2015-01-01

    We numerically study the impact of impulse stops on pedestrian flow for a straight corridor with multiple attractions. The impulse stop is simulated by the switching behavior model, a function of the social influence strength and the number of attendees near the attraction. When the pedestrian influx is low, one can observe a stable flow where attendees make a complete stop at an attraction and then leave the attraction after a certain amount of time. When the pedestrian influx is high, an unstable flow is observed for strong social influence. In the unstable flow, attendees near the attraction are crowded out from the clusters by others due to the interpersonal repulsion. The expelled pedestrians impede the pedestrian traffic between the left and right boundaries of the corridor. These collective patterns of pedestrian flow are summarized in a schematic phase diagram.

  10. Energy Flow Models for the Steel Industry 

    E-Print Network [OSTI]

    Hyman, B.; Andersen, J. P.

    1998-01-01

    Energy patterns in the U. S. steel industry are examined using several models. First is an end-use model based on data in the 1994 Manufacturing Energy Consumption Survey (MECS). Then a seven-step process model is presented and material flow through...

  11. Gas custody measurement accuracy improved in Saudi Arabia

    SciTech Connect (OSTI)

    Ali, I. (Saudi Arabian Oil Co., Dhahran (Saudi Arabia))

    1994-06-06

    To comply with new and more accurate gas measurement standards, Saudi Arabian Oil Co. (Saudi Aramco) modified software for existing flow computers and installed an on-line gas chromatograph for measuring natural gas and ethane-rich gas sales. For gases of varying composition (e.g., ethane-rich gas), a knowledge of the pressure, volume, and temperature (PVT) relationship is required for determining supercompressibility factors. The BWR-Starling equation of state was determined to best represent ethane-rich gas properties and is programmed in the new flow computers. The paper discusses gas sales, previous installations, previous calculations, revised calculations, application to ethane-rich gas, the orifice-flow constant, and field modifications of computers.

  12. Gas turbine engine with radial diffuser and shortened mid section

    DOE Patents [OSTI]

    Charron, Richard C.; Montgomery, Matthew D.

    2015-09-08

    An industrial gas turbine engine (10), including: a can annular combustion assembly (80), having a plurality of discrete flow ducts configured to receive combustion gas from respective combustors (82) and deliver the combustion gas along a straight flow path at a speed and orientation appropriate for delivery directly onto the first row (56) of turbine blades (62); and a compressor diffuser (32) having a redirecting surface (130, 140) configured to receive an axial flow of compressed air and redirect the axial flow of compressed air radially outward.

  13. Radiative Flow in a Luminous Disk II

    E-Print Network [OSTI]

    Jun Fukue

    2006-01-07

    Radiatively-driven transfer flow perpendicular to a luminous disk is examined in the subrelativistic regime of $(v/c)^1$, taking into account the gravity of the central object. The flow is assumed to be vertical, and the gas pressure is ignored, while internal heating is assumed to be proportional to the gas density. The basic equations were numerically solved as a function of the optical depth, and the flow velocity, the height, the radiative flux, and the radiation pressure were obtained for a given radius, an initial optical depth, and initial conditions at the flow base (disk ``inside''), whereas the mass-loss rate was determined as an eigenvalue of the boundary condition at the flow top (disk ``surface''). For sufficiently luminous cases, the flow resembles the case without gravity. For less-luminous cases, however, the flow velocity decreases, and the flow would be impossible due to the existence of gravity in the case that the radiative flux is sufficiently small. Application to a supercritical accretion disk with mass loss is briefly discussed.

  14. Theoretical and experimental studies of churn flow in vertical tubes. Final technical report

    SciTech Connect (OSTI)

    Not Available

    1986-01-27

    The pattern known as churn flow is a highly unsteady pattern with stochastic features and is extremely complex. However, calculations show that for many geothermal wells the condition of churn flow consists over much of the length of the two phase zone. Furthermore, it frequently exists at the surface so that design of separation equipment and surface piping depends on the accurate modelling of this type of flow. It has been the long term purpose of this project to develop physically based models for churn flow which can be used as a basis for predicting holdup, frictional loss and heat transfer rates for this flow pattern in geothermal systems. To achieve this end, it was necessary to develop new methods for measuring the time dependent characteristics of the flow and thus be able to uncover the basic physics of the flow. Models can then be developed based on this understanding which characterizes the flow and equations for holdup, friction and heat transfer evolved.

  15. Liquid-Liquid Two-Phase Flow Systems Neima Brauner

    E-Print Network [OSTI]

    Brauner, Neima

    prediction of oil-water flow charac- teristics, such as flow pattern, water holdup and pressure gradient in the petroleum industry, where mixtures of oil and water are transported in pipes over long distances. Accurate particular extreme of two-fluid systems characterized by low-density ratio and low viscosity ratio. In liquid

  16. Fixture for forming evaporative pattern (EPC) process patterns

    DOE Patents [OSTI]

    Turner, Paul C. (Albany, OR); Jordan, Ronald R. (Albany, OR); Hansen, Jeffrey S. (Corvallis, OR)

    1993-01-01

    A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.

  17. Natural gas 1995: Issues and trends

    SciTech Connect (OSTI)

    1995-11-01

    Natural Gas 1995: Issues and Trends addresses current issues affecting the natural gas industry and markets. Highlights of recent trends include: Natural gas wellhead prices generally declined throughout 1994 and for 1995 averages 22% below the year-earlier level; Seasonal patterns of natural gas production and wellhead prices have been significantly reduced during the past three year; Natural gas production rose 15% from 1985 through 1994, reaching 18.8 trillion cubic feet; Increasing amounts of natural gas have been imported; Since 1985, lower costs of producing and transporting natural gas have benefitted consumers; Consumers may see additional benefits as States examine regulatory changes aimed at increasing efficiency; and, The electric industry is being restructured in a fashion similar to the recent restructuring of the natural gas industry.

  18. Two-phase flow and pressure drop in flow passages of compact heat exchangers

    SciTech Connect (OSTI)

    Wambsganss, M.W.; Jendrzejczyk, J.A.; France, D.M.

    1992-01-01

    Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 {times} 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m{sup 2}s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.

  19. Two-phase flow and pressure drop in flow passages of compact heat exchangers

    SciTech Connect (OSTI)

    Wambsganss, M.W.; Jendrzejczyk, J.A.; France, D.M.

    1992-02-01

    Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 {times} 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m{sup 2}s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.

  20. Passive gas separator and accumulator device

    DOE Patents [OSTI]

    Choe, H.; Fallas, T.T.

