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1

Pressure boundary conditions for computing incompressible flows with SPH  

Science Conference Proceedings (OSTI)

In Smoothed Particle Hydrodynamics (SPH) methods for fluid flow, incompressibility may be imposed by a projection method with an artificial homogeneous Neumann boundary condition for the pressure Poisson equation. This is often inconsistent with physical ... Keywords: Boundary conditions, Flow around obstacle, Incompressibility, Open-boundary flows, Pressure Poisson equation, Projection scheme, Smoothed Particle Hydrodynamics

S. Majid Hosseini; James J. Feng

2011-08-01T23:59:59.000Z

2

Importance of considering intraborehole flow in solute transport modeling under highly dynamic flow conditions  

SciTech Connect

Correct interpretation of tracer test data is critical for understanding transport processes in the subsurface. This task can be greatly complicated by the presence of intraborehole flows in a highly dynamic flow environment. At a new tracer test site (Hanford IFRC) a dynamic flow field created by changes in the stage of the adjacent Columbia River, coupled with a heterogeneous hydraulic conductivity distribution, leads to considerable variations in vertical hydraulic gradients. These variations, in turn, create intraborehole flows in fully-screened (6.5 m) observation wells with frequently alternating upward and downward movement. This phenomenon, in conjunction with a highly permeable aquifer formation and small horizontal hydraulic gradients, makes modeling analysis and model calibration a formidable challenge. Groundwater head data alone were insufficient to define the flow model boundary conditions, and the movement of the tracer was highly sensitive to the dynamics of the flow field. This study shows that model calibration can be significantly improved by explicitly considering (a) dynamic flow model boundary conditions and (b) intraborehole flow. The findings from this study underscore the difficulties in interpreting tracer tests and understanding solute transport under highly dynamic flow conditions.

Ma, Rui; Zheng, Chunmiao; Tonkin, Matthew J.; Zachara, John M.

2011-04-01T23:59:59.000Z

3

A Conductivity Relationship for Steady-state Unsaturated Flow Processes under Optimal Flow Conditions  

SciTech Connect

Optimality principles have been used for investigating physical processes in different areas. This work attempts to apply an optimal principle (that water flow resistance is minimized on global scale) to steady-state unsaturated flow processes. Based on the calculus of variations, we show that under optimal conditions, hydraulic conductivity for steady-state unsaturated flow is proportional to a power function of the magnitude of water flux. This relationship is consistent with an intuitive expectation that for an optimal water flow system, locations where relatively large water fluxes occur should correspond to relatively small resistance (or large conductance). Similar results were also obtained for hydraulic structures in river basins and tree leaves, as reported in other studies. Consistence of this theoretical result with observed fingering-flow behavior in unsaturated soils and an existing model is also demonstrated.

Liu, H. H.

2010-09-15T23:59:59.000Z

4

The effects between two slotted plate flow meter under single, two, three components flow condition  

E-Print Network (OSTI)

In previous work on the slotted flow meter, repeatibility and reproducibility were studied under different flow conditions and different configurations. In accordance with previous work, the effects of the distance between the slotted plate were identified as an area requring further investigation. The preset 5D distance is expanded to the 10D distance. The flow coefficient KY, the pressure drop, and the uncertainty analysis is conducted. There were definite deference in the results between the 5D distance and the 10D distance in many aspects. As a base line, the flow coefficient KY showed 0.8% ~ 2% difference between the 5D and the 10D distance case. Depending upon the upstream flow conditions, the reproducibility of the slotted flow meter was affected. The pressure drop increased as the upstream Reynolds number increased. The result from the analysis of the water cut meter showed that there are definite relationships between the parameteres of the water cut meter and the parameters of the flow.

Park, Sang Hyan

2004-12-01T23:59:59.000Z

5

Date","Time if available","Events -- Flow Conditions","Collection  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

-- Flow Conditions","Collection" "applicationvnd.ms-excel",,"Explosion and fire; oil and gas flow up riser to ocean surface","None" "applicationvnd.ms-excel",,"Rig sinks;...

6

Method and apparatus for measuring coupled flow, transport, and reaction processes under liquid unsaturated flow conditions  

DOE Patents (OSTI)

The present invention is a method and apparatus for measuring coupled flow, transport and reaction processes under liquid unsaturated flow conditions. The method and apparatus of the present invention permit distinguishing individual precipitation events and their effect on dissolution behavior isolated to the specific event. The present invention is especially useful for dynamically measuring hydraulic parameters when a chemical reaction occurs between a particulate material and either liquid or gas (e.g. air) or both, causing precipitation that changes the pore structure of the test material.

McGrail, Bernard P. (Pasco, WA); Martin, Paul F. (Richland, WA); Lindenmeier, Clark W. (Richland, WA)

1999-01-01T23:59:59.000Z

7

Smolt Responses to Hydrodynamic Conditions in Forebay Flow Nets of Surface Flow Outlets, 2007  

DOE Green Energy (OSTI)

This study provides information on juvenile salmonid behaviors at McNary and The Dalles dams that can be used by the USACE, fisheries resource managers, and others to support decisions on long-term measures to enhance fish passage. We researched smolt movements and ambient hydrodynamic conditions using a new approach combining simultaneous acoustic Doppler current profiler (ADCP) and acoustic imaging device (AID) measurements at surface flow outlets (SFO) at McNary and The Dalles dams on the Columbia River during spring and summer 2007. Because swimming effort vectors could be computed from the simultaneous fish and flow data, fish behavior could be categorized as passive, swimming against the flow (positively rheotactic), and swimming with the flow (negatively rheotactic). We present bivariate relationships to provide insight into fish responses to particular hydraulic variables that engineers might consider during SFO design. The data indicate potential for this empirical approach of simultaneous water/fish measurements to lead to SFO design guidelines in the future.

Johnson, Gary E.; Richmond, Marshall C.; Hedgepeth, J. B.; Ploskey, Gene R.; Anderson, Michael G.; Deng, Zhiqun; Khan, Fenton; Mueller, Robert P.; Rakowski, Cynthia L.; Sather, Nichole K.; Serkowski, John A.; Steinbeck, John R.

2009-04-01T23:59:59.000Z

8

Numerical Study on Flow Pass of a Three-Dimensional Obstacle under a Strong Stratification Condition  

Science Conference Proceedings (OSTI)

A three-dimensional, nonhydrostatic, numerical turbulent model was used to study the flow pass of a three-dimensional obstacle under a strong stratification condition. The numerical results clarify the behavior of the flow at a low Froude number, ...

W. Sha; K. Nakabayashi; H. Ueda

1998-10-01T23:59:59.000Z

9

Effect of magnetic boundary conditions on the dynamo threshold of von Karman swirling flows  

E-Print Network (OSTI)

We study the effect of different boundary conditions on the kinematic dynamo threshold of von Karman type swirling flows in a cylindrical geometry. Using an analytical test flow, we model different boundary conditions: insulating walls all over the flow, effect of sodium at rest on the cylinder side boundary, effect of sodium behind the impellers, effect of impellers or side wall made of a high-magnetic-permeability material. We find that using high-magnetic-permeability boundary conditions decreases the dynamo threshold, the minimum being achieved when they are implemented all over the flow.

Christophe Gissinger; Alexei Iskakov; Stephan Fauve; Emmanuel Dormy

2008-04-11T23:59:59.000Z

10

On fluid flow in a heterogeneous medium under nonisothermal conditions  

SciTech Connect

An asymptotic technique, valid in the presence of smoothly-varying heterogeneity, provides explicit expressions for the velocity of a propagating pressure and temperature disturbance. The governing equations contain nonlinear terms due to the presence of temperature-dependent coefficients and due to the advection of fluids with differing temperatures. Two cases give well-defined expressions in terms of the parameters of the porous medium: the uncoupled propagation of a pressure disturbance and the propagation of a fully coupled temperature and pressure disturbance. The velocity of the coupled disturbance or front, depends upon the medium parameters and upon the change in temperature and pressure across the front. For uncoupled flow, the semi-analytic expression for the front velocity reduces to that associated with a linear diffusion equation. A comparison of the asymptotic travel time estimates with calculations from a numerical simulator indicates reasonably good agreement for both uncoupled and coupled disturbances.

D.W., Vasco

2010-11-01T23:59:59.000Z

11

An investigation of effects of flow conditioning on straight tube Coriolis meter  

E-Print Network (OSTI)

Coriolis meter, despite being very accurate in single phase conditions, fails to accurately measure two-phase flows. It poses a complex fluid-structure interaction problem in case of two-phase operation; there is a scarcity of theoretical models available to predict the errors reported by Coriolis meter in aforementioned conditions, hence the need for experimental research. Experiments are conducted in both single and two-phase flow conditions. Meter accuracy is excellent in single phase conditions and no significant effect is observed on use of flow conditioners, namely inlet swirl and inline mixer. Operational two-phase envelope is determined through experiments at different flowrates. Flow conditioners are used to study the effect of phase segregation and homogenization on accuracy of the meter. Testing is done to cover two-phase flows from both extreme ends, namely aerated liquids and wet gas. Use of flow conditioners show slight improvement in meter accuracy on use of inline mixer, and reduction in accuracy in case of inlet swirl, when both former and latter are compared to results obtained from experiments with no flow conditioners. The difference in accuracies between results with flow conditioner and without flow conditioners is attributed to relative motion between the phases, which is more in case of inlet swirl, due to larger bubble sizes. Flow conditioners show an insignificant effect on meter accuracy during wet gas tests. The reason proposed is annular flow regime, which is not highly affected by flow conditioners. Single phase tests demonstrate that Coriolis meter gives accurate measurement even in presence of severe flow disturbances. There is no need for flow conditioning before the meter to obtain accurate readings from it, which would be the case in other metering technologies like orifice and turbine. In two phase flows, the meter reports negative errors, which is consistent with previous experimental works available in literature. Use of flow conditioners clearly affects the reading of the meter in aerated liquids. This phenomenon can be used to get fairly accurate estimate of flow rate in low gas volume fraction liquid flows.

Shukla, Shashank

2008-05-01T23:59:59.000Z

12

Investigation of Flow-Accelerated Corrosion Under Two-Phase Flow Conditions  

Science Conference Proceedings (OSTI)

Carbon steel (CS) components in steam systems frequently suffer from flow-accelerated corrosion (FAC). Although the mechanism of FAC in fossil plants has been largely understood for almost 40 years, it remains one of the major safety issues for plant management and personnel. FAC occurs across the feedwater system from the condensate pump to the economizer inlet, with the heater drains systems being particularly susceptible. It is equally dangerous in both the single- and two-phase flow regions. ...

2013-01-30T23:59:59.000Z

13

Response of Idealized Baroclinic Wave Life Cycles to Stratospheric Flow Conditions  

Science Conference Proceedings (OSTI)

Dynamical stratosphere–troposphere coupling through a response of baroclinic waves to lower stratospheric flow conditions is investigated from an initial value approach. A series of adiabatic and frictionless nonlinear baroclinic wave life cycles ...

Torben Kunz; Klaus Fraedrich; Frank Lunkeit

2009-08-01T23:59:59.000Z

14

The Existence and Stability of Steady Circulations in a Conditionally Symmetrically Unstable Basic Flow  

Science Conference Proceedings (OSTI)

By treating the latent heating as an energy source which is implicitly related to the motion field, the existence of steady nonlinear circulations in a flow susceptible to Conditionally Symmetric Instability (CSI) is studied. Steady viscous ...

Qin Xu

1987-10-01T23:59:59.000Z

15

A Certificate Infrastructure for Machine-Checked Proofs of Conditional Information Flow  

E-Print Network (OSTI)

and embedded security devices have complex information flow policies that are crucial to fulfilling device requirements. We have previously explained [1, §1] how devices (such as "separation kernels") developed verifying complex conditional information flow policies using a relational Hoare logic. The framework allows

Appel, Andrew W.

16

Production of L-leucine nanoparticles under various conditions using an aerosol flow reactor method  

Science Conference Proceedings (OSTI)

We have studied the formation of L-leucine nanoparticles under various conditions using an aerosol flow reactor method. Temperatures and L-leucine concentrations for the experiments were selected to vary the saturation conditions for L-leucine in the ...

Anna Lähde; Janne Raula; Esko I. Kauppinen

2008-01-01T23:59:59.000Z

17

Effect of Coal Properties and Operation Conditions on Flow Behavior of Coal Slag in Entrained Flow Gasifiers: A Brief Review  

Science Conference Proceedings (OSTI)

Integrated gasification combined cycle (IGCC) is a potentially promising clean technology with an inherent advantage of low emissions, since the process removes contaminants before combustion instead of from flue gas after combustion, as in a conventional coal steam plant. In addition, IGCC has potential for cost-effective carbon dioxide capture. Availability and high capital costs are the main challenges to making IGCC technology more competitive and fully commercial. Experiences from demonstrated IGCC plants show that, in the gasification system, low availability is largely due to slag buildup in the gasifier and fouling in the syngas cooler downstream of the gasification system. In the entrained flow gasifiers used in IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter (as fly ash) is entrained with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. Therefore, it is preferable to minimize the quantity of fly ash and maximize slag. In addition, the hot raw syngas is cooled to convert any entrained molten fly slag to hardened solid fly ash prior to entering the syngas cooler. To improve gasification availability through better design and operation of the gasification process, better understanding of slag behavior and characteristics of the slagging process are needed. Slagging behavior is affected by char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio). The viscosity of the slag is used to characterize the behavior of the slag flow and is the dominating factor to determine the probability that ash particles will stick. Slag viscosity strongly depends on the temperature and chemical composition of the slag. Because coal has varying ash content and composition, different operating conditions are required to maintain the slag flow and limit problems downstream. This report briefly introduces the IGCC process, the gasification process, and the main types and operating conditions of entrained flow gasifiers used in IGCC plants. This report also discusses the effects of coal ash and slag properties on slag flow and its qualities required for the entrained flow gasifier. Finally this report will identify the key operating conditions affecting slag flow behaviors, including temperature, oxygen/coal ratio, and flux agents.

Wang,Ping; Massoudi, Mehrdad

2011-01-01T23:59:59.000Z

18

Unsteady Flow Visualization at Part-Load Conditions of a Radial Diffuser Pump: by PIV and CFD  

Science Conference Proceedings (OSTI)

The present study provides flow visualization on complex internal flows in a radial diffuser pump under part-load conditions by using the three-dimensional Navier-Stokes code CFX-10 with Detached Eddy Simulation (DES) turbulence model. Particle Image ... Keywords: CFD, Flow separation, Flow visualization, PIV, Radial pump

J. Feng; F.-K. Benra; H. J. Dohmen

2009-01-01T23:59:59.000Z

19

The Effect of Pressure Difference Control on Hydraulic Stability in a Variable Flow Air Conditioning System  

E-Print Network (OSTI)

This paper analyzes the effects of different pressure difference control methods on hydraulic stability in a variable flow air conditioning system when it is applied to different air conditioning water systems. According to control method and water system, it can be divided into direct return system pass-by control, direct return system terminal control, reversed return system pass-by control and reversed return system terminal control. The results indicate that reversed return system terminal control has the best hydraulic stability.

Zhang, Z.; Fu, Y.; Chen, Y.

2006-01-01T23:59:59.000Z

20

Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus  

E-Print Network (OSTI)

As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, the variable air volume (VAV) system and the fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air conditioning (HVAC) systems. Our objective is to examine the energy consumption of the VRF system applied to office buildings and make suggestions for evaluating and making decisions on HVAC systems in the early stages of building design. Simulation results show that the energy-saving potential of the VRF system is expected to achieve 22.2 percent and 11.7 percent, compared to the VAV system and the FPFA system, respectively. An energy-usage breakdown of electricity end-users in various systems is also presented.

Zhou, Y.; Wu, J.; Wang, R.; Shiochi, S.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

The absorbent's solution flow process, non-parametric identification into an absorption chiller for air conditioning  

Science Conference Proceedings (OSTI)

The lithium bromide chillers supplied from solar collectors are used to provide proper environmental conditions into industrial and civil buildings. To maintain the appropriate values for the temperature into the chiller's boiler, a control unit is introduced ... Keywords: absorption chiller, flow process, system identification

Adrian Danila

2011-04-01T23:59:59.000Z

22

KOOTENAI RIVER WHITE STURGEON CRITICAL HABITAT WITH FREE FLOWING AND BACKWATER CONDITIONS, BOUNDARY COUNTY, IDAHO  

E-Print Network (OSTI)

COUNTY, IDAHO: EVALUATION OF WATER DEPTH AND FLOW VELOCITY DURING 2006-09 SPAWNING SEASONS Gary J. Barton1 , Gregory Hoffman2 , Richard R. McDonald3 , and Jonathan M. Nelson3 1 U.S. Geological Survey Idaho, Boundary County, Idaho. Kootenay Lake, British Columbia, Canada, creates backwater conditions in the river

23

Symmetries of Discontinuous Flows and the Dual Rankine-Hugoniot Conditions in Fluid Dynamics  

E-Print Network (OSTI)

It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL(2,R) and the static Galilei group G. This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. In this paper we extend this result to discuss the symmetries of discontinuous flows, which further validates the explanation by taking into account shock waves, which are the driving force behind both the explosion and implosion. This is accomplished by constructing a new set of Rankine-Hugoniot conditions, which follow from Noether's conservation laws. The new set is dual to the standard Rankine-Hugoniot conditions and is related to them through the SL(2,R) transformations. The entropy condition, that the shock needs to satisfy for physical reasons, is also seen to remain invariant under the transformations.

Oliver Jahn; V. V. Sreedhar; Amitabh Virmani

2004-07-26T23:59:59.000Z

24

Estimation of steady-state unbalanced system conditions combining conventional power flow and fault analysis software  

Science Conference Proceedings (OSTI)

In real three-phase power systems the voltages and currents are not fully symmetrical. A method has been developed to estimate the effects of slight unbalanced network conditions for steady-state operation. A conventional power flow is followed by a linear incremental calculation using a three-phase model of the network. The unbalanced condition is handled like a multiple unbalanced fault. The process is illustrated for the case of a transformer bank with non-identical single phase units. The results show the effects of different transformer reactances and different voltage ratios, respectively.

Reichelt, D.; Ecknauer, E. [Nordostschweizerische Kraftwerke AG, Baden (Switzerland); Glavitsch, H. [Swiss Federal Inst. of Tech., Zurich (Switzerland)

1996-02-01T23:59:59.000Z

25

Performance Assessment of a Variable Refrigerant Flow Heat Pump Air Conditioning System  

Science Conference Proceedings (OSTI)

Variable refrigerant flow (VRF) technology uses smart integrated controls, variable speed drives, and refrigerant piping to provide energy efficiency, flexible operation, ease of installation, low noise, zone control, and comfort through all-electric technology. This report describes and documents the construction, performance, and application of a heat pump air conditioning system that uses VRF technology8212the Daikin VRV system. This variable refrigerant volume (VRV) system is manufactured by Daikin I...

2008-12-17T23:59:59.000Z

26

Distributed rate allocation for inelastic flows: Optimization frameworks, optimality conditions, and optimal algorithms  

E-Print Network (OSTI)

Abstract—A common assumption behind the recent surge in research activities on network utility maximization is that the traffic flows are elastic, which implies that the utility functions are concave and there are no hard limits on the rate allocated to each flow. These critical assumptions lead to the tractability of the analytic models of utility maximization, but also limits the applicability of the resulting rate allocation protocols. This paper focuses on inelastic flows and removes these restrictive and often invalid assumptions. We present several optimization frameworks, optimality conditions, and optimal algorithms. First we consider nonconcave utility functions, which turn utility maximization into nonconvex, constrained optimization problems that are well-known to be extremely difficult. We first show a surprising result that under certain conditions, the standard pricing algorithm for rate allocation will still converge to the globally optimal rate allocation. When the existing distributed algorithm fails, we present a new algorithm that produces the globally optimal rate allocation, with the worst case complexity being polynomial time in the number of users but exponential time in the number of links. In the second part of the paper, we provide a general problem formulation of rate allocation among time-sensitive flows from real-time and streaming applications, as well as a decomposition into subproblems coordinated by pricing. After simplifying the subproblems by leveraging the optimization structures, we highlight the difficult issues of causality and time-scale, and propose an effective pricing-based heuristics for admission control and an optimal algorithm for a special case formulation.

Mung Chiang; Shengyu Zhang; Prashanth H

2005-01-01T23:59:59.000Z

27

Critical heat-flux experiments under low-flow conditions in a vertical annulus. [PWR; BWR; LMFBR  

Science Conference Proceedings (OSTI)

An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF.

Mishima, K.; Ishii, M.

1982-03-01T23:59:59.000Z

28

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

SciTech Connect

This is the first Semiannual Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project is to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. Our approach is to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner flow controls. The Electric Power Research Institute (EPRI) is providing co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center are active participants in this project. This program contains multiple tasks and good progress is being made on all fronts. A project kickoff meeting was held in conjunction with NETL's 2002 Sensors and Control Program Portfolio Review and Roadmapping Workshop, in Pittsburgh, PA during October 15-16, 2002. Dr. Marc Cremer, REI, and Dr. Paul Wolff, EPRI I&C, both attended and met with the project COR, Susan Maley. Following the review of REI's database of wall-fired coal units, the project team selected a front wall fired 150 MW unit with a Riley Low NOx firing system including overfire air for evaluation. In addition, a test matrix outlining approximately 25 simulations involving variations in burner secondary air flows, and coal and primary air flows was constructed. During the reporting period, twenty-two simulations have been completed, summarized, and tabulated for sensitivity analysis. Based on these results, the team is developing a suitable approach for quantifying the sensitivity coefficients associated with the parametric tests. Some of the results of the CFD simulations of the single wall fired unit were presented in a technical paper entitled, ''CFD Investigation of the Sensitivity of Furnace Operational Conditions to Burner Flow Controls,'' presented at the 28th International Technical Conference on Coal Utilization and Fuel Systems in Clearwater, FL March 9-14, 2003. In addition to the work completed on the single wall fired unit, the project team made the selection of a 580 MW opposed wall fired unit to be the subject of evaluation in this program. Work is in progress to update the baseline model of this unit so that the parametric simulations can be initiated.

Marc Cremer; Kirsi St. Marie; Dave Wang

2003-04-30T23:59:59.000Z

29

Elliptic Flow from Non-equilibrium Initial Condition with a Saturation Scale  

E-Print Network (OSTI)

A current goal of relativistic heavy ion collisions experiments is the search for a Color Glass Condensate as the limiting state of QCD matter at very high density. In viscous hydrodynamics simulations, a standard Glauber initial condition leads to estimate $4\\pi \\eta/s \\sim 1$, while a Color Glass Condensate modeling leads to at least a factor of 2 larger $\\eta/s$. Within a kinetic theory approach based on a relativistic Boltzmann-like transport simulation, we point out that the out-of-equilibrium initial distribution proper of a Color Glass Condensate reduces the efficiency in building-up the elliptic flow. Our main result at RHIC energy is that the available data on $v_2$ are in agreement with a $4\\pi \\eta/s \\sim 1$ also for Color Glass Condensate initial conditions, opening the possibility to describe self-consistently also higher order flow, otherwise significantly underestimated, and to pursue further the search for signatures of the Color Glass Condensate.

M. Ruggieri; F. Scardina; S. Plumari; V. Greco

2013-03-13T23:59:59.000Z

30

Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow and Inclined Wellbore Conditions  

E-Print Network (OSTI)

the utmost importance in maximizing the reservoir energy in naturally flowing and artificial lift wells as the number of variables increases. Many parameters could be involved in these types of problems, such as gas information such as oil, gas and water flow rates, temperature, oil and gas gravity, pipe length, surface

Mohaghegh, Shahab

31

Numerical simulation of unsteady flow in centrifugal pump impeller at off-design condition by hybrid RANS/LES approaches  

Science Conference Proceedings (OSTI)

A new kind of hybrid RANS/LES turbulence modeling method - SST based SAS model is first time used for studying the stall phenomena in a centrifugal pump impeller at off-design condition in present paper. The previous reported “two channel” ... Keywords: centrifugal impeller, flow visualization, hybrid RANS/LES, off-design condition

Wei Zhang; Yunchao Yu; Hongxun Chen

2009-08-01T23:59:59.000Z

32

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

SciTech Connect

This is the Final Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project was to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. The focus of this project was to quantify the potential impacts of ''fine level'' controls rather than that of ''coarse level'' controls (i.e. combustion tuning). Although it is well accepted that combustion tuning will generally improve efficiency and emissions of an ''out of tune'' boiler, it is not as well understood what benefits can be derived through active multiburner measurement and control systems in boiler that has coarse level controls. The approach used here was to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner air and fuel flow rates. The Electric Power Research Institute (EPRI) provided co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center have been active participants in this project. CFD simulations were completed for five coal fired boilers as planned: (1) 150 MW wall fired, (2) 500 MW opposed wall fired, (3) 600 MW T-Fired, (4) 330 MW cyclone-fired, and (5) 200 MW T-Fired Twin Furnace. In all cases, the unit selections were made in order to represent units that were descriptive of the utility industry as a whole. For each unit, between 25 and 44 furnace simulations were completed in order to evaluate impacts of burner to burner variations in: (1) coal and primary air flow rate, and (2) secondary air flow rate. The parametric matrices of cases that were completed were defined in order to accommodate sensitivity analyses of the results. The sensitivity analyses provide a strategy for quantifying the rate of change of NOx or unburned carbon in the fly ash to a rate of change in secondary air or fuel or stoichiometric ratio for individual burners or groups of burners in order to assess the value associated with individual burner flow control. In addition, the sensitivity coefficients that were produced provide a basis for quantifying the differences in sensitivities for the different boiler types. In a ranking of the sensitivity of NOx emissions to variations in secondary air flow between the burners at a fixed lower furnace stoichiometric ratio in order of least sensitive to most sensitive, the results were: (1) 600 MW T-Fired Unit; (2) 500 MW Opposed Wall-Fired Unit; (3) 150 MW Wall-Fired Unit; (4) 100 MW T-Fired Unit; and (5) 330 MW Cyclone-Fired Unit.

Marc Cremer; Dave Wang; Connie Senior; Andrew Chiodo; Steven Hardy; Paul Wolff

2005-07-01T23:59:59.000Z

33

Effects of mesh density and flow conditioning in simulating 7-pin wire wrapped fuel pins.  

Science Conference Proceedings (OSTI)

In response to the goals outlined by the U.S. Department of Energy's Global Nuclear Energy Partnership program, Argonne National Laboratory has initiated an effort to create an integrated multi-physics multi-resolution thermal hydraulic simulation tool package for the evaluation of nuclear power plant design and safety. As part of this effort, the applicability of a variety of thermal hydraulic analysis methods for the prediction of heat transfer and fluid dynamics in the wire-wrapped fuel-rod bundles found in a fast reactor core is being evaluated. The work described herein provides an initial assessment of the capabilities of the general purpose commercial computational fluid dynamics code Star-CD for the prediction of fluid dynamic characteristics in a wire wrapped fast reactor fuel assembly. A 7-pin wire wrapped fuel rod assembly based on the dimensions of fuel elements in the concept Advanced Burner Test Reactor [1] was simulated for different mesh densities and domain configurations. A model considering a single axial span of the wire wrapped fuel assembly was initially used to assess mesh resolution effects. The influence of the inflow/outflow boundary conditions on the predicted flow fields in the single-span model were then investigated through comparisons with the central span region of models which included 3 and 5 spans. The change in grid refinement had minimal impact on the inter-channel exchange within the assembly resulting in roughly a 5 percent maximum difference. The central span of the 3-span and 5-span cases exhibits much higher velocities than the single span case,, with the largest deviation (15 to 20 percent) occurring furthest away from the wire spacer grids in the higher velocity regions. However, the differences between predicted flow fields in the 3-span and 5-span models are minimal.

Smith, J. G.; Babin, B. R.; Pointer, W. D.; Fischer, P. F. (Mathematics and Computer Science); ( NE); (Kansas State Univ.)

2008-01-01T23:59:59.000Z

34

Use of an Accurate DNS Particulate Flow Method to Supply and Validate Boundary Conditions for the MFIX Code  

SciTech Connect

The simulation of particulate flows for industrial applications often requires the use of two-fluid models, where the solid particles are considered as a separate continuous phase. One of the underlining uncertainties in the use of the two-fluid models in multiphase computations comes from the boundary condition of the solid phase. Typically, the gas or liquid fluid boundary condition at a solid wall is the so called no-slip condition, which has been widely accepted to be valid for single-phase fluid dynamics provided that the Knudsen number is low. However, the boundary condition for the solid phase is not well understood. The no-slip condition at a solid boundary is not a valid assumption for the solid phase. Instead, several researchers advocate a slip condition as a more appropriate boundary condition. However, the question on the selection of an exact slip length or a slip velocity coefficient is still unanswered. Experimental or numerical simulation data are needed in order to determinate the slip boundary condition that is applicable to a two-fluid model. The goal of this project is to improve the performance and accuracy of the boundary conditions used in two-fluid models such as the MFIX code, which is frequently used in multiphase flow simulations. The specific objectives of the project are to use first principles embedded in a validated Direct Numerical Simulation particulate flow numerical program, which uses the Immersed Boundary method (DNS-IB) and the Direct Forcing scheme in order to establish, modify and validate needed energy and momentum boundary conditions for the MFIX code. To achieve these objectives, we have developed a highly efficient DNS code and conducted numerical simulations to investigate the particle-wall and particle-particle interactions in particulate flows. Most of our research findings have been reported in major conferences and archived journals, which are listed in Section 7 of this report. In this report, we will present a brief description of these results.

Zhi-Gang Feng

2012-05-31T23:59:59.000Z

35

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

Science Conference Proceedings (OSTI)

As aggressive reductions in boiler emissions are mandated, the electric utility industry has been moving toward installation of improved methods of burner flow measurement and control to optimize combustion for reduced emissions. Development of cost effective controls requires an understanding of how variations in air and coal flows relate to emission rates. This project used computational fluid dynamic (CFD) modeling to quantify the impacts of variations of burner air and fuel flows on furnace operating...

2005-12-12T23:59:59.000Z

36

Minimum Cost Flow Problems with Value-at-Risk and Conditional ...  

E-Print Network (OSTI)

Stochastic minimum cost flow (SMCF) problems have been studied for applica- tions involving random ...... approach to stochastic programming of heating oil.

37

Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions.  

E-Print Network (OSTI)

??This work examines the effects of gravitational acceleration on the flow boiling process. A test facility focusing on an annular heat exchanger was designed, built… (more)

Westheimer, David Thomas

2012-01-01T23:59:59.000Z

38

The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow  

E-Print Network (OSTI)

At present, regulation of water flow by means of pump frequency conversion is one of the major methods for power-saving in central air conditioning systems. In this article, optimization regulation for central air conditioning system on the basis of coordinative optimization control for variable chilled water temperature and variable chilled water flow to obtain better power savings is put forward. According to typical meteorological year data, hourly air conditioning load of whole year for every typical room has been calculated with the transmission function method. In order to guarantee each typical room, the highest cooling load rate is used as an input parameter for optimization calculation. Based on the surface cooler check model, the smallest energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization chilled water temperature and chilled water flow were carried out. The case study for a commercial building in Guangzhou showed that the annual power consumption of the chillers and pumps of the air conditioning system is lower by 17% only with employment of variable water flow regulation by pump frequency conversion. In the case of optimization control with coordinative control of variable chilled water temperature and variable chilled water flow, the annual power consumption of the chillers and pumps of the air conditioning system is reduced by 22% in presence of remarkable power saving effects. Increasing the chilled water temperature will reduce the dehumidified capability of the air cooler, and the indoor relative humidity will increase. The simulation showed that the adjustment optimized process meets the comfort of each typical room. The lower the cooling load rate is, the more obvious the effect of power-saving is. The highest power-saving rate appears in December, which is 36.7%. Meanwhile, the least rate appears in July, which is only 14.5%.

Liu, J.; Mai, Y.; Liu, X.

2006-01-01T23:59:59.000Z

39

MIT-CTP-3519 Symmetries of Discontinuous Flows and the Dual Rankine-Hugoniot Conditions in Fluid Dynamics  

E-Print Network (OSTI)

It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL(2, R) and the static Galilei group G. This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. In this paper we extend this result to discuss the symmetries of discontinuous flows, which further validates the explanation by taking into account shock waves, which are the driving force behind both the explosion and implosion. This is accomplished by constructing a new set of Rankine-Hugoniot conditions, which follow from Noether’s conservation laws. The new set is dual to the standard Rankine-Hugoniot conditions and is related to them through the SL(2, R) transformations. The entropy condition, that the shock needs to satisfy for physical reasons, is also seen to remain invariant under the transformations.

Oliver Jahn; V. V. Sreedhar; Amitabh Virmani

2004-01-01T23:59:59.000Z

40

Sensor Fish Characterization of Fish Passage Conditions through John Day Dam Spillbay 20 with a Modified Flow Deflector  

Science Conference Proceedings (OSTI)

Fish passage conditions over a modified deflector in Spillbay 20 at John Day Dam were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE), Portland District, using Sensor Fish devices. The objectives of the study were to describe and compare passage exposure conditions at two spill discharges, 2.4 and 4.0 thousand cubic feet per second (kcfs), identifying potential fish injury regions within the routes, and to evaluate a low-tailwater condition at the 2.4-kcfs discharge. The study was performed in April 2010 concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision and shear events; 2) differences in passage conditions between treatments; and 3) relationships to live-fish injury and mortality data estimates. Nearly all Sensor Fish significant events were classified as collisions; the most severe occurred at the gate, on the spillbay chute, or at the deflector transition. Collisions in the gate region were observed only during the 2.4-kcfs discharge, when the tainter gate was open 1.2 ft. One shear event was observed during the evaluation, occurring at the deflector transition during passage at the 2.4-kcfs discharge at low tailwater. Flow quality, computed using the Sensor Fish turbulence index, was best for passage at the low-flow low-tailwater condition as well. The worst flow quality was observed for the 4.0-kcfs test condition. Contrasting the passage exposure conditions, the 2.4-kcfs low-tailwater treatment would be most deleterious to fish survival and well-being.

Duncan, Joanne P.

2011-04-29T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization  

DOE Green Energy (OSTI)

Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a smaller aperture, 96-element array and a 200-meter tall meteorological tower. Analysis of the data successfully demonstrated the ability to estimate the vertical velocity profile using coherence data from the pressure array. Also, dynamical systems analysis methods were successful in identifying and tracking a gust type event. In addition to the passive acoustic profiling method, this program also investigated a rapid response Doppler SODAR system, the optimization of wind turbine blades for enhanced power with reduced aeroacoustic noise production, and the implementation of a wireless health monitoring system for the wind turbine blades. Each of these other objectives was met successfully. The use of phase unwrapping applied to SODAR data was found to yield reasonable results for per-pulse measurements. A health monitoring system design analysis was able to demonstrate the ability to use a very small number of sensors to monitor blade health based on the blade's overall structural modes. Most notable was the development of a multi-objective optimization methodology that successfully yielded an aerodynamic blade design that produces greater power output with reduced aerodynamic loading noise. This optimization method could be significant for future design work.

Murray, Nathan E.

2012-03-12T23:59:59.000Z

42

Energy studies on central and variable refrigerant flow air-conditioning systems  

Science Conference Proceedings (OSTI)

Air-conditioning is a major contributor to energy end-use in commercial buildings. Different types of airconditioning systems are installed in commercial buildings including packaged systems

2012-01-01T23:59:59.000Z

43

Design of Air-cooled Microchannel Condensers for Mal-distributed Air Flow Conditions .  

E-Print Network (OSTI)

??Air-cooled condensers are routinely designed for a variety of applications, including residential air-conditioning systems. Recent attempts at improving the performance of these heat exchangers have… (more)

Subramaniam, Vishwanath

2004-01-01T23:59:59.000Z

44

Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions  

SciTech Connect

A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

2012-08-29T23:59:59.000Z

45

Comparison of in-cylinder scavenging flows in a two-stroke cycle engine under motored and fired conditions  

Science Conference Proceedings (OSTI)

The in-cylinder flow field of a loop-scavenged, two-stroke engine has been characterized using laser Doppler velocimetry. The radial component of gas velocity was measured along the axis of the cylinder for both motored and fired operation. Measurements were obtained under conditions simulating both crankcase and external blower driven scavenging. Mean profiles of the radial velocity show marked differences in the global flow structure between motored and fired operation for both scavenging methods. These differences persist throughout the scavenging process and survive compression of the fresh charge. Root mean square (rms) velocity fluctuations near TDC were also determined, and significant differences between motored and fired operation are observed. The rms fluctuations are found to correlate well with the mean shear during compression.

Miles, P.C.; Green, R.M.; Witze, P.O.

1994-06-01T23:59:59.000Z

46

Flow Boundaries in Random-Flight Dispersion Models: Enforcing the Well-Mixed Condition  

Science Conference Proceedings (OSTI)

Lagrangian stochastic (LS) dispersion models often use trajectory reflection to limit the domain accessible to a particle. It is shown how the well-mixed condition (Thomson) can he expressed in the Chapman-Kolmogorov equation for a discrete-time ...

John D. Wilson; Thomas K. Flesch

1993-11-01T23:59:59.000Z

47

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

48

D0 Silicon Upgrade: Calculating Mass Flow Rates at Sub-Sonic Conditions Trhough Venturis (FT-4052-H & FT-4053-H) and an Orifice Plate (F)-2019-H)  

SciTech Connect

The purpose of this engineering note is to explain the method involved in calculating the mass flow rates through venturis and orifice plates at sub-sonic conditions. In particular, the mass flow rate calculations are required for two FLOW-DYNE venturi flow meters, serial no. 35821 and no. 35822, and an orifice plate flow meter, serial no. 35823. The two venturis, FT-4052-H and FT-4053-H, are located in the D-Zero VLPC valve box at the refrigerator and the orifice plate, FO-2019-H, is on the high pressure helium supply line in the assembly building.

Zaczek, Mauiusz; /Fermilab

1996-08-15T23:59:59.000Z

49

Development of a laminar flow desiccant bed for solar air conditioning application  

DOE Green Energy (OSTI)

Mass transfer in silica gel beds of different configurations is reviewed in connection with use in the Solar-Desiccant-Evaporative Cooling System. A laminar flow, coated-sheet concept is proposed since it ensures a low pressure drop and minimal solid side mass transfer resistance. A preliminary bed design gives 1/3 the pressure drop of a previous packed particle bed design and a large reduction in volume and silica gel inventory. The construction of a packing module and test rig is described, and test results reported for a particle size of 0.12 mm (60 to 200 mesh) with a passage width of about 1.5 mm. In order to compare theory and experiment, an existing code, NUMINT, which solves the partial differential equations governing heat and mass transfer in silica gel beds, was revised to include the effects of substrate heat capacity, and non-adiabatic operation. Comparisons between theory and experiment were found to be generally satisfactory, though it was found that specification of the bed initial water content for adsorption tests presented some difficulties. The effect of solid side mass transfer resistance was found to be small, which suggests that an optimum design may incorporate a larger particle size. Topics for further work are suggested.

Kim, S.

1983-02-01T23:59:59.000Z

50

Statistical evaluation of the effects of fall and winter flows on the spring condition of rainbow and brown trout in the green river downstream of Flaming Gorge Dam.  

DOE Green Energy (OSTI)

Flaming Gorge Dam, a hydroelectric facility operated by the Bureau of Reclamation (Reclamation), is located on the Green River in Daggett County, northeastern Utah. In recent years, single peak releases each day or steady flows have been the operational pattern during the winter period. A double-peak pattern (two flow peaks each day) was implemented during the winter of 2006-2007 by Reclamation. Because there is no recent history of double-peaking at Flaming Gorge Dam, the potential effects of double-peaking operations on the body condition of trout in the dam's tailwater are not known. A study plan was developed that identified research activities to evaluate potential effects from double-peaking operations during winter months. Along with other tasks, the study plan identified the need to conduct a statistical analysis of existing data on trout condition and macroinvertebrate abundance to evaluate potential effects of hydropower operations. This report presents the results of this analysis. We analyzed historical data to (1) describe temporal patterns and relationships among flows, benthic macroinvertebrate abundance, and condition of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in the tailwaters of Flaming Gorge Dam and (2) to evaluate the degree to which flow characteristics (i.e., flow volumes and flow variability) and benthic macroinvertebrate abundance affect the condition of trout in this area. This information, together with further analyses of size-stratified trout data, may also serve as baseline data to which the effects of potential future double-peaking flows can be compared. The condition (length, weight and/or relative weight) of rainbow trout (Oncorhynchus mykiss) at two sites in the Green River downstream of Flaming Gorge Dam (Tailrace and Little Hole) and weight of brown trout (Salmo trutta) at the Little Hole site has been decreasing since 1990 while the abundance of brown trout has been increasing at the two sites. At the same time, flow variability in the river has decreased and the abundance of total benthic macroinvertebrates at the Tailrace site has increased. The condition of trout in spring (averaged across all sampled trout) was positively correlated with fall and winter flow variability (including within-day skewness, within-season skewness and/or change in flow between days) at both locations. No negative correlations between trout condition and any measure of flow variability were detected. The length and weight of rainbow trout at the Little Hole site were negatively correlated with increasing fall and winter flow volume. The condition of brown trout at Little Hole and the condition of brown and rainbow trout at Tailrace were not correlated with flow volume. Macroinvertebrate variables during October were either positively correlated or not correlated with measures of trout condition at the Tailrace and Little Hole sites. With the exception of a positive correlation between taxa richness of macroinvertebrates in January and the relative weight of brown trout at Tailrace, the macroinvertebrate variables during January and April were either not correlated or negatively correlated with measures of trout condition. We hypothesize that high flow variability increased drift by dislodging benthic macroinvertebrates, and that the drift, in turn, resulted in mostly lower densities of benthic macroinvertebrates, which benefited the trout by giving them more feeding opportunities. This was supported by negative correlations between benthic macroinvertebrates and flow variability. Macroinvertebrate abundance (with the exception of ephemeropterans) was also negatively correlated with flow volume. The change in trout condition from fall to spring, as measured by the ratio of spring to fall relative weight, was evaluated to determine their usefulness as a standardized index to control for the initial condition of the fish as they enter the winter period. The ratio values were less correlated with the fall condition values than the spring condition values and did not show the same re

Magnusson, A. K.; LaGory, K. E.; Hayse, J. W.; Environmental Science Division

2009-01-09T23:59:59.000Z

51

Experimental study of the performance of a laminar flow silica gel desiccant packing suitable for solar air conditioning application  

DOE Green Energy (OSTI)

An experimental study of the performance of a low pressure drop silica gel desiccant packing has been carried out. The packing is in the form of narrow passages lined with a single layer of small silica gel particles. A near optimum particle size of 0.25 mm, and a range of passage widths of 1.46 to 3.75 mm were chosen based on the predictions of a computer simulation model. A test chamber was constructed with sufficient thermal insulation to allow close to adiabatic conditions for the 12 cm x 12 cm cross section of packing. Step change adsorption and desorption tests were performed for various plate spacings, air flow rates, air inlet conditions, and gel initial water contents. Air outlet moisture content and temperature, as well as pressure drop were measured. The experimental results were compared with predictions of the computer simulation model: This model is based on gas side controlled heat and mass transfer, with the small solid side mass transfer resistance incorporated in a crude manner, and heat transfer into the packing handled as a lumped thermal capacitance. Reasonable agreement was obtained between theoretical prediction and experiment. The match was found to improve with increased passage width. The discrepancies are chiefly attributed to an excessive air bypass, and to inaccurate accounting for heat transfer from the sides of the unit. Use of the computer code for prototype scale design purposes is recommended.

Biswas, P.

1983-02-01T23:59:59.000Z

52

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

1985) for fluid and heat flow in fractured porous media. Theflows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

53

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 ... Keywords: CO2 geological storage, Environmental remediation, Multi-phase flow, Nuclear waste geological disposal, Reactive transport, TOUGHREACT

Tianfu Xu; Nicolas Spycher; Eric Sonnenthal; Guoxiang Zhang; Liange Zheng; Karsten Pruess

2011-06-01T23:59:59.000Z

54

Some Influences of Background Flow Conditions on the Generation of Turbulence due to Gravity Wave Breaking above Deep Convection  

Science Conference Proceedings (OSTI)

Deep moist convection generates turbulence in the clear air above and around developing clouds, penetrating convective updrafts and mature thunderstorms. This turbulence can be due to shearing instabilities caused by strong flow deformations near ...

Todd P. Lane; Robert D. Sharman

2008-11-01T23:59:59.000Z

55

Seabed Stresses in Combined Wave and Steady Flow Conditions on the Nova Scotia Continental Shelf: Field Measurements and Predictions  

Science Conference Proceedings (OSTI)

A tripod holding electromagnetic flowmeters at two heights within 1 m above the seabed has been deployed at two shallow sites (25 and 45 m depths) on the continental shelf off Nova Scotia, Canada. Wave flows are comparable with the small mean ...

D. A. Huntley; D. G. Hazen

1988-02-01T23:59:59.000Z

56

Step-flow anisotropy of the m-plane GaN (1100) grown under nitrogen-rich conditions by plasma-assisted molecular beam epitaxy  

Science Conference Proceedings (OSTI)

The homoepitaxial growth of m-plane (1100) GaN was investigated by plasma-assisted molecular beam epitaxy under nitrogen-rich conditions. The surface morphologies as a function of sample miscut were studied, providing evidence for a strong growth anisotropy that is a consequence of the anisotropy of Ga adatom diffusion barriers on the m-plane surface recently calculated ab initio[Lymperakis and Neugebauer, Phys. Rev. B 79, 241308(R) (2009)]. We found that substrate miscut toward [0001] implies a step flow toward while substrate miscut toward [0001] causes formation of atomic steps either perpendicular or parallel to the [0001] direction, under N-rich conditions at 730 deg C. We describe the growth conditions for achieving atomically flat m-plane GaN layers with parallel atomic steps.

Sawicka, Marta; Siekacz, Marcin; Skierbiszewski, Czeslaw [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); TopGaN Ltd., Sokolowska 29/37, PL-01-142 Warszawa (Poland); Turski, Henryk; Krysko, Marcin; DziePcielewski, Igor; Grzegory, Izabella [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); Smalc-Koziorowska, Julita [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); TopGaN Ltd., Sokolowska 29/37, PL-01-142 Warszawa (Poland); Warsaw University of Technology, Faculty of Material Science and Engineering, Woloska 141, PL-02-507 Warszawa (Poland)

2011-06-15T23:59:59.000Z

57

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

DOE Green Energy (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

2010-08-01T23:59:59.000Z

58

Littoral blasts: Pumice-water heat transfer and the conditions for steam explosions when pyroclastic flows enter the ocean  

E-Print Network (OSTI)

Littoral blasts: Pumice-water heat transfer and the conditions for steam explosions when June 2007; accepted 26 July 2007; published 16 November 2007. [1] Steam explosions, or littoral blasts, phenomena. The development of steam explosions rather than passive steam production is related to the rate

Manga, Michael

59

Thermal-fluid and electrochemical modeling and performance study of a planar solid oxide electrolysis cell : analysis on SOEC resistances, size, and inlet flow conditions.  

DOE Green Energy (OSTI)

Argonne National Laboratory and Idaho National Laboratory researchers are analyzing the electrochemical and thermal-fluid behavior of solid oxide electrolysis cells (SOECs) for high temperature steam electrolysis using computational fluid dynamics (CFD) techniques. The major challenges facing commercialization of steam electrolysis technology are related to efficiency, cost, and durability of the SOECs. The goal of this effort is to guide the design and optimization of performance for high temperature electrolysis (HTE) systems. An SOEC module developed by FLUENT Inc. as part of their general CFD code was used for the SOEC analysis by INL. ANL has developed an independent SOEC model that combines the governing electrochemical mechanisms based on first principals to the heat transfer and fluid dynamics in the operation of SOECs. The ANL model was embedded into the commercial STAR-CD CFD software, and is being used for the analysis of SOECs by ANL. The FY06 analysis performed by ANL and reported here covered the influence of electrochemical properties, SOEC component resistances and their contributing factors, SOEC size and inlet flow conditions, and SOEC flow configurations on the efficiency and expected durability of these systems. Some of the important findings from the ANL analysis are: (1) Increasing the inlet mass flux while going to larger cells can be a compromise to overcome increasing thermal and current density gradients while increasing the cell size. This approach could be beneficial for the economics of the SOECs; (2) The presence of excess hydrogen at the SOEC inlet to avoid Ni degradation can result in a sizeable decrease in the process efficiency; (3) A parallel-flow geometry for SOEC operation (if such a thing be achieved without sealing problems) yields smaller temperature gradients and current density gradients across the cell, which is favorable for the durability of the cells; (4) Contact resistances can significantly influence the total cell resistance and cell temperatures over a large range of operating potentials. Thus it is important to identify and avoid SOEC stack conditions leading to such high resistances due to poor contacts.

Yildiz, B.; Smith, J.; Sofu, T.; Nuclear Engineering Division

2008-06-25T23:59:59.000Z

60

On conditions of negativity of friction resistance for non-stationary modes of blood flow and possible mechanism of affecting of environmental factors on energy effectiveness of cardio-vascular system functioning  

E-Print Network (OSTI)

It is shown that initiated by action of molecular viscosity impulse flow, directed usually from the moving fluid to limiting it solid surface, can, under certain conditions, turn to zero and get negative values in the case of non-stationary flow caused by alternating in time longitudinal (along the pipe axis) pressure gradient. It is noted that this non-equilibrium mechanism of negative friction resistance in the similar case of pulsating blood flow in the blood vessels, in addition to the stable to turbulent disturbances swirled blood flow structure providing, can also constitute hydro-mechanical basis of the observed but not explained yet paradoxically high energy effectiveness of the normal functioning of the cardio-vascular system (CVS). We consider respective mechanism of affecting on the stability of the normal work of CVS by environmental variable factors using shifting of hydro-dynamic mode with negative resistance realization range boundaries and variation of linear hydro-dynamic instability leading ...

Chefranov, S G

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Turbulence Considerations for Comparing Ecosystem Exchange over Old-Growth and Clear-Cut Stands For Limited Fetch and Complex Canopy Flow Conditions  

SciTech Connect

Carbon dioxide, water vapor and energy fluxes were measured using eddy covariance (EC) methodology over three adjacent forests in southern Washington State to identify stand-level age-effects on ecosystem exchange. The sites represent Douglas-fir forest ecosystems at two contrasting successional stages: old-growth (OG) and early seral (ES). Here we present eddy flux and meteorological data from two early seral stands and the Wind River AmeriFlux old-growth forest during the growing season (March-October) in 2006 and 2007. We show an alternative approach to the usual friction velocity (u*) method for determining periods of adequate atmospheric boundary layer (ABL) mixing based on the ratio of mean horizontal ({bar u}) and vertical ({bar w}) wind flow to a modified turbulent kinetic energy scale (uTKE). This new parameter in addition to footprint modeling showed that daytime CO{sub 2} fluxes (F{sub NEE}) in small clear-cuts (< 10 hectares) can be measured accurately with EC if micrometeorological conditions are carefully evaluated. Peak midday CO{sub 2} fluxes (F{sub NEE} = -14.0 to -12.3 {micro}mol m{sup -2} s{sup -1}) at OG were measured in April in both 2006 and 2007 before bud break when air and soil temperatures and vapor pressure deficit were relatively low, and soil moisture and light levels were favorable for photosynthesis. At the early seral stands, peak midday CO{sub 2} fluxes (F{sub NEE} = -11.0 to -8.7 {micro}mol m{sup -2} s{sup -1}) were measured in June and July while spring-time CO{sub 2} fluxes were much smaller (F{sub NEE} = -3.8 to -3.6 {micro}mol m{sup -2} s{sup -1}). Overall, we measured lower evapotranspiration (OG = 230 mm; ES = 297 mm) higher midday F{sub NEE} (OG F{sub NEE} = -9.0 {micro}mol m{sup -2} s{sup -1}; ES F{sub NEE} = -7.3 {micro}mol m{sup -2} s{sup -1}) and higher Bowen ratios (OG {beta} = 2.0. ES {beta} = 1.2) at the old-growth forest than at the ES sites during the summer months (May-August). Eddy covariance studies such as ours add critical land-atmosphere exchange data for an abundant, but rarely studied Douglas-fir age class.

Wharton, S; Schroeder, M; Paw U, K T; Falk, M; Bible, K

2009-01-08T23:59:59.000Z

62

Portable wastewater flow meter  

DOE Patents (OSTI)

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.

Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

1999-02-02T23:59:59.000Z

63

Portable wastewater flow meter  

DOE Patents (OSTI)

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.

Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

1990-01-01T23:59:59.000Z

64

MHD duct flows under hydrodynamic “slip” condition  

E-Print Network (OSTI)

metal blankets of a fusion reactor), H a ? 10 3 ? 10 5 . Ineld typical to future fusion reactors, the estimate for thewith those in the fusion reactor, are used. Finally, it

Smolentsev, S.

2009-01-01T23:59:59.000Z

65

Information Flow in Ensemble Weather Predictions  

Science Conference Proceedings (OSTI)

In a weather prediction, information flows from the initial conditions to a later prediction. The uncertainty in the initial conditions implies that such a flow should be quantified with tools from probability theory. Using several recent ...

Richard Kleeman

2007-03-01T23:59:59.000Z

66

Lattice Boltzmann modeling of microchannel flow in slip flow regime  

Science Conference Proceedings (OSTI)

We present the lattice Boltzmann equation (LBE) with multiple relaxation times (MRT) to simulate pressure-driven gaseous flow in a long microchannel. We obtain analytic solutions of the MRT-LBE with various boundary conditions for the incompressible ... Keywords: Gas flow through microchannel, Lattice Boltzmann equation with multiple relaxation times, Slip flow

Frederik Verhaeghe; Li-Shi Luo; Bart Blanpain

2009-01-01T23:59:59.000Z

67

Increased Power Flow Guidebook  

Science Conference Proceedings (OSTI)

The Increased Power Flow (IPF) Guidebook is a state-of-the-art and best practices guidebook on increasing power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates alternatives with case studies, and analyzes costs and benefits of differe...

2005-11-16T23:59:59.000Z

68

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

Amarnath, M. Blatt, Variable refrigerant flow: where, why,simulation in the variable refrigerant flow air-conditioningsimulation of the variable refrigerant flow air conditioning

Hong, Tainzhen

2010-01-01T23:59:59.000Z

69

Hydromagnetic Instability in Differentially Rotating Flows  

E-Print Network (OSTI)

We study the stability of a compressible differentially rotating flows in the presence of the magnetic field, and we show that the compressibility profoundly alters the previous results for a magnetized incompressible flow. The necessary condition of newly found instability can be easily satisfied in various flows in laboratory and astrophysical conditions and reads $B_{s} B_{\\phi} \\Omega' \

Bonanno, A

2006-01-01T23:59:59.000Z

70

UZ Flow Models and Submodels  

SciTech Connect

The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

Y. Wu

2004-11-01T23:59:59.000Z

71

Dryout droplet distribution and dispersed flow film boiling  

E-Print Network (OSTI)

Dispersed flow film boiling is characterized by liquid-phase droplets entrained in a continuous vapor-phase flow. In a previous work at MIT, a model of dispersed flow heat transfer was developed, called the Local Conditions ...

Hill, Wayne S.

1982-01-01T23:59:59.000Z

72

Computer controlled air conditioning systems  

SciTech Connect

This patent describes an improvement in a computer controlled air conditioning system providing for circulation of air through an air conditioned house in contact with concrete walls requiring a humidity within a critical range. The improvement consists of: a computer for processing sensed environmental input data including humidity and oxygen to produce output control signals for affecting the humidity of the air in the house; provision for an air flow circulation path through the house in contact with the concrete walls; sensing responsive to the amount of oxygen in the house for providing input signals to the computer; mixing for combining with the air in the house a variable amount of fresh atmospheric air to supply fresh oxygen; and humidity modifying means for modifying the humidity of the air flowing in the flow path responsive to the control signals.

Dumbeck, R.F.

1986-02-04T23:59:59.000Z

73

Evaluation of low flow characteristics of the Vermont Yankee plant  

Science Conference Proceedings (OSTI)

Boiling water reactor (BWR) core flow instrumentation inaccuracies under low-flow conditions have been the subject of both reactor vendor and regulatory communications in response to incidents of the reported core flow being less than the flow corresponding to the natural-circulation line on the power flow map. During single recirculation loop operation, low-flow conditions exist in the idle recirculation loop, and these flow inaccuracies can affect the usefulness of the reported core flow. Accurate core flow indications are needed above 25% power to administer fuel thermal limits and comply with restrictions associated with the potential for thermal-hydraulic instability. While the natural-circulation line on the power flow map is recognized to be a nominal estimate of the flow expected at and near natural-circulation conditions, the boundaries of the stability regions are associated with conditions assumed in safety analyses performed to demonstrate compliance with general design criteria 10 and 12.

Ganther, S.; LeFrancoi, M.; Bergeron, P. [Yankee Atomic Electric Co., Bolton, MA (United States)

1997-12-01T23:59:59.000Z

74

Characterization of Foam Flow in Pipes Using Two Flow Regime Concept.  

E-Print Network (OSTI)

??The objective of this study is to investigate the characteristics of foam flow behavior in pipes in a wide range of experimental conditions, including two… (more)

Gajbhiye, Rahul Narayanrao

2011-01-01T23:59:59.000Z

75

FLOW GATING  

DOE Patents (OSTI)

BS>This invention is a fast gating system for eiectronic flipflop circuits. Diodes connect the output of one circuit to the input of another, and the voltage supply for the receiving flip-flop has two alternate levels. When the supply is at its upper level, no current can flow through the diodes, but when the supply is at its lower level, current can flow to set the receiving flip- flop to the same state as that of the circuit to which it is connected. (AEC)

Poppelbaum, W.J.

1962-12-01T23:59:59.000Z

76

Flow cytometer  

DOE Patents (OSTI)

A Faraday cage enclosing the flow chamber of a cytometer and ground planes associated with each field deflection plate in concert therewith inhibit electric fields from varying the charge on designated events/droplets and further concentrates and increases forces applied to a charged event passing therethrough for accurate focus thereof while concomitantly inhibiting a potential shock hazard.

van den Engh, Ger (Seattle, WA)

1995-01-01T23:59:59.000Z

77

Flow cytometer  

DOE Patents (OSTI)

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.

Van den Engh, G.

1995-11-07T23:59:59.000Z

78

Increased Power Flow Guidebook - 2012  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best- practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment, without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case ...

2012-12-31T23:59:59.000Z

79

Increased Power Flow Guidebook - 2013  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best- practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment, without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case ...

2013-11-18T23:59:59.000Z

80

Date | 1Refrigeration and Air Conditioning EMA Education and Training Date | 2Refrigeration and Air Conditioning EMA Education and Training  

E-Print Network (OSTI)

Date | 1Refrigeration and Air Conditioning EMA Education and Training #12;Date | 2Refrigeration Flow Coil Design etc. Finger Print Relationship Every evaporator is unique Unstable Region * = examples

Oak Ridge National Laboratory

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

DRAFT STAFF PAPER EXPECTED PATH 26 POWER FLOWS  

E-Print Network (OSTI)

under varying temperature conditions. Keywords: Electricity, demand, imports, transmission flows Marshall, Marc Pryor, David Vidaver Electricity Analysis Office Electricity Supply Assessment Division a 2008 staff assessment of electricity flows over Path 26 during heat spells in the summers of 2006

82

Smoke Flow Visualization in a Tributary of a Deep Valley  

Science Conference Proceedings (OSTI)

Smoke pot and oil fog smoke tracers have been used to plan meteorological instrument placement and quantitatively estimate air volume flow from a tributary during nocturnal drainage wind conditions. The estimated volume flow agrees well with ...

W. M. Porch; S. Barr; W. E. Clements; J. A. Archuleta; A. B. Fernandez; C. W. King; W. D. Neff; R. P. Hosker

1989-01-01T23:59:59.000Z

83

Fuel conditioning process  

SciTech Connect

A fuel conditioning process and apparatus for use where natural gas is compressed by a field compressor driven by a natural gas powered engine. The fuel portion of the compressed raw natural gas is passed through an adsorption vessel containing an adsorbent material capable of adsorbing impurities. The outlet gas from the adsorption vessel is accumulated and mixed for averaging and controlling the heating value of the outlet gas used for fuel. Regeneration of the adsorption material, when employing multiple adsorption vessels, is accomplished by connecting one adsorption vessel to the suction side of the compressor, purified gas from another adsorption vessel in adsorption service is backflowed through the loaded adsorption vessel to desorb the previously adsorbed impurities, the flow of the compressed raw natural gas to the other adsorption vessel is terminated and the pressure within the two adsorption vessels is equalized. The regenerated adsorption vessel is then repressured with the compressed raw natural gas prior to returning it to the adsorption mode.

McGill, J. C.; Alley, J. R.; Coombs, D. W.

1985-07-09T23:59:59.000Z

84

Improved Fluid Flow Measurements: Feedwater Flow  

Science Conference Proceedings (OSTI)

This report describes the combined results of a utility survey and site visits concerning feedwater flow measurement in fossil-fueled power plants. In addition, a summary is provided of the technologies available to measure the volumetric feedwater flow rate in plants. This volumetric flow rate can be converted to a mass flow rate by knowing the pressure and temperature of the flow media. Velocity meters, differential pressure meters, and other closed-conduit flowmeters are discussed along with ...

2012-11-28T23:59:59.000Z

85

Flow Properties in Rotating, Stratified Hydraulics  

Science Conference Proceedings (OSTI)

This paper discusses three distinct features of rotating, stratified hydraulics, using a reduced-gravity configuration. First, a new upstream condition is derived corresponding to a wide, almost motionless basin, and this is applied to flow ...

Peter D. Killworth

1992-09-01T23:59:59.000Z

86

Development of a low density jet flow apparatus.  

E-Print Network (OSTI)

??An apparatus was designed and constructed to study supersonic fluid flow in a low temperature and low pressure environment similar to the same conditions associated… (more)

Smith, Nicholas Edward

2010-01-01T23:59:59.000Z

87

Preferential flow paths and heat pipes: Results from laboratory experiments on heat-driven flow in natural and artificial rock fractures  

SciTech Connect

Water flow in fractures under the conditions of partial saturation and thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. Water flowing in fast pathways may ultimately contact waste packages at Yucca Mountain and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize liquid flow in glass fracture models, a transparent epoxy fracture replica, and a rock/replica fracture assembly. Spatially resolved thermal monitoring was performed in seven of these experiments to evaluate heat-pipe formation. Depending on the fracture apertures and flow conditions, various flow regimes were observed including continuous rivulet flow for high flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for low flow rates and wide apertures. These flow regimes were present in both fracture models and in the replica of a natural fracture. Heat-pipe conditions indicated by low thermal gradients were observed in five experiments. Conditions conducive to heat-pipe formation include an evaporation zone, condensation zone, adequate space for vapor and liquid to travel, and appropriate fluid driving forces. In one of the two experiments where heat pipe conditions were not observed, adequate space for liquid-vapor counterflow was not provided. Heat pipe conditions were not established in the other, because liquid flow was inadequate to compensate for imbibition and the quantity of heat contained within the rock.

Kneafsey, T.J.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-06-01T23:59:59.000Z

88

Hydromagnetic Instability in plane Couette Flow  

E-Print Network (OSTI)

We study the stability of a compressible magnetic plane Couette flow and show that compressibility profoundly alters the stability properties if the magnetic field has a component perpendicular to the direction of flow. The necessary condition of a newly found instability can be satisfied in a wide variety of flows in laboratory and astrophysical conditions. The instability can operate even in a very strong magnetic field which entirely suppresses other MHD instabilities. The growth time of this instability can be rather short and reach $\\sim 10$ shear timescales.

Bonanno, Alfio

2007-01-01T23:59:59.000Z

89

Algebraic Characterizations of Flow-Network Typings  

E-Print Network (OSTI)

A flow network N is a capacited finite directed graph, with multiple input ports/arcs and multiple output ports/arcs. A flow f in N assigns a non-negative real number to every arc and is feasible if it satisfies flow conservation at every node and respects lower-bound/upper-bound capacities at every arc. We develop an algebraic theory of feasible flows in such networks with several beneficial consequences. We define algorithms to infer, from a given flow network N, an algebraic classification, which we call a typing for N, of all assignments f0 of values to the input and output arcs of N that can be extended to a feasible flow f. We then establish necessary and sufficient conditions on an arbitrary typing T guaranteeing that T is a valid typing for some flow network N. Based on these necessary and sufficient conditions, we define operations on typings that preserve their validity (to be typings for flow networks), and examine the implications for a typing theory of flow networks.

Assaf Kfoury

2012-01-01T23:59:59.000Z

90

flow_measurements_cryogenic  

Science Conference Proceedings (OSTI)

... A dynamic weighing system is used to measure ... using liquid nitrogen at flow rates of 1 ... For volumetric flow rate measurement, the uncertainty in fluid ...

2013-06-17T23:59:59.000Z

91

Multiphase flow calculation software  

DOE Patents (OSTI)

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.

Fincke, James R. (Idaho Falls, ID)

2003-04-15T23:59:59.000Z

92

Multiphase Flow Modeling Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Chris Guenther, Director Computational Science Division RUA Spring Meeting, Morgantown, WV March 2013 2 NETL's Multiphase Flow Science Team * The Multiphase Flow Science...

93

Semiclassical energy conditions  

E-Print Network (OSTI)

We present and develop several nonlinear energy conditions suitable for use in the semiclassical regime. In particular, we consider the recently formulated "flux energy condition" (FEC), and the novel "trace-of-square" (TOSEC) and "determinant" (DETEC) energy conditions. As we shall show, these nonlinear energy conditions behave much better than the classical linear energy conditions in the presence of semiclassical quantum effects. Moreover, whereas the quantum extensions of these nonlinear energy conditions seem to be quite widely satisfied as one enters the quantum realm, analogous quantum extensions are generally not useful for the linear classical energy conditions.

Martin-Moruno, Prado

2013-01-01T23:59:59.000Z

94

Flow assurance and multiphase pumping  

E-Print Network (OSTI)

A robust understanding and planning of production enhancement and flow assurance is required as petroleum E&P activities are targeting deepwaters and long distances. Different flow assurance issues and their solutions are put together in this work. The use of multiphase pumps as a flow assurance solution is emphasized. Multiphase pumping aids flow assurance in different ways. However, the problem causing most concern is sand erosion. This work involved a detection-based sand monitoring method. Our objectives are to investigate the reliability of an acoustic sand detector and analyze the feasibility of gel injection as a method to mitigate sand erosion. Use of a sand detector coupled with twin-screw pumps is studied under varying flow conditions. The feasibility of gel injection to reduce slip and transport produced solids through twin-screw pump is investigated. A unique full-scale laboratory with multiphase pumps was utilized to carry out the experimental tests. The test results indicate that acoustic sand detection works in a narrow window around the calibration signature. An empirical correlation for predicting the twin-screw pump performance with viscous fluids was developed. It shows good agreement in the practical operational limits – 50% to 100% speed. The results indicate that viscous gel injection should be an effective erosion mitigation approach as it reduces slip, the principle cause of erosive wear. To correlate the performance of viscous fluid injection to hydroabrasive wear, further experimental investigation is needed.

Nikhar, Hemant G.

2006-12-01T23:59:59.000Z

95

Air Conditioning and lungs  

NLE Websites -- All DOE Office Websites (Extended Search)

Air Conditioning and lungs Name: freeman Status: NA Age: NA Location: NA Country: NA Date: Around 1993 Question: What affect does air conditioning have upon the lungs of the...

96

Directed and elliptic flow in Au + Au at intermediate energies  

E-Print Network (OSTI)

Directed and elliptic flow for the Au + Au system at incident energies between 40 and 150 MeV per nucleon has been measured using the INDRA 4 pi multi-detector. For semi-central collisions, the elliptic flow of Z directed flow changes sign at a bombarding energy between 50 and 60 MeV per nucleon and remains negative at lower energies. The conditions for the appearance and possible origins of negative flow are discussed.

J. Lukasik; G. Auger; M. L. Begemann-Blaich; N. Bellaize; R. Bittiger; F. Bocage; B. Borderie; R. Bougault; B. Bouriquet; J. L. Charvet; A. Chbihi; R. Dayras; D. Durand; J. D. Frankland; E. Galichet; D. Gourio; D. Guinet; S. Hudan; P. Lautesse; F. Lavaud; A. Le Fevre; R. Legrain; O. Lopez; U. Lynen; W. F. J. Mueller; L. Nalpas; H. Orth; E. Plagnol; E. Rosato; A. Saija; C. Schwarz; C. Sfienti; B. Tamain; W. Trautmann; A. Trzcinski; K. Turzo; E. Vient; M. Vigilante; C. Volant; B. Zwieglinski

2004-10-20T23:59:59.000Z

97

Conditional belief types  

E-Print Network (OSTI)

We study type spaces where a player’s type at a state is a conditional probability on the space. We axiomatize these type spaces using conditional belief operators, and examine three additional axioms of increasing strength. First, introspection, which requires the agent to be unconditionally certain of her beliefs. Second, echo, according to which the unconditional beliefs implied by the condition must be held given the condition. Third, determination, which says that the conditional beliefs are the unconditional beliefs that are conditionally certain. The echo axiom implies that conditioning on an event is the same as conditioning on the event being certain, which formalizes the standard informal interpretation of conditioning in probability theory. The echo axiom also implies that the conditional probability given an event is a prior of the unconditional probability. The game-theoretic application of our model, which we treat in the context of an example, sheds light on a number of basic issues in the analysis of extensive form games. Type spaces are closely related to the sphere models of counterfactual conditionals and to models of hypothetical knowledge, and we discuss these relationships in detail.

Alfredo Di; Tillio Joseph; Y. Halpern; Dov Samet

2013-01-01T23:59:59.000Z

98

EPRI Increased Power Flow Guidebook -- 2011  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best-practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case studies, and analyzes th...

2011-12-12T23:59:59.000Z

99

Unsteady flow volumes  

SciTech Connect

Flow volumes are extended for use in unsteady (time-dependent) flows. The resulting unsteady flow volumes are the 3 dimensional analog of streamlines. There are few examples where methods other than particle tracing have been used to visualize time varying flows. Since particle paths can become convoluted in time there are additional considerations to be made when extending any visualization technique to unsteady flows. We will present some solutions to the problems which occur in subdivision, rendering, and system design. We will apply the unsteady flow volumes to a variety of field types including moving multi-zoned curvilinear grids.

Becker, B.G.; Lane, D.A.; Max, N.L.

1995-03-01T23:59:59.000Z

100

Terms and Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Terms and Conditions Terms and Conditions Terms and Conditions As a premier national research and development laboratory, LANL seeks to do business with qualified companies that offer value and high quality products and services. Contact Small Business Office (505) 667-4419 Email Use information below as guideline to doing business An "Appendix SFA-1" contains FAR and DEAR Clauses that are incorporated by reference into a particular subcontract. "Exhibit A General Conditions" are the general terms and conditions applicable to a particular subcontract. Note: The contents of the SFA-1 and Exhibit A (below) are not the only terms and conditions that will be in a LANS subcontract but represent the terms that generally do not change in a particular type of procurement. The

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Flow cytometer jet monitor system  

DOE Patents (OSTI)

A direct jet monitor illuminates the jet of a flow cytometer in a monitor wavelength band which is substantially separate from the substance wavelength band. When a laser is used to cause fluorescence of the substance, it may be appropriate to use an infrared source to illuminate the jet and thus optically monitor the conditions within the jet through a CCD camera or the like. This optical monitoring may be provided to some type of controller or feedback system which automatically changes either the horizontal location of the jet, the point at which droplet separation occurs, or some other condition within the jet in order to maintain optimum conditions. The direct jet monitor may be operated simultaneously with the substance property sensing and analysis system so that continuous monitoring may be achieved without interfering with the substance data gathering and may be configured so as to allow the front of the analysis or free fall area to be unobstructed during processing.

Van den Engh, Ger (Seattle, WA)

1997-01-01T23:59:59.000Z

102

Movements in air conditioning.  

E-Print Network (OSTI)

??Movements in Air Conditioning is a collection of poems that explores the obstacles inherent in creating a new sense of home in a country that… (more)

Hitt, Robert D. (Robert David)

2013-01-01T23:59:59.000Z

103

Operating Conditions Opportunity  

NLE Websites -- All DOE Office Websites (Extended Search)

Components in Aggressive Operating Conditions Opportunity Research is active on the patent-pending technology, titled "3-Dimensional Functionally Gradient Coatings for...