    1994-08-02

    A separation device employing a gas separation filter and swirler vanes for separating gas from a gas-liquid mixture is provided. The cylindrical filter utilizes the principle that surface tension in the pores of the filter prevents gas bubbles from passing through. As a result, the gas collects in the interior region of the filter and coalesces to form larger bubbles in the center of the device. The device is particularly suited for use in microgravity conditions since the swirlers induce a centrifugal force which causes liquid to move from the inner region of the filter, pass the pores, and flow through the outlet of the device while the entrained gas is trapped by the filter. The device includes a cylindrical gas storage screen which is enclosed by the cylindrical gas separation filter. The screen has pores that are larger than those of the filters. The screen prevents larger bubbles that have been formed from reaching and interfering with the pores of the gas separation filter. The device is initially filled with a gas other than that which is to be separated. This technique results in separation of the gas even before gas bubbles are present in the mixture. Initially filling the device with the dissimilar gas and preventing the gas from escaping before operation can be accomplished by sealing the dissimilar gas in the inner region of the separation device with a ruptured disc which can be ruptured when the device is activated for use. 3 figs.

  1. Serial cooling of a combustor for a gas turbine engine

    DOE Patents [OSTI]

    Abreu, Mario E. (Poway, CA); Kielczyk, Janusz J. (Escondido, CA)

    2001-01-01

    A combustor for a gas turbine engine uses compressed air to cool a combustor liner and uses at least a portion of the same compressed air for combustion air. A flow diverting mechanism regulates compressed air flow entering a combustion air plenum feeding combustion air to a plurality of fuel nozzles. The flow diverting mechanism adjusts combustion air according to engine loading.

  2. High Temperature Gas Reactors Andrew C. Kadak, Ph.D.

    E-Print Network [OSTI]

    Heat Exchanger Design · Core Power Distribution Monitoring · Pebble Flow Experiments · Non Reactors #12;GT-MHR Module General Arrangement #12;GT-MHR Combines Meltdown-Proof Advanced Reactor and Gas MWt and 600 MWt Cores #12;GT-MHR Flow Schematic #12;Flow through Power Conversion Vessel #12;Modular

  3. Chemoresistive gas sensor

    DOE Patents [OSTI]

    Hirschfeld, T.B.

    1987-06-23

    A chemoresistive gas sensor is provided which has improved sensitivity. A layer of organic semiconductor is disposed between two electrodes which, in turn, are connected to a voltage source. High conductivity material is dispersed within the layer of organic semiconductor in the form of very small particles, or islands. The average interisland spacing is selected so that the predominant mode of current flow is by way of electron funneling. Adsorption of gaseous contaminant onto the layer of organic semiconductor modulates the tunneling current in a quantitative manner. 2 figs.

  4. Produce diesel from gas

    SciTech Connect (OSTI)

    Singleton, A.H.; Regier, S.

    1983-05-01

    The Gulf Badger process converts natural gas directly to hydrocarbon liquids by a catalytic chemical route. Fischer-Tropsch process--which is a carbon monoxide polymerization/ hydrogenation process--is used. Because the process is exothermal, heat removal by either tubular fixed bed, fluidized bed, or slurry are considered. A wax build up of high molecular weight material is removed by hydro-stripping two-bed system. The demonstration plant flow diagram shows the process to be: natural gas is compressed, recycled with CO/sub 2/, sulfur is removed in a zinc oxide drum, CO is removed in amine scrubbers, H/sub 2//CO ratio is adjusted to produce a hydrogen rich stream, and stabilization and distribution follow. A monitoring system using computers is part of the demonstration unit.

  5. Flammable Gas Detection for the D-Zero Gas System

    SciTech Connect (OSTI)

    Spires, L.D.; Foglesong, J.; /Fermilab

    1991-02-11

    The use of flammable gas and high voltage in detector systems is common in many experiments at Fermilab. To mitigate the hazards associated with these systems, Fermilab Engineering Standard SD-45B (Ref. 1) was adopted. Since this note is meant to be a guide and not a mandatory standard, each experiment is reviewed for compliance with SD-45B by the flammable gas safety subcommittee. Currently, there are only two types of flammable gas in use, ethane (Appendix A) and methane (Appendix B). The worst flammable-gas case is C2H6 (ethane), which has an estimated flow rate that is 73% of the CH4 (methane) flow but a heat of combustion (in kcal/g-mole) that is 173% of that of methane. In the worst case, if ethane were to spew through its restricting orifice into its gas line at 0 psig and then through a catastrophic leak into Room 215 (TRD) or Room 511 (CDC/FDCNTX), the time that would be required to build up a greater than Class 1 inventory (0.4kg H2 equivalent) would be 5.2 hours (Ref. 2). Therefore a worst-case flammable gas leak would have to go undetected for over 5 hours in order to transform a either mixing room to an environment with a Risk Class greater than Class 1. The mixing systems, gas lines, and detectors themselves will be thoroughly leak checked prior to active service. All vessels that are part of the mixing systems will be protected from overpressure by safety valves vented outside the building. Both the input and output of all detector volumes are protected from overpressure in the same way. The volume immediately outside the central tracking detectors is continuously purged by nitrogen from boiloff from the main nitrogen dewar at the site. However, if flammable gas were to build up in the mixing rooms or particular detector areas, no matter how unlikely, flammable gas detectors that are part of the interlock chain of each gas mixing system will shut down the appropriate system. This includes shutting off the output of flammable gas manifolds within the gas shed. Similarly, if a fire were to break out anywhere in the D-ZERO Hall, fire sensors would stop the output of all flammable gas manifolds within the gas shed, by unpowering electrically controlled solenoid valves that are normally closed in the event of a power failure. Fire sensor contacts have not yet been installed.

  6. Anisotropic electro-osmotic flow over superhydrophobic surfaces

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Patterned surfaces with large effective slip lengths, such as super-hydrophobic surfaces containing trapped gas bubbles, have the potential to greatly enhance electrokinetic phenomena. Existing theories assume either ...

  7. Computational fluid dynamics simulation of the air/suppressant flow in an uncluttered F18 engine nacelle

    SciTech Connect (OSTI)

    Lopez, A.R.; Gritzo, L.A.; Hassan, B.

    1997-06-01

    For the purposes of designing improved Halon-alternative fire suppression strategies for aircraft applications, Computational Fluid Dynamics (CFD) simulations of the air flow, suppressant transport, and air-suppressant mixing within an uncluttered F18 engine nacelle were performed. The release of inert gases from a Solid Propellant Gas Generator (SPGG) was analyzed at two different injection locations in order to understand the effect of injection position on the flow patterns and the mixing of air and suppression agent. An uncluttered engine nacelle was simulated to provide insight into the global flow features as well as to promote comparisons with previous nacelle fire tests and recent water tunnel tests which included little or no clutter. Oxygen concentration levels, fuel/air residence times that would exist if a small fuel leak were present, velocity contours, and streamline patterns are presented inside the engine nacelle. The numerical results show the influence of the gent release location on regions of potential flame extinction due to oxygen inerting and high flame strain. The occurrence of inflow through the exhaust ducts on the aft end of the nacelle is also predicted. As expected, the predicted oxygen concentration levels were consistently higher than the measured levels since a fire was not modeled in this analysis. Despite differences in the conditions of these simulations and the experiments, good agreement was obtained between the CFD predictions and the experimental measurements.