104

High differential pressure, radial flow characteristics of gun perforations  

Science Conference Proceedings (OSTI)

Tubing conveyed completion techniques are being utilized more frequently than in the past, because of the apparent advantages derived from underbalanced perforating. These advantages include cleaner perforations, reductions of additional stimulation treatments and reduced completion times. This paper presents the results of a laboratory study of gun perforations made under high differential pressure, radial flow conditions. In this study, Berea sandstone cores, modified to permit radial flow, are used to determine the relationship between perforation characteristics and the time-dependent pressure differential between pore pressure (i.e. formation pressure) and ''well bore'' pressure during the completion process. The primary perforation characteristic investigated (Radial Flow Ratio) is defined as the ratio of the perforated flow rate to the flow rate of the unperforated core under identical conditions. The perforated flow rate is measured in radial flow after the perforation has been made under various time-dependent pressure differentials.

Regalbuto, J.A.; Riggs, R.S.

1985-01-01T23:59:59.000Z

105

Structure of Offshore Flow  

Science Conference Proceedings (OSTI)

The horizontal and vertical structure of the mean flow and turbulent fluxes are examined using aircraft observations taken near a barrier island on the east coast of the United States during offshore flow periods. The spatial structure is ...

Dean Vickers; L. Mahrt; Jielun Sun; Tim Crawford

2001-05-01T23:59:59.000Z

106

Myocardial blood flow during induced aortic hypertension in dogs  

SciTech Connect

Myocardial blood flow was measured in anesthetized dogs during control conditions and under conditions where the aortic pressure was increased due to aortic constriction or during infusion. Blood flow was measured using the radioactive microsphere technique. Radioactive microspheres (15 m Ce-141, Sr-85, and Sc-46) were injected under control, aortic constriction and arterenol infusion in four dogs and under control conditions in two others. All microsphere injections were performed under stabilized conditions. It was found that coronary blood flow rose by 80% during aortic constriction and by 158% during arterenol infusion (P < 0.05). This increase in blood flow was not uniform throughout the heart, and higher increases were observed in the middle and apex regions of the left ventricle. Furthermore, under hypertension the increase in blood flow in LAD (left anterior descending) perfused territories was slightly higher than that in CFX (left circumflex) perfused territories.

Thai, B.N.; Levesque, M.J.; Nerem, R.M.

1986-03-01T23:59:59.000Z

107

Ultrasonic flow metering system  

DOE Patents (OSTI)

A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.

Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

108

Elbow mass flow meter  

SciTech Connect

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.

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

1994-01-01T23:59:59.000Z

109

Simplified Space Conditioning  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Simplified Space Conditioning Simplified Space Conditioning Duncan Prahl, RA IBACOS, Inc. Building America Technical Update April 29, 2013 Simplified Space Conditioning Rethinking HVAC Design * Traditional Method - Assume envelope losses dictate the load - Room by room load analysis - Pick Equipment and distribute to meet the load in each room * New Method - Consider how the occupants live in the building - Seriously consider internal gains in both heating and cooling - Consider ventilation strategy - Design system Simplified Space Conditioning If you are: * A production builder * Participating in "above code" programs * Following ACCA Manual RS or ASHRAE 55 * Need to prove "delivering heat to each habitable room" * Concerned about litigation * Play it safe, Use Manual J, S & D and condition every

110

Columbia University flow instability experimental program: Volume 3. Single tube parallel flow tests  

SciTech Connect

The coolant in the Savannah River Site (SRS) production nuclear reactor assemblies is circulated as a subcooled liquid under normal operating conditions. This coolant is evenly distributed throughout multiple annular flow channels with a uniform pressure profile across each coolant flow channel. During the postulated Loss of Coolant Accident (LOCA), which is initiated by a hypothetical guillotine pipe break, the coolant flow through the reactor assemblies is significantly reduced. The flow reduction and accompanying power reduction (after shutdown is initiated) occur in the first 1--2 seconds of the LOCA. This portion of the LOCA is referred to as the Flow Instability phase. A series of down flow experiments have been conducted on three different size single tubes. The objective of these experiments was to determine the effect of a parallel flow path on the occurrence of flow instability. In all cases, it has been shown that the point of flow instability (OFI) determined under controlled flow operation does not change when operating in a controlled pressure drop mode (parallel path operation).

Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

1990-06-01T23:59:59.000Z

111

Redox Flow Batteries: a Review  

NLE Websites -- All DOE Office Websites (Extended Search)

1137-1164 Date Published 102011 ISSN 1572-8838 Keywords Flow battery, Flow cell, Redox, Regenerative fuel cell, Vanadium Abstract Redox flow batteries (RFBs) are enjoying a...

112

Silica gel sorption properties under adiabatic conditions  

DOE Green Energy (OSTI)

The SERI Sorption Test Facility was modified from isothermal operation to adiabatic operating conditions so that we could measure the adsorption/desorption characteristics of silica-gel-coated, parallel-channel geometry as a function of operating conditions and aspect ratio under adiabatic conditions. We performed single-blow experiments on two single-passage test cells with different aspect ratios, air flow rates, and inlet conditions. Both adsorption and desorption runs were performed. As the air flow rate and aspect ratio increase when other parameters are kept constant, the desiccant matrix loses its sorption capacity faster. The test cell operated near isothermal conditions rather than adiabatically because the cell walls had a large thermal mass compared with the amount of desiccant used. Since constructing single-passage test cells with small thermal masses that can be operated adiabatically at the Sorption Test Facility is difficult, further testing at this facility will be primarily for isothermal operation. The adiabatic experiments can best be done with multipassage test cells having small thermal masses relative to desiccant mass. A single-blow test facility for performing experiments with multipassage test cells was fabricated in FY 1984, and experiments were performed in an FY 1985 desiccant project.

Pesaran, A.A.; Choudhury, K.

1986-02-01T23:59:59.000Z

113

Lateral flow strip assay  

DOE Patents (OSTI)

A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

Miles, Robin R. (Danville, CA); Benett, William J. (Livermore, CA); Coleman, Matthew A. (Oakland, CA); Pearson, Francesca S. (Livermore, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

2011-03-08T23:59:59.000Z

114

Cost Sensitive Conditional Planning  

E-Print Network (OSTI)

While POMDPs provide a general platform for conditional planning under a wide range of quality metrics they have limited scalability. On the other hand, uniform probability conditional planners scale very well, but many lack the ability to optimize plan quality metrics. We present an innovation to planning graph based heuristics that helps uniform probability conditional planners both scale and generate high quality plans when using actions with non uniform costs. We make empirical comparisons with two state of the art planners to show the benefit of our techniques.

Daniel Bryce; Subbarao Kambhampati

2005-01-01T23:59:59.000Z

115

Inhomogeneity of fluid flow in Stirling engine regenerators  

SciTech Connect

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

Jones, J.D. (School of Engineering Science, Simon Fraser Univ. Burnaby, British Columbia (CA))

1989-10-01T23:59:59.000Z

116

ARM - Measurement - Surface condition  

NLE Websites -- All DOE Office Websites (Extended Search)

condition condition ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Surface condition State of the surface, including vegetation, land use, surface type, roughness, and such; often provided in model output. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments NAV : Navigational Location and Attitude SURFLOG : SGP Surface Conditions Observations by Site Technicians S-TABLE : Stabilized Platform MET : Surface Meteorological Instrumentation

117

Anemometry in Icing Conditions  

Science Conference Proceedings (OSTI)

The accuracy of wind measurements in icing conditions is discussed, and wind tunnel calibrations as well as field comparisons are presented for three heated anemometers that use different measuring principles. It is pointed out that ice-free ...

Lasse Makkonen; Pertti Lehtonen; Lauri Helle

2001-09-01T23:59:59.000Z

118

Terms and Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Terms and Conditions Terms and Conditions R&D Overview 100G Testbed Testbed Description Testbed Results Current Testbed Research Proposal Process Terms and Conditions Virtual Circuits (OSCARS) Performance (perfSONAR) Tools Development Green Networking Authentication & Trust Federation (ATF) Partnerships Contact Us Technical Assistance: 1 800-33-ESnet (Inside the US) 1 800-333-7638 (Inside the US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Terms and Conditions Researchers must provide ESnet copies of any articles, presentations, and publications based on testbed research for posting on the ESnet Testbed web site. All publications based on work conducted on the testbed must include the following statement:

119

Exponential Conditional Volatility Models  

E-Print Network (OSTI)

- relation function (ACF) is less straightforward than it is for a GARCHmodel, analytic expressions can be obtained and these expressions are more general. Speci?cally, formulae for the ACF of the (absolute values of ) the observations raised to any power can... proposes an exponential link function for the conditional mean in gamma and Weibull distributions. As well as setting out the conditions for the asymptotic theory to be valid, expressions for moments, ACFs and multi-step forecasts are derived. Leverage...

Harvey, Andrew

2010-08-24T23:59:59.000Z

120

Method for identifying anomalous terrestrial heat flows  

DOE Patents (OSTI)

A method for locating and mapping the magnitude and extent of terrestrial heat-flow anomalies from 5 to 50 times average with a tenfold improved sensitivity over orthodox applications of aerial temperature-sensing surveys as used for geothermal reconnaissance. The method remotely senses surface temperature anomalies such as occur from geothermal resources or oxidizing ore bodies by: measuring the spectral, spatial, statistical, thermal, and temporal features characterizing infrared radiation emitted by natural terrestrial surfaces; deriving from these measurements the true surface temperature with uncertainties as small as 0.05 to 0.5 K; removing effects related to natural temperature variations of topographic, hydrologic, or meteoric origin, the surface composition, detector noise, and atmospheric conditions; factoring out the ambient normal-surface temperature for non-thermally enhanced areas surveyed under otherwise identical environmental conditions; distinguishing significant residual temperature enhancements characteristic of anomalous heat flows and mapping the extent and magnitude of anomalous heat flows where they occur.

Del Grande, Nancy Kerr (San Leandro, CA)

1977-01-25T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Bypass flow computations on the LOFA transient in a VHTR  

Science Conference Proceedings (OSTI)

Bypass flow in the prismatic gas-cooled very high temperature reactor (VHTR) is not intentionally designed to occur, but is present in the gaps between graphite blocks. Previous studies of the bypass flow in the core indicated that the cooling provided by flow in the bypass gaps had a significant effect on temperature and flow distributions for normal operating conditions. However, the flow and heat transports in the core are changed significantly after a Loss of Flow Accident (LOFA). This study aims to study the effect and role of the bypass flow after a LOFA in terms of the temperature and flow distributions and for the heat transport out of the core by natural convection of the coolant for a 1/12 symmetric section of the active core which is composed of images and mirror images of two sub-region models. The two sub-region models, 9 x 1/12 and 15 x 1/12 symmetric sectors of the active core, are employed as the CFD flow models using computational grid systems of 70.2 million and 117 million nodes, respectively. It is concluded that the effect of bypass flow is significant for the initial conditions and the beginning of LOFA, but the bypass flow has little effect after a long period of time in the transient computation of natural circulation.

Yu-Hsin Tung; Richard W. Johnson; Yuh-Ming Ferng; Ching-Chang Chieng

2014-01-01T23:59:59.000Z

122

Potential Vorticity of Flow along the Alps  

Science Conference Proceedings (OSTI)

Observations from the German Front Experiment are presented here that show the existence—in conditions with a dominant flow component parallel to the main Alpine chain—of a mesoscale region to the north of the Alps where the absolute and ...

Alan J. Thorpe; Hans Volkert; Dietrich Heimann

1993-06-01T23:59:59.000Z

123

Solids mass flow determination  

DOE Patents (OSTI)

Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)

1981-01-01T23:59:59.000Z

124

Turbulent flow in graphene  

E-Print Network (OSTI)

We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

Kumar S. Gupta; Siddhartha Sen

2009-11-03T23:59:59.000Z

125

ECWEBTermsandConditions.doc  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

US DEPARTMENT OF ENERGY US DEPARTMENT OF ENERGY ELECTRONIC COMMERCE PROCEDURES, TERMS AND CONDITIONS Version 1.0 May 1, 1998 PROCEDURES What follows prescribes the general procedures and policies to be followed when Electronic Data Interchange (EDI) is used for transmitting requests for quote, quotations, purchase orders, or other business information in lieu of creating one or more paper documents normally associated with conducting business with the Government. See the Terms and Conditions section below for a list of the standard FAR (Federal Acquisition Regulation) and DEAR (Department of Energy Acquisition Regulation) clauses and provisions mandated to be included in Government contracting actions. The Terms and Conditions together with any clauses specified in the specific contract transaction,

126

Multiple sort flow cytometer  

DOE Patents (OSTI)

A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane.

Van den Engh, Ger (Seattle, WA); Esposito, Richard J. (Seattle, WA)

1996-01-01T23:59:59.000Z

127

Droplet Laden Flow Data  

Science Conference Proceedings (OSTI)

... Flow Past a Heated Cylinder, Atomization and Sprays, 2006, 16(6 ... Numerical Modeling and Experimental Measurements of Water Spray Impact and ...

2013-07-15T23:59:59.000Z

128

Black String Flow  

E-Print Network (OSTI)

We give an exact description of the steady flow of a black string into a planar horizon. The event horizon is out of equilibrium and provides a simple, exact instance of a `flowing black funnel' in any dimension D>=5. It is also an approximation to a smooth intersection between a black string and a black hole, in the limit in which the black hole is much larger than the black string thickness. The construction extends easily to more general flows, in particular charged flows.

Emparan, Roberto

2013-01-01T23:59:59.000Z

129

Visualization of Fluid Flow  

Science Conference Proceedings (OSTI)

... Goujon and J. Devaney, Large Scale Simulations of Single and Multi- Component Flow in Porous Media in Proceedings of SPIE: The International ...

2010-12-15T23:59:59.000Z

130

NETL: Gasifipedia - Entrained Flow Gasifiers  

NLE Websites -- All DOE Office Websites (Extended Search)

Entrained Flow Gasifiers Entrained Flow Gasifiers Uhde - Prenflo PRENFLO(tm) is a pressurized (>40 bar), entrained-flow gasification technology first demonstrated in the late 1980s, and currently offered by Uhde (Krupp Koppers merged with Uhde in 1997). Notably, PRENFLO(tm) is the gasification technology used at the world's largest solid feedstock-based gasifier at ELCOGAS's Puertollano IGCC plant in Spain (which is fueled with a 50%/50% mix of petcoke and coal). PRENFLO(tm) is offered in two varieties, the PRENFLO(tm) PSG (with steam generation) depicted in Figures 1 & 2, and PRENFLO(tm) PDQ (direct quench) as depicted in Figures 3 & 4. The gasifier conditions and feed characteristics are similar, but PRENFLO(tm) PSG includes an integrated waste heat boiler and uses compressed recirculated quench gas as illustrated in Figure 2, resulting in relatively low moisture raw syngas at relatively high exit temperature. PRENFLO(tm) PDQ uses direct quench, resulting in considerably lower raw syngas exit temperature (200-250°C) which is saturated. Uhde notes that PDQ has lower investment cost and shorter construction and supply schedule than PSG, though this would be at the performance expense of somewhat lower thermal efficiency and slightly higher concentration of CO2 in raw syngas.

131

Mineralogy under extreme conditions  

Science Conference Proceedings (OSTI)

We have performed measurements of minerals based on the synchrotron source for single crystal and powder X-ray diffraction, inelastic scattering, spectroscopy and radiography by using diamond anvil cells. We investigated the properties of iron (Fe), iron-magnesium oxides (Fe, Mg)O, silica(SiO{sub 2}), iron-magnesium silicates (Fe, Mg)SiO{sub 3} under simulated high pressure-high temperature extreme conditions of the Earth's crust, upper mantle, low mantle, core-mantle boundary, outer core, and inner core. The results provide a new window on the investigation of the mineral properties at Earth's conditions.

Shu, Jinfu (CIW)

2012-02-07T23:59:59.000Z

132

Dual flow--temperature--humidity control system operating manual  

SciTech Connect

The manual contains operating, maintenance, and troubleshooting procedures for a dual flow--temperature--humidity control system used at the Lawrence Livermore Laboratory to prepare test atmospheres for industrial hygiene and air pollution studies. The system consists of two basic components: a commercially available temperature/humidity indicator unit and a specially built dual flow--temperature--humidity control module that provides two air sources controlled at the same conditions of flow, temperature, and relative humidity.

Nelson, G.O.; Taylor, R.D.

1978-12-15T23:59:59.000Z

133

Summer Wind Flow Regimes over the Sacramento Valley  

Science Conference Proceedings (OSTI)

This study utilized conditional sampling to identify three frequent wind regimes in the lower Sacramento Valley. The major flow features of the mean diurnal wind patterns in the southern Sacramento Valley and surrounding areas were analyzed for ...

Laura L. Zaremba; John J. Carroll

1999-10-01T23:59:59.000Z

134

Instability Analysis of Terrain-Induced Canopy Flows  

Science Conference Proceedings (OSTI)

Tall vegetation and complex terrain create difficult conditions for measuring and modeling net ecosystem–atmosphere exchanges of carbon, water vapor, and pollutants. The instability of canopy flow regimes over complex terrain is critical for ...

Chuixiang Yi

2009-07-01T23:59:59.000Z

135

Dynamic Response of Single Electrode Conductivity Probes in Slow Flows  

Science Conference Proceedings (OSTI)

Four designs of single electrode conductivity probes, three of them new, were tested for response characteristics in conditions simulating laboratory internal wave flows. Two of the new designs were shown to be significantly superior in sensing ...

William F. Simmons; Barry R. Ruddick

1984-03-01T23:59:59.000Z

136

A Comparison of Nocturnal Drainage Flow in Three Tributaries  

Science Conference Proceedings (OSTI)

The characteristics of tributary drainage flow in stable, nocturnal conditions in three closely located tributaries are compared. The orientation of the tributaries with respect to Kimball Creek, into which they drain, appears to be a controlling ...

Richard L. Coulter; Timothy J. Martin; William M. Porch

1991-02-01T23:59:59.000Z

137

Update on the Long-Term Flow Testing Program  

DOE Green Energy (OSTI)

Preliminary flow and pressure testing of the Phase II Hot Dry Rock (HDR) reservoir at Fenton Hill, New Mexico, as part of the preparations for the initial 90-day segment of the Long-Term Flow Test, has revealed several significant features concerning the hydraulic behavior of this reservoir as a function of injection and production pressure levels. Of most significance to the future operation of HDR power plants is the influence of elevated production backpressure on the effective reservoir flow impedance (i.e., the difference between injection and production pressures, divided by the production flow rate). It has been found that the effective flow impedance at high backpressure is significantly lower than the corresponding impedance at low backpressure. At an injection pressure of 3700 psi and a back-pressure of 2210 psi, the effective flow impedance for the present reservoir is 20 psi/gpm--less than 40% of the effective flow impedance for similar injection conditions, but at low backpressure (about 170 psi). Recently, a 10-day reservoir flow test was conducted at a somewhat lower backpressure of 1500 psi, and at a slightly higher injection pressure of 3750 psi. At these new conditions, there was an increase in the effective reservoir flow impedance to 23.6 psi/gpm, but also a significant increase in the production flow rate and temperature--from 74 gpm to 95 gpm, and from 154 C to 180 C. The net reservoir water loss rate averaged over the last 5 days of this latest flow test was 7.3 gpm, which corresponds to a net recovery of 93% of the injected water--a very significant result that has been obtained from our preliminary reservoir flow testing. Under both of these high backpressure flow conditions, the reservoir was not extending, as evidenced by a very low rate of water loss and the absence of microseismic activity.

Brown, Donald W.

1992-03-24T23:59:59.000Z

138

Capabilities for information flow  

Science Conference Proceedings (OSTI)

This paper presents a capability-based mechanism for permissive yet secure enforcement of information-flow policies. Language capabilities have been studied widely, and several popular implementations, such as Caja and Joe-E, are available. By making ... Keywords: capabilities, information flow control

Arnar Birgisson; Alejandro Russo; Andrei Sabelfeld

2011-06-01T23:59:59.000Z

139

Elbow mass flow meter  

DOE Patents (OSTI)

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.

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

1994-08-16T23:59:59.000Z

140

Investigation of flow characteristics of gas turbines  

SciTech Connect

Measurements carried out in the process of assimilation of gas turbine (GT) plants of 16 different types in starting and working conditions to estimate the operational conditions and characteristics of the main elements (in particular of the turbines) have created a basis for generaliztion of flow characteristics of different turbines and for extending them to a wider range of operational conditions. The studies showed that: flow characteristics of the investigated turbines, independently of the number of stages and the degree of reaction, are described by the elliptic flowrate equation; throughput of similar turbines, i.e., of turbines formed of stages with high reaction, which have low design degrees of expansion, can be determined with satisfactory accuracy by the unique function of the degree of expansion; and in operating the gas turbine plants considerable changes in throughput of the turbines are possible.

Ol' khovskii, G.G.; Ol' khovskaya, N.I.

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Evaluation of uncertainties due to hydrogeological modeling and groundwater flow analysis: Steady flow, transient flow, and thermal studies  

SciTech Connect

Starting with regional geographic, geologic, surface and subsurface hydrologic, and geophysical data for the Tono area in Gifu, Japan, we develop an effective continuum model to simulate subsurface flow and transport in a 4 km by 6 km by 3 km thick fractured granite rock mass overlain by sedimentary layers. Individual fractures are not modeled explicitly. Rather, continuum permeability and porosity distributions are assigned stochastically, based on well-test data and fracture density measurements. Lithologic layering and one major fault, the Tsukiyoshi Fault, are assigned deterministically. We conduct three different studies: (1) the so-called base case, in which the model simulates the steady-state groundwater flow through the site, and then stream trace analysis is used to calculate travel times to the model boundary from specified release points; (2) simulations of transient flow during long term pump tests (LTPT) using the base-case model; and (3) thermal studies in which coupled heat flow and fluid flow are modeled, to examine the effects of the geothermal gradient on groundwater flow. The base-case study indicates that the choice of open or closed lateral boundaries has a strong influence on the regional groundwater flow patterns produced by the models, but no field data exist that can be used to determine which boundary conditions are more realistic. The LTPT study cannot be used to distinguish between the alternative boundary conditions, because the pumping rate is too small to produce an analyzable pressure response at the model boundaries. In contrast, the thermal study shows that the temperature distributions produced by the open and closed models differ greatly. Comparison with borehole temperature data may be used to eliminate the closed model from further consideration.

Doughty, Christine; Karasaki, Kenzi

2002-12-11T23:59:59.000Z

142

Parametric System Curves: Correlations Between Fan Pressure Rise and Flow for Large Commercial Buildings  

E-Print Network (OSTI)

distribution, duct design, system curve, fans, leakage iiifan pressure rise and flow measurements over a range of operating conditions. During design,

Sherman, Max

2010-01-01T23:59:59.000Z

143

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

comparison of VAV and VRF air conditioning systems in anThe variable refrigerant flow (VRF) and ground source heatthe energy efficiency of VRF systems compared with GSHP

Hong, Tainzhen

2010-01-01T23:59:59.000Z

144

Flow dynamics and solute transport in unsaturated rock fractures  

DOE Green Energy (OSTI)

Rock fractures play an important role in flow and contaminant transport in fractured aquifers, production of oil from petroleum reservoirs, and steam generation from geothermal reservoirs. In this dissertation, phenomenological aspects of flow in unsaturated fractures were studied in visualization experiments conducted on a transparent replica of a natural, rough-walled rock fracture for inlet conditions of constant pressure and flow rate over a range of angles of inclination. The experiments demonstrated that infiltrating liquid proceeds through unsaturated rock fractures along non-uniform, localized preferential flow paths. Even in the presence of constant boundary conditions, intermittent flow was a persistent flow feature observed, where portions of the flow channel underwent cycles of snapping and reforming. Two modes of intermittent flow were observed, the pulsating blob mode and the rivulet snapping mode. A conceptual model for the rivulet snapping mode was proposed and examined using idealized, variable-aperture fractures. The frequency of intermittent flow events was measured in several experiments and related to the capillary and Bond numbers to characterize this flow behavior.

Su, G. W.

1999-10-01T23:59:59.000Z

145

Sampling Conditioned Hypoelliptic Diffusions  

E-Print Network (OSTI)

A series of recent articles introduced a method to construct stochastic partial differential equations (SPDEs) which are invariant with respect to the distribution of a given conditioned diffusion. These works are restricted to the case of elliptic diffusions where the drift has a gradient structure, and the resulting SPDE is of second order parabolic type. The present article extends this methodology to allow the construction of SPDEs which are invariant with respect to the distribution of a class of hypoelliptic diffusion processes, subject to a bridge conditioning. This allows the treatment of more realistic physical models, for example one can use the resulting SPDE to study transitions between meta-stable states in mechanical systems with friction and noise. In this situation the restriction of the drift being a gradient can also be lifted.

Hairer, Martin; Voss, Jochen

2009-01-01T23:59:59.000Z

146

Boiler Condition Assessment Guideline  

Science Conference Proceedings (OSTI)

This report Boiler Condition Assessment Guideline provides a concise overview of procedures developed by the Electric Power Research Institute EPRI to help power plant operators cost-effectively determine the extent of degradation and remaining life of key boiler components. The Guideline draws from EPRIs detailed area-specific guidelines, which in turn are based on extensive research findings by EPRI, member companies, and other organizations. This Guideline offers a starting point for power plant perso...

2010-12-23T23:59:59.000Z

147

Conditional SIC-POVMs  

E-Print Network (OSTI)

In this paper we examine a generalization of the symmetric informationally complete POVMs. SIC-POVMs are the optimal measurements for full quantum tomography, but if some parameters of the density matrix are known, then the optimal SIC POVM should be orthogonal to a subspace. This gives the concept of the conditional SIC-POVM. The existence is not known in general, but we give a result in the special cases when the diagonal is known of the density matrix.

D. Petz; L. Ruppert; A. Szanto

2012-02-26T23:59:59.000Z

148

Conditional SIC-POVMs  

E-Print Network (OSTI)

In this paper we examine a generalization of the symmetric informationally complete POVMs. SIC-POVMs are the optimal measurements for full quantum tomography, but if some parameters of the density matrix are known, then the optimal SIC POVM should be orthogonal to a subspace. This gives the concept of the conditional SIC-POVM. The existence is not known in general, but we give a result in the special cases when the diagonal is known of the density matrix.

Petz, D; Szanto, A

2012-01-01T23:59:59.000Z

149

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Stringfield, R.M.; Wheat, R.M. Jr.

1989-02-21T23:59:59.000Z

150

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

151

Solar air conditioning  

DOE Green Energy (OSTI)

Development of a hybrid solar-assisted air conditioning system that combines a vapor compression section for sensible cooling with a desiccant section for dehumidification and that uses both solar energy and condenser waste heat to drive the dehumidifier has been under way for the last two years (1981 and 1982). The results of this research are included in this report: utilizing solar energy in an economical way has proven quite difficult.

Robison, H.

1981-01-01T23:59:59.000Z

152

Fuel gas conditioning process  

DOE Patents (OSTI)

A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

Lokhandwala, Kaaeid A. (Union City, CA)

2000-01-01T23:59:59.000Z

153

Heat flow of Oregon  

DOE Green Energy (OSTI)

An extensive new heat flow and geothermal gradient data set for the State of Oregon is presented on a contour map of heat flow at a scale of 1:1,000,000 and is summarized in several figures and tables. The 1:1,000,000 scale heat flow map is contoured at 20 mW/m/sup 2/ (0.5 HFU) intervals. Also presented are maps of heat flow and temperature at a depth of 1 km averaged for 1/sup 0/ x 1/sup 0/ intervals. Histograms and averages of geothermal gradient and heat flow for the State of Oregon and for the various physiographic provinces within Oregon are also included. The unweighted mean flow for Oregon is 81.3 +- 2.7 mW/m/sup 2/ (1.94 +- 0.06 HFU). The average unweighted geothermal gradient is 65.3 +- 2.5/sup 0/C/km. The average heat flow value weighted on the basis of geographic area is 68 +- 5 mW/m/sup 2/ (1.63 +- 0.12 HFU) and the average weighted geothermal gradient is 55.0 +- 5/sup 0/C/km.

Blackwell, D.D.; Hull, D.A.; Bowen, R.G.; Steele, J.L.

1978-01-01T23:59:59.000Z

154

Multiphase Flow Modeling Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Science Chris Guenther, Director Computational Science Division RUA Spring Meeting, Morgantown, WV March 2013 2 NETL's Multiphase Flow Science Team * The Multiphase Flow Science Team develops physics-based simulation models to conduct applied scientific research. - Development of new theory - Extensive on-site and collaborative V&V efforts and testing - Engages in technology transfer - Applies the models to industrial scale problems. 3 Why is Multiphase Flow Science Needed? * Industry is increasingly relying on multiphase technologies to produce clean and affordable energy with carbon capture. * Unfortunately, the presence of a solid phase reduces the operating capacity of a typical energy device from its original design on average by 40% [1].

155

Shroud leakage flow discouragers  

SciTech Connect

A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.

Bailey, Jeremy Clyde (Middle Grove, NY); Bunker, Ronald Scott (Niskayuna, NY)

2002-01-01T23:59:59.000Z

156

Attachment K TERMS AND CONDITIONS  

E-Print Network (OSTI)

Attachment K TERMS AND CONDITIONS AWARD # #12;TERMS AND CONDITIONS TABLE OF CONTENTS SECTION PAGE ............................................................................... 24 i #12;TERMS AND CONDITIONS 1. Grant Agreement This project is being funded with a grant from, the Terms and Conditions, and all attachments. These Terms and Conditions are standard requirements

157

RMOTC - Testing - Flow Assurance  

NLE Websites -- All DOE Office Websites (Extended Search)

Flow Assurance Flow Assurance RMOTC Flow Loop Facility Layout Notice: As of July 15th 2013, the Department of Energy announced the intent to sell Naval Petroleum Reserve Number 3 (NPR3). The sale of NPR-3 will also include the sale of all equipment and materials onsite. A decision has been made by the Department of Energy to complete testing at RMOTC by July 1st, 2014. RMOTC will complete testing in the coming year with the currently scheduled testing partners. For more information on the sale of NPR-3 and sale of RMOTC equipment and materials please join our mailing list here. Over a decade ago, RMOTC began cooperatively building a full-scale facility to test new flow assurance technology, mainly in the areas of hydrates and paraffins. Today, RMOTC's test facility consists of five individual loop

158

Maple Sap Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

I know a little about this topic even though I am from Illinois which is far from the heart of maple syrup country. Sap flows from a maple tree by internal pressure caused by the...

159

Modons in Shear Flow  

Science Conference Proceedings (OSTI)

Modons in shear flow are computed as equilibrium solutions of the equivalent barotropic vorticity equation using a numerical Newton–Kantorovich iterative technique with double Fourier spectral expansion. The model is given a first guess of an ...

Sue Ellen Haupt; James C. McWilliams; Joseph J. Tribbia

1993-05-01T23:59:59.000Z

160

Stochastically scalable flow control  

Science Conference Proceedings (OSTI)

Recent advances in the mathematical analysis of flow control have prompted the creation of the Scalable TCP (STCP) and Exponential RED (E-RED) algorithms. These are designed to be scalable under the popular deterministic delay ...

Thomas Voice

2009-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

RG flows and instantons  

Science Conference Proceedings (OSTI)

In these two lectures I discuss RG flow solutions in (1,0) six dimensional supergravity involving SU(2) Yang-Mills instantons. in the conformally flat part of the 6D metric. The solutions interpolate between two (4,0) supersymmetric AdS{sub 3} Multiplication-Sign S{sup 3} backgrounds with different values of AdS{sub 3} and S{sup 3} radii and describe RG flows in the dual 2D SCFT. The flows described are of v.e.v. type, driven by a vacuum expectation value of a (not exactly) marginal operator of dimension 2 in the UV. We give an interpretation of the supergravity solution in terms of the D1/D5 system in type I string theory on K3, whose effective field theory is expected to flow to a (4,0) SCFT in the infrared.

Gava, Edi [INFN, Trieste (Italy)

2012-09-24T23:59:59.000Z

162

Parallel flow diffusion battery  

DOE Patents (OSTI)

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)

1984-08-07T23:59:59.000Z

163

Islands in Zonal Flow  

Science Conference Proceedings (OSTI)

The impact of a meridional gradient in sea surface temperature (warm toward the equator, cold toward the pole) on the circulation around an island is investigated. The upper-ocean eastward geostrophic flow that balances such a meridional gradient ...

Michael A. Spall

2003-12-01T23:59:59.000Z

164

Parallel flow diffusion battery  

DOE Patents (OSTI)

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, H.C.; Cheng, Y.S.

1984-01-01T23:59:59.000Z

165

Casting Flow Chart  

Science Conference Proceedings (OSTI)

Figure: ...Fig. 1 Simplified flow diagram of the basic operations for producing a steel casting. Similar diagrams can be applied to other ferrous and nonferrous alloys produced by sand

166

Analysis of Chemically Reacting Gas Flow and Heat Transfer in Methane Reforming Processes  

Science Conference Proceedings (OSTI)

This paper presents simulation and analysis of gas flow and heat transfer affected by chemical reactions relating to steam reforming of methane in a compact reformer. The reformer conditions such as the combined thermal boundary conditions on solid walls, ...

Guogang Yang; Danting Yue; Xinrong Lv; Jinliang Yuan

2009-10-01T23:59:59.000Z

167

Scaled Experimental Modeling of VHTR Plenum Flows  

DOE Green Energy (OSTI)

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.

ICONE 15

2007-04-01T23:59:59.000Z

168

Three dimensional flow processor  

DOE Patents (OSTI)

The 3D-flow processor is a general purpose programmable data stream pipelined device that allows fast data movement in six directions for digital signal processing applications such as identifying objects in a matrix in a programmable form. The 3D-flow processor can be used in one dimensional, two dimensional, and three dimensional topologies capable of sustaining an input data rate of up to 100 million data (or frames) per second in a parallel processing system.

Crosetto, D.B.

1992-01-01T23:59:59.000Z

169

Forced convective flow and heat transfer of upward cocurrent air-water slug flow in vertical plain and swirl tubes  

SciTech Connect

This experimental study comparatively examined the two-phase flow structures, pressured drops and heat transfer performances for the cocurrent air-water slug flows in the vertical tubes with and without the spiky twisted tape insert. The two-phase flow structures in the plain and swirl tubes were imaged using the computerized high frame-rate videography with the Taylor bubble velocity measured. Superficial liquid Reynolds number (Re{sub L}) and air-to-water mass flow ratio (AW), which were respectively in the ranges of 4000-10000 and 0.003-0.02 were selected as the controlling parameters to specify the flow condition and derive the heat transfer correlations. Tube-wise averaged void fraction and Taylor bubble velocity were well correlated by the modified drift flux models for both plain and swirl tubes at the slug flow condition. A set of selected data obtained from the plain and swirl tubes was comparatively examined to highlight the impacts of the spiky twisted tape on the air-water interfacial structure and the pressure drop and heat transfer performances. Empirical heat transfer correlations that permitted the evaluation of individual and interdependent Re{sub L} and AW impacts on heat transfer in the developed flow regions of the plain and swirl tubes at the slug flow condition were derived. (author)

Chang, Shyy Woei [Thermal Fluids Laboratory, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China); Yang, Tsun Lirng [Department of Marine Engineering, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China)

2009-10-15T23:59:59.000Z

170

Advanced Flow-Battery Systems  

Science Conference Proceedings (OSTI)

Presentation Title, Advanced Flow-Battery Systems ... Abstract Scope, Flow- battery systems (FBS) were originally developed over 30 years ago and have since ...

171

Fluid Metrology Calibration Services - Water Flow  

Science Conference Proceedings (OSTI)

Fluid Metrology Calibration Services - Water Flow. Water Flow Calibrations 18020C. ... NIST provides calibration services for water flow meters. ...

2011-10-03T23:59:59.000Z

172

Conditional sterility in plants  

DOE Patents (OSTI)

The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

Meagher, Richard B. (Athens, GA); McKinney, Elizabeth (Athens, GA); Kim, Tehryung (Taejeon, KR)

2010-02-23T23:59:59.000Z

173

Battery condition indicator  

SciTech Connect

A battery condition indicator is described for indicating both the charge used and the life remaining in a rechargeable battery comprising: rate multiplying and counting means for indirectly measuring the charge useed by the battery between charges; means for supplying variable rate clock pulse to the rate multiplying and counting means, the rate of the clock pulses being a function of whether a high current consumption load is connected to the battery or not; timing means for measuring the total time in service of the battery; charge used display means responsive to the rate multiplying and counting means for providing an indication of the charge remaining in the battery; and age display means responsive to the timing means for providing an indication of the life or age of the battery.

Fernandez, E.A.

1987-01-20T23:59:59.000Z

174

Energy Flow Models for the Steel Industry  

E-Print Network (OSTI)

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 each step is calibrated against Commerce Dept. data. Third, a detailed energy flow model is presented for coke ovens and blast furnaces, two very energy-intensive steps in our seven step model of steelmaking. This process-step model is calibrated against both our energy end use and material flow models. These models can serve as the base case for simulating changes in energy utilization and waste streams for steelmaking spurred by economic or regulatory conditions or technology innovations.

Hyman, B.; Andersen, J. P.

1998-04-01T23:59:59.000Z

175

Experiment DTA report for semiscale transparent vessel countercurrent flow tests  

SciTech Connect

Steady state air-water tests were performed as part of the Semiscale Blowdown and Emergency Core Cooling (ECC) Project to investigate downcomer countercurrent flow and downcomer bypass flow phenomena. These tests were performed in a plexiglass representation of the Semiscale pressure vessel which allowed changes to be madein the geometry of the upper annulus and downcomer for the purpose of investigating the sensitivity of downcomer and bypass flow to changes in system geometry. Tests were also performed to investigate the effects of two-phase inlet flows and different initial system pressures on countercurrent and bypass flow. Results for each test are presented in the form of computer printout of the measurements and of a summary of the pertinent calculated flow rates, pressures, and dimensionless volumetric fluxes. Descriptions of the test facility, instrumentation, operating procedures, and test conditions are also presented. An error analysis is presented for selected volumetric flux calculations. 10 references. (auth)

Hanson, D.J.

1975-10-01T23:59:59.000Z

176

Meridional Flow Field of Axisymmetric Flows in a Rotating Annulus  

Science Conference Proceedings (OSTI)

Measurements of the flow field were made of the axisymmetric flow in a differentially heated rotating fluid annulus by using a long-term tracking of a tracer particle. Its meridional flow profile is composed of a flow circulating in a large ...

T. Tajima; T. Nakamura

2000-09-01T23:59:59.000Z

177

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network (OSTI)

The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two-dimensional flow were solved using the SIMPLE method. The results indicate that the pressure, shear stress, and friction factor under linear heat flux boundary conditions are considerably smoother, and hence, more closely approximate the real situation. As the heat flux increases, the pressure drop increases, but the friction factor demonstrates only a slight change for different heat flux conditions. The size and shape of the micro heat pipe vapor space was shown to have a significant influence on the vapor flow behavior for micro heat pipes. When the vapor space area decreases, the pressure drop, shear stress, and friction factor all significantly increase.

Liu, Xiaoqin

1996-01-01T23:59:59.000Z

178

Attachment J TERMS AND CONDITIONS  

E-Print Network (OSTI)

Attachment J TERMS AND CONDITIONS AWARD # PON-10-603 #12;TERMS AND CONDITIONS TABLE OF CONTENTS ............................................................................... 24 i #12;TERMS AND CONDITIONS 1. Grant Agreement This project is being funded with a grant from is comprised of the grant funding award, the Terms and Conditions, and all attachments. These Terms

179

Formation flow channel blocking  

SciTech Connect

A method is claimed for selectively blocking high permeability flow channels in an underground hydrocarbon material bearing formation having flow channels of high permeability and having flow channels of lesser permeability. The method includes the following steps: introducing a blocking material fluid comprising a blocking material in a carrier into the flow channels through an injection well in communication with the formation; introducing a buffer fluid into the formation through the injection well for the buffer fluid to displace the blocking material fluid away from the injection well; allowing the blocking material to settle in the channels to resist displacement by fluid flowing through the channels; introducing a quantity of an activating fluid into the channels through the injection well at a sufficient rate for the activating fluid to displace the buffer fluid and finger into the high permeability channels to reach the blocking material in the high permeability channels without reaching the blocking material in the low permeability channels, the activating fluid being adapted to activate the blocking material which it reaches to cause blocking of the high permeability channels.

Kalina, A.I.

1982-11-30T23:59:59.000Z

180

Power-Flow Management - Technology Perspectives  

Science Conference Proceedings (OSTI)

The report provides a technical overview for power-flow management technologies with special emphasis on power electronic-based technologies. This includes both thyristor-based and converter-based technologies. The report thoroughly describes the fundamental relationships of alternating current (AC) power transmission at steady-state and dynamic conditions; the document also describes transmission problems and needs. This overview clearly demonstrates the role of power electronic-based Controllers and th...

2007-11-05T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

A heuristic for minimizing the makespan in no-idle permutation flow shops  

Science Conference Proceedings (OSTI)

The paper deals with the problem of finding a job sequence that minimizes the makespan in m-machine flow shops under the no-idle condition. This condition requires that each machine must process jobs without any interruption from the start of processing ... Keywords: Flow shop, Heuristics, Makespan, No-idle machines, Scheduling

Pawel Jan Kalczynski; Jerzy Kamburowski

2005-08-01T23:59:59.000Z

182

Two-phase flow studies  

DOE Green Energy (OSTI)

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.

Hanold, R.J.

1983-12-01T23:59:59.000Z

183

Microwave fluid flow meter  

DOE Patents (OSTI)

A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

Billeter, Thomas R. (Richland, WA); Philipp, Lee D. (Richland, WA); Schemmel, Richard R. (Lynchburg, VA)

1976-01-01T23:59:59.000Z

184

Flow Test | Open Energy Information  

Open Energy Info (EERE)

Flow Test Flow Test Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Flow Test Details Activities (38) Areas (33) Regions (1) NEPA(3) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Testing Techniques Parent Exploration Technique: Well Testing Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Flow tests provide information on permeability, recharge rates, reservoir pressures, fluid chemistry, and scaling. Thermal: Flow tests can measure temperature variations with time to estimate characteristics about the heat source. Dictionary.png Flow Test: Flow tests are typically conducted shortly after a well has been drilled to test its productivity. The well is opened and fluids are released, the

185

Mass-Loaded Flows  

E-Print Network (OSTI)

A key process within astronomy is the exchange of mass, momentum, and energy between diffuse plasmas in many types of astronomical sources (including planetary nebulae, wind-blown bubbles, supernova remnants, starburst superwinds, and the intracluster medium) and dense, embedded clouds or clumps. This transfer affects the large scale flows of the diffuse plasmas as well as the evolution of the clumps. I review our current understanding of mass-injection processes, and examine intermediate-scale structure and the global effect of mass-loading on a flow. I then discuss mass-loading in a variety of diffuse sources.

J. M. Pittard

2006-07-13T23:59:59.000Z

186

Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry  

E-Print Network (OSTI)

Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry using energy flow method Azimuthal angle distribution at Q2 >100 GeV2 Energy flow method.Ukleja on behalf of the ZEUS Collaboration #12; Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I

187

Binary fish passage models for uniform and nonuniform flows  

Science Conference Proceedings (OSTI)

Binary fish passage models are considered by many fisheries managers to be the best 21 available practice for culvert inventory assessments and for fishway and barrier design. 22 Misunderstandings between different binary passage modeling approaches often arise, 23 however, due to differences in terminology, application and presentation. In this paper 24 one-dimensional binary fish passage models are reviewed and refined to clarify their 25 origins and applications. For uniform flow, a simple exhaustion-threshold (ET) model 26 equation is derived that predicts the flow speed threshold in a fishway or velocity barrier 27 that causes exhaustion at a given maximum distance of ascent. Flow speeds at or above 28 the threshold predict failure to pass (exclusion). Flow speeds below the threshold predict 29 passage. The binary ET model is therefore intuitive and easily applied to predict passage 30 or exclusion. It is also shown to be consistent with the distance-maximizing model. The 31 ET model s limitation to uniform flow is addressed by deriving a passage model that 32 accounts for nonuniform flow conditions more commonly found in the field, including 33 backwater profiles and drawdown curves. Comparison of these models with 34 experimental observations of volitional passage for Gambusia affinis in uniform and 35 nonuniform flows indicates reasonable prediction of binary outcomes (passage or 36 exclusion) if the flow speed is not near the threshold flow velocity. More research is 37 needed on fish behavior, passage strategies under nonuniform flow regimes and 38 stochastic methods that account for individual differences in swimming performance at or 39 near the threshold flow speed. Future experiments should track and measure ground 40 speeds of ascending fish to test nonuniform flow passage strategies and to improve model 41 predictions. Stochastic models, such as Monte-Carlo techniques, that account for 42 different passage performance among individuals and allow prediction of the percentage 43 of fish passing would be particularly useful near flow speed thresholds where binary 44 passage models are clearly limited.

Neary, Vincent S [ORNL

2011-01-01T23:59:59.000Z

188

Inhibition of Mild Steel Corrosion under Hydrodynamic Conditions  

Science Conference Proceedings (OSTI)

The inhibition of mild steel corrosion by 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) in 2.5 M H{sub 2}SO{sub 4} solution and the effect of hydrodynamic condition on inhibition process were studied. The hydrodynamic condition experiments are simulated by rotating cylinder electrode (RCE). Change of open circuit potential (OCP) with immersion time and potentiodynamic polarization were used to study the effect of hydrodynamic conditions on the inhibition process. Results obtained from changes of open circuit potential (OCP) with immersion time, and potentiodynamic polarization are in good agreement and indicated that the inhibition process was flow velocity dependence.

Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Takriff, Mohd Sobri; Kamarudin, Siti Kartom [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor (Malaysia); Daud, Abdul Razak [School of Applied Physics, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor (Malaysia)

2010-07-07T23:59:59.000Z

189

Flow cytometry apparatus  

DOE Patents (OSTI)

An obstruction across the flow chamber creates a one-dimensional convergence of a sheath fluid. A passageway in the obstruction directs flat cells near to the area of one-dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates. 6 figs.

Pinkel, D.

1987-11-30T23:59:59.000Z

190

Flow cytometry apparatus  

DOE Patents (OSTI)

An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.

Pinkel, Daniel (Walnut Creek, CA)

1991-01-01T23:59:59.000Z

191

US energy flow, 1991  

SciTech Connect

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.

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

1992-06-01T23:59:59.000Z

192

Racing for conditional independence inference  

Science Conference Proceedings (OSTI)

In this article, we consider the computational aspects of deciding whether a conditional independence statement t is implied by a list of conditional independence statements L using the implication related to the method of structural imsets. ...

Remco R. Bouckaert; Milan Studený

2005-07-01T23:59:59.000Z

193

A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California  

SciTech Connect

This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

2006-05-16T23:59:59.000Z

194

Energy conditions and their implications  

E-Print Network (OSTI)

Energy conditions and their implications Matt Visser Physics Department Washington University Saint;#16;s (Los Alamos) Midwest Relativity 9 November 1999. #12; Abstract: The energy conditions of general- itational #12;elds and cosmological geometries. However, the energy conditions are beginning to look a lot

Visser, Matt

195

The Regional Atmospheric Water Budget over Southwestern Germany under Different Synoptic Conditions  

Science Conference Proceedings (OSTI)

This study addresses the question of how complex topography in a low-mountain region affects the partitioning and the variability of the atmospheric water budget components (WBCs) as a function of synoptic-scale flow conditions. The WBCs are ...

Romi Sasse; Gerd Schädler; Christoph Kottmeier

2013-02-01T23:59:59.000Z

196

Stability analysis of natural circulation in BWRs at high pressure conditions  

E-Print Network (OSTI)

At rated conditions, a natural circulation boiling water reactor (NCBWR) depends completely on buoyancy to remove heat from the reactor core. This raises the issue of potential unstable flow. oscillations. The objective ...

Hu, Rui, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

197

E – ? model of spray-laden near-sea atmospheric layer in high wind conditions  

Science Conference Proceedings (OSTI)

In-depth understanding and accurate modelling of the interaction between ocean spray and a turbulent flow under high-wind conditions is essential for improving intensity forecasts of hurricanes and severe storms. Here we consider the E – ? closure ...

Yevgenii Rastigejev; Sergey A. Suslov

198

Bhopal Gas Leak: A Numerical Investigation of the Prevailing Meteorological Conditions  

Science Conference Proceedings (OSTI)

A three-dimensional mesoscale model was used to understand the meteorological conditions and the influence of the terrain on the local flow pattern during the Bhopal methyl isocyanate (MIC) gas leak. The study reveals that under the prevailing ...

Maithili Sharan; S. G. Gopalakrishnan; R. T. McNider; M. P. Singh

1996-10-01T23:59:59.000Z

199

Ice Formation by Sulfate and Sulfuric Acid Aerosol Particles under Upper-Tropospheric Conditions  

Science Conference Proceedings (OSTI)

Ice formation in ammoniated sulfate and sulfuric acid aerosol particles under upper-tropospheric conditions was studied using a continuous flow thermal diffusion chamber. This technique allowed for particle exposure to controlled temperatures and ...

Yalei Chen; Paul J. DeMott; Sonia M. Kreidenweis; David C. Rogers; D. Eli Sherman

2000-11-01T23:59:59.000Z

200

SATURATED-SUBCOOLED STRATIFIED FLOW IN HORIZONTAL PIPES  

Science Conference Proceedings (OSTI)

Advanced light water reactor systems are designed to use passive emergency core cooling systems with horizontal pipes that provide highly subcooled water from water storage tanks or passive heat exchangers to the reactor vessel core under accident conditions. Because passive systems are driven by density gradients, the horizontal pipes often do not flow full and thus have a free surface that is exposed to saturated steam and stratified flow is present.

Richard Schultz

2010-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Self-Organized Network Flows  

E-Print Network (OSTI)

A model for traffic flow in street networks or material flows in supply networks is presented, that takes into account the conservation of cars or materials and other significant features of traffic flows such as jam formation, spillovers, and load-dependent transportation times. Furthermore, conflicts or coordination problems of intersecting or merging flows are considered as well. Making assumptions regarding the permeability of the intersection as a function of the conflicting flows and the queue lengths, we find self-organized oscillations in the flows similar to the operation of traffic lights.

Helbing, D; Lämmer, S; Helbing, Dirk; Siegmeier, Jan; L\\"{a}mmer, Stefan

2007-01-01T23:59:59.000Z

202

MHK Technologies/Uppsala Cross flow Turbine | Open Energy Information  

Open Energy Info (EERE)

flow Turbine flow Turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Uppsala Cross flow Turbine.gif Technology Profile Primary Organization Uppsala University Technology Resource Click here Wave Technology Type Click here Cross Flow Turbine Technology Readiness Level Click here TRL 4 Proof of Concept Technology Description A cross flow turbine with fixed blade pitch is directly connected i e no gearbox to a low speed generator The generator is designed to give good efficiency over a wide range of speeds and loads The output voltage and current from the generator will be rectified and then inverted to grid specifications Mooring Configuration Gravity base Optimum Marine/Riverline Conditions Not yet determined Research concerns velocities below and above 1 m s

203

Designing Axial Flow Fan for Flow and Noise  

E-Print Network (OSTI)

A comprehensive finite element methodology is developed to predict the compressible flow performance of a non-symmetric 7-blade axial flow fan, and to quantify the source strength and sound pressure levels at any location in the system. The acoustic and flow performances of the fan are predicted simultaneously using a computational aero-acoustic technique combining transient flow analysis and noise propagation. The calculated sound power levels compare favorably with the measured sound power data per AMCA 300-96 code.

Subrata Roy; Phillip Cho; Fred Périé; International Off-highway

1999-01-01T23:59:59.000Z

204

Sommerfeld radiation condition at threshold  

E-Print Network (OSTI)

We prove Besov space bounds of the resolvent at low energies in any dimension for a class of potentials that are negative and obey a virial condition with these conditions imposed at infinity only. We do not require spherical symmetry. The class of potentials includes in dimension $\\geq3$ the attractive Coulomb potential. There are two boundary values of the resolvent at zero energy which we characterize by radiation conditions. These radiation conditions are zero energy versions of the well-known Sommerfeld radiation condition.

Erik Skibsted

2011-06-23T23:59:59.000Z

205

flow_loop.indd  

NLE Websites -- All DOE Office Websites (Extended Search)

FLOW ASSURANCE TEST LOOP FLOW ASSURANCE TEST LOOP Objective O ver a decade ago, RMOTC began cooperatively building a full-scale facility to test new fl ow assurance technology, mainly in the areas of hydrates and paraffi ns. Today, RMOTC's test facility consists of fi ve individual loop sections, including chilling and heated pipe-in-pipe water sections, bare lines, and a mixing section. The facility was designed to represent typical deepwater production systems in order to simulate full-scale tests and apply the results to fl ow assurance fi eld applications and technology. The current facility design consists of a 6" x 3,600 maximum allowable operating pressure test pipeline in fi ve separate loops. The test loops begin and ter- minate at a central location just north

206

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

Turbulent Turbulent Flow with Implicit LES L.G. Margolin 1 Proceedings of the Joint Russian-American Five Laboratory Conference on Computational Mathematics/Physics 19-23 June, 2005 Vienna, Austria 1 Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, len@lanl.gov 1 Abstract Implicit large eddy simulation (ILES) is a methodology for modeling high Reynolds' num- ber flows that combines computational efficiency and ease of implementation with predictive calculations and flexible application. Although ILES has been used for more than fifteen years, it is only recently that significant effort has gone into providing a physical rationale that speaks to its capabilities and its limitations. In this talk, we will present new theoret- ical results aimed toward building a justification and discuss some remaining gaps in our understanding and our practical

207

Flow shear induced Compton scattering of electron drift instability  

SciTech Connect

Plasma flow shear effects on nonlinear saturation of electron drift waves are analyzed in the weak turbulence regime. Flow shear can enhance ion Compton scattering of long wavelength electron drift waves not only by modifying the beat wave-ion resonance condition, but also via the radial dependence of linear susceptibility. A nonlinear dispersion relation is obtained as a solution of the radially nonlocal nonlinear eigenmode equation. At nonlinear saturation, the spectral intensity of the fluctuations scales with flow shear as ({partial derivative}V{var phi}/{partial derivative}r){sup {minus}2} in addition to the linear dependence on the linear growth rate.

Hahm, T.S.

1992-02-01T23:59:59.000Z

208

Flow shear induced Compton scattering of electron drift instability  

Science Conference Proceedings (OSTI)

Plasma flow shear effects on nonlinear saturation of electron drift waves are analyzed in the weak turbulence regime. Flow shear can enhance ion Compton scattering of long wavelength electron drift waves not only by modifying the beat wave-ion resonance condition, but also via the radial dependence of linear susceptibility. A nonlinear dispersion relation is obtained as a solution of the radially nonlocal nonlinear eigenmode equation. At nonlinear saturation, the spectral intensity of the fluctuations scales with flow shear as ({partial_derivative}V{var_phi}/{partial_derivative}r){sup {minus}2} in addition to the linear dependence on the linear growth rate.

Hahm, T.S.

1992-02-01T23:59:59.000Z

209

A fracture network model for water flow and solute transport  

DOE Green Energy (OSTI)

This paper summarizes code development work and sample calculations for FRACNET, a two-dimensional steady state simulator of fluid flow and solute transport in fractured porous media. The model analyzes flow and transport by generating a fracture network based on statistical characteristics of fractures obtained from well logs and other data. After a network is generated, flow and tracer transport are computed for appropriate boundary conditions and wellbore source/sink terms. In addition, for a given realization, the code can be used to indicate whether the medium can be treated as an equivalent porous medium. 18 refs., 7 figs.

Robinson, B.A.

1989-01-01T23:59:59.000Z

210

TEP process flow diagram  

SciTech Connect

This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

211

Vanadium Redox Flow Batteries  

Science Conference Proceedings (OSTI)

The vanadium redox flow battery, sometimes abbreviated as VRB, is an energy storage technology with significant potential for application in a wide range of contexts. Vanadium redox batteries have already been used in a number of demonstrations in small-scale utility-scale applications, and it is believed that the technology is close to being viable for more widespread use. This report examines the vanadium redox technology, including technical performance and cost issues that drive its application today...

2007-03-30T23:59:59.000Z

212

Electric grid operators monitoring drought conditions - Today ...  

U.S. Energy Information Administration (EIA)

Energy Information Administration ... A lack of adequate water flow can also limit the use of hydroelectric power due to reduced reservoir levels and stream flow.

213

Importance of Design Conditions for Sizing Air-Conditioning Plant  

E-Print Network (OSTI)

Design conditions based on the meteorological data collected at two weather stations located less than 10 km away from each other within Kuwait City are presented for dry-bulb temperature (DBT) and web-bulb temperature (WBT) prioritization. The proposed design conditions specific to the location and the application are drastically different than currently used single design conditions for all application and locations. Cooling load estimates fro two building located in Kuwait have been analyzed for the proposed and the current design conditions to highlight over- or under-sizing the air-conditioning (A/C) plant capacity. Finally, a number of recommendations are made for architects and designers to use proper design conditions to ensure year-round comfort and energy conservation.

Shaban, N.; Maheshwari, G. P.; Suri, R. K.

2000-01-01T23:59:59.000Z

214

Convective heat flow probe  

DOE Patents (OSTI)

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

215

Momentum Balance of Gravity Flows  

Science Conference Proceedings (OSTI)

A unified scale analysis of the momentum balance of downslope gravity flows is developed to organize previous theories for the case of negligible ambient flow and fixed temperature deficit scale. The values of several nondimensional parameters ...

L. Mahrt

1982-12-01T23:59:59.000Z

216

HYDROLYZED WOOD SLURRY FLOW MODELING  

E-Print Network (OSTI)

LBL-10090 UC-61 HYDROLYZED WOOD SLURRY FLOW MODELING JimLBL-10090 HYDROLYZED WOOD SLURRY FLOW MODELING Jim Wrathallconversion of hydrolyzed wood slurry to fuel oil, Based on

Wrathall, Jim

2012-01-01T23:59:59.000Z

217

Katabatic Wind in Opposing Flow  

Science Conference Proceedings (OSTI)

This paper presents a one-dimensional model of katabatic winds in ambient flow and examines types of possible solutions. Results presented in dimensionless form indicate that 1) cooling along a slope with upslope ambient flow can lead to tranquil ...

David R. Fitzjarrald

1984-04-01T23:59:59.000Z

218

Modelling Information Flows in Financial Markets  

E-Print Network (OSTI)

This paper presents an overview of information-based asset pricing. In this approach, an asset is defined by its cash-flow structure. The market is assumed to have access to "partial" information about future cash flows. Each cash flow is determined by a collection of independent market factors called X-factors. The market filtration is generated by a set of information processes, each of which carries information about one of the X-factors, and eventually reveals the X-factor. Each information process has two terms, one of which contains a "signal" about the associated X-factor, and the other of which represents "market noise". The price of an asset is given by the expectation of the discounted cash flows in the risk-neutral measure, conditional on the information provided by the market. When the market noise is modelled by a Brownian bridge one is able to construct explicit formulae for asset prices, as well as semi-analytic expressions for the prices and greeks of options and derivatives. In particular, op...

Brody, Dorje C; Macrina, Andrea

2010-01-01T23:59:59.000Z

219

Using Metering Signals at Roundabouts with Unbalanced Flows to Improve the Traffic Condition; Using Metering Signals at Roundabouts with Unbalanced Flows to Improve the Traffic Condition.  

E-Print Network (OSTI)

?? In some roundabouts, just relying on the "right of way" regulations results in long queues forming along the approaches. This usually happens when a… (more)

Mosslemi, Marjan

2008-01-01T23:59:59.000Z

220

Automobile air-conditioning unit. Final report  

SciTech Connect

In this study the refrigerant in the automobile air-conditioner is compressed by thermal energy in a unique compression system rather than by work in a standard compressor. The compression uses an intermittent compression process with a solid absorbent. The vapor is absorbed by an absorbent at relatively low temperature and ejected as the absorbent temperature is raised. A set of one way valves limits flow to one direction. Major contributions are heat transfer requirements, molecular sieve-refrigerant matching, minimizing non-producing mass, solving thermal fatigue and shock problems, and applying this to automobile air-conditioning. The performance study shows energy savings up to fifty percent are possible, depending on engine load. A twenty percent energy savings with the vehicle tested with the air-conditioner in operation is average. The study also showed that less fuel is used with the windows open than with the air-conditioner operating.

Schaetzle, W.J.

1982-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Motivation for a combined data flow-control flow processor  

Science Conference Proceedings (OSTI)

Data flow sequencing and the directed graph program representation provide two important tools for the development of computer architectures which can exploit problem parallelism. Classical (control flow) architecture deal efficiently with other problems such as serial sequences and data storage which are not handled so well by a data flow architecture. A hybrid which incorporates features of a data flow architecture along with features of a control flow architecture has the potential to become an effective parallel architecture for a wide class of problems. 10 references.

Oxley, D.W.

1981-01-01T23:59:59.000Z

222

On integrating LES and laboratory turbulent flow experiments  

SciTech Connect

Critical issues involved in large eddy simulation (LES) experiments relate to the treatment of unresolved subgrid scale flow features and required initial and boundary condition supergrid scale modelling. The inherently intrusive nature of both LES and laboratory experiments is noted in this context. Flow characterization issues becomes very challenging ones in validation and computational laboratory studies, where potential sources of discrepancies between predictions and measurements need to be clearly evaluated and controlled. A special focus of the discussion is devoted to turbulent initial condition issues.

Grinstein, Fernando Franklin [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

223

Information flow analysis for javascript  

Science Conference Proceedings (OSTI)

Modern Web 2.0 pages combine scripts from several sources into a single client-side JavaScript program with almost no isolation. In order to prevent attacks from an untrusted third-party script or cross-site scripting, tracking provenance of data is ... Keywords: eval, hybrid program analysis, implicit flow, information flow control, unstructured control flow

Seth Just; Alan Cleary; Brandon Shirley; Christian Hammer

2011-10-01T23:59:59.000Z

224

Brine flow in heated geologic salt.  

Science Conference Proceedings (OSTI)

This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

Kuhlman, Kristopher L.; Malama, Bwalya

2013-03-01T23:59:59.000Z

225

SFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 16 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

226

LFS Exhibit B Special Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

B (Rev. 9, 12/13/12) Exhibit B Special Conditions B (Rev. 9, 12/13/12) Exhibit B Special Conditions Dated 5-20-13 Subcontract No. 241314 Page 1 of 11 EXHIBIT "B" SPECIAL CONDITIONS TABLE OF CONTENTS SC Title Page SC-2 AUTHORITY OF PERSONNEL (Apr 2012) ............................................................................... 2 SC-3A COMMENCEMENT, PROGRESS AND COMPLETION OF THE WORK (Jun 2009 - Deviation) ................................................................................................................................... 3 SC-10B INSURANCE REQUIREMENTS (Jan 2010) ............................................................................. 3 SC-11B INVOICING AND PAYMENT (Mar 2012) .................................................................................. 5

227

CPFFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 20 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

228

EFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 26 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

229

EFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 39 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2 AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Apr 2013) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

230

AES Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 18 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

231

Energy Conditions in Jordan Frame  

E-Print Network (OSTI)

The null energy condition, in its usual form, can appear to be violated by transformations in the conformal frame of the metric. We propose a generalization of the form of the null energy condition to Jordan frame, in which matter is non-minimally coupled, which reduces to the familiar form in Einstein frame. Using our version of the null energy condition, we provide a direct proof of the second law of black hole thermodynamics in Jordan frame.

Saugata Chatterjee; Damien A. Easson; Maulik Parikh

2012-12-27T23:59:59.000Z

232

SFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

1, 4/9/13) Exhibit A General Conditions 1, 4/9/13) Exhibit A General Conditions Page 1 of 29 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

233

Optimization of Air Conditioning Cycling.  

E-Print Network (OSTI)

??Systems based on the vapor compression cycle are the most widely used in a variety of air conditioning applications. Despite the vast growth of modern… (more)

Seshadri, Swarooph

2012-01-01T23:59:59.000Z

234

FPC conditioning cart at BNL  

SciTech Connect

The 703 MHz superconducting gun for the BNL Energy Recovery Linac (ERL) prototype has two fundamental power couplers (FPCs), and each of them will deliver up to 500 kW of CW RF power. In order to prepare the couplers for high power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A conditioning cart based test stand, which includes a vacuum pumping system, controllable bake-out system, diagnostics, interlocks and data log system has been designed, constructed and commissioned by collaboration of BNL and AES. This paper presents FPC conditioning cart systems and the conditioning process.

Xu, W.; Ben-Zvi, I.; Altinbas, F.Z.; Belomestnykh, S.; Burrill, A.; Cole, M.; Deonarine, J.; Jamilkowski, J.; Kayran, D.; Laloudakis, N.; Masi Jr, L.; McIntyre, G.; Pate, D.; Philips, D.; Seda, T.; Steszyn, A.; Tallerico, T.; Todd, R.; Weiss, D.; White, G.; Zaltsman, A.

2011-03-28T23:59:59.000Z

235

The Instability of Long's Stationary Solution and the Evolution toward Severe Downslope Windstorm Flow. Part II: The Application of Finite-Amplitude Local Wave-Activity Flow Diagnostics  

Science Conference Proceedings (OSTI)

An analysis of severe downslope windstorm evolution, from flow conditions initially described by Long's stationary solution, is considered through the application of finite-amplitude wave-activity diagnostics. Such quantities satisfy a local ...

J. F. Scinocca; W. R. Peltier

1994-02-01T23:59:59.000Z

236

Investor Flows and the 2008 Boom/Bust in Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

Investor Investor Flows and Speculation New Evidence on Investor Flows and Oil Prices References Investor Flows and the 2008 Boom/Bust in Oil Prices Kenneth J. Singleton Graduate School of Business Stanford University August, 2011 Introduction Investor Flows and Speculation New Evidence on Investor Flows and Oil Prices References Investor Flows, Speculation, and Oil Prices The role of speculation (broadly construed) in the dramatic rise and subsequent sharp decline in oil prices during 2008? Many attribute these swings to changes in fundamentals of supply and demand, within representative agent models. At the same time there is mounting evidence of the "financialization" of commodity markets. Objective: investigate the impact of investor flows and financial market conditions on crude-oil futures prices. Introduction Investor Flows and Speculation New Evidence on

237

Two-phase flow modeling with discrete particles  

SciTech Connect

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between the intractable local instantaneous and the averaged two-fluid model. This new model uses a combination of an Eulerian and a Lagrangian representation of the two phases. The dispersed particles (bubbles or drops) are modeled individually using a large representative number of particles, each with their own Lagrangian description. The continuous phases (liquid or gas) use an Eulerian description.

Mortensen, G.A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Trapp, J.A. (Colorado Univ., Denver, CO (United States) EG and G Idaho, Inc., Idaho Falls, ID (United States))

1992-03-23T23:59:59.000Z

238

ATTACHMENT E TERMS AND CONDITIONS  

E-Print Network (OSTI)

ATTACHMENT E TERMS AND CONDITIONS TABLE OF CONTENTS SECTION PAGE NO. 1. Vehicle Buy-Down Incentive Program Agreement................................................ 1 2. Term of the Agreement..................................................................................................... 14 #12;TERMS AND CONDITIONS 1. Vehicle Buy-Down Incentive Program Agreement The Vehicle Buy

239

Multiple mapping conditioning of velocity in turbulent jet flames  

Science Conference Proceedings (OSTI)

Multiple mapping conditioning (MMC) has emerged as a new approach to model turbulent reacting flows. This study revises the standard MMC closure for velocity in turbulent jet flows from linearity in the reference space to linearity in the composition space. This modeling amendment ensures that the standard velocity model in conditional moment closure studies can now be used for MMC computation as well. A simplified model for the velocity-dependence of MMC drift coefficients is derived without loss of generality and is implemented for the revised velocity closure. Modeling results have been corroborated against the Direct Numerical Simulation database of a spatially evolving, planar turbulent jet flame. The revised model shows marked improvement over standard MMC closure in predicting velocity statistics close to the nozzle. (author)

Vaishnavi, P. [Mechanical Engineering Department, Imperial College, London SW7 2AZ (United Kingdom); Kronenburg, A. [Institut fuer Technische Verbrennung, Universitaet Stuttgart, 70174 Stuttgart (Germany)

2010-10-15T23:59:59.000Z

240

Fluid flow monitoring device  

DOE Patents (OSTI)

This invention consists of a flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.

McKay, M.D.; Sweeney, C.E.

1991-03-05T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Ellipsoidal cell flow system  

SciTech Connect

The disclosure relates to a system incorporating an ellipsoidal flow chamber having light reflective walls for low level light detection in practicing cellular analysis. The system increases signal-to-noise ratio by a factor of ten over prior art systems. In operation, laser light passes through the primary focus of the ellipsoid. A controlled flow of cells simultaneously passes through this focus so that the laser light impinges on the cells and is modulated by the cells. The reflective walls of the ellipsoid reflect the cell-modulated light to the secondary focus of the ellipsoid. A tapered light guide at the secondary focus picks up a substantial portion of modulated reflective light and directs it onto a light detector to produce a signal. The signal is processed to obtain the intensity distribution of the modulated light and hence sought after characteristics of the cells. In addition, cells may be dyed so as to fluoresce in response to the laser light and their fluorescence may be processed as cell-modulated light above described. A light discriminating filter would be used to distinguish reflected modulated laser light from reflected fluorescent light.

Salzman, Gary C. (Los Alamos, NM); Mullaney, Paul F. (Los Alamos, NM)

1976-01-01T23:59:59.000Z

242

Radial flow heat exchanger  

DOE Patents (OSTI)

A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

Valenzuela, Javier (Hanover, NH)

2001-01-01T23:59:59.000Z

243

Split-flow regeneration in absorptive air separation  

DOE Patents (OSTI)

A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.

Weimer, R.F.

1987-11-24T23:59:59.000Z

244

MATERIALS AND INFORMATION FLOWS FOR HVAC DUCTWORK FABRICATION AND SITE  

E-Print Network (OSTI)

MATERIALS AND INFORMATION FLOWS FOR HVAC DUCTWORK FABRICATION AND SITE INSTALLATION Matt Holzemer,1, and air-conditioning (HVAC) systems requires a set of complex activities and handoffs between multiple architecture-, engineering-, and construction practitioners. This paper highlights one part of the HVAC

Tommelein, Iris D.

245

Uranyl Nitrate Flow Loop  

Science Conference Proceedings (OSTI)

The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO{sub 2}), uranium tetrafluoride (UF{sub 4}), and uranium hexafluoride (UF{sub 6})] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF{sub 6} product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study was sponsored by the U.S. Department of Energy (DOE) NA-241, Office of Dismantlement and Transparency.

Ladd-Lively, Jennifer L [ORNL

2008-10-01T23:59:59.000Z

246

Achronal averaged null energy condition  

Science Conference Proceedings (OSTI)

The averaged null energy condition (ANEC) requires that the integral over a complete null geodesic of the stress-energy tensor projected onto the geodesic tangent vector is never negative. This condition is sufficient to prove many important theorems in general relativity, but it is violated by quantum fields in curved spacetime. However there is a weaker condition, which is free of known violations, requiring only that there is no self-consistent spacetime in semiclassical gravity in which ANEC is violated on a complete, achronal null geodesic. We indicate why such a condition might be expected to hold and show that it is sufficient to rule out closed timelike curves and wormholes connecting different asymptotically flat regions.

Graham, Noah; Olum, Ken D. [Department of Physics, Middlebury College, Middlebury, Vermont 05753 (United States) and Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

2007-09-15T23:59:59.000Z

247

Achronal averaged null energy condition  

E-Print Network (OSTI)

The averaged null energy condition (ANEC) requires that the integral over a complete null geodesic of the stress-energy tensor projected onto the geodesic tangent vector is never negative. This condition is sufficient to prove many important theorems in general relativity, but it is violated by quantum fields in curved spacetime. However there is a weaker condition, which is free of known violations, requiring only that there is no self-consistent space-time in semiclassical gravity in which ANEC is violated on a complete, {\\em achronal} null geodesic. We indicate why such a condition might be expected to hold and show that it is sufficient to rule out wormholes and closed timelike curves.

Noah Graham; Ken D. Olum

2007-05-22T23:59:59.000Z

248

Flux Measurement with Conditional Sampling  

Science Conference Proceedings (OSTI)

A method is proposed to measure scalar fluxes using conditional sampling. Only the mean concentrations of updraft and downdraft samples, the standard deviation of the vertical velocity, and a coefficient of proportionality, b, need to be known. ...

Joost A. Businger; Steven P. Oncley

1990-04-01T23:59:59.000Z

249

Conditions for learning from animations  

Science Conference Proceedings (OSTI)

Animated diagrams representing dynamic systems hold great potential for improving the way people learn. However, so far the literature failed to find clear benefits of animated diagrams. Consequently it is worthwhile to investigate conditions under which ...

Herre Van Oostendorp; Michiel J. Beijersbergen; Sam Solaimani

2008-06-01T23:59:59.000Z

250

When Does Aid Conditionality Work?  

E-Print Network (OSTI)

GR. Aid conditionality: does foreign aid support autocrats,New York: Routledge; 1998. Knack S. Does foreign aid promotePress; 2000. Remmer KL. Does foreign aid promote the

Montinola, Gabriella R.