  8. The effects of laminar mixing on reaction fronts and patterns I. Introduction

    E-Print Network [OSTI]

    Solomon, Tom

    The effects of laminar mixing on reaction fronts and patterns I. Introduction A wide variety scales that are often smaller than a micron. For small Re, the flow is laminar; in this situation

  9. Statistical estimation of multiple faults in aircraft gas turbine engines

    E-Print Network [OSTI]

    Ray, Asok

    415 Statistical estimation of multiple faults in aircraft gas turbine engines S Sarkar, C Rao of multiple faults in aircraft gas-turbine engines, based on a statistical pattern recognition tool called commercial aircraft engine. Keywords: aircraft propulsion, gas turbine engines, multiple fault estimation

  10. Pattern Alteration: Lengthening & Shortening 

    E-Print Network [OSTI]

    2006-08-04

    Lengthening or shortening a pattern is often the only adjustment needed to correct fitting problems. This well-illustrated publication guides you through the steps to fix major fitting points associated with a garment that is too short or too long...

  11. Gas-Surface Energy Exchange in Collisions of Helium Atoms with Aligned Single-Walled Carbon

    E-Print Network [OSTI]

    Maruyama, Shigeo

    1 Gas-Surface Energy Exchange in Collisions of Helium Atoms with Aligned Single-Walled Carbon #12;2 ABSTRACT Since gas flows in micro/nano devices are dominated by the interaction of gas molecules accommodation of gas molecules on surfaces. The scattering of gas molecules on quartz surfaces covered with VA

  12. Use of finite volume radiation for predicting the Knudsen minimum in 2D channel flow

    SciTech Connect (OSTI)

    Malhotra, Chetan P.; Mahajan, Roop L.

    2014-12-09

    In an earlier paper we employed an analogy between surface-to-surface radiation and free-molecular flow to model Knudsen flow through tubes and onto planes. In the current paper we extend the analogy between thermal radiation and molecular flow to model the flow of a gas in a 2D channel across all regimes of rarefaction. To accomplish this, we break down the problem of gaseous flow into three sub-problems (self-diffusion, mass-motion and generation of pressure gradient) and use the finite volume method for modeling radiation through participating media to model the transport in each sub-problem as a radiation problem. We first model molecular self-diffusion in the stationary gas by modeling the transport of the molecular number density through the gas starting from the analytical asymptote for free-molecular flow to the kinetic theory limit of gaseous self-diffusion. We then model the transport of momentum through the gas at unit pressure gradient to predict Poiseuille flow and slip flow in the 2D gas. Lastly, we predict the generation of pressure gradient within the gas due to molecular collisions by modeling the transport of the forces generated due to collisions per unit volume of gas. We then proceed to combine the three radiation problems to predict flow of the gas over the entire Knudsen number regime from free-molecular to transition to continuum flow and successfully capture the Knudsen minimum at Kn ? 1.

  13. Passive gas separator and accumulator device

    DOE Patents [OSTI]

    Choe, Hwang (Saratoga, CA); Fallas, Thomas T. (Berkeley, CA)

    1994-01-01

    A separation device employing a gas separation filter and swirler vanes for separating gas from a gasliquid mixture is provided. The cylindrical filter utilizes the principle that surface tension in the pores of the filter prevents gas bubbles from passing through. As a result, the gas collects in the interior region of the filter and coalesces to form larger bubbles in the center of the device. The device is particularly suited for use in microgravity conditions since the swirlers induce a centrifugal force which causes liquid to move from the inner region of the filter, pass the pores, and flow through the outlet of the device while the entrained gas is trapped by the filter. The device includes a cylindrical gas storage screen which is enclosed by the cylindrical gas separation filter. The screen has pores that are larger than those of the filters. The screen prevents larger bubbles that have been formed from reaching and interfering with the pores of the gas separation filter. The device is initially filled with a gas other than that which is to be separated. This technique results in separation of the gas even before gas bubbles are present in the mixture. Initially filling the device with the dissimilar gas and preventing the gas from escaping before operation can be accomplished by sealing the dissimilar gas in the inner region of the separation device with a ruptured disc which can be ruptured when the device is activated for use.

  14. Propeller Flow Meter 

    E-Print Network [OSTI]

    Enciso, Juan; Santistevan, Dean; Hla, Aung K.

    2007-10-01

    Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....

  15. Bacteria in shear flow

    E-Print Network [OSTI]

    Marcos, Ph.D. Massachusetts Institute of Technology

    2011-01-01

    Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

  16. Dispersed flow film boiling

    E-Print Network [OSTI]

    Yoder, Graydon L.

    1980-01-01

    Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

  17. Boosting devices with integral features for recirculating exhaust gas

    DOE Patents [OSTI]

    Wu, Ko-Jen

    2015-12-22

    According to one embodiment of the invention, a turbine housing includes a turbine inlet in fluid communication with a turbine volute configured to house a turbine wheel, the turbine inlet configured to direct an exhaust gas flow from an engine to the turbine wheel. The turbine housing also includes a turbine outlet in fluid communication with the turbine volute, the turbine outlet configured to direct the exhaust gas flow to an exhaust gas conduit and a first exhaust gas recirculation supply port located on and in fluid communication with the turbine outlet, the first exhaust gas recirculation supply port being configured to direct a portion of the exhaust gas flow to an exhaust gas recirculation supply conduit.

  18. Natural gas pipeline technology overview.

    SciTech Connect (OSTI)

    Folga, S. M.; Decision and Information Sciences

    2007-11-01

    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by transmission companies. Compressor stations at required distances boost the pressure that is lost through friction as the gas moves through the steel pipes (EPA 2000). The natural gas system is generally described in terms of production, processing and purification, transmission and storage, and distribution (NaturalGas.org 2004b). Figure 1.1-2 shows a schematic of the system through transmission. This report focuses on the transmission pipeline, compressor stations, and city gates.

  19. Process for separating carbon dioxide from flue gas using sweep-based membrane separation and absorption steps

    DOE Patents [OSTI]

    Wijmans, Johannes G.; Baker, Richard W.; Merkel, Timothy C.

    2012-08-21

    A gas separation process for treating flue gases from combustion processes, and combustion processes including such gas separation. The invention involves routing a first portion of the flue gas stream to be treated to an absorption-based carbon dioxide capture step, while simultaneously flowing a second portion of the flue gas across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas to the combustor.

  20. FLOW-THROUGH POROUS ELECTRODES

    E-Print Network [OSTI]

    Trainham, III, James Arthur

    2011-01-01

    configurations for flow redox battery applications: (i) theporous electrodes A flow-redox battery using flow-by poroustrue in battery applications, Flow..through porous

  1. INCREASED FLEXIBILITY OF TURBO-COMPRESSORS IN NATURAL GAS TRANSMISSION THROUGH DIRECT SURGE CONTROL

    SciTech Connect (OSTI)

    Robert J. McKee; Danny M. Deffenbaugh

    2004-12-01

    This annual progress report describes the third year's technical progress in a three-year program. This report introduces the benefits of improved surge detection and summarizes what is known about internal flows as surge precursors in centrifugal compressors. Early research results and findings concerning surge in centrifugal compressors and possible precursors to surge are presented. Laboratory test results in modern compressors with 3D impellers are described in detail and used to show the changes in internal flow patterns that occur as a compressor approaches surge. It was found that older compressors with recessed impeller blading (2D geometry) do not have the same accessible flow patterns. The laboratory test results indicate a large increase in potential operating range for modern compressors. This annual report also presents results from the field testing conducted during the course of this third year. The field test results showed similar changes in the surge probe strain signals and the same type, although of less magnitude, of indication that the compressor is approaching surge. An algorithm for identifying the nearness of surge has been proposed and evaluated with the available data. This project is co-funded by the Gas Machinery Research Council (GMRC) and by Siemens Energy and Automation (Siemens). The results of the project include a step-by-step process for design, sizing, and installation of surge detection probes and for implementation of the direct surge control in centrifugal compressor controllers. This work is considered a step towards the successful implementation of direct surge control for improved flexibility and efficiency in natural gas transmission compressors.