2010-01-01T23:59:59.000Z

251

Instrumentation for Increased Power Flow  

Science Conference Proceedings (OSTI)

This report is the second Technical Update of the Instrumentation for Managing Increased Power Flow project, part of EPRI's Increased Power Flow (IPF) program. The project, initiated in 2006 and expected to continue for several years, studies the feasibility of new instrumentation to support increased power flow strategies. In 2007 the work focused on two primary developments: the Backscatter Sensor for the real-time measurement of transmission line temperature and current and the Emissivity Test Instrum...

2007-12-06T23:59:59.000Z

252

Condition Monitoring of Wind Turbines  

Science Conference Proceedings (OSTI)

Based on industry experience, after four years of operation, failures of wind turbine gearboxes, generators, and other major components become common, and each failure typically requires major repairs and/or component replacement. Wind project owners and operators who apply lube oil monitoring, vibration-signature analysis, and other condition monitoring technology can expect to detect subtle changes in machine condition that often lead to major failures if left unrepaired. The estimated cost savings of ...

2006-03-27T23:59:59.000Z

253

HYDROCARBON LIQUID FLOW CALIBRATION SERVICE ...  

Science Conference Proceedings (OSTI)

... and is the cross correlation coefficient ... a NIST Hydrocarbon Liquid Flow Calibration Facility ... FED2004-56790, 2004 Heat Transfer/Fluids Engineering ...

2012-05-21T23:59:59.000Z

254

Flow Batteries: A Historical Perspective  

NLE Websites -- All DOE Office Websites (Extended Search)

Marvin Warshay *1976 Shunt Current Model, Paul Prokopius *1976 Interfaced an RFB with solar cells *1977 Electrode-Membrane-Flow Battery Testing *Largest polarization @ negative...

255

EPRI Coal-Flow Loop  

Science Conference Proceedings (OSTI)

This report is targeted at plant personnel responsible for coal-flow measurement and mill balancing that are using or are considering the use of online, in situ measurement technologies. Optimum combustion in a boiler requires careful control of coal and air flow to individual burners. Measuring in near real-time the mass flow rate of pneumatically conveyed pulverized coal in burner feed pipes is a critical element of such control. This report summarizes the findings for two online coal-flow instruments ...

2006-12-01T23:59:59.000Z

256

Flow Patterns Around a Complex Building  

DOE Green Energy (OSTI)

The authors compare the results of a computer simulated flow field around building 170 (B170) at Lawrence Livermore National Laboratory (LLNL) with field measurements. In order to aid in the setup of the field experiments, the simulations were performed first. B170 was chosen because of its architectural complexity and because a relatively simple fetch exists upwind (a field lies southwest of the site). Figure 1 shows a computational model of the building which retains the major architectural features of the real building (e.g., courtyard, alcoves, and a multi-level roof). Several important characteristics of the cases presented here are: (1) the flow was assumed neutral and no heat flux was imposed at the ground, representing cloudy or morning conditions, (2) a simple canopy parameterization was used to model the effect of a large row of eucalyptus trees which is located to the northeast of the building, (3) the wind directions studied were 200, 225, 250 degrees measured clockwise from true north (the prevailing winds at LLNL are from the southwest in the summer), (4) the incoming wind profile was modeled as logarithmic with a maximum of about 3 meters per second. In addition, note that the building is rotated counterclockwise by 25 degrees with respect to the east/west axis. For convenience, the flow is modeled in a coordinate system that has been rotated with the building.

Calhoun, R; Chan, S; Lee, R; Leone, J, Shinn, J; Stevens, D

1999-09-24T23:59:59.000Z

257

Patterns in Flowing Sand: Understanding the Physics of Granular Flow  

E-Print Network (OSTI)

Dense granular flows are often unstable and form inhomogeneous structures. Although significant advances have been recently made in understanding simple flows, instabilities of such flows are often not understood. We present experimental and numerical results that show the formation of longitudinal stripes that arise from instability of the uniform flowing state of granular media on a rough inclined plane. The form of the stripes depends critically on the mean density of the flow with a robust form of stripes at high density that consists of fast sliding plug-like regions (stripes) on top of highly agitated boiling material - a configuration reminiscent of the Leidenfrost effect when a droplet of liquid lifted by its vapor is hovering above a hot surface.

Tamas Borzsonyi; Robert E. Ecke; Jim N. McElwaine

2009-10-01T23:59:59.000Z

258

Linear Theory of Stratified Flow past an Isolated Mountain in Isosteric Coordinates  

Science Conference Proceedings (OSTI)

The linear theory for hydrostatic nonrotating flow over an axisymmetric hill is redone in isosteric (i.e., constant specific volume) coordinates, thus allowing the lower boundary condition(LBC) to be exactly satisfied. This results in a more ...

Ronald B. Smith

1988-12-01T23:59:59.000Z

259

Low-Frequency Velocity and Temperature Fluctuations in Katabatic Valley Flows  

Science Conference Proceedings (OSTI)

Observations of velocity and temperature fluctuations made during katabatic flow conditions in two deeply incised valleys are analyzed using variance, coherence, and phase spectra. Variance spectra obtained at valley floor sidewall locations show ...

G. L. Stone; D. E. Hoard

1989-06-01T23:59:59.000Z

260

Bubble behavior in subcooled flow boiling on surfaces of variable wettability  

E-Print Network (OSTI)

Flow boiling is important in energy conversion and thermal management due to its potential for very high heat fluxes. By improving understanding of the conditions leading to bubble departure, surfaces can be designed that ...

Tow, Emily W

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Stratified Flow over Two-Dimensional Topography in Fluid of Infinite Depth: A Laboratory Simulation  

Science Conference Proceedings (OSTI)

This paper describes some laboratory experiments with two-dimensional stratified flow over isolated topography, in which a novel configuration simulating a radiating upper boundary condition is employed. Several experimental tests show that the ...

Peter G. Baines; Klaus P. Hoinka

1985-08-01T23:59:59.000Z

262

Novel hybrid approach to data-packet-flow prediction for improving network traffic analysis  

Science Conference Proceedings (OSTI)

Forecast of the flow of data packets between client and server for a network traffic analysis is viewed as a part of web analytics. Thousands of web-smart businesses depend on web analytics to improve website conversions, reduce marketing costs, facilitate ... Keywords: Adaptive neuro-fuzzy inference system, Flow of data packets, Network traffic analysis, Nonlinear generalized autoregressive conditional heteroscedasticity, Quantum minimization

Bao Rong Chang; Hsiu Fen Tsai

2009-06-01T23:59:59.000Z

263

Influence of biofuels on the internal flow in diesel injector nozzles  

Science Conference Proceedings (OSTI)

In this paper, the behavior of the internal nozzle flow of a standard diesel fuel has been compared against a biodiesel fuel (soybean oil) at cavitating and non-cavitating conditions, using a homogeneous equilibrium model. The model takes into account ... Keywords: Biodiesel, Cavitation, Diesel injector, Internal flow, Nozzle, OpenFOAM®

F. J. Salvador; J. MartíNez-LóPez; J. -V. Romero; M. -D. Roselló

2011-10-01T23:59:59.000Z

264

Money versus Time: Evaluation of Flow Control in Terms of Energy Consumption and Convenience  

E-Print Network (OSTI)

Flow control with the goal of reducing the skin friction drag on the fluid-solid interface is an active fundamental research area, motivated by its potential for significant energy savings and reduced emissions in the transport sector. Customarily, the performance of drag reduction techniques in internal flows is evaluated under two alternative flow conditions, i.e. at constant mass flow rate or constant pressure gradient. Successful control leads to reduction of drag and pumping power within the former approach, whereas the latter leads to an increase of the mass flow rate and pumping power. In practical applications, however, money and time define the flow control challenge: a compromise between the energy expenditure (money) and the corresponding convenience (flow rate) achieved with that amount of energy has to be reached so as to accomplish a goal which in general depends on the specific application. Based on this idea, we derive two dimensionless parameters which quantify the total energy consumption an...

Frohnapfel, Bettina; Quadrio, Maurizio

2012-01-01T23:59:59.000Z

265

Split flow gasifier  

DOE Patents (OSTI)

A-moving bed coal gasifier for the production of tar-free, low ammonia fuel gas is described. The gasifier employs a combustion zone in a free-aboard area above the moving bed to burn coal fines to provide hot combustion gases for pyrolyzing and gasifying coal particulates in the moving bed to form fuel gas as the hot gases move co-currently with the downwardly moving coal particulates. The fuel gas contains entrained tars and ammonia compounds which contact hot char and ash in the moving bed and are cracked so that the fuel gas removed from the gasifier at a midpoint off-take is essentially tar-free and of low ammonia content. Concurrently with this gasification reaction, steam and an oxidant are introduced into a region below the moving bed to flow countercurrently to the downwardly moving bed to contact and react with carbon remaining in the char to create additional fuel gas which is also extracted from the gasifier at the mid-point off-take.

Halow, J.S.

1991-12-31T23:59:59.000Z

266

Air Conditioning | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Conditioning Conditioning Air Conditioning July 1, 2012 - 6:28pm Addthis Air conditioners cost U.S. homeowners more than $11 billion each year, and regular maintenance can keep your air conditioner running efficiently. | Photo courtesy of ©iStockphoto/JaniceRichard Air conditioners cost U.S. homeowners more than $11 billion each year, and regular maintenance can keep your air conditioner running efficiently. | Photo courtesy of ©iStockphoto/JaniceRichard How does it work? An air conditioner uses energy -- usually electricity -- to transfer heat from the interior of your home to the relatively warm outside environment. Two-thirds of all homes in the United States have air conditioners. Air conditioners use about 5% of all the electricity produced in the United States, at an annual cost of more than $11 billion to homeowners. As a

267

Two-phase gas-liquid flow characteristics inside a plate heat exchanger  

Science Conference Proceedings (OSTI)

In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-water mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)

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)

2010-11-15T23:59:59.000Z

268

LFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Page 1 of 31 Page 1 of 31 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

269

The Numerical Simulation of Drainage Winds in a Small Urban Valley under Conditions with Supercritical Richardson Numbers  

Science Conference Proceedings (OSTI)

A two-dimensional numerical model is used to simulate nocturnal drainage flow in a small urban valley with light prevailing winds and conditions of supercritical Richardson numbers (Ri). The model uses a hydrostatic and Boussinesq system of ...

Raymond K. W. Wong; Keith D. Hage; Leslie D. Phillips

1987-10-01T23:59:59.000Z

270

Groundwater flow near the Shoal Site, Sand Springs Range, Nevada: Impact of density-driven flow  

Science Conference Proceedings (OSTI)

The nature of flow from a highland recharge area in a mountain range in north-central Nevada to discharge areas on either side of the range is evaluated to refine a conceptual model of contaminant transport from an underground nuclear test conducted beneath the range. The test, known as the Shoal event, was conducted in 1963 in granitic rocks of the Sand Springs Range. Sparse hydraulic head measurements from the early 1960s suggest flow from the shot location to the east to Fairview Valley, while hydrochemistry supports flow to salt pans in Fourmile Flat to the west. Chemical and isotopic data collected from water samples and during well-logging arc best explained by a reflux brine system on the west side of the Sand Springs Range, rather than a typical local flow system where all flow occurs from recharge areas in the highlands to a central discharge area in a playa. Instead, dense saline water from the playa is apparently being driven toward the range by density contrasts. The data collected between the range and Fourmile Flat suggest the groundwater is a mixture of younger, fresher recharge water with older brine. Chemical contrasts between groundwater in the east and west valleys reflect the absence of re-flux water in Fairview Valley because the regional discharge area is distant and thus there is no accumulation of salts. The refluxing hydraulic system probably developed after the end of the last pluvial period and differences between the location of the groundwater divide based on hydraulic and chemical indicators could reflect movement of the divide as the groundwater system adjusts to the new reflux condition.

Chapman, J.; Mihevc, T.; McKay, A.

1994-09-01T23:59:59.000Z

271

Turbine blade tip flow discouragers  

SciTech Connect

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.

Bunker, Ronald Scott (Niskayuna, NY)

2000-01-01T23:59:59.000Z

272

Physics of two-phase flow: choked flow  

DOE Green Energy (OSTI)

It is shown that the basic equations governing the flow of a two-phase fluid, i.e., liquid and vapor, are natural extensions of those equations that describe single-phase flow. The exact form of the equations depends on the particular assumptions used to characterize the two-phase flow, i.e., the equations depend on the model chosen. In general the mathematical model is selected so as to retain as much of the physics of the phenomena as possible while at the same time permitting solutions to be obtained without undue complexity. The following quantities were computed for saturated water substance over the temperature range 100 to 250/sup 0/C and for saturated Refrigerant -114 over the range -20 to +70/sup 0/C: choking velocity, critical or choking flow density, and saturation properties. Tables of the results are given along with graphs of selected functions.

Maeder, P.F.; DiPippo, R.; Delor, M.; Dickinson, D.

1981-05-01T23:59:59.000Z

273

The transition from two phase bubble flow to slug flow  

E-Print Network (OSTI)

The process of transition from bubble to slug flow in a vertical pipe has been studied analytically and experimentally. An equation is presented which gives the agglomeration time as a function of void fraction, channel ...

Radovcich, Nick A.

1962-01-01T23:59:59.000Z

274

HYDROGEN ELECTROLYZER FLOW DISTRIBUTOR MODEL  

DOE Green Energy (OSTI)

The hybrid sulfur process (HyS) hydrogen electrolyzer consists of a proton exchange membrane (PEM) sandwiched between two porous graphite layers. An aqueous solution of sulfuric acid with dissolved SO{sub 2} gas flows parallel to the PEM through the porous graphite layer on the anode side of the electrolyzer. A flow distributor, consisting of a number of parallel channels acting as headers, promotes uniform flow of the anolyte fluid through the porous graphite layer. A numerical model of the hydraulic behavior of the flow distributor is herein described. This model was developed to be a tool to aid the design of flow distributors. The primary design objective is to minimize spatial variations in the flow through the porous graphite layer. The hydraulic data from electrolyzer tests consists of overall flowrate and pressure drop. Internal pressure and flow distributions are not measured, but these details are provided by the model. The model has been benchmarked against data from tests of the current electrolyzer. The model reasonably predicts the viscosity effect of changing the fluid from water to an aqueous solution of 30 % sulfuric acid. The permeability of the graphite layer was the independent variable used to fit the model to the test data, and the required permeability for a good fit is within the range literature values for carbon paper. The model predicts that reducing the number of parallel channels by 50 % will substantially improve the uniformity of the flow in the porous graphite layer, while maintaining an acceptable pressure drop across the electrolyzer. When the size of the electrolyzer is doubled from 2.75 inches square to 5.5 inches square, the same number of channels as in the current design will be adequate, but it is advisable to increase the channel cross-sectional flow area. This is due to the increased length of the channels.

Shadday, M

2006-09-28T23:59:59.000Z

275

Proper planning improves flow drilling  

Science Conference Proceedings (OSTI)

Underbalanced operations reduce formation damage, especially in horizontal wells where zones are exposed to mud for longer time periods. Benefits, risks, well control concerns, equipment and issues associated with these operations are addressed in this paper. Flow drilling raises many concerns, but little has been published on horizontal well control and flow drilling operations. This article covers planning considerations for flow drilling, but does not address horizontal ''overbalanced'' drilling because considerations and equipment are the same as in vertical overbalanced drilling and many references address that subject. The difference in well control between vertical and horizontal overbalanced drilling is fluid influx behavior and how that behavior affects kill operations.

Collins, G.J. (Marathon Oil Co., Houston, TX (United States))

1994-10-01T23:59:59.000Z

276

Aeroelastic instabilities simulations on turbofan HP compressorblisk at surge-like reversed flow conditions.  

E-Print Network (OSTI)

?? This paper presents the work done at the High Pressure Compressor design division of Safran Snecma to simulate the flutter behaviour of a compressor… (more)

Murray, Raphael

2013-01-01T23:59:59.000Z

277

Heat Transfer in Intermediate Heat Exchanger Under Low Flow Rate Conditions  

Science Conference Proceedings (OSTI)

Technical Paper / Special Issue on the 2008 International Congress on Advances in Nuclear Power Plants / Thermal Hydraulics

Hiroyasu Mochizuki

278

Kinetics of Fe(II)-catalyzed transformation of 6-line ferrihydrite under anaerobic flow conditions  

E-Print Network (OSTI)

Radiation Lightsource (SSRL). A wavelength of 0.7293 (Both beamlines at ALS and SSRL are equipped with areaEETD of LBNL and Sam Webb at SSRL for their help on TEM and

Yang, L.

2010-01-01T23:59:59.000Z

279

Application of Mechanistic Models in Predicting Flow Behavior in Deviated Wells Under UBD Conditions.  

E-Print Network (OSTI)

??Underbalanced drilling (UBD) has increased in recent years because of the many advantages associated with it. These include increase in the rate of penetration and… (more)

ALAdwani, Faisal Abdullah

2003-01-01T23:59:59.000Z

280

Method and apparatus for controlling the flow rate of mercury in a flow system  

DOE Patents (OSTI)

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.

Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Condition assessment of nonlinear processes  

DOE Patents (OSTI)

There is presented a reliable technique for measuring condition change in nonlinear data such as brain waves. The nonlinear data is filtered and discretized into windowed data sets. The system dynamics within each data set is represented by a sequence of connected phase-space points, and for each data set a distribution function is derived. New metrics are introduced that evaluate the distance between distribution functions. The metrics are properly renormalized to provide robust and sensitive relative measures of condition change. As an example, these measures can be used on EEG data, to provide timely discrimination between normal, preseizure, seizure, and post-seizure states in epileptic patients. Apparatus utilizing hardware or software to perform the method and provide an indicative output is also disclosed.

Hively, Lee M. (Philadelphia, TN); Gailey, Paul C. (Athens, OH); Protopopescu, Vladimir A. (Knoxville, TN)

2002-01-01T23:59:59.000Z

282

Necessary conditions on entanglement catalysts  

E-Print Network (OSTI)

Given a pure state transformation $\\psi\\mapsto\\phi$ restricted to entanglement-assisted local operations with classical communication, we determine a lower bound for the dimension of a catalyst allowing that transformation. Our bound is stated in terms of the generalised concurrence monotones (the usual concurrence of two qubits is one such monotone). We further provide tools for deriving further conditions upon catalysts of pure state transformations.

Sanders, Yuval

2009-01-01T23:59:59.000Z

283

Necessary conditions on entanglement catalysts  

E-Print Network (OSTI)

Given a pure state transformation $\\psi\\mapsto\\phi$ restricted to entanglement-assisted local operations with classical communication, we determine a lower bound for the dimension of a catalyst allowing that transformation. Our bound is stated in terms of the generalised concurrence monotones (the usual concurrence of two qubits is one such monotone). We further provide tools for deriving further conditions upon catalysts of pure state transformations.

Yuval Sanders; Gilad Gour

2009-04-14T23:59:59.000Z

284

LFS Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Dated 5-20-13 Dated 5-20-13 Subcontract No. 241314 Page 1 of 19 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012 - Deviation) ........................................................................................ 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 4 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

285

Condition-Based Maintenance Guideline  

Science Conference Proceedings (OSTI)

Since the 1980s, EPRI has published various documents relating to predictive or condition-based maintenance (CBM) programs. These documents have served as a foundation for predictive maintenance programs within our industry. Many of these published documents are now more than 10 years old. As a result, EPRI is reviewing these documents to compare them with current practices and programs. EPRIs initial goal is to revise and update the guidance and create a principal core document on predictive and conditi...

2011-11-16T23:59:59.000Z

286

Vibration effects of two-phase cross flow on heat exchangers  

SciTech Connect

Excessive flow-induced vibration in tube bundles causes costly tube failures by fatigue or fretting wear. This is a common condition in many shell-and-tube heat exchangers, such as condensers and reboilers. However, designers can't plan for phenomena that they don't understand. To avoid cross-flow vibration damage, the designer must determine flow-behavior effects on tube bundles under these conditions. And this is very true when discussing two-phase cross-flow vibration. Two-phase cross-flow vibration does cause tube/tube bundle failure. Early research used single-phase flow models, which failed to accurately predict vibration behavior in a two-phase system. Consequently, single-phase models and assumptions don't apply to two-phase systems and don't accurately describe vibration-behavior for exchanger tubes. Improved heat exchanger design requires more emphasis and development on cross-flow vibration parameters. The paper describes tube vibrations; flow conditions; void-fraction effects; vortex-induced vibration; fluid excitation forces; and tube response.

Lian, H.Y.; Kawaji, M. (Univ. of Toronto, Ontario (Canada)); Chan, A.M.C. (Ontario Hydro Research Div., Toronto (Canada))

1993-03-01T23:59:59.000Z

287

Update of Columbia River flow and temperature data measured at Priest Rapids Dam and Vernita Bridge  

DOE Green Energy (OSTI)

Columbia River temperatures and flow rates are collected daily at Priest Rapids Dam and Vernita Bridge. These data are necessary for assessing trends or changes in river conditions downstream of Priest Rapids Dam. In order to analyze this data, Pacific Northwest Laboratory developed a computerized data base using existing US Geological Survey flow and temperature records at Priest Rapids Dam and Vernita Bridge. Daily-averaged temperature and daily flow information on the Columbia River just downstream of Priest Rapids Dam and upstream of river mile 380 were collected and stored in a data base. A newly developed computer model, COLSTAT (Columbia River Statistical Update), used the data base to statistically analyze temperature and flow conditions by computing the frequency of occurrence and duration of selected temperatures and flow rates for the Columbia River. Information regarding the data base is presented, as well as, a description of the COLSTAT model.

Whelan, G.; Newbill, C.A.

1983-09-01T23:59:59.000Z

288

Assessment of Smolt Condition for Travel Time Analysis, 1991-1992 Annual Report.  

Science Conference Proceedings (OSTI)

Regression techniques were used to determine the effects of several biotic and abiotic variables on the migration rates of juvenile spring chinook salmon and steelhead in the Columbia and Snake rivers. Comparisons of the effects of river flow and smoltification, assessed using gill Na{sup +}-K{sup +} ATPase activity, were of primary interest. Day of the year, water temperature, change in flow, condition factor, and fork length were also considered as independent variables. Groups of fish were sampled to assess smoltification 2-3 times per week during the spring outmigrations during 1989-1992. These groups were assumed to be representative of other fish which were PIT-tagged and released as a part of the Smolt Monitoring Program in the Columbia Basin. River flow, gill ATPase activity, condition factor, water temperature, and change in flow were significant variables in regressions predicting the time for juvenile spring chinook salmon to travel between specific points (travel time), whereas river flow was the only significant contributor to models describing travel times of steelhead. Predicted travel times of wild steelhead were shorter than those of hatchery steelhead. River flow was the only variable common to all regression equations. Based on the characteristic, changes in river flow would be the most logical means to decrease travel times of both juvenile spring chinook salmon and steelhead in the Columbia and Snake rivers.

Maule, Alec G.; Beeman, John W.; Schrock, Robin M. (Seattle National Fishery Research Center, Columbia River Field Station, Cook, WA)

1994-05-01T23:59:59.000Z

289

Definition: Flow Test | Open Energy Information  

Open Energy Info (EERE)

Flow Test Jump to: navigation, search Dictionary.png Flow Test Flow tests are typically conducted shortly after a well has been drilled to test its productivity. The well is opened...

290

Transitions between Baroclinic Flow Regimes  

Science Conference Proceedings (OSTI)

we use truncated spectral Eady models with two Ekman layers of different strength to investigate the baroclinic flow transitions observed in annulus experiments. Our analysis is both analytical and numerical As the dissipation parameter is varied ...

H-Y. Weng; A. Barcilon; J. Magnan

1986-08-01T23:59:59.000Z

291

Coal flows | OpenEI  

Open Energy Info (EERE)

Coal flows Coal flows Dataset Summary Description This dataset comes from the Energy Information Administration (EIA), and is part of the 2011 Annual Energy Outlook Report (AEO2011). This dataset is table 142, and contains only the reference case. The dataset uses million short tons. The data is broken down into steam coal exports to Europe, Asia and America. Source EIA Date Released April 26th, 2011 (3 years ago) Date Updated Unknown Keywords 2011 AEO Coal flows countries EIA exporting importing Data application/vnd.ms-excel icon AEO2011: World Steam Coal Flows By Importing Regions and Exporting Countries- Reference Case (xls, 103.7 KiB) Quality Metrics Level of Review Peer Reviewed Comment Temporal and Spatial Coverage Frequency Annually Time Period 2008-2035 License

292

Essays on international capital flows  

E-Print Network (OSTI)

This dissertation consists of three chapters on international capital flows. Chapter 1 emphasizes the importance of innovations in the investment opportunity set, captured by changes in expected asset returns, as an important ...

Brandão, Tatiana Glindmeier Didier

2008-01-01T23:59:59.000Z

293

Lattice splitting under intermittent flows  

E-Print Network (OSTI)

We study the splitting of regular square lattices subject to stochastic intermittent flows. By extensive Monte Carlo simulations we reveal how the time span until the occurence of a splitting depends on various flow patterns imposed on the lattices. Increasing the flow fluctuation frequencies shortens this time span which reaches a minimum before rising again due to inertia effects incorporated in the model. The size of the largest connected component after the splitting is rather independent of the flow fluctuations but sligthly decreases with the link capacities. Our results are relevant for assessing the robustness of real-life systems, such as electric power grids with a large share of renewable energy sources including wind turbines and photovoltaic systems.

Schläpfer, Markus

2010-01-01T23:59:59.000Z

294

Miniaturized flow injection analysis system  

DOE Patents (OSTI)

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.

Folta, James A. (Livermore, CA)

1997-01-01T23:59:59.000Z

295

Miniaturized flow injection analysis system  

DOE Patents (OSTI)

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.

Folta, J.A.

1997-07-01T23:59:59.000Z

296

Flow Acceleration and Mountain Drag*  

Science Conference Proceedings (OSTI)

Dynamic explanations of mountain drag usually invoke viscous effects and/or wave momentum flux by either Rossby or internal gravity waves. This paper explores an alternative mechanism in terms of the unsteadiness of the incident flow. The ...

Peter R. Bannon

1985-12-01T23:59:59.000Z

297

Studies of Flows in Plasmas  

SciTech Connect

Note a pdf document "DOE-flow-final-report' should be attached. If it somehow is not please notify Walter Gekelman (gekelman@physics.ucla.edu) who will e mail it directly

Gekelman, Walter; Morales, George; Maggs, James

2009-03-07T23:59:59.000Z

298

Longitudinal dispersion in vegetated flow  

E-Print Network (OSTI)

Vegetation is ubiquitous in rivers, estuaries and wetlands, strongly influencing both water conveyance and mass transport. The plant canopy affects both mean and turbulent flow structure, and thus both advection and ...

Murphy, Enda

2006-01-01T23:59:59.000Z

299

Parabolic flows on complex manifolds  

E-Print Network (OSTI)

Chapter 2 Convergence of the parabolic complex Monge-Amp`ere65] Streets, J. , Tian, G. A parabolic flow of pluriclosedGill, M. Convergence of the parabolic complex Monge-Amp` ere

Gill, Matthew Franklin

2012-01-01T23:59:59.000Z

300

Multiscale modeling in granular flow  

E-Print Network (OSTI)

Granular materials are common in everyday experience, but have long-resisted a complete theoretical description. Here, we consider the regime of slow, dense granular flow, for which there is no general model, representing ...

Rycroft, Christopher Harley

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Subcooled flow boiling of fluorocarbons  

E-Print Network (OSTI)

A study was conducted of heat transfer and hydrodynamic behavior for subcooled flow boiling of Freon-113, one of a group of fluorocarbons suitable for use in cooling of high-power-density electronic components. Problems ...

Murphy, Richard Walter

1971-01-01T23:59:59.000Z

302

2007 Estimated International Energy Flows  

Science Conference Proceedings (OSTI)

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.

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

2011-03-10T23:59:59.000Z

303

Acoustic concentration of particles in fluid flow  

DOE Patents (OSTI)

An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)

2010-11-23T23:59:59.000Z

304

A Baroclinic Model of turbulent dusty flows  

SciTech Connect

The problem considered here is the numerical simulation of the turbulent dusty flow induced by explosions over soil surfaces. Some of the unresolved issues are: (1) how much dust is scoured from such surfaces; (2) where does the dust go in the boundary layer; (3) what is the dusty boundary layer height versus time; (4) what are the dusty boundary layer profiles; (5) how much of the dust mass becomes entrained into the dust stem; and (6) where does the dust go in the buoyant cloud? The author proposes a Baroclinic Model for flows with large density variations that actually calculates the turbulent mixing and transport of dust on an adaptive grid. The model is based on the following idealizations: (1) a loose dust bed; (2) an instantaneous shock fluidization of the dust layer; (3) the dust and air are in local equilibrium (so air viscosity enforces the no-slip condition); (4) the dust-air mixture is treated as a continuum dense fluid with zero viscosity; and (5) the turbulent mixing is dominated by baroclinically-generated vorticity. These assumptions lead to an inviscid set of conservation laws for the mixture, which are solved by means of a high-order Godunov algorithm for gasdynamics. Adaptive Mesh Refinement (AMR) is used to capture the turbulent mixing processes on the grid. One of the unique characteristics of these flows is that mixing occurs because vorticity is produced by an inviscid, baroclinic mechanism. A number of examples are presented to illustrate these baroclinic effects including shock interactions with dense-gas layers and dust beds, and dusty wall jets of airblast precursors. The conclusion of these studies is that dusty boundary layers grow because of mass entrainment from the fluidized bed (and not because of viscous wall drag) as proven by the Mass Integral Equation.

Kuhl, A.L.

1992-04-01T23:59:59.000Z

305

Single-phase Flow in Composite Poro-elastic Media  

E-Print Network (OSTI)

. The mathematical formulation and analysis of the Barenblatt-Biot model of elastic deformation and laminar flow in a heterogeneous porous medium is discussed. This describes consolidation processes in a fluid-saturated double-diffusion model of fractured rock. The model includes various degenerate cases, such as incompressible constituents or totally fissured components, and it is extended to include boundary conditions arising from partially exposed pores. The quasi-static initial-boundary problem is shown to have a unique weak solution, and this solution is strong when the data are smoother. 1. Introduction Any model of fluid flow through a deformable solid matrix must account for the coupling between the mechanical behavior of the matrix and the fluid dynamics. For example, compression of the medium leads to increased pore pressure, if the compression is fast relative to the fluid flow rate. Conversely, an increase in pore pressure induces a dilation of the matrix in response to t...

R. E. Showalter; Bahareh Momken

2002-01-01T23:59:59.000Z

306

Monitoring downhole pressures and flow rates critical for underbalanced drilling  

Science Conference Proceedings (OSTI)

True underbalanced drilling, and not just flow drilling, requires thorough engineering and monitoring of downhole pressures and flow rates to ensure the formations are drilled without formation damage. Underbalanced drilling involves intentionally manipulating the bottom hole circulating pressure so that it is less than static reservoir pressure. This underbalanced pressure condition allows reservoir fluids to enter the well bore while drilling continues, preventing fluid loss and many causes of formation damage. Applied correctly, this technology can address problems of formation damage, lost circulation, and poor penetration rates. Another important benefit of drilling underbalanced is the ability to investigate the reservoir in real time. The paper discusses the reasons for under balanced drilling, creating underbalance, well site engineering, fluids handling, rotating flow divertor injection gas, survey techniques, data acquisition, operations, maintaining under-balance, routine drilling, rate of penetration, misconceptions, and economics.

Butler, S.D.; Rashid, A.U.; Teichrob, R.R. [Flow Drilling Engineering Ltd., Calgary, Alberta (Canada)

1996-09-16T23:59:59.000Z

307

Heat flow studies, Coso Geothermal Area, China Lake, California. Technical  

Open Energy Info (EERE)

studies, Coso Geothermal Area, China Lake, California. Technical studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Heat flow studies, Coso Geothermal Area, China Lake, California. Technical report Details Activities (1) Areas (1) Regions (0) Abstract: Heat flow studies in the Coso Geothermal Area were conducted at China Lake, California. Temperature measurements were completed in nine of the heat flow boreholes. Temperatures were measured at five meter intervals from the ground surface to the deepest five meter interval. Subsequently, temperatures were remeasured two or three times in each borehole in order to demonstrate that equilibrium thermal conditions existed. The maximum difference in temperature, at any of the five meter intervals, was 0.03 deg

308

Nuclear reactor flow control method and apparatus  

DOE Patents (OSTI)

Method and apparatus for improving coolant flow in a nuclear reactor during accident as well as nominal conditions. The reactor has a plurality of fuel elements in sleeves and a plenum above the fuel and through which the sleeves penetrate. Holes are provided in the sleeve so that coolant from the plenum can enter the sleeve and cool the fuel. The number and size of the holes are varied from sleeve to sleeve with the number and size of holes being greater for sleeves toward the center of the core and less for sleeves toward the periphery of the core. Preferably the holes are all the same diameter and arranged in rows and columns, the rows starting from the bottom of every sleeve and fewer rows in peripheral sleeves and more rows in the central sleeves.

Church, J.P.

1993-03-30T23:59:59.000Z

309

Nuclear reactor flow control method and apparatus  

DOE Patents (OSTI)

This document describes method and apparatus for improving coolant flow in a nuclear reactor during accident as well as nominal conditions. The reactor has a plurality of fuel elements in sleeves and a plenum above the fuel and through which the sleeves penetrate. Holes are provided in the sleeve so that coolant from the plenum can enter the sleeve and cool the fuel. The number and size of the holes are varied from sleeve to sleeve with the number and size of holes being greater for sleeves toward the center of the core and less for sleeves toward the periphery of the core. Preferably the holes are all the same diameter and arranged in rows and columns, the rows starting from the bottom of every sleeve and fewer rows in peripheral sleeves and more rows in the central sleeves.

Church, J.P.

1991-04-23T23:59:59.000Z

310

Conditioned Unitary Transformation on biphotons  

E-Print Network (OSTI)

A conditioned unitary transformation ($90^o$ polarization rotation) is performed at single-photon level. The transformation is realized by rotating polarization for one of the photons of a polarization-entangled biphoton state (signal photon) by means of a Pockel's cell triggered by the detection of the other (idler) photon after polarization selection. As a result, polarization degree for the signal beam changes from zero to the value given by the idler detector quantum efficiency. This result is relevant to practical realization of various quantum information schemes and can be used for developing a new method of absolute quantum efficiency calibration.

G. Brida; M. Chekhova; M. Genovese; M. Gramegna; L. Krivitsky; S. Kulik

2003-12-29T23:59:59.000Z

311

Fixture conditions affect lamp performance  

SciTech Connect

This article discusses the major parameters that affect fluorescent lamp performance under fixture conditions. These parameters include fixture type, and HVAC integration, which directly determine the minimum lamp wall temperature (MLWT), and therefore, the resulting light output of the lamp/ballast system. Experimental data is presented showing that the lumen output of the lamp/ballast system can vary by as much as 20% and that the system efficacy can vary by 10% depending upon the type of fixture and HVAC system employed. 4 refs., 5 figs., 1 tab.

Siminovitch, M.J.; Rubinstein, F.M.; Verderber, R.R.

1986-11-01T23:59:59.000Z

312

Confined superadiabatic premixed flame-flow interaction  

Science Conference Proceedings (OSTI)

Laminar premixed unity-Lewis number flames are studied numerically, to examine flow-flame interaction in a two-dimensional closed domain. Two opposed planar flame fronts are perturbed sinusoidally and allowed to develop by consuming premixed reactants. Combustion heat release leads to global pressure and temperature rise in the domain, due to confinement. A superadiabatic condition, with products temperature rising with distance behind the flame front, is observed due to stagnation pressure rise. Variations in tangential strain rate behind the perturbed flame fronts, due to flame curvature and heat release, result in a modified local superadiabatic temperature gradient in the products. These variations in temperature gradients are shown to determine the net local confinement-heating rate in the products, leading to corresponding deviations in products temperature, and the local reaction rate along the flame front. These observations, which are not consistent with one-dimensional superadiabatic stagnation flame behavior, are a direct result of the unrestrained unsteady nature of two-dimensional flame-flow interaction.

Najm, H.N.

1995-12-31T23:59:59.000Z

313

Characterization of non-Darcy multiphase flow in petroleum bearing formations. Annual status report, May 14, 1991--May 13, 1992  

SciTech Connect

The objectives of this research are: Develop a proper theoretical model for characterizing non-Darcy multi-phase flow in petroleum bearing formations. Develop an experimental technique for measuring non-Darcy flow coefficients under multiphase flow at insitu reservoir conditions. Develop dimensional consistent correlations to express the non-Darcy flow coefficient as a function of rock and fluid properties for consolidated and unconsolidated porous media. The research accomplished during the period May 1991--May 1992 focused upon theoretical and experimental studies of multiphase non-Darcy flow in porous media.