  2. Model Order Reduction in Porous Media Flow Simulation and Optimization 

    E-Print Network [OSTI]

    Ghasemi, Mohammadreza

    2015-05-06

    Subsurface flow modeling and simulation is ubiquitous in many energy related processes, including oil and gas production. These models are usually large scale and simulating them can be very computationally demanding, particularly in work...

  3. Temperature Effect in Multiphase Flow Meter Using Slotted Orifice Plate 

    E-Print Network [OSTI]

    Sihombing, Dohar Jono

    2015-04-30

    Multiphase flow metering is one of the major focuses to develop in oil and gas industries. A combination of slotted orifice plate and electrical impedance technique was investigated in order to provide further development ...

  4. Fission gas release restrictor for breached fuel rod

    DOE Patents [OSTI]

    Kadambi, N. Prasad (Gaithersburg, MD); Tilbrook, Roger W. (Monroeville, PA); Spencer, Daniel R. (Unity Twp., PA); Schwallie, Ambrose L. (Greensburg, PA)

    1986-01-01

    In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes. In the event of a breach in the cladding, the gas pervious means in the gas bottle means constitutes a sufficient restriction to the rapid flow of gas therethrough that under maximum design pressure differential conditions, the fission gas flow through the breach will not significantly reduce the heat transfer from the affected rod and adjacent rods to the liquid metal heat transfer fluid flowing therebetween.

  5. Design of Pattern Matching Systems: Pattern, Algorithm, and Scanner 

    E-Print Network [OSTI]

    Wang, Hao

    2013-10-23

    Pattern matching is at the core of many computational problems, e.g., search engine, data mining, network security and information retrieval. In this dissertation, we target at the more complex patterns of regular expression ...

  6. Space-Time Discontinuous Galerkin Finite Element Method for Two-Fluid Flows.

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed columns, fluidized beds, granular flows and ink spraying. The flow patterns in these problems are complex evolution, Rayleigh-Taylor and Kelvin-Helmholtz instabil- ities and industrial processes such as bubble

  7. Electro-osmotic flow and mixing in heterogeneous microchannels Jin-bai Zhang,1,4

    E-Print Network [OSTI]

    Liu, Feng

    Electro-osmotic flow and mixing in heterogeneous microchannels Jin-bai Zhang,1,4 Guo-wei He,1 September 2005; published 12 May 2006 Analytical and numerical studies of secondary electro-osmotic flow EOF which could exhibit the complex flow patterns that offer op- portunities for rapid mixing. Electro-osmotic

  8. Interplay between Turing Mechanisms can Increase Pattern Diversity Shai Kinast,1

    E-Print Network [OSTI]

    Meron, Ehud

    to study a general problem of complex pattern-forming systems: multiple pattern-forming instabilities of water transport can be distinguished: overland water flow induced by higher infiltration rates in denser vegetation patches ("infiltration feedback"), water conduction by laterally extended root zones that further

  9. General single phase wellbore flow model

    SciTech Connect (OSTI)

    Ouyang, Liang-Biao; Arbabi, S.; Aziz, K.

    1997-02-05

    A general wellbore flow model, which incorporates not only frictional, accelerational and gravitational pressure drops, but also the pressure drop caused by inflow, is presented in this report. The new wellbore model is readily applicable to any wellbore perforation patterns and well completions, and can be easily incorporated in reservoir simulators or analytical reservoir inflow models. Three dimensionless numbers, the accelerational to frictional pressure gradient ratio R{sub af}, the gravitational to frictional pressure gradient ratio R{sub gf}, and the inflow-directional to accelerational pressure gradient ratio R{sub da}, have been introduced to quantitatively describe the relative importance of different pressure gradient components. For fluid flow in a production well, it is expected that there may exist up to three different regions of the wellbore: the laminar flow region, the partially-developed turbulent flow region, and the fully-developed turbulent flow region. The laminar flow region is located near the well toe, the partially-turbulent flow region lies in the middle of the wellbore, while the fully-developed turbulent flow region is at the downstream end or the heel of the wellbore. Length of each region depends on fluid properties, wellbore geometry and flow rate. As the distance from the well toe increases, flow rate in the wellbore increases and the ratios R{sub af} and R{sub da} decrease. Consequently accelerational and inflow-directional pressure drops have the greatest impact in the toe region of the wellbore. Near the well heel the local wellbore flow rate becomes large and close to the total well production rate, here R{sub af} and R{sub da} are small, therefore, both the accelerational and inflow-directional pressure drops can be neglected.

  10. Flow Distances on Open Flow Networks

    E-Print Network [OSTI]

    Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

    2015-01-01

    Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...

  11. Seasonality in the Natural Gas Balancing Item: Historical Trends and Corrective Measures

    Reports and Publications (EIA)

    2010-01-01

    This special report examines an underlying cause of the seasonal pattern in the balancing item published in the Natural Gas Monthly.

  12. Transition to turbulence in duct flow

    E-Print Network [OSTI]

    Biau, Damien; Bottaro, Alessandro; 10.1017/S0022112007009536

    2010-01-01

    The transition of the flow in a duct of square cross-section is studied. Like in the similar case of the pipe flow, the motion is linearly stable for all Reynolds numbers; this flow is thus a good candidate to investigate the 'bypass' path to turbulence. Initially the so-called 'linear optimal perturbation problem' is formulated and solved, yielding optimal disturbances in the form of longitudinal vortices. Such optimals, however, fail to elicit a significant response from the system in the nonlinear regime. Thus, streamwise-inhomogeneous, sub-optimal disturbances are focussed upon; nonlinear quadratic interactions are immediately evoked by such initial perturbations and an unstable streamwise-homogeneous large amplitude mode rapidly emerges. The subsequent evolution of the flow, at a value of the Reynolds number at the edge between fully developed turbulence and relaminarization, shows the alternance of patterns with two pairs of large scale vortices near opposing parallel walls. Such edge states bear a rese...