Evans, R.D.; Civan, F.

1992-12-31T23:59:59.000Z

314

Characterization of non-Darcy multiphase flow in petroleum bearing formations. [Quarterly] report, January 1--March 30, 1993  

SciTech Connect

The objectives of this research are: Develop a proper theoretical model for characterizing non-Darcy multi-phase flow in petroleum bearing formations. Develop an experimental technique for measuring non-Darcy flow coefficients under multiphase flow at insitu reservoir conditions. Develop dimensional consistent correlations to express the non-Darcy flow coefficient as a function of rock and fluid properties for consolidated and unconsolidated porous media. The research accomplished during the period January 1993--March 1993 was focused upon theoretical and experimental studies to more accurately describe multiphase flow in porous media.

Evans, R.D.; Civan, F.

1993-12-31T23:59:59.000Z

315

Fluid-Structure Interaction for Coolant Flow in Research-type Nuclear Reactors  

Science Conference Proceedings (OSTI)

The High Flux Isotope Reactor (HFIR), located at the Oak Ridge National Laboratory (ORNL), is scheduled to undergo a conversion of the fuel used and this proposed change requires an extensive analysis of the flow through the reactor core. The core consists of 540 very thin and long fuel plates through which the coolant (water) flows at a very high rate. Therefore, the design and the flow conditions make the plates prone to dynamic and static deflections, which may result in flow blockage and structural failure which in turn may cause core damage. To investigate the coolant flow between fuel plates and associated structural deflections, the Fluid-Structure Interaction (FSI) module in COMSOL will be used. Flow induced flutter and static deflections will be examined. To verify the FSI module, a test case of a cylinder in crossflow, with vortex induced vibrations was performed and validated.

Curtis, Franklin G [ORNL; Ekici, Kivanc [ORNL; Freels, James D [ORNL

2011-01-01T23:59:59.000Z

316

Nonequilibrium flows with smooth particle applied mechanics  

SciTech Connect

Smooth particle methods are relatively new methods for simulating solid and fluid flows through they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image particles is a good way to prevent a density anomaly at the boundary and to keep the fluxes continuous there. Boundary values of temperature and velocity can be separately controlled. The gradient algorithm, based on differentiating the smooth particle expression for (u{rho}) and (T{rho}), does not show numerical instabilities for the stress tensor and heat flux vector quantities which require second derivatives in space when Fourier`s heat-flow law and Newton`s viscous force law are used. Smooth particle methods show an interesting parallel linking to them to molecular dynamics. For the inviscid Euler equation, with an isentropic ideal gas equation of state, the smooth particle algorithm generates trajectories isomorphic to those generated by molecular dynamics. The shear moduli were evaluated based on molecular dynamics calculations for the three weighting functions, B spline, Lucy, and Cusp functions. The accuracy and applicability of the methods were estimated by comparing a set of smooth particle Rayleigh-Benard problems, all in the laminar regime, to corresponding highly-accurate grid-based numerical solutions of continuum equations. Both transient and stationary smooth particle solutions reproduce the grid-based data with velocity errors on the order of 5%. The smooth particle method still provides robust solutions at high Rayleigh number where grid-based methods fails.

Kum, O.

1995-07-01T23:59:59.000Z

317

Accuracy of flow hoods in residential applications  

SciTech Connect

To assess whether houses can meet performance expectations, the new practice of residential commissioning will likely use flow hoods to measure supply and return grille airflows in HVAC systems. Depending on hood accuracy, these measurements can be used to determine if individual rooms receive adequate airflow for heating and cooling, to determine flow imbalances between different building spaces, to estimate total air handler flow and supply/return imbalances, and to assess duct air leakage. This paper discusses these flow hood applications and the accuracy requirements in each case. Laboratory tests of several residential flow hoods showed that these hoods can be inadequate to measure flows in residential systems. Potential errors are about 20% to 30% of measured flow, due to poor calibrations, sensitivity to grille flow non-uniformities, and flow changes from added flow resistance. Active flow hoods equipped with measurement devices that are insensitive to grille airflow patterns have an order of magnitude less error, and are more reliable and consistent in most cases. Our tests also show that current calibration procedures for flow hoods do not account for field application problems. As a result, a new standard for flow hood calibration needs to be developed, along with a new measurement standard to address field use of flow hoods. Lastly, field evaluation of a selection of flow hoods showed that it is possible to obtain reasonable results using some flow hoods if the field tests are carefully done, the grilles are appropriate, and grille location does not restrict flow hood placement.

Wray, Craig P.; Walker, Iain S.; Sherman, Max H.

2002-05-01T23:59:59.000Z

318

Hanford Tank Farms Waste Certification Flow Loop Test Plan  

Science Conference Proceedings (OSTI)

A future requirement of Hanford Tank Farm operations will involve transfer of wastes from double shell tanks to the Waste Treatment Plant. As the U.S. Department of Energy contractor for Tank Farm Operations, Washington River Protection Solutions anticipates the need to certify that waste transfers comply with contractual requirements. This test plan describes the approach for evaluating several instruments that have potential to detect the onset of flow stratification and critical suspension velocity. The testing will be conducted in an existing pipe loop in Pacific Northwest National Laboratory’s facility that is being modified to accommodate the testing of instruments over a range of simulated waste properties and flow conditions. The testing phases, test matrix and types of simulants needed and the range of testing conditions required to evaluate the instruments are described

Bamberger, Judith A.; Meyer, Perry A.; Scott, Paul A.; Adkins, Harold E.; Wells, Beric E.; Blanchard, Jeremy; Denslow, Kayte M.; Greenwood, Margaret S.; Morgen, Gerald P.; Burns, Carolyn A.; Bontha, Jagannadha R.

2010-01-01T23:59:59.000Z

319

Design of regulated velocity flow assurance device for petroleum industry  

E-Print Network (OSTI)

The petroleum industry faces problems in transportation of crude petroleum be- cause of the deposition of paraffins, hydrates and asphaltenes on the insides of the pipeline. These are conventionally removed using either chemical inhibitors or mechani- cal devices, called pigs, which travel through the pipeline and mechanically scrape away the deposits. These pigs are propelled by the pipeline product itself and hence travel at the same velocity as the product. Research has indicated that cleaning would be better if the pigs are traveling at a relatively constant velocity of around 70% of the product velocity. This research utilizes the concept of regulating the bypass flow velocity in order to maintain the pig velocity. The bypass flow is regulated by the control unit based on the feedback from the turbine flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data gathered during the pig run. This data can then be analyzed and the condition of the pipeline predicted. Thus, this research addresses the problem of designing a pig to maintain a constant velocity in order to achieve better cleaning. It also helps gather elementary data that can be used to predict the internal conditions in the pipe.

Yardi, Chaitanya Narendra

2004-12-01T23:59:59.000Z

320

Numerical Simulation of Inter-basin Groundwater Flow into Northern Yucca Flat, Nevada National Security Site, Using the Death Valley Regional Flow System Model  

SciTech Connect

Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.

Pohlmann Karl,Ye Ming

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Air conditioning: Impact on the built environment  

Science Conference Proceedings (OSTI)

The topics discussed in this book are: Introduction. 1. Air Conditioning - An Ever Expanding Market. 2. Building Envelope Design and Air Contitioning. 3. Air Conditioning and Energy - The CIBSE Building Energy Code. 4. Thermal Storage in Air Conditioning Systems. 5. Good Practice in the Design and Construction of Air Conditioning Systems. 6. Software for Air Conditioning Load Analysis and Design. 7. Lloyd's of London - The Architecture of Air Conditioning - Prediction of the Environment.

Sherratt, A.F.C.

1987-01-01T23:59:59.000Z

322

Oxygen Absorption in Cooling Flows  

E-Print Network (OSTI)

The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of the galaxy, NGC 1399, the group, NGC 5044, and the cluster, A1795. These systems have amongst the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below ~0.4 keV the most reasonable model for the absorber is warm, collisionally ionized gas with T=10^{5-6} K where ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT, and also is consistent with the negligible atomic and molecular H inferred from HI, and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified by Chandra, XMM, and ASTRO-E.

David A. Buote

2000-01-19T23:59:59.000Z

323

Testing of air-flow windows for evaluation and application  

DOE Green Energy (OSTI)

A description is given of how the performance of air-flow windows was assessed in comparison to a conventional window of good current design. Tests were performed in the University Building Environment and Energy Laboratory which allowed tests quite representative of actual application conditions in a variety of vertical orientations. The actual application condition requirement necessitated some approximations to the energy measurements which are not found in guarded hot box or calorimeter kinds of approaches to performance evaluations. The testing technique and required approximations are described. A possible type of solar-residential application is also described briefly.

Boehm, R.F.; Brandle, K.

1980-12-01T23:59:59.000Z

324

Investigation into Flow-Accelerated Corrosion at Low Temperatures  

Science Conference Proceedings (OSTI)

Flow-accelerated corrosion (FAC) is a mechanism that damages carbon steel under conditions commonly found in power plants. Because of problems caused by FAC, there has been a large amount of research performed studying parametric effects, materials behavior, detection techniques, and countermeasures. Damage caused by FAC is normally encountered between about 200 and 450°F (90230°C). However, damage to higher temperature components, and occasionally lower temperature components have been reported...

2007-11-08T23:59:59.000Z

325

Bull Run Fossil Plant Online Coal Flow Adjustable Riffler Test  

Science Conference Proceedings (OSTI)

Boiler optimization at fossil-fired power plants would be enhanced if the flow of coal and air in individual pulverizer fuel delivery lines could be balanced. The static splitter devices currently in service do not adequately maintain coal balance, especially when plant conditions change. This report summarizes the results of a test program to demonstrate the feasibility of using a novel riffler to make online adjustments to a stream of pneumatically conveyed pulverized coal at a working plant. The demon...

2008-03-13T23:59:59.000Z

326

Building Technologies Office: Simplified Space Conditioning Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

Simplified Space Conditioning Systems for Energy Efficient Homes Expert Meeting to someone by E-mail Share Building Technologies Office: Simplified Space Conditioning Systems for...

327

Building Technologies Office: Simplified Space Conditioning Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

Simplified Space Conditioning Systems for Energy Efficient Homes Expert Meeting Building America hosted the "Simplified Space Conditioning Systems for Energy Efficient Homes"...

328

Converting Unconditioned Basement to Conditioned Space - Code...  

NLE Websites -- All DOE Office Websites (Extended Search)

Conditioned Space - Code Notes Converting a basement to conditioned space increases the living space of a house. As with most construction activities, the conversion or...

329

EMSL: User Access: Terms and Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Terms and Conditions The following terms and conditions apply for using EMSL resources. Additional Information User Portal 2014 Call for Proposals 2014 Proposal Guidance 2014...

330

Conditions on Electric Power Generation  

NLE Websites -- All DOE Office Websites (Extended Search)

An Analysis of the Effects of Drought An Analysis of the Effects of Drought Conditions on Electric Power Generation in the Western United States April 2009 DOE/NETL-2009/1365 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,

331

Heat Transfer Enhancement in Separated and Vortex Flows  

SciTech Connect

This document summarizes the research performance done at the Heat Transfer Laboratory of the University of Minnesota on heat transfer and energy separation in separated and vortex flow supported by DOE in the period September 1, 1998--August 31, 2003. Unsteady and complicated flow structures in separated or vortex flows are the main reason for a poor understanding of heat transfer under such conditions. The research from the University of Minnesota focused on the following important aspects of understanding such flows: (1) Heat/mass transfer from a circular cylinder; (2) study of energy separation and heat transfer in free jet flows and shear layers; and (3) study of energy separation on the surface and in the wake of a cylinder in crossflow. The current study used three different experimental setups to accomplish these goals. A wind tunnel and a liquid tunnel using water and mixtures of ethylene glycol and water, is used for the study of prandtl number effect with uniform heat flux from the circular cylinder. A high velocity air jet is used to study energy separation in free jets. A high speed wind tunnel, same as used for the first part, is utilized for energy separation effects on the surface and in the wake of the circular cylinder. The final outcome of this study is a substantial advancement in this research area.

Richard J. Goldstein

2004-05-27T23:59:59.000Z

332

Hash Tables for Efficient Flow Monitoring: Vulnerabilities and Countermeasures  

E-Print Network (OSTI)

Aggregation modules within flow-based network monitoring tools make use of fast lookup methods to be able to quickly assign received packets to their corresponding flows. In software-based aggregators, hash tables are usually used for this task, as these offer constant lookup times under optimal conditions. The hash functions used for mapping flow keys to hash values need to be chosen carefully to ensure optimal utilization of the hash table. If attackers would be able to create collisions, the hash table degenerates to linked lists with worstcase lookup times of O(n) and greatly reduces the performance of the aggregation modules. Thus, independent of the available computational power of the monitor, an attacker would easily be able to overload the system. In this report, we analyze the aggregation modules of the software-based flow meters Vermont and nProbe. We evaluate the resilience strength of used hash functions by theoretical analysis and confirm the results by performing real attacks. These attacks show how easily flow monitors can be overloaded if the hash algorithm has not been chosen carefully. Based on our observations, we finally present a hash function which we believe has none of the weaknesses we have discovered.

David Eckhoff; Tobias Limmer; Falko Dressler

2009-01-01T23:59:59.000Z

333

Development, Verification, and Validation of Multiphase Models for Polydisperse Flows  

Science Conference Proceedings (OSTI)

This report describes in detail the technical findings of the DOE Award entitled 'Development, Verification, and Validation of Multiphase Models for Polydisperse Flows.' The focus was on high-velocity, gas-solid flows with a range of particle sizes. A complete mathematical model was developed based on first principles and incorporated into MFIX. The solid-phase description took two forms: the Kinetic Theory of Granular Flows (KTGF) and Discrete Quadrature Method of Moments (DQMOM). The gas-solid drag law for polydisperse flows was developed over a range of flow conditions using Discrete Numerical Simulations (DNS). These models were verified via examination of a range of limiting cases and comparison with Discrete Element Method (DEM) data. Validation took the form of comparison with both DEM and experimental data. Experiments were conducted in three separate circulating fluidized beds (CFB's), with emphasis on the riser section. Measurements included bulk quantities like pressure drop and elutriation, as well as axial and radial measurements of bubble characteristics, cluster characteristics, solids flux, and differential pressure drops (axial only). Monodisperse systems were compared to their binary and continuous particle size distribution (PSD) counterparts. The continuous distributions examined included Gaussian, lognormal, and NETL-provided data for a coal gasifier.

Christine Hrenya; Ray Cocco; Rodney Fox; Shankar Subramaniam; Sankaran Sundaresan

2011-12-31T23:59:59.000Z

334

Visualization and Diagnostics of Thermal Plasma Flows  

Science Conference Proceedings (OSTI)

Flow visualization is a key tool for the study of thermal plasma flows. Because of their high temperature and associated self emission, standard and high speed photography is commonly used for flow and temperature field visualization. Tracer techniques ... Keywords: d.c. plasma jet, enthalpy probe techniques, induction plasma, laser strobe, photographic techniques, schlieren, thermal plasma flows

M. I. Boulos

2001-01-01T23:59:59.000Z

335

Numerical length estimation for tubular flow reactors  

Science Conference Proceedings (OSTI)

Keywords: free boundary value problems, noniterative and iterative numerical methods, tubular flow reactors

Riccardo Fazio

1992-08-01T23:59:59.000Z

336

AnalyzeHOLE: An Integrated Wellbore Flow Analysis Tool  

SciTech Connect

Conventional interpretation of flow logs assumes that hydraulic conductivity is directly proportional to flow change with depth. However, well construction can significantly alter the expected relation between changes in fluid velocity and hydraulic conductivity. Strong hydraulic conductivity contrasts between lithologic intervals can be masked in continuously screened wells. Alternating intervals of screen and blank casing also can greatly complicate the relation between flow and hydraulic properties. More permeable units are not necessarily associated with rapid fluid-velocity increases. Thin, highly permeable units can be misinterpreted as thick and less permeable intervals or not identified at all. These conditions compromise standard flow-log interpretation because vertical flow fields are induced near the wellbore. AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction. A pumping well and adjacent aquifer system are simulated with an axisymmetric, radial geometry in a two-dimensional MODFLOW model. Hydraulic conductivities are distributed by depth and estimated with PEST by minimizing squared differences between simulated and measured flows and drawdowns. Hydraulic conductivity can vary within a lithology but variance is limited with regularization. Transmissivity of the simulated system also can be constrained to estimates from single-well, pumping tests. Water-quality changes in the pumping well are simulated with simple mixing models between zones of differing water quality. These zones are differentiated by backtracking thousands of particles from the well screens with MODPATH. An Excel spreadsheet is used to interface the various components of AnalyzeHOLE by (1) creating model input files, (2) executing MODFLOW, MODPATH, PEST, and supporting FORTRAN routines, and (3) importing and graphically displaying pertinent results.

Keith J. Halford

2009-10-01T23:59:59.000Z

337

Valve for controlling solids flow  

DOE Patents (OSTI)

A valve for controlling the flow of solids comprises a vessel having an overflow point, an inlet line for discharging solids into the vessel positioned within the vessel such that the inlet line's discharge point is lower than the vessel's overflow point, and apparatus for introducing a fluidizing fluid into the vessel. The fluidizing fluid fluidizes the solids within the vessel so that they overflow at the vessel's overflow point. For the removal of nuclear waste product the vessel may be placed within a sealed container having a bottom connected transport line for transporting the solids to storage or other sites. The rate of solids flow is controlled by the flow rate of the fluidizing fluid and by V-notch weirs of different sizes spaced about the top of the vessel.

Staiger, M. Daniel (Idaho Falls, ID)

1985-01-01T23:59:59.000Z

338

Monitoring probe for groundwater flow  

DOE Patents (OSTI)

A monitoring probe for detecting groundwater migration. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow.

Looney, Brian B. (Aiken, SC); Ballard, Sanford (Albuquerque, NM)

1994-01-01T23:59:59.000Z

339

Hot conditioning equipment conceptual design report  

SciTech Connect

This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

Bradshaw, F.W., Westinghouse Hanford

1996-08-06T23:59:59.000Z

340

Wind Turbine Drivetrain Condition Monitoring (Presentation)  

DOE Green Energy (OSTI)

This presentation details the Gearbox Reliability Collaborative Condition Monitoring program at NREL.

Sheng, S.

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Property:Optimum Marine/Riverline Conditions | Open Energy Information  

Open Energy Info (EERE)

Marine/Riverline Conditions Marine/Riverline Conditions Jump to: navigation, search Property Name Optimum Marine/Riverline Conditions Property Type Text Pages using the property "Optimum Marine/Riverline Conditions" Showing 25 pages using this property. (previous 25) (next 25) M MHK Technologies/Aegir Dynamo + Proprietary MHK Technologies/AirWEC + 15kW per meter of wave front or greater MHK Technologies/Aquantis + The Aquantis Current Plane C Plane technology is a marine current turbine designed to extract the kinetic energy from the flow and is capable of achieving reliable competitively priced base load power generation The technology is suitable for both steady marine currents and tidal currents although there are system differences and specific arraying and deployment requirements for each Aquantis is designed to harness the energy from the Gulf Stream and other steady marine currents around the world Aquantis deployment is projected to be cost competitive with thermal power generation when CO2 emissions and other environmental costs are accounted for

342

Cosmological milestones and energy conditions  

E-Print Network (OSTI)

Until recently, the physically relevant singularities occurring in FRW cosmologies had traditionally been thought to be limited to the "big bang", and possibly a "big crunch". However, over the last few years, the zoo of cosmological singularities considered in the literature has become considerably more extensive, with "big rips" and "sudden singularities" added to the mix, as well as renewed interest in non-singular cosmological events such as "bounces" and "turnarounds". In this talk, we present an extensive catalogue of such cosmological milestones, both at the kinematical and dynamical level. First, using generalized power series, purely kinematical definitions of these cosmological events are provided in terms of the behaviour of the scale factor a(t). The notion of a "scale-factor singularity" is defined, and its relation to curvature singularities (polynomial and differential) is explored. Second, dynamical information is extracted by using the Friedmann equations (without assuming even the existence of any equation of state) to place constraints on whether or not the classical energy conditions are satisfied at the cosmological milestones. Since the classification is extremely general, and modulo certain technical assumptions complete, the corresponding results are to a high degree model-independent.

Celine Cattoen; Matt Visser

2006-09-18T23:59:59.000Z

343

Fuel conditioning facility material accountancy  

SciTech Connect

The operation of the Fuel conditioning Facility (FCF) is based on the electrometallurgical processing of spent metallic reactor fuel. It differs significantly, therefore, from traditional PUREX process facilities in both processing technology and safeguards implications. For example, the fissile material is processed in FCF only in batches and is transferred within the facility only as solid, well-characterized items; there are no liquid steams containing fissile material within the facility, nor entering or leaving the facility. The analysis of a single batch lends itself also to an analytical relationship between the safeguards criteria, such as alarm limit, detection probability, and maximum significant amount of fissile material, and the accounting system`s performance, as it is reflected in the variance associated with the estimate of the inventory difference. This relation, together with the sensitivity of the inventory difference to the uncertainties in the measurements, allows a thorough evaluation of the power of the accounting system. The system for the accountancy of the fissile material in the FCF has two main components: a system to gather and store information during the operation of the facility, and a system to interpret this information with regard to meeting safeguards criteria. These are described and the precision of the inventory closure over one batch evaluated.

Yacout, A.M.; Bucher, R.G.; Orechwa, Y.

1995-08-01T23:59:59.000Z

344

Stability analyses of two-temperature radiative shocks formulation, eigenfunctions, luminosity response and boundary conditions  

E-Print Network (OSTI)

We present a general formulation for stability analyses of radiative shocks with multiple cooling processes, longitudinal and transverse perturbations, and unequal electron and ion temperatures. Using the accretion shocks of magnetic cataclysmic variables as an illustrative application, we investigate the shock instabilities by examining the eigenfunctions of the perturbed hydrodynamic variables. We also investigate the effects of varying the condition at the lower boundary of the post-shock flow from a zero-velocity fixed wall to several alternative type of boundaries involving the perturbed hydrodynamic variables, and the variations of the emission from the post-shock flow under different modes of oscillations. We found that the stability properties for flow with a stationary-wall lower boundary are not significantly affected by perturbing the lower boundary condition, and they are determined mainly by the energy-transport processes. Moreover, there is no obvious correlation between the amplitude or phase o...

Saxton, C J; Saxton, Curtis J.; Wu, Kinwah

2001-01-01T23:59:59.000Z

345

Flow meter evaluation for U.S. Navy Public Works Center, San Diego, California  

Science Conference Proceedings (OSTI)

The U.S. Navy Public Works Center San Diego (PWCSD) was concerned about the accuracy of various flow meters on steam and compressed air lines serving Naval facilities in San Diego, California. The flow meters had experienced various inconsistencies that had not been resolved prior to July 1993. Pacific Northwest Laboratory, Richland, Washington, evaluated the operation of 10 out of 79 steam and compressed air flow meters at PWCSD. The evaluation was limited to analysis of historical information and review of existing operating procedures. On-site investigation of the flow meters was limited to external observations of the flow-sensing equipment and a check of the flow computer program. PNL did not remove installed sensing equipment (i.e., flow meters or temperature or pressure sensors) to evaluate existing condition or check calibration. Although many of the flow meter errors can be traced to improperly normalized readings and to meters improperly compensated for temperature and pressure, lack of regular maintenance, including proper calibration, was evidenced throughout this study. A strict calibration schedule should be established for all steam and air flow meters, including calibration of the temperature sensor, pressure sensor, and flow turbine. It is recommended that the most crucial flow meters (such as the 10 evaluated in this study) be calibrated yearly. The remaining 69 flow meters could be placed on a staggered, biyearly calibration schedule. Calibration should be done by qualified personnel only. Improper calibration is often worse than no calibration at all. An outside firm is recommended to be contracted with to perform all maintenance and calibration on flow meters at the Naval facilities. Use of an outside firm would better facilitate regular, reliable calibration while removing liability for damaged parts.

Chvala, W.D. Jr.; McMordie, K.L.; Szydlowski, R.F.

1995-06-01T23:59:59.000Z

346

Flow in geothermal wells. Part IV. Transition criteria for two-phase flow patterns  

DOE Green Energy (OSTI)

Detailed considerations justifying the criteria for transitions between flow patterns are presented. The following are covered: transition from bubble to plug (or slug) flow, transition from plug flow to froth flow, transition from froth to annular mist flow, and model comparisons. (MHR)

Bilicki, Z.; Kestin, J.

1980-12-01T23:59:59.000Z

347

No-slip boundary condition in finite-size dissipative particle dynamics  

Science Conference Proceedings (OSTI)

Dissipative particle dynamics (DPD) is an efficient, particle based mesoscopic numerical scheme to simulate dynamics of complex fluids and micro-flows, with spatio-temporal scales in the range of micrometers and microseconds. While the traditional DPD ... Keywords: Boundary conditions, DPD, Density fluctuations, Impenetrability, No-slip, Tunable slip

S. Kumar Ranjith; B. S. V. Patnaik; Srikanth Vedantam

2013-01-01T23:59:59.000Z

348

Analysis of microbial diversity and optimal conditions for enhanced biogas production from swine waste anaerobic digestion  

Science Conference Proceedings (OSTI)

Swine wastewater pretreated by solid–liquid separation was optimized for biogas production and water purification. Dynamic diversity of the bacterial community in the anaerobic plug flow reactor was investigated under various temperatures and hydraulic retention times (HRT). Results of batch experiments indicated that under optimal operating conditions

Hsiao-Hsien Lin

2013-01-01T23:59:59.000Z

349

Wind turbine aerodynamics using ALE---VMS: validation and the role of weakly enforced boundary conditions  

Science Conference Proceedings (OSTI)

In this article we present a validation study involving the full-scale NREL Phase VI two-bladed wind turbine rotor. The ALE---VMS formulation of aerodynamics, based on the Navier---Stokes equations of incompressible flows, is employed in conjunction ... Keywords: ALE---VMS, Finite elements, NREL 5MW offshore, NREL Phase VI, Weakly enforced essential boundary conditions, Wind turbine aerodynamics

Ming-Chen Hsu; Ido Akkerman; Yuri Bazilevs

2012-10-01T23:59:59.000Z

350

Assessment of Smolt Condition for Travel Time Analysis, 1993-1994 Annual Report.  

SciTech Connect

The assessment of smolt condition for travel time analysis (ASCTTA) project provided information on the level of smoltification in Columbia River hatchery and wild salmonid stocks to the Fish Passage Center (FPC), for the primary purpose of in-river management of flows.

Schrock, Robin M; Beeman, John W; VanderKooi, Scott P [US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA

1999-02-01T23:59:59.000Z

351

EFFECT OF CLIMATE CHANGE ON WATERSHED RUNOFF FLOW - UPPER COOSA RIVER BASIN UPSTREAM FROM PLANT HAMMOND  

Science Conference Proceedings (OSTI)

The ability of water managers to maintain adequate supplies in the coming decades depends on future weather conditions, as climate change has the potential to reduce stream flows from their current values due to potentially less precipitation and higher temperatures, and possibly rendering them unable to meet demand. The upper Coosa River basin, located in northwest Georgia, plays an important role in supplying water for industry and domestic use in northern Georgia, and has been involved in water disputes in recent times. The seven-day ten-year low flow (7Q10 flow) is the lowest average flow for seven consecutive days that has an average recurrence interval of 10 years. The 7Q10 flow is statistically derived from the observed historical flow data, and represents the low flow (drought) condition for a basin. The upper Coosa River basin also supplies cooling water for the 935MW coal-fired Hammond plant, which draws about 65% of the 7Q10 flow of the upper Coosa River to dissipate waste heat. The water is drawn through once and returned to the river directly from the generator (i.e., no cooling tower is used). Record low flows in 2007 led to use of portable cooling towers to meet temperature limits. Disruption of the Plant Hammond operation may trigger closure of area industrial facilities (e.g. paper mill). The population in Georgia is expected to double from 9 million to 18 million residents in the next 25 years, mostly in the metropolitan Atlanta area. Therefore, there will be an even greater demand for potable water and for waste assimilation. Climate change in the form of persistent droughts (causing low flows) and high ambient temperatures create regulatory compliance challenges for Plant Hammond operating with a once-through cooling system. Therefore, the Upper Coosa River basin was selected to study the effect of potential future weather change on the watershed runoff flow.

Chen, K.

2011-10-24T23:59:59.000Z

352

On the Spectral Integration of the Quasi-Geostrophic Equations for Doubly-Periodic and Channel Flow  

Science Conference Proceedings (OSTI)

The spectral integration of the quasi-geostrophic equations is reexamined for simple boundary conditions in Cartesian geometry. For doubly-periodic flow, it is shown that the mean shear must be constant in time or its evolution specified; grid ...

Geoffrey K. Vallis

1985-01-01T23:59:59.000Z

353

Impact of Surface Flux Formulations and Geostrophic Forcing on Large-Eddy Simulations of Diurnal Atmospheric Boundary Layer Flow  

Science Conference Proceedings (OSTI)

The impact of surface flux boundary conditions and geostrophic forcing on multiday evolution of flow in the atmospheric boundary layer (ABL) was assessed using large-eddy simulations (LES). The LES investigations included several combinations of ...

Vijayant Kumar; Gunilla Svensson; A. A. M. Holtslag; Charles Meneveau; Marc B. Parlange

2010-07-01T23:59:59.000Z

354

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

355

Rinse trough with improved flow  

SciTech Connect

Novel rinse troughs accomplish thorough uniform rinsing. The troughs are suitable for one or more essentially planar objects having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs provide uniform rinse fluid flow over the objects' surfaces to accomplish a more thorough rinse than prior art troughs.

O' Hern, Timothy J. (Albuquerque, NM); Grasser, Thomas W. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

356

Redox flow batteries: a review  

Science Conference Proceedings (OSTI)

Redox flow batteries (RFBs) are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of RFBs with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.

Weber, Adam Z. [Lawrence Berkeley National Laboratory (LBNL); Mench, Matthew M [ORNL; Meyers, Jeremy [University of Texas, Austin; Ross, Philip N. [Lawrence Berkeley National Laboratory (LBNL); Gostick, Jeffrey T. [McGill University, Montreal, Quebec; Liu, Qinghua [University of Tennessee, Knoxville (UTK)

2011-01-01T23:59:59.000Z

357

Wave–Mean Flow Statistics  

Science Conference Proceedings (OSTI)

A relation between the statistics of large-scale waves and the mean flow is derived from the potential enstrophy equations integrated over an isobaric surface. The difference between time-averaged zonal-mean state and the radiative-dynamical ...

Mark R. Schoeberl

1982-10-01T23:59:59.000Z

358

Shallow Water Flows in Channels  

Science Conference Proceedings (OSTI)

We consider the shallow water equations for flows through channels with arbitrary cross section. The system forms a hyperbolic set of balance laws. Exact steady-state solutions are available and are controlled by the relation between the bottom topography ... Keywords: Balance laws, Hyperbolic conservation laws, Steady-state solutions, Upwind schemes

Gerardo Hernández-Dueñas; Smadar Karni

2011-07-01T23:59:59.000Z

359

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

1995-02-14T23:59:59.000Z

360

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Flow visualization around cylinders in a channel flow using Particle Image Velocimetry  

E-Print Network (OSTI)

The objective of the undertaken study was to apply state-of the-art Particle Image Velocimetry to measure full field turbulent flow around cylinders, starting with one cylinder and eventually to a quad cylinder arrangement. Particle Image Velocimetry as used herein is identical to the techniques in use in Texas A&M University's Pulsed Laser Velocimetry Laboratory where the test facilities include a flow bench, a ND-YAG pulsed laser, and data acquistion equipment, consisting of a CCD camera and attendant PC's programmed to control the laser and camera, and to acquire and store the digitized data. The data can then be retrieved for analysis. The data was analyzed using an existing algorithm, the Cross Correlation Code. Full-field, fluid two-dimensional velocity around, about, and past the test specimens was obtained with the digital camera which captured the images of light reflected from seeds flowing within the fluid within a given time exposure time of 53.8 ms. The viewing field area (approximately 5 cm by 5 cm) was illuminated by two light sheets impinging on the test specimens from opposing sides at angles less than 90' from the horizontal. The impinging angles were selected to create the least amount of shading by the test specimen and the incident target on the test specimen was common to both light sheets so that they would superimpose on the target, thus reinforcing the illumination intensity. The two light sheets were created by splitting the pulsing beam into two beams, and then each beam directed with, and to, mirrors which were part of an optical train consisting of three cylindrical lenses which converted the beam into a light sheet 0.5 to 1.0mm thick and 5 cm wide. The test conditions had a range of from 0.043 to 0.0579 m/s for the average velocity of the fluid and a range of Reynolds number of 7142 to 8140. Given these test conditions, vector plots representing the flow fieldwere generated for one test run on each of the these specimens. The velocity component of the plotted vectors was derived from a scale within the plots. Thus, two-dimensional velocities could be read anywhere within the plots. A mix of quantitative and qualitative data was obtained for the one, two, three, and quad cylinder arrangement test specimens.

Martinez, Ramiro Serna

1994-01-01T23:59:59.000Z

362

BEM for 3D unsteady-state flow problems in porous media with a finite-conductivity horizontal wellbore  

Science Conference Proceedings (OSTI)

This paper presents a Boundary Element Method (BEM) for the solution of unsteady-state fluid flow problems in a 3D domain. A general 3D reservoir model was developed in a bounded porous media with Neumann's, Dirichlet's or mixed boundary conditions. ... Keywords: 3D unsteady-state flow problem, BEM, Coupled reservoir/wellbore model, Horizontal well

Yueming Cheng; Duane A. McVay; W. John Lee

2005-04-01T23:59:59.000Z

363

A ghost fluid, level set methodology for simulating multiphase electrohydrodynamic flows with application to liquid fuel injection  

Science Conference Proceedings (OSTI)

In this paper, we present the development of a sharp numerical scheme for multiphase electrohydrodynamic (EHD) flows for a high electric Reynolds number regime. The electric potential Poisson equation contains EHD interface boundary conditions, which ... Keywords: Conservative level set, DNS, Electrohydrodynamics, Ghost fluid method, Multiphase flow, Primary atomization

B. P. Van Poppel; O. Desjardins; J. W. Daily

2010-10-01T23:59:59.000Z

364

Fluid Flow Within Fractured Porous Media  

Science Conference Proceedings (OSTI)

Fractures provide preferential flow paths to subterranean fluid flows. In reservoir scale modeling of geologic flows fractures must be approximated by fairly simple formulations. Often this is accomplished by assuming fractures are parallel plates subjected to an applied pressure gradient. This is known as the cubic law. An induced fracture in Berea sandstone has been digitized to perform numerical flow simulations. A commercially available computational fluid dynamics software package has been used to solve the flow through this model. Single phase flows have been compared to experimental works in the literature to evaluate the accuracy with which this model can be applied. Common methods of fracture geometry classification are also calculated and compared to experimentally obtained values. Flow through regions of the fracture where the upper and lower fracture walls meet (zero aperture) are shown to induce a strong channeling effect on the flow. This model is expanded to include a domain of surrounding porous media through which the flow can travel. The inclusion of a realistic permeability in this media shows that the regions of small and zero apertures contribute to the greatest pressure losses over the fracture length and flow through the porous media is most prevalent in these regions. The flow through the fracture is shown to be the largest contributor to the net flow through the media. From this work, a novel flow relationship is proposed for flow through fractured media.

Crandall, D.M.; Ahmadi, G. (Clarkson Univ., Potsdam, NY); Smith, D.H.; Bromhal, G.S.

2006-10-01T23:59:59.000Z

365

Soluble Lead Flow Battery: Soluble Lead Flow Battery Technology  

SciTech Connect

GRIDS Project: General Atomics is developing a flow battery technology based on chemistry similar to that used in the traditional lead-acid battery found in nearly every car on the road today. Flow batteries store energy in chemicals that are held in tanks outside the battery. When the energy is needed, the chemicals are pumped through the battery. Using the same basic chemistry as a traditional battery but storing its energy outside of the cell allows for the use of very low cost materials. The goal is to develop a system that is far more durable than today’s lead-acid batteries, can be scaled to deliver megawatts of power, and which lowers the cost of energy storage below $100 per kilowatt hour.