  13. Slugging in multiphase flow as a mixed initial-boundary value problem for a quasilinear hyperbolic system

    E-Print Network [OSTI]

    the multiphasis slugging flow phenomenon occurring in oil wells and flow lines. The main con- tribution is a low-dimensional distributed parameters model, comprising the gas mass fraction, the pressure, and gas velocity as states taking the form of a low-dimensional hyperbolic system of conservation laws. Slugging is a two-phase flow

  14. Gas hydrates

    SciTech Connect (OSTI)

    Not Available

    1985-04-01

    There is a definite need for the US government to provide leadership for research in gas hydrates and to coordinate its activities with academia, industry, private groups, federal agencies, and their foreign counterparts. In response to this need, the DOE Morgantown Energy Technology Center implemented a gas hydrates R and D program. Understanding the resource will be achieved through: assessment of current technology; characterization of gas hydrate geology and reservoir engineering; and development of diagnostic tools and methods. Research to date has focused on geology. As work progressed, areas where gas hydrates are likely to occur were identified, and specific high potential areas were targeted for future detailed investigation. Initial research activities involved the development of the Geologic Analysis System (GAS); which will provide, through approximately 30 software packages, the capability to manipulate and correlate several types of geologic and petroleum data into maps, graphics, and reports. Preliminary mapping of hydrate prospects for the Alaskan North Slope is underway. Geological research includes physical system characterization which focuses on creating synthetic methane hydrates and developing synthetic hydrate cores using tetrahydrofuran, consolidated rock cores, frost base mixtures, water/ice base mixtures, and water base mixtures. Laboratory work produced measurements of the sonic velocity and electrical resistivity of these synthetic hydrates. During 1983, a sample from a natural hydrate core recovered from the Pacific coast of Guatemala was tested for these properties by METC. More recently, a natural hydrate sample from the Gulf of Mexico was also acquired and testing of this sample is currently underway. In addition to the development of GAS, modeling and systems analysis work focused on the development of conceptual gas hydrate production models. 16 figs., 6 tabs.

  15. Using NMR to Validate First-Principles Granular Flow Equations

    E-Print Network [OSTI]

    D. Candela; C. Huan; K. Facto; R. Wang; R. W. Mair; R. L. Walsworth

    2005-10-23

    Nuclear magnetic resonance (NMR) experiments are described for two granular-flow systems, the vibrofluidized bed and the gas-fluidized bed. Using pulsed field gradient, magnetic resonance imaging, and hyperpolarized gas NMR, detailed information is obtained for the density and motions of both grains and interstitial gas. For the vibrofluidized bed, the granular temperature profile is measured and compared with a first-principles formulation of granular hydrodynamics. For the gas-fluidized bed, dynamic correlations in the grain density are used to measure the bubble velocity and hyperpolarized xenon gas NMR is used to measure the bubble-emulsion exchange rate. A goal of these measurements is to verify in earth gravity first-principles theories of granular flows, which then can be used to make concrete predictions for granular flows in reduced gravity.

  16. Controlled pilot oxidizer for a gas turbine combustor

    DOE Patents [OSTI]

    Laster, Walter R. (Oviedo, FL); Bandaru, Ramarao V. (Greer, SC)

    2010-07-13

    A combustor (22) for a gas turbine (10) includes a main burner oxidizer flow path (34) delivering a first portion (32) of an oxidizer flow (e.g., 16) to a main burner (28) of the combustor and a pilot oxidizer flow path (38) delivering a second portion (36) of the oxidizer flow to a pilot (30) of the combustor. The combustor also includes a flow controller (42) disposed in the pilot oxidizer flow path for controlling an amount of the second portion delivered to the pilot.

  17. Inhomogeneity of fluid flow in Stirling engine regenerators

    SciTech Connect (OSTI)

    Jones, J.D. )

    1989-10-01

    The literature relating to inhomogeneity of flow regenerators is briefly reviewed. It is noted that, in contrast to other applications of regenerators, relatively little attention has been paid to the consequences of flow inhomogeneity for thermal regeneration in Stirling cycle machines. The construction of regenerator capsules for a large stationary Stirling engine is described. A test rig is developed to measure the gas velocity profile across the face of the packed regenerator capsules under steady flow conditions. Measured flow profiles for a number of different matrix materials and construction techniques are presented, and it is noted that stacked-mesh regenerator matrices tend to display marked inhomogeneities of flow. The consequences of flow inhomogeneity for flow friction and regenerator effectiveness are analyzed theoretically, and approximate formulae deduced. One method for reducing flow inhomogeneity in stacked-screen matrice

  18. Horizontal-flow anaerobic immobilized sludge (HAIS) reactor for paper industry wastewater treatment

    SciTech Connect (OSTI)

    Foresti, E.; Cabral, A.K.A.; Zaiat, M.; Del Nery, V.

    1996-11-01

    Immobilized cell reactors are known to permit the continuous operation without biomass washout and also for increasing the time available for cells` catalytic function in a reaction or in a series of reactions. Several cell immobilization supports have been used in different reactors for anaerobic wastewater treatment, such as: agar gel, acrylamide, porous ceramic, and polyurethane foam besides the self-immobilized biomass from UASB reactors. However, the results are not conclusive as to the advantages of these different reactors with different supports as compared to other anaerobic reactor configurations. This paper describes a new anaerobic attached growth reactor configuration, herein referred as horizontal-flow anaerobic immobilized sludge (HAIS) reactor and presents the results of its performance test treating kraft paper industry wastewater. The reactor configuration was conceived aiming to increase the ratio useful volume/total volume by lowering the volume for gas separation. The HAIS reactor conception would permit also to incorporate the reactor hydrodynamic characteristics in its design criteria if the flow pattern could be approximated as plug-flow.

  19. High ratio recirculating gas compressor

    DOE Patents [OSTI]

    Weinbrecht, John F. (601 Oakwood Pl., NE., Albuquerque, NM 87123)

    1989-01-01

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

  20. High ratio recirculating gas compressor

    DOE Patents [OSTI]

    Weinbrecht, J.F.

    1989-08-22

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

  1. The Canoe Ridge Natural Gas Storage Project

    SciTech Connect (OSTI)

    Reidel, Steve P.; Spane, Frank A.; Johnson, Vernon G.

    2003-06-18

    In 1999 the Pacific Gas and Electric Gas Transmission Northwest (GTN) drilled a borehole to investigate the feasibility of developing a natural gas-storage facility in a structural dome formed in Columbia River basalts in the Columbia Basin of south-central Washington State. The proposed aquifer storage facility will be an unconventional one where natural gas will be initially injected (and later retrieved) in one or multiple previous horizons (interflow zones) that are confined between deep (>700 meters) basalt flows of the Columbia River Basalt Group. This report summarizes the results of joint investigations on that feasibility study by GTN and the US Department of Energy.

  2. Oil and Gas CDT Downscaling-Upscaling: A Robust Method of Linking

    E-Print Network [OSTI]

    Henderson, Gideon

    Oil and Gas CDT Downscaling-Upscaling: A Robust Method of Linking Geomechanical Simulations and Fluid Flow Simulations Heriot-Watt University, Institute of Petroleum Engineering Supervisory Team Prof Geomechanical simulation; fractures; strain; flow upscaling Overview Geomechanical simulations of trap

  3. LINEAR TRANSIENT FLOW SOLUTION FOR PRIMARY OIL RECOVERY

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    in a low-permeability, compressible, layered reservoir filled with oil, water and gas. The sample for pressure support and incremental oil recovery. We analyze the pressure response and fluid flow ratesLINEAR TRANSIENT FLOW SOLUTION FOR PRIMARY OIL RECOVERY WITH INFILL AND CONVERSION TO WATER

  4. Flows of Dense Granular Yoel Forterre and Olivier Pouliquen

    E-Print Network [OSTI]

    Forterre, Yoël

    explore the different flow regimes and discuss the granular solid-liquid and liquid-gas transition are aware that a collection of solid grains can behave macroscopically like a liquid and flow. However in geophysics for the description and prediction of natural hazards such as landslides, rock avalanches

  5. Flume simulation of sedimentation in recirculating flow

    SciTech Connect (OSTI)

    Schmidt, J.C. (Middlebury College, VT (USA)); Rubin, D.M. (Geological Survey, Menlo Park, CA (USA)); Ikeda, H. (Univ. of Tsukuba (Japan))

    1990-05-01

    A 4-m-wide flume at the University of Tsukuba Environmental Research Center was used to simulate flow conditions near debris fans in bedrock gorges. Flow was constricted to 2 m by a semicircular obstruction. During the authors experiments (discharge = 600 L/sec; Froude number of constricted flow = 1) a zone of recirculating current extended 25-30 m downstream from the separation point at the constriction. The pattern and velocity of surface flow was determined using time-lapse photography; subsurface velocity was measured with a two-dimensional electromagnetic current meter. During 32-hr of run time, a fine, very coarse sand mixture was fed into the flow at a rate between 0.5-1 kg/sec. Oscillation ripples developed beneath the separation surface that bounds the recirculation zone, and upstream-migrating dunes and ripples developed within the recirculation zone upstream from the reattachment point. A mid-channel expansion bar was deposited downstream from the reattachment point. Sedimentation within the recirculation zone continued by vertical aggradation and by upstream migration of dunes and ripples. Sediments within the recirculation zone were areally sorted with the finest sediment deposited near the separation point. These patterns are consistent with field observations of bars along the Colorado River in the Grand Canyon.

  6. Portable wastewater flow meter

    DOE Patents [OSTI]

    Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

    1999-02-02

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  7. Portable wastewater flow meter

    DOE Patents [OSTI]

    Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

    1990-01-01

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  8. Gas Drill 

    E-Print Network [OSTI]

    Unknown

    2011-09-05

    .C. Wang, B.T. Lovell, Program, Summary Report TE4258-5-84, J. McCrank, "Topping of a Combined Gas DOE/ET/11292, Oct. 1984. and Steam Turbine Powerplant using a TAM Combustor," Thermo Electron [4J Final Report: "Thermionic Energy Report No. 4258... for each Btu fired in the burners has been cal culated with the process gas temperature as a variable. It was shown [2 ] that the maximum thermionic power produced is 18 kW per million Btu fired per hour. All com bustors are similar but progressively...

  9. Comparative analysis of remaining oil saturation in waterflood patterns based on analytical modeling and simulation 

    E-Print Network [OSTI]

    Azimov, Anar Etibar

    2006-08-16

    in oilfield operations, making the method very attractive. The areal distribution technique estimates two major uncertainties: vertical loss of injected water into nontarget areas or areal loss into surrounding patterns, and injected water for gas fill...

  10. Spatial statistics for predicting flow through a rock fracture

    SciTech Connect (OSTI)

    Coakley, K.J.

    1989-03-01

    Fluid flow through a single rock fracture depends on the shape of the space between the upper and lower pieces of rock which define the fracture. In this thesis, the normalized flow through a fracture, i.e. the equivalent permeability of a fracture, is predicted in terms of spatial statistics computed from the arrangement of voids, i.e. open spaces, and contact areas within the fracture. Patterns of voids and contact areas, with complexity typical of experimental data, are simulated by clipping a correlated Gaussian process defined on a N by N pixel square region. The voids have constant aperture; the distance between the upper and lower surfaces which define the fracture is either zero or a constant. Local flow is assumed to be proportional to local aperture cubed times local pressure gradient. The flow through a pattern of voids and contact areas is solved using a finite-difference method. After solving for the flow through simulated 10 by 10 by 30 pixel patterns of voids and contact areas, a model to predict equivalent permeability is developed. The first model is for patterns with 80% voids where all voids have the same aperture. The equivalent permeability of a pattern is predicted in terms of spatial statistics computed from the arrangement of voids and contact areas within the pattern. Four spatial statistics are examined. The change point statistic measures how often adjacent pixel alternate from void to contact area (or vice versa ) in the rows of the patterns which are parallel to the overall flow direction. 37 refs., 66 figs., 41 tabs.

  11. Perforation patterned electrical interconnects

    DOE Patents [OSTI]

    Frey, Jonathan

    2014-01-28

    This disclosure describes systems and methods for increasing the usable surface area of electrical contacts within a device, such as a thin film solid state device, through the implementation of electrically conductive interconnects. Embodiments described herein include the use of a plurality of electrically conductive interconnects that penetrate through a top contact layer, through one or more multiple layers, and into a bottom contact layer. The plurality of conductive interconnects may form horizontal and vertical cross-sectional patterns. The use of lasers to form the plurality of electrically conductive interconnects from reflowed layer material further aids in the manufacturing process of a device.

  12. Mann 3600 Pattern Generator

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport)PriceHistoric Manhattan Project Sites inMann 3600 Pattern

  13. Oil, gas tanker industry responding to demand, contract changes

    SciTech Connect (OSTI)

    True, W.R.

    1998-03-02

    Steady if slower growth in demand for crude oil and natural gas, low levels of scrapping, and a moderate newbuilding pace bode well for the world`s petroleum and natural-gas shipping industries. At year-end 1997, several studies of worldwide demand patterns and shipping fleets expressed short and medium-term optimism for seaborne oil and gas trade and fleet growth. The paper discusses steady demand and shifting patterns, the aging fleet, the slowing products traffic, the world`s fleet, gas carriers, LPG demand, and LPG vessels.