None

2010-09-01T23:59:59.000Z

366

Experimental investigation of ice slurry flow pressure drop in horizontal tubes  

SciTech Connect

Pressure drop behaviour of ice slurry based on ethanol-water mixture in circular horizontal tubes has been experimentally investigated. The secondary fluid was prepared by mixing ethyl alcohol and water to obtain initial alcohol concentration of 10.3% (initial freezing temperature -4.4 C). The pressure drop tests were conducted to cover laminar and slightly turbulent flow with ice mass fraction varying from 0% to 30% depending on test conditions. Results from flow tests reveal much higher pressure drop for higher ice concentrations and higher velocities in comparison to the single phase flow. However for ice concentrations of 15% and higher, certain velocity exists at which ice slurry pressure drop is same or even lower than for single phase flow. It seems that higher ice concentration delay flow pattern transition moment (from laminar to turbulent) toward higher velocities. In addition experimental results for pressure drop were compared to the analytical results, based on Poiseulle and Buckingham-Reiner models for laminar flow, Blasius, Darby and Melson, Dodge and Metzner, Steffe and Tomita for turbulent region and general correlation of Kitanovski which is valid for both flow regimes. For laminar flow and low buoyancy numbers Buckingham-Reiner method gives good agreement with experimental results while for turbulent flow best fit is provided with Dodge-Metzner and Tomita methods. Furthermore, for transport purposes it has been shown that ice mass fraction of 20% offers best ratio of ice slurry transport capability and required pumping power. (author)

Grozdek, Marino; Khodabandeh, Rahmatollah; Lundqvist, Per [Royal Institute of Technology, Department of Energy Technology, Division of Applied Thermodynamics and Refrigeration, Brinellvaegen 68, 10044 Stockholm (Sweden)

2009-01-15T23:59:59.000Z

367

Effect of radial transport on compressor tip clearance flow structures and enhancement of stable flow range  

E-Print Network (OSTI)

The relation between tip clearance flow structure and axial compressor stall is interrogated via numerical simulations, to determine how casing treatment can result in improved flow range. Both geometry changes and flow ...

Nolan, Sean Patrick Rock

2005-01-01T23:59:59.000Z

368

ACHIEVING THE REQUIRED COOLANT FLOW DISTRIBUTION FOR THE ACCELERATOR PRODUCTION OF TRITIUM (APT) TUNGSTEN NEUTRON SOURCE  

SciTech Connect

The Accelerator Production of Tritium neutron source consists of clad tungsten targets, which are concentric cylinders with a center rod. These targets are arranged in a matrix of tubes, producing a large number of parallel coolant paths. The coolant flow required to meet thermal-hydraulic design criteria varies with location. This paper describes the work performed to ensure an adequate coolant flow for each target for normal operation and residual heat-removal conditions.

D. SIEBE; K. PASAMEHMETOGLU

2000-11-01T23:59:59.000Z

369

New Technologies and Methods to Improve Computational Speed and Robustness of Power Flow Analysis  

Science Conference Proceedings (OSTI)

The power flow problem consists of determining the steady-state operating point of an electrical transmission network under specific loading conditions. This report describes the development of power flow techniques designed to improve the efficiency and reliability of an electrical power network. Leveraging advancements in computing technologies, data processing, and sophisticated computational methods can improve the performance of power system analysis tools, specifically their accuracy, speed, ...

2013-12-20T23:59:59.000Z

370

A laboratory scale supersonic combustive flow system  

DOE Green Energy (OSTI)

A laboratory scale supersonic flow system [Combustive Flow System (CFS)] which utilizes the gaseous products of methane-air and/or liquid fuel-air combustion has been assembled to provide a propulsion type exhaust flow field for various applications. Such applications include providing a testbed for the study of planar two-dimensional nozzle flow fields with chemistry, three-dimensional flow field mixing near the exit of rectangular nozzles, benchmarking the predictive capability of various computational fluid dynamic codes, and the development and testing of advanced diagnostic techniques. This paper will provide a detailed description of the flow system and data related to its operation.

Sams, E.C.; Zerkle, D.K.; Fry, H.A.; Wantuck, P.J.

1995-02-01T23:59:59.000Z

371

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect

Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.

Boeder, A; Zimm, C

2006-09-30T23:59:59.000Z

372

Photovoltaic power conditioning subsystem: state of the art and development opportunities  

DOE Green Energy (OSTI)

Photovoltaic sytems, the state of the art of power conditioning subsystem components, and the design and operational interaction between photovoltaic systems and hot utilities are detailed in this document. Major technical issues relating to the design and development of power conditioning systems for photovoltaic application are also considered, including: (1) standards, guidelines, and specifications; (2) cost-effective hardware design; (3) impact of advanced components on power conditioning development; (4) protection and safety; (5) quality of power; (6) system efficiency; and (7) system integration with the host utility. In addition, theories of harmonic distortion and reactive power flow are discussed, and information about power conditioner hardware and manufacturers is provided.

Krauthamer, S.; Bahrami, K.; Das, R.; Macie, T.; Rippel, W.

1984-01-15T23:59:59.000Z

373

Flow Test At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) |  

Open Energy Info (EERE)

Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Flow Test At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Exploration Activity Details Location Lassen Volcanic National Park Area Exploration Technique Flow Test Activity Date Usefulness not indicated DOE-funding Unknown Notes Water samples were collected during nitrogen-stimulated flow tests in 1978, but no information was provided on sampling conditions. The well was flowed again for the last time in 1982, but the flow test lasted only 1 h (Thompson, 1985). References Cathy J. Janik, Marcia K. McLaren (2010) Seismicity And Fluid Geochemistry At Lassen Volcanic National Park, California- Evidence For Two

374

Free-surface flow simulations for discharge-based operation of hydraulic structure gates  

E-Print Network (OSTI)

We combine non-hydrostatic flow simulations of the free surface with a discharge model based on elementary gate flow equations for decision support in operation of hydraulic structure gates. A water level-based gate control used in most of today's general practice does not take into account the fact that gate operation scenarios producing similar total discharged volumes and similar water levels may have different local flow characteristics. Accurate and timely prediction of local flow conditions around hydraulic gates is important for several aspects of structure management: ecology, scour, flow-induced gate vibrations and waterway navigation. The modelling approach is described and tested for a multi-gate sluice structure regulating discharge from a river to the sea. The number of opened gates is varied and the discharge is stabilized with automated control by varying gate openings. The free-surface model was validated for discharge showing a correlation coefficient of 0.994 compared to experimental data. A...

Erdbrink, C D; Sloot, P M A

2012-01-01T23:59:59.000Z

375

Subcooled and saturated water flow boiling pressure drop in small diameter helical coils at low pressure  

SciTech Connect

Experimental pressure drop results on boiling water flow through three helical coils of tube inner diameter of 4.03 mm and 4.98 mm and coil diameter to tube diameter ratio of 26.1, 64.1 and 93.3 are presented. Both subcooled and saturated flow boiling are investigated, covering operating pressures from 120 to 660 kPa, mass fluxes from 290 to 690 kg m{sup -2} s{sup -1} and heat fluxes from 50 to 440 kW m{sup -2}. Existing correlations for subcooled flow pressure drop are found not capable to fit the present subcooled database, while the measurements in saturated flow conditions are successfully reproduced by existing correlations for both straight and coiled pipe two-phase flow. The experimental database is included in tabular form. (author)

Cioncolini, Andrea; Santini, Lorenzo; Ricotti, Marco E. [Department of Nuclear Engineering, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy)

2008-05-15T23:59:59.000Z

376

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca  

Open Energy Info (EERE)

Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Details Activities (0) Areas (0) Regions (0) Abstract: A three-dimensional unsaturated-zone numerical model has been developed to simulate flow and distribution of moisture, gas and heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor, air and heat in the highly heterogeneous, fractured porous rock in the unsaturated zone (UZ). This model is intended for use in the prediction of the current and future conditions in the UZ so

377

Categorical Exclusion Determinations: National Energy Technology Laboratory  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

, 2013 , 2013 CX-010816: Categorical Exclusion Determination Effects of Exhaust Gas Recirculation (EGR) on Turbulent Combustion and Emissions in Advanced Gas... CX(s) Applied: A9, B3.6 Date: 08/01/2013 Location(s): New Jersey Offices(s): National Energy Technology Laboratory August 1, 2013 CX-010815: Categorical Exclusion Determination Effects of Exhaust Gas Recirculation (EGR) on Turbulent Combustion and Emissions in Advanced Gas... CX(s) Applied: A9, B3.6 Date: 08/01/2013 Location(s): Indiana Offices(s): National Energy Technology Laboratory July 30, 2013 CX-010826: Categorical Exclusion Determination Evaluation of Flow and Heat Transfer Inside Lean Pre-Mixed Combustor Systems under Reacting Flow Conditions CX(s) Applied: B3.6 Date: 07/30/2013 Location(s): Virginia Offices(s): National Energy Technology Laboratory

378

FRIEND: A CYBER-PHYSICAL SYSTEM FOR TRAFFIC FLOW RELATED INFORMATION AGGREGATION AND DISSEMINATION  

E-Print Network (OSTI)

The major contribution of this thesis is to lay the theoretical foundations of FRIEND – A cyber-physical system for traffic Flow-Related Information aggrEgatioN and Dissemination. By integrating resources and capabilities at the nexus between the cyber and physical worlds, FRIEND will contribute to aggregating traffic flow data collected by the huge fleet of vehicles on our roads into a comprehensive, near real-time synopsis of traffic flow conditions. We anticipate providing drivers with a meaningful, color-coded, at-a-glance view of flow conditions ahead, alerting them to congested traffic. FRIEND can be used to provide accurate information about traffic flow and can be used to propagate this information. The workhorse of FRIEND is the ubiquitous lane delimiters (a.k.a. cat’s eyes) on our roadways that, at the moment, are used simply as dumb reflectors. Our main vision is that by endowing cat’s eyes with a modest power source, detection and communication capabilities they will play an important role in collecting, aggregating and disseminating traffic flow conditions to the driving public. We envision the cat’s eyes system to be supplemented by road-side units (RSU) deployed at regular intervals (e.g. every kilometer or so). The RSUs placed on opposite sides of the roadway constitute a logical

Samy S. El-tawab; Stephan Olariu (director; Hussein Abdel-wahab (member; Michele C. Weigle (member; Samy S. El-tawab; Director Dr. Stephan Olariu

2012-01-01T23:59:59.000Z

379

Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control  

Science Conference Proceedings (OSTI)

The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

2006-07-01T23:59:59.000Z

380

Viscous potential free-surface flows in a fluid layer of finite depth  

E-Print Network (OSTI)

It is shown how to model weakly dissipative free-surface flows using the classical potential flow approach. The Helmholtz-Leray decomposition is applied to the linearized 3D Navier-Stokes equations. The governing equations are treated using Fourier--Laplace transforms. We show how to express the vortical component of the velocity only in terms of the potential and free-surface elevation. A new predominant nonlocal viscous term is derived in the bottom kinematic boundary condition. The resulting formulation is simple and does not involve any correction procedure as in previous viscous potential flow theories [Joseph2004]. Corresponding long wave model equations are derived.

Denys Dutykh; Frederic Dias

2007-05-09T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Vertical Flow Wetland Pilot Study  

Science Conference Proceedings (OSTI)

This is an interim report to present the preliminary results of a study conducted by Duke Energy to test the potential effectiveness of vertical flow wetlands (VFWs) for the removal of selenium, mercury, and other related compounds from a flue gas desulfurization (FGD) discharge. These compounds commonly are found in and regulated for coal-fired utility water discharges. There is a widespread need for a cost-effective alternative to physiochemical treatment to maintain compliance for these parameters, on...

2008-12-08T23:59:59.000Z

382

Economics of Increased Power Flow  

Science Conference Proceedings (OSTI)

This report focuses on methodologies for evaluating the costs and benefits of the diverse technologies that can be used either individually or jointly to increase the flow of power through the transmission system. It begins by describing a broad slate of potential technologies and approaches for increasing transmission capacity and improving system efficiency and then provides an overall framework for assessing the benefits and costs of these technologies. Later sections cover the practical implementatio...

2010-12-21T23:59:59.000Z

383

Flow duct for nuclear reactors  

DOE Patents (OSTI)

Improved liquid sodium flow ducts for nuclear reactors are described wherein the improvement comprises varying the wall thickness of each of the walls of a polygonal tubular duct structure so that each of the walls is of reduced cross-section along the longitudinal center line and of a greater cross-section along wall junctions with the other walls to form the polygonal tubular configuration.

Straalsund, Jerry L. (Richland, WA)

1978-01-01T23:59:59.000Z

384

Countercurrent flow absorber and desorber  

DOE Patents (OSTI)

Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system. 9 figs.

Wilkinson, W.H.

1984-10-16T23:59:59.000Z

385

Freeway Short-Term Traffic Flow Forecasting by Considering Traffic Volatility Dynamics and Missing Data Situations  

E-Print Network (OSTI)

Short-term traffic flow forecasting is a critical function in advanced traffic management systems (ATMS) and advanced traveler information systems (ATIS). Accurate forecasting results are useful to indicate future traffic conditions and assist traffic managers in seeking solutions to congestion problems on urban freeways and surface streets. There is new research interest in short-term traffic flow forecasting due to recent developments in ITS technologies. Previous research involves technologies in multiple areas, and a significant number of forecasting methods exist in literature. However, forecasting reliability is not properly addressed in existing studies. Most forecasting methods only focus on the expected value of traffic flow, assuming constant variance when perform forecasting. This method does not consider the volatility nature of traffic flow data. This paper demonstrated that the variance part of traffic flow data is not constant, and dependency exists. A volatility model studies the dependency among the variance part of traffic flow data and provides a prediction range to indicate the reliability of traffic flow forecasting. We proposed an ARIMA-GARCH (Autoregressive Integrated Moving Average- AutoRegressive Conditional Heteroskedasticity) model to study the volatile nature of traffic flow data. Another problem of existing studies is that most methods have limited forecasting abilities when there is missing data in historical or current traffic flow data. We developed a General Regression Neural Network(GRNN) based multivariate forecasting method to deal with this issue. This method uses upstream information to predict traffic flow at the studied site. The study results indicate that the ARIMA-GARCH model outperforms other methods in non-missing data situations, while the GRNN model performs better in missing data situations.

Zhang, Yanru

2011-08-01T23:59:59.000Z

386

Flow and heat transfer due to a buoyant ceiling jet turning downward at a corner  

Science Conference Proceedings (OSTI)

An experimental investigation has been carried out on the flow and heat transfer characteristics of a horizontal buoyant ceiling jet that turns downward at a corner to yield a vertical negatively buoyant wall flow. In this study, a two-dimensional jet of heated air is discharged adjacent to the lower surface of an isothermal horizontal plate. An isothermal vertical plate is attached at the other end of the horizontal surface, making a right angle corner. The vertical penetration distance of the resulting downward flow is measured and is related to the inflow conditions, particularly to the temperature and velocity at the jet discharge. This penetration distance is found to increase as the distance between the discharge location and the corner is reduced and also as the relative buoyancy level in the inlet flow is decreased. Velocity and temperature measurements are also carried out over the flow region. These indicate that the ceiling flow separates from the horizontal surface just before reaching the corner and then reattaches itself to the vertical wall at a finite distance vertically below the corner. The local surface heat flux measurements show a minimum in the heat transfer rate before the turn, along with a recovery in the heat transfer rate after the turn and the existence of a small recirculation zone near the corner. The net entrainment into the flow and heat transfer rate to the solid boundaries are also measured and correlated with the jet discharge conditions. 22 refs., 12 figs., 1 tab.

Kapoor, K.; Jaluria, Y. [Rutgers - State Univ. of New Jersey, New Brunswick, NJ (United States)

1996-02-01T23:59:59.000Z

387

Wind Turbine Drivetrain Condition Monitoring - An Overview  

DOE Green Energy (OSTI)

This paper provides an overview of wind turbine drivetrain condition monitoring based on presentations from a condition monitoring workshop organized by the National Renewable Energy Laboratory in 2009 and on additional references.

Sheng, S; Veers, P.

2011-10-01T23:59:59.000Z

388

A Database and Meta-Analysis of Ecological Responses to Flow in the South Atlantic Region  

Science Conference Proceedings (OSTI)

Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitative relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we utilized ecological gains or losses, where each represents a benefit or reduction to ecosystem services, respectively. Variables explained 49% of the variation in ecological gains and losses for all ecological groups combined. Altogether, our results suggested that the source of flow change and the ecological group of interest played primary roles in determining the direction and magnitude of ecological responses. Furthermore, our results suggest that developing broadly generalized relationships between ecology and changes in flow at a regional scale is unlikely unless relationships are placed within meaningful contexts, such as environmental flow components or by geomorphic setting.

McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University (Virginia Tech); Davis, Dr, Mary [Southeastern Aquatic Resources Partnership; Kauffman, John [John Kauffman LLC.

2013-01-01T23:59:59.000Z

389

The hidden geometry of ocean flows  

E-Print Network (OSTI)

We introduce a new global Lagrangian descriptor that is applied to flows with general time dependence (altimetric datasets). It succeeds in detecting simultaneously, with great accuracy, invariant manifolds, hyperbolic and non-hyperbolic flow regions.

Carolina Mendoza; Ana M Mancho

2010-03-01T23:59:59.000Z

390

Deep-Flow Variability at Drake Passage  

Science Conference Proceedings (OSTI)

A rotary empirical orthogonal function analysis of the currents measured in central Drake Passage during DRAKE 79 shows that the deep (2500 m) flow has the same spatial and temporal structure as the flow at 500 m, suggesting that current ...

John M. Klinck; Eileen E. Hofmann

1986-07-01T23:59:59.000Z

391

Flow interference in bluff body wakes  

Science Conference Proceedings (OSTI)

This paper presents a two-dimensional numerical simulation of fluid flow around a couple of identical circular cylinders aligned, respectively, along and orthogonal to the main-flow direction, at several distances. A lattice-Boltzmann method (LB) is ...

Rodrigo Surmas; Luís Orlando Emerich Dos Santos; Paulo Cesar Philippi

2003-06-01T23:59:59.000Z

392

Regional Drainage Flows in the Pacific Northwest  

Science Conference Proceedings (OSTI)

An analysis of regional drainage flows in the Pacific Northwest is presented using results from a network of surface observations and a series of simulations carried out with a nested mesoscale model. The flows, which occur regularly in ...

J. C. Doran; S. Zhong

1994-06-01T23:59:59.000Z

393

Preservation of probabilistic information flow under refinement  

Science Conference Proceedings (OSTI)

Information flow properties, which describe confidentiality requirements, are not generally preserved under behavior refinement. This article describes a formal framework for refinement relations between nondeterministic probabilistic processes that ... Keywords: CSP, Confidentiality, Information flow property, Information theory, Process calculus, Refinement, Security

Thomas Santen

2008-02-01T23:59:59.000Z

394

Turbulent Channel Flows on a Rotating Earth  

Science Conference Proceedings (OSTI)

This paper deals with flow in a rectilinear channel on a rotating earth. The flow is directed perpendicular to the background planetary vorticity; both an analytical theory and numerical simulations are employed. The analytical approach assumes ...

Robert A. Handler; Richard P. Mied; Gloria J. Lindemann; Thomas E. Evans

2009-04-01T23:59:59.000Z

395

Turbulent Mixing in Stably Stratified Shear Flows  

Science Conference Proceedings (OSTI)

Vertical mixing of momentum and heat is investigated in turbulent stratified shear flows. It is assumed that the flow has uniform shear and stratification with homogeneous turbulence and that an equilibrium is reached between kinetic and ...

U. Schumann; T. Gerz

1995-01-01T23:59:59.000Z

396

Optical flow using phase information for deblurring  

E-Print Network (OSTI)

This thesis presents a method for reconstructing motion-degraded images by using velocity information generated with a phase-based optical flow calculation. The optical flow method applies a set of frequency-tuned Gabor ...

Texin, Cheryl (Cheryl A.)

2007-01-01T23:59:59.000Z

397

Apparatus for monitoring two-phase flow  

DOE Patents (OSTI)

A method and apparatus for monitoring two-phase flow is provided that is particularly related to the monitoring of transient two-phase (liquid-vapor) flow rates such as may occur during a pressurized water reactor core blow-down. The present invention essentially comprises the use of flanged wire screens or similar devices, such as perforated plates, to produce certain desirable effects in the flow regime for monitoring purposes. One desirable effect is a measurable and reproducible pressure drop across the screen. The pressure drop can be characterized for various known flow rates and then used to monitor nonhomogeneous flow regimes. Another useful effect of the use of screens or plates in nonhomogeneous flow is that such apparatus tends to create a uniformly dispersed flow regime in the immediate downstream vicinity. This is a desirable effect because it usually increases the accuracy of flow rate measurements determined by conventional methods.

Sheppard, John D. (Oak Ridge, TN); Tong, Long S. (Gaithersburg, MD)

1977-03-01T23:59:59.000Z

398

Stratified Tidal Flow over a Bump  

Science Conference Proceedings (OSTI)

The interaction of a stratified flow with an isolated topographic feature can introduce numerous disturbances into the flow, including turbulent wakes, internal waves, and eddies. Measurements made near a “bump” east of Race Rocks, Vancouver ...

Richard Dewey; David Richmond; Chris Garrett

2005-10-01T23:59:59.000Z

399

Large Scale Simulation of Particulate Flows  

Science Conference Proceedings (OSTI)

Simulations of particles in fluid flows are of great interest to numerous industries using sedimentation, fluidization, lubricated transport, and hydraulic fracturing of hydrocarbon reservoirs. Simulating incompressible viscoelastic flows with millions ...

Ahmed H. Sameh; Vivek Sarin

1999-04-01T23:59:59.000Z

400

Resonant Power Conditioning and Compact Pulse Power ...  

Science Conference Proceedings (OSTI)

... (FEEDBACK) HV RECTIFIER AND FILTER NETWORK ... Los Alamos High Frequency “Polyphase Resonant Power Conditioning” ... 30 KW Loss ...

2012-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Components for Advanced Power Conditioning Techniques  

Science Conference Proceedings (OSTI)

Symposium, Advanced Materials for Power Electronics, Power Conditioning, and Power Conversion ... Potential Ceramic Dielectrics for Air Force Applications.

402

Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions  

SciTech Connect

In this program, Rochester Institute of Technology (RIT), General Motors (GM) and Michigan Technological University (MTU) have focused on fundamental studies that address water transport, accumulation and mitigation processes in the gas diffusion layer and flow field channels of the bipolar plate. These studies have been conducted with a particular emphasis on understanding the key transport phenomena which control fuel cell operation under freezing conditions. Technical accomplishments are listed below: • Demonstrated that shutdown air purge is controlled predominantly by the water carrying capacity of the purge stream and the most practical means of reducing the purge time and energy is to reduce the volume of liquid water present in the fuel cell at shutdown. The GDL thermal conductivity has been identified as an important parameter to dictate water accumulation within a GDL. • Found that under the normal shutdown conditions most of the GDL-level water accumulation occurs on the anode side and that the mass transport resistance of the membrane electrode assembly (MEA) thus plays a critically important role in understanding and optimizing purge. • Identified two-phase flow patterns (slug, film and mist flow) in flow field channel, established the features of each pattern, and created a flow pattern map to characterize the two-phase flow in GDL/channel combination. • Implemented changes to the baseline channel surface energy and GDL materials and evaluated their performance with the ex situ multi-channel experiments. It was found that the hydrophilic channel (contact angle ? ? 10?) facilitates the removal of liquid water by capillary effects and by reducing water accumulation at the channel exit. It was also found that GDL without MPL promotes film flow and shifts the slug-to-film flow transition to lower air flow rates, compared with the case of GDL with MPL. • Identified a new mechanism of water transport through GDLs based on Haines jump mechanism. The breakdown and redevelopment of the water paths in GDLs lead to an intermittent water drainage behavior, which is characterized by dynamic capillary pressure and changing of breakthrough location. MPL was found to not only limit the number of water entry locations into the GDL (thus drastically reducing water saturation), but also stabilizes the water paths (or morphology). • Simultaneously visualized the water transport on cathode and anode channels of an operating fuel cell. It was found that under relatively dry hydrogen/air conditions at lower temperatures, the cathode channels display a similar flow pattern map to the ex-situ experiments under similar conditions. Liquid water on the anode side is more likely formed via condensation of water vapor which is transported through the anode GDL. • Investigated the water percolation through the GDL with pseudo-Hele-Shaw experiments and simulated the capillary-driven two-phase flow inside gas diffusion media, with the pore size distributions being modeled by using Weibull distribution functions. The effect of the inclusion of the microporous layer in the fuel cell assembly was explored numerically. • Developed and validated a simple, reliable computational tool for predicting liquid water transport in GDLs. • Developed a new method of determining the pore size distribution in GDL using scanning electron microscope (SEM) image processing, which allows for separate characterization of GDL wetting properties and pore size distribution. • Determined the effect of surface wettability and channel cross section and bend dihedral on liquid holdup in fuel cell flow channels. A major thrust of this research program has been the development of an optimal combination of materials, design features and cell operating conditions that achieve a water management strategy which facilitates fuel cell operation under freezing conditions. Based on our various findings, we have made the final recommendation relative to GDL materials, bipolar design and surface properties, and the combination of materials, design featur

Kandlikar, S.G.; Lu, Z.; Rao, N.; Sergi, J.; Rath, C.; Dade, C.; Trabold, T.; Owejan, J.; Gagliardo, J.; Allen, J.; Yassar, R.S.; Medici, E.; Herescu, A.

2010-05-30T23:59:59.000Z

403

A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements  

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Details Activities (0) Areas (0) Regions (0) Abstract: A comprehensive database of temperature, heat flow, thermal conductivity and geochemistry is the basis of geothermal modelling. The latest revision (1987) of the UK Geothermal Catalogue (UKGC) contains over 2600 temperatures at over 1150 sites and over 200 observations of heat flow. About 93% of the temperature data are from depths less than 2000 m and about 50% are Bottom Hole Temperatures (BHT). Heat-flow density

404

Space-Conditioning System Selection Guide  

Science Conference Proceedings (OSTI)

This handbook represents a single-source guide to the selection of space-conditioning equipment for commercial facilities. Written for the utility marketing representative, it provides information on these topics: heating, cooling, ventilation, and dehumidification requirements of commercial buildings; customer needs when selecting a space-conditioning system; and, the options among energy-efficient electric space-conditioning systems for commercial buildings.

1994-01-22T23:59:59.000Z

405

TERMS AND CONDITIONS TABLE OF CONTENTS  

E-Print Network (OSTI)

EXHIBIT C TERMS AND CONDITIONS TABLE OF CONTENTS SECTION PAGE NO. 1. Grant Agreement .......................................................................... 19 i #12;EXHIBIT C TERMS AND CONDITIONS TABLE OF CONTENTS ii 21. Confidentiality..................................................................................................................... 33 #12;EXHIBT C TERMS AND CONDITIONS 1. Grant Agreement This project is being funded with a grant

406

Conditional copulas, association measures and their applications  

Science Conference Proceedings (OSTI)

One way to model a dependence structure is through the copula function which is a mean to capture the dependence structure in the joint distribution of variables. Association measures such as Kendall's tau or Spearman's rho can be expressed as functionals ... Keywords: Asymptotic bias, Asymptotic variance, Conditional Kendall's tau, Conditional Spearman's rho, Conditional copula, Empirical estimation, Global and local bandwidths, Local dependencies, Smoothing

Irène Gijbels; Noël Veraverbeke; Marel Omelka

2011-05-01T23:59:59.000Z

407

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

Science Conference Proceedings (OSTI)

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, ... Keywords: Double porosity, Fracture propagation, Hydraulic fracturing, Poromechanics, Shale gas, Tensile failure

Jihoon Kim, George J. Moridis

2013-10-01T23:59:59.000Z

408

Anisotropic collective flow of a Lorentz gas  

E-Print Network (OSTI)

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

Nicolas Borghini; Clement Gombeaud

2011-06-29T23:59:59.000Z

409

Toeplitz CAR flows and type I factorizations  

E-Print Network (OSTI)

Toeplitz CAR flows are a class of E_0-semigroups including the first type III example constructed by R. T. Powers. We show that the Toeplitz CAR flows contain uncountably many mutually non cocycle conjugate E_0-semigroups of type III. We also generalize the type III criterion for Toeplitz CAR flows employed by Powers (and later refined by W. Arveson), and show that Toeplitz CAR flows are always either of type I or type III.

Izumi, Masaki

2009-01-01T23:59:59.000Z

410

CFD SIMULATION OF PROPOSED VALIDATION DATA FOR A FLOW PROBLEM RECONFIGURED TO ELIMINATE AN UNDESIRABLE FLOW INSTABILITY  

DOE Green Energy (OSTI)

The U. S. Department of Energy (DOE) is supporting the development of a next generation nuclear plant (NGNP), which will be based on a very high temperature reactor (VHTR) design. The VHTR is a single-phase helium-cooled reactor wherein the helium will be heated initially to 750 °C and later to temperatures approaching 1000 °C. The high temperatures are desired to increase reactor efficiency and to provide a heat source for the manufacture of hydrogen and other applications. While computational fluid dynamics (CFD) has not been used in the past to design or license nuclear reactors in the U. S., it is expected that CFD will be used in the design and safety analysis of forthcoming designs. This is partly because of the maturity of CFD and partly because detailed information is desired of the flow and heat transfer inside the reactor to avoid hot spots and other conditions that might compromise reactor safety. Numerical computations of turbulent flow should be validated against experimental data for flow conditions that contain some or all of the physics expected in the thermal fluid machinery of interest. To this end, a scaled model of a narrow slice of the lower plenum of the prismatic VHTR was constructed and installed in the Idaho National Laboratory’s (INL) matched index of refraction (MIR) test facility and data were taken. The data were then studied and compared to CFD calculations to help determine their suitability for validation data. One of the main findings was that the inlet data, which were measured and controlled by calibrated mass flow rotameters and were also measured using detailed stereo particle image velocimetry (PIV) showed considerable discrepancies in mass flow rate between the two methods. The other finding was that a randomly unstable recirculation zone occurs in the flow. This instability has a very significant effect on the flow field in the vicinity of the inlet jets. Because its time scale is long and because it is apparently a random instability, it was deemed undesirable for a validation data set. It was predicted using CFD that by eliminating the first of the four jets, the recirculation zone could be stabilized. The present paper reports detailed results for the three-jet case with comparisons to the four-jet data inasmuch as three-jet data are still unavailable. Hence, the present simulations are true or blind predictions.

Richard W. Johnson; Hugh M. McIlroy

2010-08-01T23:59:59.000Z

411

Multiphase Turbulent Flow Ken Kiger -UMCP  

E-Print Network (OSTI)

of the dispersion: · Size & geometry · Volume fraction #12;Bubbly Pipe Flow ­ heat exchangers in power plants, A/C units Gas-Liquid Flow #12;Aeration: -produced by wave action - used as reactor in chemical processing delivery Liquid-Gas Flow http://www.mywindpowersystem.com/2009/07/wind-power-when-nature

Gruner, Daniel S.

412

Pebble Flow Experiments For Pebble Bed Reactors  

E-Print Network (OSTI)

Pebble Flow Experiments For Pebble Bed Reactors Andrew C. Kadak1 Department of Nuclear Engineering of Technology 2nd International Topical Meeting on High Temperature Reactor Technology Institute of Nuclear in such a reactor would conform to granular flow theory which suggested rapid mixing as opposed to linear flow lines

Bazant, Martin Z.

413

Liquid cooled counter flow turbine bucket  

DOE Patents (OSTI)

Means and a method are provided whereby liquid coolant flows radially outward through coolant passages in a liquid cooled turbine bucket under the influence of centrifugal force while in contact with countercurrently flowing coolant vapor such that liquid is entrained in the flow of vapor resulting in an increase in the wetted cooling area of the individual passages.

Dakin, James T. (Schenectady, NY)

1982-09-21T23:59:59.000Z

414

A three phase load flow algorithm for Shipboard Power Systems  

E-Print Network (OSTI)

Load Flow (Power Flow) is the determination of the steady state operating conditions for the system. This is a very important tool utilized by many real time applications in power systems. Traditional load flow methods, which incorporate Gauss-Seidel and/or Newton Raphson techniques, were primarily developed for transmission system analysis. Distribution load flow analysis must incorporate its unique characteristics such as unbalanced loads, distributed loads, radial network structure, and one, two, or three phase lines. Also, there are a variety of components included in distribution systems such as switches, transformers, voltage regulators, and distributed generators. Therefore, the traditional methods cannot be directly applied to distribution systems since the assumptions made for transmission systems are not valid for the unique characteristics of distribution systems. A Shipboard Power System (SPS) is a finite inertia electric power system. The generation, transmission, and distribution systems in SPSs are tightly coupled. In reality, the transmission system consists of the lines that interconnect the generator buses in a ring configuration. The distribution system consists of lines, transformers, and loads connected in a radial configuration. When analyzing a SPS, its distinct characteristics must be taken into consideration. Therefore, just as transmission and distribution systems have unique methods of analysis, SPSs also need a unique method of analysis. A load flow algorithm for a SPS must consider its distribution system characteristics as well as the unique characteristics of SPSs. The work presented in this thesis discussed a load flow algorithm developed for Shipboard Power Systems and terrestrial wye and delta connected radial distribution systems. The issues in developing a load flow algorithm for a SPS are addressed and the solution is presented. This solution combines three methods that addressed the issues of multiple sources, ring configuration, and radial load flow. This algorithm was tested on the IEEE 37 Bus Radial Distribution Test Feeder and a simplified Shipboard Power Test System developed by researchers in the Power System Automation Laboratory. The results produced minimal percent error when compared to the actual output results.

Medina-Calder?on, M?onica M

2003-01-01T23:59:59.000Z

415

Air Flow Distribution in the Sales Area of a Supermarket  

E-Print Network (OSTI)

Many kinds of goods are displayed in a supermarket, which have their own particularities. The consumer flow rate is great and the type of shelved goods varies significantly, thereby influencing the objects that generate heat, and the demands of air temperature, air velocity and humidity in different zones. The results of a study of a sales area of a supermarket in Harbin are presented in this paper, including air temperature, air velocity and humidity. According to the assessment index of air flow distribution (EDT, ADPI, temperature efficiency, energy coefficient of utilization, coefficient of ununiformity and so on), the experimental data were analyzed. The rationality of airflow distribution was then evaluated. Suggestions for air conditioning system design are also presented in this paper.

Fang, X.; Song, C.; Zhao, J.; Wang, Z.

2006-01-01T23:59:59.000Z

416

Cold Feedback in Cooling-Flow Galaxy Clusters  

E-Print Network (OSTI)

We put forward an alternative view to the Bondi-driven feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow galaxies and clusters. We adopt the popular view that the heating is due to an active galactic nucleus (AGN), i.e. a central black hole accreting mass and launching jets and/or winds. We propose that the feedback occurs with the entire cool inner region (5-30 kpc). A moderate cooling flow does exist here, and non-linear over-dense blobs of gas cool fast and are removed from the ICM before experiencing the next major AGN heating event. Some of these blobs may not accrete on the central black hole, but may form stars and cold molecular clouds. We discuss the conditions under which the dense blobs may cool to low temperatures and feed the black hole.

Fabio Pizzolato

2006-11-07T23:59:59.000Z

417

Cold Feedback in Cooling–Flow Galaxy Clusters  

E-Print Network (OSTI)

Summary. We put forward an alternative view to the Bondi–driven feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow (CF) galaxies and clusters. We adopt the popular view that the heating is due to an active galactic nucleus (AGN), i.e. a central black hole accreting mass and launching jets and/or winds. We propose that the feedback occurs with the entire cool inner region (r ? 5?30 kpc). A moderate cooling flow does exist here, and non–linear over–dense blobs of gas cool fast and are removed from the ICM before experiencing the next major AGN heating event. Some of these blobs may not accrete on the central black hole, but may form stars and cold molecular clouds. We discuss the conditions under which the dense blobs may cool to low temperatures and feed the black hole. 1

Fabio Pizzolato

2006-01-01T23:59:59.000Z

418

Cold Feedback in Cooling-Flow Galaxy Clusters  

E-Print Network (OSTI)

We put forward an alternative view to the Bondi-driven feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow galaxies and clusters. We adopt the popular view that the heating is due to an active galactic nucleus (AGN), i.e. a central black hole accreting mass and launching jets and/or winds. We propose that the feedback occurs with the entire cool inner region (5-30 kpc). A moderate cooling flow does exist here, and non-linear over-dense blobs of gas cool fast and are removed from the ICM before experiencing the next major AGN heating event. Some of these blobs may not accrete on the central black hole, but may form stars and cold molecular clouds. We discuss the conditions under which the dense blobs may cool to low temperatures and feed the black hole.