  14. Gas sensor

    DOE Patents [OSTI]

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  15. Philadelphia Inquirer Op Ed Gas drilling yields a gusher of hogwash

    E-Print Network [OSTI]

    Engelder, Terry

    Philadelphia Inquirer Op Ed Gas drilling yields a gusher of hogwash Both sides of shale debate extracting natural gas from the Marcellus Shale has followed that pattern. A pocket of gas may have exploded on the Marcellus Shale is supported by nearly a dozen leaders in the shale gas industry. More than one

  16. Nonpremixed Combustion in an Accelerating Turning Transonic Flow Undergoing Transition

    E-Print Network [OSTI]

    Liu, Feng

    burning fuel in the turbine stages. For the ground-based gas turbine, benefits have been shown to occur the turbine passage offer, therefore, an opportunity for a major technological improvement. The gas turbine the range of engine operation. Since the flow in a turbine passage is accelerating and power is extracted

  17. Gas permeability of carbon aerogels

    SciTech Connect (OSTI)

    Kong, F.; LeMay, J.D.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W. (Chemistry and Materials Science Department, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States))

    1993-12-01

    Carbon aerogels are synthesized via the aqueous polycondensation of resorcinol with formaldehyde, followed by supercritical drying and subsequent pyrolysis at 1050 [degree]C. As a result of their interconnected porosity, ultrafine cell/pore size, and high surface area, carbon aerogels have many potential applications such as supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, the permeability of carbon aerogels was calculated from equations based upon Darcy's law. Our measurements show that carbon aerogels have permeabilities on the order of 10[sup [minus]12] to 10[sup [minus]10] cm[sup 2] over the density range from 0.05--0.44 g/cm[sup 3]. Like many other aerogel properties, the permeability of carbon aerogels follows a power law relationship with density, reflecting differences in the average mesopore size. Comparing the results from this study with the permeability of silica aerogels reported by other workers, we found that the permeability of aerogels is governed by a simple universal flow equation. This paper discusses the relationship between permeability, pore size, and density in carbon aerogels.

  18. Price Discovery in the Natural Gas Markets of the United States and Canada 

    E-Print Network [OSTI]

    Olsen, Kyle

    2011-02-22

    Canadian markets in a North American natural gas market study. Causal flows modeling using directed acyclic graphs in conjunction with time series analysis are used to explain the relationships among the markets. Daily gas price data from 1994 to 2009...

  19. Experimental Graduation Project Visualization of cavitating flow through a ribbed pipe

    E-Print Network [OSTI]

    the offshore-industries. To be specific: The transport of Liquefied Natural Gas (LNG) over short distances (e of natural gas · resistant to very low temperatures · thermally insulating to prevent the LNG to heat up All/cavitating behavior of the LNG-flow. Different flow regimes as a function of cavitation-intensity and geometry

  20. Flow visualization study of inverted U-bend two-phase flow

    SciTech Connect (OSTI)

    Ishii, M.; Kim, S.B.; Lee, R.

    1986-12-01

    A hot-leg U-bend experiment was performed. The experimental condition simulated the two-phase flow in a B and W primary loop during a small break loss of coolant accident or during some other abnormal transients. The loop design was based on the scaling criteria developed previously and the loop was operated either in a natural circulation mode or in a forced circulation mode using nitrogen gas and water. The two-phase flow regimes at the hot-leg were identified on the basis of visual observation. The phase separation at the top of the inverted U-bend was observed at low gas flow rate. The void fractions were measured using differential pressure transducers and compared with the prediction from the drift-flux model. The natural circulation flow interruption occurred in two different modes, namely, quasi-periodic and semi-permanent modes. This phenomenon is mainly dependent on the difference in the hydrostatic head in the riser and downcomer, and the flow regime at hot-leg. Besides this flow interruption phenomenon, dynamic flow instabilities of considerable amplitudes have been observed.

  1. Gas block mechanism for water removal in fuel cells

    DOE Patents [OSTI]

    Issacci, Farrokh; Rehg, Timothy J.

    2004-02-03

    The present invention is directed to apparatus and method for cathode-side disposal of water in an electrochemical fuel cell. There is a cathode plate. Within a surface of the plate is a flow field comprised of interdigitated channels. During operation of the fuel cell, cathode gas flows by convection through a gas diffusion layer above the flow field. Positioned at points adjacent to the flow field are one or more porous gas block mediums that have pores sized such that water is sipped off to the outside of the flow field by capillary flow and cathode gas is blocked from flowing through the medium. On the other surface of the plate is a channel in fluid communication with each porous gas block mediums. The method for water disposal in a fuel cell comprises installing the cathode plate assemblies at the cathode sides of the stack of fuel cells and manifolding the single water channel of each of the cathode plate assemblies to the coolant flow that feeds coolant plates in the stack.

  2. Use of oil-emulsion mud in the Sivells Bend Field: Gas and gas condensate operations for the independent producer. 

    E-Print Network [OSTI]

    Echols, Walter Harlan

    1954-01-01

    ago: A company was buying casing head gas for gasoline extraction and selling high pressure residue gas for gas lift purposes. The purchaser of the residue gas was billed for what appeared to be an excessive amount of gas over a period of sevex'al... of processing contracts. The early processing contraots used ln gas condensate operations wexe patterned after the old NGAA Caslnghead Gasoline Contract, whexeln the producer's portion of the liquids amounted to 20 to 3g 1/3 percent of the tested liquid...

  3. Three-dimensional reconstruction of bubble distribution in two-phase bubbly flows with the dynamic programming method 

    E-Print Network [OSTI]

    Furukawa, Toru

    2002-01-01

    A three-dimensional bubble reconstruction method is proposed in this thesis to analyze two-phase bubbly flows. Gas/liquid two-phase flows have important roles in the nuclear and chemical industries and other engineering fields...

  4. Gas Test Loop Booster Fuel Hydraulic Testing

    SciTech Connect (OSTI)

    Gas Test Loop Hydraulic Testing Staff

    2006-09-01

    The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3.

  5. Scaled Experimental Modeling of VHTR Plenum Flows

    SciTech Connect (OSTI)

    ICONE 15

    2007-04-01

    Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (“thermal striping”) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.

  6. Gas Injection Apparatus for Vacuum Chamber

    SciTech Connect (OSTI)

    Almabouada, F.; Louhibi, D.; Hamici, M.

    2011-12-26

    We present in this article a gas injection apparatus which comprises the gas injector and its electronic command for vacuum chamber applications. Some of these applications are thin-film deposition by a pulsed laser deposition (PLD) or a cathodic arc deposition (arc-PVD) and the plasma generation. The electronic part has been developed to adjust the flow of the gas inside the vacuum chamber by controlling both of the injector's opening time and the repetition frequency to allow a better gas flow. In this case, the system works either on a pulsed mode or a continuous mode for some applications. In addition, the repetition frequency can be synchronised with a pulsed laser by an external signal coming from the laser, which is considered as an advantage for users. Good results have been obtained using the apparatus and testing with Argon and Nitrogen gases.

  7. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  8. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  9. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    DOE Patents [OSTI]

    Wijmans Johannes G. (Menlo Park, CA); Merkel, Timothy C. (Menlo Park, CA); Baker, Richard W. (Palo Alto, CA)

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  10. Gas turbine cooling system

    DOE Patents [OSTI]

    Bancalari, Eduardo E. (Orlando, FL)

    2001-01-01

    A gas turbine engine (10) having a closed-loop cooling circuit (39) for transferring heat from the hot turbine section (16) to the compressed air (24) produced by the compressor section (12). The closed-loop cooling system (39) includes a heat exchanger (40) disposed in the flow path of the compressed air (24) between the outlet of the compressor section (12) and the inlet of the combustor (14). A cooling fluid (50) may be driven by a pump (52) located outside of the engine casing (53) or a pump (54) mounted on the rotor shaft (17). The cooling circuit (39) may include an orifice (60) for causing the cooling fluid (50) to change from a liquid state to a gaseous state, thereby increasing the heat transfer capacity of the cooling circuit (39).

  11. Recovery of Water from Boiler Flue Gas

    SciTech Connect (OSTI)

    Edward Levy; Harun Bilirgen; Kwangkook Jeong; Michael Kessen; Christopher Samuelson; Christopher Whitcombe

    2008-09-30

    This project dealt with use of condensing heat exchangers to recover water vapor from flue gas at coal-fired power plants. Pilot-scale heat transfer tests were performed to determine the relationship between flue gas moisture concentration, heat exchanger design and operating conditions, and water vapor condensation rate. The tests also determined the extent to which the condensation processes for water and acid vapors in flue gas can be made to occur separately in different heat transfer sections. The results showed flue gas water vapor condensed in the low temperature region of the heat exchanger system, with water capture efficiencies depending strongly on flue gas moisture content, cooling water inlet temperature, heat exchanger design and flue gas and cooling water flow rates. Sulfuric acid vapor condensed in both the high temperature and low temperature regions of the heat transfer apparatus, while hydrochloric and nitric acid vapors condensed with the water vapor in the low temperature region. Measurements made of flue gas mercury concentrations upstream and downstream of the heat exchangers showed a significant reduction in flue gas mercury concentration within the heat exchangers. A theoretical heat and mass transfer model was developed for predicting rates of heat transfer and water vapor condensation and comparisons were made with pilot scale measurements. Analyses were also carried out to estimate how much flue gas moisture it would be practical to recover from boiler flue gas and the magnitude of the heat rate improvements which could be made by recovering sensible and latent heat from flue gas.

  12. Global Natural Gas Market Trends, 2. edition

    SciTech Connect (OSTI)

    2007-07-15

    The report provides an overview of major trends occurring in the natural gas industry and includes a concise look at the drivers behind recent rapid growth in gas usage and the challenges faced in meeting that growth. Topics covered include: an overview of Natural Gas including its history, the current market environment, and its future market potential; an analysis of the overarching trends that are driving a need for change in the Natural Gas industry; a description of new technologies being developed to increase production of Natural Gas; an evaluation of the potential of unconventional Natural Gas sources to supply the market; a review of new transportation methods to get Natural Gas from producing to consuming countries; a description of new storage technologies to support the increasing demand for peak gas; an analysis of the coming changes in global Natural Gas flows; an evaluation of new applications for Natural Gas and their impact on market sectors; and, an overview of Natural Gas trading concepts and recent changes in financial markets.

  13. Flow Field Flow Fractionation Method Development for Applied Bioanalysis

    E-Print Network [OSTI]

    Schachermeyer, Samantha Lynn

    2013-01-01

    E. ; Caldwell, K. , Field-Flow Fractionation Handbook. JohnJ. P. , Sedimentation field-flow-fractionation: emergence ofby sedimentation field-flow fractionation. Am. Lab. (

  14. California's Greenhouse Gas Policies: Local Solutions to a Global Problem?

    E-Print Network [OSTI]

    Bushnell, Jim B; Peterman, Carla Joy; Wolfram, Catherine D

    2007-01-01

    physical limits on how much hydro power flows south from thethe Kyoto protocol, the hydro power in British Columbia andHydro Total WECC SB1368 Compliant Supply in WECC Gas Coal CA baseload demand Figure 2 Importing Clean Power

  15. Experimental investigation of film cooling effectiveness on gas turbine blades 

    E-Print Network [OSTI]

    Gao, Zhihong

    2009-05-15

    high temperature and high pressure blades as an active cooling scheme. In this study, the film cooling effectiveness in different regions of gas turbine blades was investigated with various film hole/slot configurations and mainstream flow conditions...

  16. Business Case for Compressed Natural Gas in Municipal Fleets

    SciTech Connect (OSTI)

    Johnson, C.

    2010-06-01

    This report describes how NREL used the CNG Vehicle and Infrastructure Cash-Flow Evaluation (VICE) model to establish guidance for fleets making decisions about using compressed natural gas.

  17. Geomechanical Development of Fractured Reservoirs During Gas Production 

    E-Print Network [OSTI]

    Huang, Jian

    2013-04-05

    Within fractured reservoirs, such as tight gas reservoir, coupled processes between matrix deformation and fluid flow are very important for predicting reservoir behavior, pore pressure evolution and fracture closure. To study the coupling between...

  18. Hydrodynamic stability of inverted annular flow in an adiabatic simulation

    SciTech Connect (OSTI)

    DeJarlais, G.; Ishii, M.; Linehan, J.

    1983-07-01

    Inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from large aspect ratio nozzles, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed core droplet sizes were recorded at approximately 750 data points. Inverted annular flow destabilization lead to inverted slug flow at low relative velocities, and to dispersed droplet flow at high relative velocities. For both of these transitions from inverted annular flow, core break-up length correlations were developed by extending work on free liquid jets to include this coaxial, jet disintegration phenomenon. The results show length dependence upon D/SUB J/, Re/SUB J/, We/SUB J/, ..cap alpha.. and We/SUB G. Correlations for core shape, break-up mechanisms and dispersed core droplet size were also developed, by extending the results of free jet stability, roll wave entrainment, and churn turbulent droplet stability studies.

  19. Hydrodynamic stability of inverted annular flow in an adiabatic simulation

    SciTech Connect (OSTI)

    De Jarlais, G.; Ishii, M.; Linehan, J.

    1984-01-01

    Inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from large aspect ratio nozzle, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed core droplet sizes were recorded at approximately 750 data points. Inverted annular flow destabilization lead to inverted slug flow at low relative velocities, and to dispersed droplet flow at high relative velocities. For both of these transitions from inverted annular flow, core break-up length correlations were developed by extending work on free liquid jets to include this coaxial, jet disintegration phenomenon. The results show length dependence upon D/sub J/, Re/sub J/, ..cap alpha.. and We/sub G, rel/. Correlations for core shape, break-up mechanisms and dispersed core droplet size were also developed, by extending the results of free jet stability, roll wave entrainment, and churn turbulent droplet stability studies.

  20. Process and system for removing impurities from a gas

    DOE Patents [OSTI]

    Henningsen, Gunnar; Knowlton, Teddy Merrill; Findlay, John George; Schlather, Jerry Neal; Turk, Brian S

    2014-04-15

    A fluidized reactor system for removing impurities from a gas and an associated process are provided. The system includes a fluidized absorber for contacting a feed gas with a sorbent stream to reduce the impurity content of the feed gas; a fluidized solids regenerator for contacting an impurity loaded sorbent stream with a regeneration gas to reduce the impurity content of the sorbent stream; a first non-mechanical gas seal forming solids transfer device adapted to receive an impurity loaded sorbent stream from the absorber and transport the impurity loaded sorbent stream to the regenerator at a controllable flow rate in response to an aeration gas; and a second non-mechanical gas seal forming solids transfer device adapted to receive a sorbent stream of reduced impurity content from the regenerator and transfer the sorbent stream of reduced impurity content to the absorber without changing the flow rate of the sorbent stream.