Pizzolato, F

2006-01-01T23:59:59.000Z

419

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network (OSTI)

The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown that the off-center nozzle location can be selected judiciously so as to maintain (or even improve heat transfer) while reducing the gross shellside pressure loss. Thus, the pumping costs are minimized without sacrificing heat transfer.

Singh, K. P.

1979-01-01T23:59:59.000Z

420

Combustion Stability in Complex Engineering Flows | Argonne Leadership  

NLE Websites -- All DOE Office Websites (Extended Search)

Instantaneous contours of temperature from large eddy simulation Instantaneous contours of temperature from large eddy simulation Instantaneous contours of temperature from large eddy simulation of a hypersonic scramjet combustor at Mach 8 flight conditions. Ethylene fuel is introduced through injection ports at the upper left and mixes with air at supersonic speeds. Flow separation and recirculation in the open cavity encourages fuel/air mixing and stable combustion. To maintain hypersonic flight, the fuel must be mixed, ignited, and burned to completion all within a few milliseconds. Cascade Technologies, Inc. Combustion Stability in Complex Engineering Flows PI Name: Lee Shunn PI Email: shunn@cascadetechnologies.com Institution: Cascade Technologies, Inc. Allocation Program: INCITE Allocation Hours at ALCF: 35 Million

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Flow dynamics and solute transport in unsaturated rock fractures  

E-Print Network (OSTI)

and H. Brenner, Multiphase flow in porous media, Ann. Rev.to describe multiphase flow in porous media, involvingflow in porous media, can be generalized for multiphase flow

Su, G.W.

2011-01-01T23:59:59.000Z

422

Experimental studies of adiabatic flow boiling in fractal-like branching microchannels  

SciTech Connect

Experimental results of adiabatic boiling of water flowing through a fractal-like branching microchannel network are presented and compared to numerical model simulations. The goal is to assess the ability of current pressure loss models applied to a bifurcating flow geometry. The fractal-like branching channel network is based on channel length and width ratios between adjacent branching levels of 2{sup -1/2}. There are four branching sections for a total flow length of 18 mm, a channel height of 150 {mu}m and a terminal channel width of 100 {mu}m. The channels were Deep Reactive Ion Etched (DRIE) into a silicon disk. A Pyrex disk was anodically bonded to the silicon to form the channel top to allow visualization of the flow within the channels. The flow rates ranged from 100 to 225 g/min and the inlet subcooling levels varied from 0.5 to 6 C. Pressure drop along the flow network and time averaged void fraction in each branching level were measured for each of the test conditions. The measured pressure drop ranged from 20 to 90 kPa, and the measured void fraction ranged from 0.3 to 0.9. The measured pressure drop results agree well with separated flow model predictions accounting for the varying flow geometry. The measured void fraction results followed the same trends as the model; however, the scatter in the experimental results is rather large. (author)

Daniels, Brian J.; Liburdy, James A.; Pence, Deborah V. [Mechanical Engineering, Oregon State University, Corvallis, OR 97330 (United States)

2011-01-15T23:59:59.000Z

423

Echo Tomography of Black Hole Accretion Flows  

E-Print Network (OSTI)

We discuss technologies for micro-arcsec echo mapping of black hole accretion flows in Active Galactic Nuclei (AGN). Echo mapping employs time delays, Doppler shifts, and photoionisation physics to map the geometry, kinematics, and physical conditions in the reprocessing region close to a compact time-variable source of ionizing radiation. Time delay maps are derived from detailed analysis of variations in lightcurves at different wavelengths. Echo mapping is a maturing technology at a stage of development similar to that of radio interferometry just before the VLA. The first important results are in, confirming the basic assumptions of the method, measuring the sizes of AGN emission line regions, delivering dozens of black hole masses, and showing the promise of the technique. Resolution limits with existing AGN monitoring datasets are typically ~5-10 light days. This should improve down to 1-2 light days in the next-generation echo mapping experiments, using facilities like Kronos and Robonet that are designed for and dedicated to sustained spectroscopic monitoring. A light day is 0.4 micro-arcsec at redshift 0.1, thus echo mapping probes regions 10^3 times smaller than VLBI, and 10^5 times smaller than HST.

Keith Horne

2003-01-14T23:59:59.000Z

424

Self-regulating flow control device  

DOE Patents (OSTI)

A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.

Humphreys, Duane A. (Pittsburgh, PA)

1984-01-01T23:59:59.000Z

425

Automated flow-temperature-humidity control system  

SciTech Connect

An automated system that controls air flow, temperature, and humidity was developed from a commercially available temperature-humidity indicator and a specially built flow-temperature-humidity control module. Parameters are set using direct-reading dials on the control module. The air flow is maintained using a mass-flow controller while process controllers connected to the indicator regulate humidity and temperature. The system will run indefinitely without need for operator intervention. If the module and indicator are calibrated properly, accurate air flows (+-2% of full scale), temperatures (+-0.3/sup 0/C), and humidities (+-2% RH) can be achieved.

Nelson, G.O.; Taylor, R.D.

1980-10-01T23:59:59.000Z

426

Chemical preconcentrator with integral thermal flow sensor  

DOE Patents (OSTI)

A chemical preconcentrator with integral thermal flow sensor can be used to accurately measure fluid flow rate in a microanalytical system. The thermal flow sensor can be operated in either constant temperature or constant power mode and variants thereof. The chemical preconcentrator with integral thermal flow sensor can be fabricated with the same MEMS technology as the rest of the microanlaytical system. Because of its low heat capacity, low-loss, and small size, the chemical preconcentrator with integral thermal flow sensor is fast and efficient enough to be used in battery-powered, portable microanalytical systems.

Manginell, Ronald P. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)

2003-01-01T23:59:59.000Z

427

Turbine Vanes and Endwalls with Realistic Surface Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

Vanes and Endwalls with Vanes and Endwalls with Realistic Surface Conditions SCIES Project 03-01-SR110 DOE COOPERATIVE AGREEMENT DE-FC26-02NT41431 Tom J. George, Program Manager, DOE/NETL Richard Wenglarz, Manager of Research, SCIES Project Awarded (7/1/2003, 36 Month Duration) $572,385 Total Contract Value ($572,385 DOE) PI: Karen A. Thole Co-PI: David G. Bogard Graduate Research Assistants: Nicholas Cardwell Patricia Demling Narayan Sundaram Scot Wye Gas Turbine Needs * Account for the effects of roughness from particle deposition and corrosion resulting from the use of synfuels * Account for the effects of blocked holes and gap leakages on predicting airfoil temperatures Overall Project Objectives * Determine effects of flow leakages at component interfaces occurring due to expansions/contractions

428

An Evaluation of Boundary Conditions for Modeling Urban Boundary Layers  

DOE Green Energy (OSTI)

Numerical modeling of the urban boundary layer is complicated by the need to describe airflow patterns outside of the computational domain. These patterns have an impact on how successfully the simulation is able to model the turbulence associated with the urban boundary layer. This talk presents experiments with the model boundary conditions for simulations that were done to support two Department of Energy observational programs involving the Salt Lake City basin. The Chemical/Biological Non-proliferation Program (CBNP) is concerned with the effects of buildings on influencing dispersion patterns in urban environments. The Vertical Transport and Mixing Program (VTMX) investigating mixing mechanisms in the stable boundary layer and how they are influenced by the channeling caused by drainage flows or by obstacles such as building complexes. Both of these programs are investigating the turbulent mixing caused by building complexes and other urban obstacles.

Calhoun, R.J.; Chan, S.T.; Lee, R.L.

2000-05-18T23:59:59.000Z

429

Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint  

SciTech Connect

This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.

Woods, J.; Kozubal, E.

2012-10-01T23:59:59.000Z

430

Analytical and Numerical Investigation of Ant Behavior Under Crowded Conditions  

E-Print Network (OSTI)

Swarm intelligence is widely recognized as a powerful paradigm of self-organized optimization, with numerous examples of successful applications in distributed artificial intelligence. However, the role of physical interactions in the organization of traffic flows in ants under crowded conditions has only been studied very recently. The related results suggest new ways of congestion control and simple algorithms for optimal resource usage based on local interactions and, therefore, decentralized control concepts. Here, we present a mathematical analysis of such a concept for an experiment with two alternative ways with limited capacities between a food source and the nest of an ant colony. Moreover, we carry out microscopic computer simulations for generalized setups, in which ants have more alternatives or the alternative ways are of different lengths. In this way and by variation of interaction parameters, we can get a better idea, how powerful congestion control based on local repulsive interactions may be...

Peters, Karsten; Dussutour, Audrey; Helbing, Dirk

2008-01-01T23:59:59.000Z

431

Momentum Transport in Granular Flows  

E-Print Network (OSTI)

We investigate the error induced by only considering binary collisions in the momentum transport of hard-sphere granular materials, as is done in kinetic theories. In this process, we first present a general microscopic derivation of the momentum transport equation and compare it to the kinetic theory derivation, which relies on the binary collision assumption. These two derivations yield different microscopic expressions for the stress tensor, which we compare using simulations. This provides a quantitative bound on the regime where binary collisions dominate momentum transport and reveals that most realistic granular flows occur in the region of phase space where the binary collision assumption does not apply.

Gregg Lois; Anael Lemaitre; Jean M. Carlson

2006-02-10T23:59:59.000Z

432

Liquid hydrogen flow problems in Kiwi reactors  

DOE Green Energy (OSTI)

The Kiwi series of reactors were the first ones tested in the US Rover Program in the development of nuclear rocket engines for space propulsion. The early experiments with liquid hydrogen showed that parallel flow systems were prone to uneven flow distributions and violent fluctuations in pressure and flow that were capable of destroying a reactor core. Kiwi flow distribution problems were solved by using multiple feed lines into the nozzle cooling system and carefully balancing impedance among them. The violent pressure and flow fluctuations were eliminated after their cause was identified as resonance phenomena driven by the response to flow disturbances of heat transfer through a superheated hydrogen layer. Smooth flow operations were assured by rapidly bringing operating pressures beyond several times the critical pressure of hydrogen. After this initial rough start, solid core nuclear rocket engines successfully passed milestones of achievements during the remainder of the Rover program.

Thurston, R.S.

1992-09-01T23:59:59.000Z

433

Effects of Acclimation on Poststocking Dispersal and Physiological Condition of Age-1 Pallid Sturgeon  

Science Conference Proceedings (OSTI)

A propagation program for pallid sturgeon Scaphirhynchus albus in the upper Missouri River was implemented by the U. S. Fish and Wildlife Service in 1997. Preliminary research indicated that many hatchery-reared pallid sturgeon were experiencing significant downstream poststocking dispersal, negatively affecting their recruitment. Therefore, the objective of this study was to evaluate the effects of acclimation to flow and site-specific physicochemical water conditions on poststocking dispersal and physiological condition of age-1 pallid sturgeon. Fish from three acclimation treatments were radio-tagged, released at two locations (Missouri River and Marias River), and monitored using passive telemetry stations. Marias treatment was acclimated to flow and site-specific physicochemical conditions, Bozeman treatment was acclimated to flow only, and traditional treatment had no acclimation (reared under traditional protocol). During both years fish released in the Missouri River dispersed less than fish released in the Marias River. In 2005, Marias treatment dispersed less and nearly twice as many fish remained in the Missouri River reach than traditional treatment. In 2006, pallid sturgeon dispersed similarly among treatments and fish remaining in the Missouri River reach were similar among all treatments. Differences in poststocking dispersal between years may be related to fin curl. Fin curl was present in all fish in 2005 and 27% of the fish in 2006. Pallid sturgeon from all treatments in both years had a greater affinity for the lower reaches of the Missouri River than the upper reaches. Thus, habitat at release site influenced poststocking dispersal more than acclimation treatment. No difference was observed in relative growth rate among treatments in 2006. However, acclimation to flow (i.e., exercise conditioning) may reduce liver fat content. Acclimation conditions used in this study may not benefit pallid sturgeon unless physiological maladies are present. Further, natural resource agencies need to consider stocking location carefully to reduce poststocking dispersal.

Oldenburg, Eric W.; Guy, Christopher S.; Cureton, Eli S.; Webb, Molly H.; Gardner, William M.

2011-03-28T23:59:59.000Z

434

Field-Flow Fractionation of Carbon Nanotubes and Related Materials  

Science Conference Proceedings (OSTI)

During the grant period, we carried out FFF studies of carbonaceous soot, single-walled and multi-walled carbon nanotubes, carbon nano-onions and polyoxometallates. FFF alone does not provide enough information to fully characterize samples, so our suite of characterization techniques grew to include light scattering (especially Photon Correlation Spectroscopy), scanning and transmission electron microscopy, thermogravimetric analysis and spectroscopic methods. We developed convenient techniques to deposit and examine minute FFF fractions by electron microscopy. In collaboration with Arthur Cammers (University of Kentucky), we used Flow Field-Flow Fractionation (Fl-FFF) to monitor the solution-phase growth of keplerates, a class of polyoxometallate (POM) nanoparticles. We monitored the evolution of Mo-POM nanostructures over the course of weeks by by using flow field-flow fractionation and corroborated the nanoparticle structures by using transmission electron microscopy (TEM). Total molybdenum in the solution and precipitate phases was monitored by using inductively coupled plasma analyses, and total Mo-POM concentration by following the UV-visible spectra of the solution phase. We observe crystallization-driven formation of (Mo132) keplerate and solution phase-driven evolution of structurally related nanoscopic species (3-60 nm). FFF analyses of other classes of materials were less successful. Attempts to analyze platelets of layered materials, including exfoliated graphite (graphene) and TaS2 and MoS2, were disappointing. We were not able to optimize flow conditions for the layered materials. The metal sulfides react with the aqueous carrier liquid and settle out of suspension quickly because of their high density.

John P. Selegue

2011-11-17T23:59:59.000Z

435

DECORRELATION TIMES OF PHOTOSPHERIC FIELDS AND FLOWS  

SciTech Connect

We use autocorrelation to investigate evolution in flow fields inferred by applying Fourier local correlation tracking (FLCT) to a sequence of high-resolution (0.''3), high-cadence ({approx_equal} 2 minute) line-of-sight magnetograms of NOAA active region (AR) 10930 recorded by the narrowband filter imager of the Solar Optical Telescope aboard the Hinode satellite over 2006 December 12 and 13. To baseline the timescales of flow evolution, we also autocorrelated the magnetograms, at several spatial binnings, to characterize the lifetimes of active region magnetic structures versus spatial scale. Autocorrelation of flow maps can be used to optimize tracking parameters, to understand tracking algorithms' susceptibility to noise, and to estimate flow lifetimes. Tracking parameters varied include: time interval {Delta}t between magnetogram pairs tracked, spatial binning applied to the magnetograms, and windowing parameter {sigma} used in FLCT. Flow structures vary over a range of spatial and temporal scales (including unresolved scales), so tracked flows represent a local average of the flow over a particular range of space and time. We define flow lifetime to be the flow decorrelation time, {tau}. For {Delta}t > {tau}, tracking results represent the average velocity over one or more flow lifetimes. We analyze lifetimes of flow components, divergences, and curls as functions of magnetic field strength and spatial scale. We find a significant trend of increasing lifetimes of flow components, divergences, and curls with field strength, consistent with Lorentz forces partially governing flows in the active photosphere, as well as strong trends of increasing flow lifetime and decreasing magnitudes with increases in both spatial scale and {Delta}t.

Welsch, B. T. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Kusano, K.; Yamamoto, T. T. [Solar Terrestrial Environment Laboratory, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Muglach, K. [Code 674, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-03-10T23:59:59.000Z

436

The Pandora Particle Flow Algorithm  

E-Print Network (OSTI)

A high-energy e+e- collider, such as the ILC or CLIC, is arguably the best option to complement and extend the LHC physics programme. A lepton collider will allow for exploration of Standard Model Physics, such as precise measurements of the Higgs, top and gauge sectors, in addition to enabling a multitude of New Physics searches. However, physics analyses at such a collider will place unprecedented demands on calorimetry, with a required jet energy resolution of \\sigma(E)/E energy resolution by fully reconstructing the paths of individual particles through the detector. The energies of charged particles can then be extracted from precise inner detector tracker measurements, whilst photon energies will be measured in the ECAL, and only neutral hadron energies (10% of jet energies) will be measured in the HCAL, largely avoiding the typically poor HCAL resolution. This document introduces the Pandora particle flow algorithms, which offer the current state of the art in particle flow calorimetry for the ILC and CLIC. The performance of the algorithms is investigated by examining the reconstructed jet energy resolution and the ability to separate the hadronic decays of W and Z bosons.

J. S. Marshall; M. A. Thomson

2013-08-21T23:59:59.000Z

437

Central Air Conditioning | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Central Air Conditioning Central Air Conditioning Central Air Conditioning May 30, 2012 - 8:01pm Addthis Central air conditioners circulate cool air through a system of supply and return ducts. | Photo courtesy of ©iStockphoto/DonNichols. Central air conditioners circulate cool air through a system of supply and return ducts. | Photo courtesy of ©iStockphoto/DonNichols. What does this mean for me? Central air conditioning systems are thermostatically controlled and convenient to use. Central air conditioning systems must be installed properly to operate efficiently. Central air conditioning systems can share ductwork with your heating system. Central air conditioners circulate cool air through a system of supply and return ducts. Supply ducts and registers (i.e., openings in the walls,

438

Energy conditions in f(R)-gravity  

E-Print Network (OSTI)

In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from the Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R)-gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R)-cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.

Santos, J; Rebouças, M J; Carvalho, F C

2007-01-01T23:59:59.000Z

439

Energy conditions in f(R)-gravity  

E-Print Network (OSTI)

In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from the Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R)-gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R)-cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.

J. Santos; J. S. Alcaniz; M. J. Reboucas; F. C. Carvalho

2007-08-02T23:59:59.000Z

440

Methods of Conditioning Direct Methanol Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Methods of Conditioning Direct Methanol Fuel Cells Methods of Conditioning Direct Methanol Fuel Cells Methods of Conditioning Direct Methanol Fuel Cells Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. Available for thumbnail of Feynman Center (505) 665-9090 Email Methods of Conditioning Direct Methanol Fuel Cells Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer

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to obtain the most current and comprehensive results.


441

Definition: Equipment Condition Monitor | Open Energy Information  

Open Energy Info (EERE)

Condition Monitor Condition Monitor Jump to: navigation, search Dictionary.png Equipment Condition Monitor A monitoring device that automatically measures and communicates equipment characteristics that are related to the "health" and maintenance of the equipment. These characteristics can include, but are not limited to temperature, dissolved gas, and loading. These devices can automatically generate alarm signals if conditions exceed preset thresholds.[1] Related Terms sustainability References ↑ https://www.smartgrid.gov/category/technology/equipment_condition_monitor [[C LikeLike UnlikeLike You like this.Sign Up to see what your friends like. ategory: Smart Grid Definitions|Template:BASEPAGENAME]] Retrieved from "http://en.openei.org/w/index.php?title=Definition:Equipment_Condition_Monitor&oldid=502601"

442

Time and Materials Exhibit A General Conditions  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 6/14/13) Exhibit A General Conditions 2, 6/14/13) Exhibit A General Conditions Page 1 of 20 EXHIBIT "A" GENERAL CONDITIONS TABLE OF CONTENTS GC Title Page GC-1 DEFINITIONS (Aug 2012) .......................................................................................................... 3 GC-2A AUTHORIZED REPRESENTATIVES, COMMUNICATIONS AND NOTICES (Jan 2010) ........................................................................................................................................... 3 GC-3 INDEPENDENT CONTRACTOR (Jun 2009) ............................................................................. 4 GC-4 SUBCONTRACT INTERPRETATION (Jun 2009) ...................................................................... 4 GC-5 NOTICE TO PROCEED (Jul 2011)............................................................................................. 4

443

Generalized integrability conditions and target space geometry  

E-Print Network (OSTI)

In some higher dimensional nonlinear field theories integrable subsectors with infinitely many conservation laws have been identified by imposing additional integrability conditions. Originally, the complex eikonal equation was chosen as integrability condition, but recently further generalizations have been proposed. Here we show how these new integrability conditions may be derived from the geometry of the target space and, more precisely, from the Noether currents related to a certain class of target space transformations.

C. Adam; J. Sanchez-Guillen

2005-08-01T23:59:59.000Z

444

Terms and Conditions for Site Transition | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Terms and Conditions for Site Transition Terms and Conditions for Site Transition Terms and Conditions for Site Transition Terms and Conditions for Site Transition More Documents &...

445

Numerical simulation of water flow around a rigid fishing net  

E-Print Network (OSTI)

This paper is devoted to the simulation of the flow around and inside a rigid axisymmetric net. We describe first how experimental data have been obtained. We show in detail the modelization. The model is based on a Reynolds Averaged Navier-Stokes turbulence model penalized by a term based on the Brinkman law. At the out-boundary of the computational box, we have used a "ghost" boundary condition. We show that the corresponding variational problem has a solution. Then the numerical scheme is given and the paper finishes with numerical simulations compared with the experimental data.

Roger Lewandowski; Géraldine Pichot

2006-12-20T23:59:59.000Z

446

Mathematical modeling of methane flow in coal beds  

Science Conference Proceedings (OSTI)

The paper offers to describe the free and occlude gas filtration and diffusion in a coal bed by a numerical model in the form of a system of heterogenous parabolic equations. The gas flow as a shock and depression wave has been considered, and the desorption isotherm conditions for these waves to arise in a coal bed are formulated. By analyzing experimental data on cavities generated by a sudden coal and gas outburst, the authors construct the numerical model describing gas and coal mix outflow in a mine.

Fedorov, A.V.; Fedorchenko, I.A. [Russian Academy of Sciences, Novosibirsk (Russian Federation)

2009-01-15T23:59:59.000Z

447

Flow visualization study of the MOD-2 wind turbine wake  

DOE Green Energy (OSTI)

The specific objectives of the study reported were: to determine the geometry of the MOD-2 wind turbine wake in terms of wake height and width as a function of downstream distance under two conditions of atmospheric stability; to estimate the mean velocity deficit at several downstream stations in the turbine wake; and to investigate the behavior of the rotor-generated vortices, particularly their configuration and persistence. The background of the wake problem is briefly examined, including a discussion of the critical issues that the flow visualization study addresses. Experimental techniques and data analysis methods are described in detail. (LEW)

Liu H.T.; Waite, J.W.; Hiester, T.R.; Tacheron, P.H.; Srnsky, R.A.

1983-06-01T23:59:59.000Z

448

Methodology for extracting local constants from petroleum cracking flows  

DOE Patents (OSTI)

A methodology provides for the extraction of local chemical kinetic model constants for use in a reacting flow computational fluid dynamics (CFD) computer code with chemical kinetic computations to optimize the operating conditions or design of the system, including retrofit design improvements to existing systems. The coupled CFD and kinetic computer code are used in combination with data obtained from a matrix of experimental tests to extract the kinetic constants. Local fluid dynamic effects are implicitly included in the extracted local kinetic constants for each particular application system to which the methodology is applied. The extracted local kinetic model constants work well over a fairly broad range of operating conditions for specific and complex reaction sets in specific and complex reactor systems. While disclosed in terms of use in a Fluid Catalytic Cracking (FCC) riser, the inventive methodology has application in virtually any reaction set to extract constants for any particular application and reaction set formulation. The methodology includes the step of: (1) selecting the test data sets for various conditions; (2) establishing the general trend of the parametric effect on the measured product yields; (3) calculating product yields for the selected test conditions using coupled computational fluid dynamics and chemical kinetics; (4) adjusting the local kinetic constants to match calculated product yields with experimental data; and (5) validating the determined set of local kinetic constants by comparing the calculated results with experimental data from additional test runs at different operating conditions.

Chang, Shen-Lin (Woodridge, IL); Lottes, Steven A. (Naperville, IL); Zhou, Chenn Q. (Munster, IN)

2000-01-01T23:59:59.000Z

449

Comparing Variable Refrigerant Flow to Traditional Heating and Cooling Technologies: Assessing VRF Performance in Mobile, Alabama  

Science Conference Proceedings (OSTI)

In America, most conditioned air is delivered by ductwork, which is often made of sheet metal covered in insulation and installed during construction. However, in Japan and Europe, because the office buildings often pre-date the invention of air conditioning, it is easier and more common for refrigerant pipes to run to wall- or ceiling-mounted heat exchangers. Using refrigerant pipes instead of ducting can eliminate duct loss and offer more precise control. Are Variable Refrigerant Flow (VRF) ...

2013-09-04T23:59:59.000Z

450

Thin films flowing down inverted substrates: two dimensional flow  

E-Print Network (OSTI)

We consider free surface instabilities of films flowing on inverted substrates within the framework of lubrication approximation. We allow for the presence of fronts and related contact lines, and explore the role which they play in instability development. It is found that a contact line, modeled by a commonly used precursor film model, leads to free surface instabilities of convective type without any additional natural or excited perturbations. A single parameter D=(3Ca)^{1/3}cot\\alpha, where Ca is the capillary number and \\alpha is the inclination angle, is identified as a governing parameter in the problem. This parameter may be interpreted to reflect the combined effect of inclination angle, film thickness, Reynolds number and the fluid flux. Variation of D leads to change of the wave-like properties of the instabilities, allowing to observe traveling wave behavior, mixed waves, and the waves resembling solitary ones.

Lin, Te-sheng

2009-01-01T23:59:59.000Z

451

Air Distribution and Microenvironment Evaluation of a Desktop Task Conditioning System  

E-Print Network (OSTI)

Task conditioning aims to provide each occupant with personalized clean air direct to the breathing zone. The microenvironment of a typical office workplace, consisting of two desktop task conditioning systems (a Horizontal Desk Grill (HDG) and Vertical Desk Grill (VDG)) were studied by numerical simulation. Numerical simulation by k- 3-D turbulent flow was separately conducted to study the influence of supply velocity on the microenvironment of these two desktop task conditioning systems. Three task conditioning velocities were studied. Temperature and velocity distribution, Draught Rating (DR) and Predicted Percentage of Dissatisfied (PPD) of the room and workstation were applied to study the performance of task air conditioning. Results show that the performances of HDG and VDG are almost the same. Results also show that task conditioning can provide excellent working environment when supply velocity is well designed. The supply velocity of task conditioning can be set between 0.8-1.0 m/s. However, task conditioning may cause draught, and engineers should seriously consider this problem. The results can provide important references for design and optimization of the task conditioning system.

Zheng, G.

2006-01-01T23:59:59.000Z

452

167 Normalizing Condition-Microstructures-Mechanical Properties ...  

Science Conference Proceedings (OSTI)

... gas household usage, of which consumption is constantly expanding especially in ... 019 Effect of Cooling Conditions on the Glass Forming Ability of the TeO2 ...

453

Rings with the Beachy-Blair condition  

E-Print Network (OSTI)

A ring satisfies the left Beachy-Blair condition if each of its faithful left ideal is cofaithful. Every left zip ring satisfies the left Beachy-Blair condition, but both properties are not equivalent. In this paper we will study the similarities and the differences between zip rings and rings with the Beachy-Blair condition. We will also study the relationship between the Beachy-Blair condition of a ring and its skew polynomial and skew power series extensions. We give an example of a right zip ring that is not left zip, proving that the zip property is not symmetric.

Rodríguez-Jorge, Elena

2010-01-01T23:59:59.000Z

454

QUADRATIC ORDER CONDITIONS FOR BANG-SINGULAR ...  

E-Print Network (OSTI)

First, we obtain second order necessary optimality conditions. Secondly, we get a ... enters linearly, is that the corresponding second variation does not contain.

455

Range conditions for a spherical mean transform  

E-Print Network (OSTI)

The paper is devoted to the range description of the Radon type transform that averages a function over all spheres centered on a given sphere. Such transforms arise naturally in thermoacoustic tomography, a novel method of medical imaging. Range descriptions have recently been obtained for such transforms, and consisted of smoothness and support conditions, moment conditions, and some additional orthogonality conditions of spectral nature. It has been noticed that in odd dimensions, surprisingly, the moment conditions are superfluous and can be eliminated. It is shown in this text that in fact the same happens in any dimension.

Mark Agranovsky; David Finch; Peter Kuchment

2009-02-25T23:59:59.000Z

456

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

SciTech Connect

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.

X. Wang; X. Sun; H. Zhao

2011-09-01T23:59:59.000Z

457

Energy Consumption Measuring and Diagnostic Analysis of Air-conditioning Water System in a Hotel Building in Harbin  

E-Print Network (OSTI)

This paper introduces an air-conditioning water system in a hotel building in Harbin, finishes its air-conditioning energy consumption measurement in summer conditions, and presents an estimation index of performance of chiller, pump and motor. By means of testing data analysis, it is indicated that several problems such as unsuitable operation schedule of the chiller, low COP, irrational matching of pump and motor, unbalanced conditions of chilled water flow, and low working stability and efficiency ratio of the pump are existent. The paper presents suggestions for improvement with relevance based on the induction and analysis of system fault found in measurements.

Zhao, T.; Zhang, J.; Li, Y.

2006-01-01T23:59:59.000Z

458

User terms & conditions v1.2-27 April 2004.doc USER TERMS AND CONDITIONS  

E-Print Network (OSTI)

User terms & conditions v1.2- 27 April 2004.doc 1 USER TERMS AND CONDITIONS The following Terms and Conditions will apply to Your use of the Website and the Service:- 1. Definitions In these Terms the detailed information and conditions relating to a Lot, including the relevant online purchase terms

459

Laser velocimetry study of the flow field in a centrifugal pump  

E-Print Network (OSTI)

The flow field in the impeller passages in a centrifugal pump was measured using a two dimensional laser 2-focus velocimeter. Measurements were taken at three circumferential (azimuthal) locations at the design and off-design operating conditions for the pump. The velocity components, flow directions and turbulence kinetic energy were determined for the flow. At design operating condition the vectors representing absolute and relative velocities do not show any sign of distortion in the flow direction. However, the off-design flow direction is somewhat distorted at the impeller inlet near the front wall (z/H = 0. 18) of the blades. A leakage flow is evident from the impeller exit to the inlet. Static pressure measured across the front casing shows an asymmetry in the pressure distribution. Higher value of wall pressure and a high turbulence were observed at the volute tongue near the discharge side. The velocity profile in the pipe upstream of the inlet showed a basically uniform distribution with only a slight asymmetry while the velocity profile downstream of the pump discharge was distorted.

Rashid, Kazi M.

1993-01-01T23:59:59.000Z

460

Thermal/chemical degradation of ceramic cross-flow filter materials  

Science Conference Proceedings (OSTI)

This report summarizes the 14-month, Phase 1 effort conducted by Westinghouse on the Thermal/Chemical Degradation of Ceramic Cross-Flow Filter Materials program. In Phase 1 expected filter process conditions were identified for a fixed-bed, fluid-bed, and entrained-bed gasification, direct coal fired turbine, and pressurized fluidized-bed combustion system. Ceramic cross-flow filter materials were also selected, procured, and subjected to chemical and physical characterization. The stability of each of the ceramic cross-flow materials was assessed in terms of potential reactions or phase change as a result of process temperature, and effluent gas compositions containing alkali and fines. In addition chemical and physical characterization was conducted on cross-flow filters that were exposed to the METC fluid-bed gasifier and the New York University pressurized fluidized-bed combustor. Long-term high temperature degradation mechanisms were proposed for each ceramic cross-flow material at process operating conditions. An experimental bench-scale test program is recommended to be conducted in Phase 2, generating data that support the proposed cross-flow filter material thermal/chemical degradation mechanisms. Papers on the individual subtasks have been processed separately for inclusion on the data base.

Alvin, M.A.; Lane, J.E.; Lippert, T.E.

1989-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Advances in gas-liquid flows 1990  

SciTech Connect

Gas-liquid two-phase flows commonly occur in nature and industrial applications. Rain, clouds, geysers, and waterfalls are examples of natural gas-liquid flow phenomena, whereas industrial applications can be found in nuclear reactors, steam generators, boilers, condensers, evaporators, fuel atomization, heat pipes, electronic equipment cooling, petroleum engineering, chemical process engineering, and many others. The household-variety phenomena such as garden sprinklers, shower, whirlpool bath, dripping faucet, boiling tea pot, and bubbling beer provide daily experience of gas-liquid flows. The papers presented in this volume reflect the variety and richness of gas-liquid two-phase flow and the increasing role it plays in modern technology. This volume contains papers dealing with some recent development in gas-liquid flow science and technology, covering basic gas-liquid flows, measurements and instrumentation, cavitation and flashing flows, countercurrent flow and flooding, flow in various components and geometries liquid metals and thermocapillary effects, heat transfer, nonlinear phenomena, instability, and other special and general topics related to gas-liquid flows.

Kim, J.M. (Texas Univ., Austin, TX (United States). Nuclear Reactor Lab.); Rohatgi, U.S. (Brookhaven National Lab., Upton, NY (United States)); Hashemi, A. (Lockheed Missiles and Space Company (US))

1990-01-01T23:59:59.000Z

462

Variables optimization of building air conditioning system  

Science Conference Proceedings (OSTI)

A heating and climatizer system based on selective absorption of solar energy by a selective collector. The experimental study shows that the performance of this system depends on several variables: the nature of the colporteur fluid, the flow of the ... Keywords: heating and climatisation, modelation and optimization, solar energy

Marius-Constantin Popescu; Cornelia Aida Bulucea; Gheorghe Manolea; Cristian Vladu

2009-10-01T23:59:59.000Z

463

A constitutive law for dense granular flows  

E-Print Network (OSTI)

A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.

Pierre Jop; Yoël Forterre; Olivier Pouliquen

2006-12-05T23:59:59.000Z

464

Potential Flow Calculations of Axisymmetric Ducted Wind Turbines  

E-Print Network (OSTI)

An incompressible potential-flow vortex method has been constructed to analyze the flow field of a ducted

Widnall, Sheila

2009-09-02T23:59:59.000Z

465

NIST Pipeline-Scale Flow Measurement Standards for Natural ...  

Science Conference Proceedings (OSTI)

Pipeline-Scale Flow Measurement Standards for Natural Gas. Summary: NIST natural gas flow calibrations are performed ...

2013-01-28T23:59:59.000Z

466

Flow and temperature fields in a free discharge inductively coupled plasma  

SciTech Connect

Computations were made of the flow and temperature fields in an inductively coupled argon plasma at atmospheric pressure under confined and free discharge conditions. The model takes into account gravity effects and swirl in the sheath gas. Natural convection was found to have a negligible effect on the flow and temperature fields under confined discharge conditions but a significant effect for the free discharge. The back flow in the discharge was substantially reduced in the presence of swirl for swirl velocities over the range 0-50 m/s. Also with a mode-rate increase in swirl, the conduction heat flux to the wall decreased but increased with the further increase in swirl. From an overall energy balance point of view, conductive heat flux to the wall of the plasma confinement tube was substantially lower for a free plasma discharge compared to that for a confined plasma.

Gagne, R.; Boulos, M.I.; Barnes, R.M.

1979-01-01T23:59:59.000Z

467

The Effect of Reduced Evaporator Air Flow on the Performance of a Residential Central Air Conditioner  

E-Print Network (OSTI)

This paper discusses the measured degradation in performance of a residential air conditioning system operating under reduced evaporator air flow. Experiments were conducted using a R-22 three-ton split-type cooling system with a short-tube orifice expansion device. Results are presented here for a series of tests in which the evaporator air flow was reduced from 25 to 90% below what is normally recommended for this air conditioner. At present, very little information is available which quantifies the performance of a residential cooling system operating under degraded conditions such as reduced evaporator air flow. Degraded performance measurements can provide information which could help electric utilities evaluate the potential impact of system-wide maintenance programs.

Palani, M.; O'Neal, D.; Haberl, J.

1992-05-01T23:59:59.000Z

468

Energy conditions outside a dielectric ball  

SciTech Connect

We show analytically that the vacuum electromagnetic stress-energy tensor outside a ball with constant dielectric constant and permeability always obeys the weak, null, dominant, and strong energy conditions. There are still no known examples in quantum field theory in which the averaged null energy condition in flat spacetime is violated.

Graham, Noah; Olum, Ken D.; Schwartz-Perlov, Delia [Department of Physics, Middlebury College, Middlebury, Vermont 05753 (United States); Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

2004-11-15T23:59:59.000Z

469

Energy conditions outside a dielectric ball  

E-Print Network (OSTI)

We show analytically that the vacuum electromagnetic stress-energy tensor outside a ball with constant dielectric constant and permeability always obeys the weak, null, dominant, and strong energy conditions. There are still no known examples in quantum field theory in which the averaged null energy condition in flat spacetime is vio