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1

Fluctuating initial conditions and fluctuations in elliptic and triangular flow  

E-Print Network [OSTI]

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. With fluctuating initial conditions, flow coefficients will also fluctuate. In a hydrodynamic model, we study the fluctuations in elliptic and triangular flow, due to fluctuating initial conditions. Both elliptic and triangular flow fluctuates strongly, triangular flow more strongly than the elliptic flow. Strong fluctuations greatly reduce the sensitivity of elliptic and triangular flow to viscosity.

A. K. Chaudhuri

2012-02-24T23:59:59.000Z

2

Fluctuating initial conditions and fluctuations in elliptic and triangular flow  

E-Print Network [OSTI]

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. In a hydrodynamic model with fluctuating initial conditions, we study the fluctuations in elliptic and triangular flow. Both elliptic and triangular flow fluctuates strongly. Strong fluctuations greatly reduces the sensitivity of elliptic and triangular flow on viscosity.

Chaudhuri, A K

2011-01-01T23:59:59.000Z

3

Analysis of pressure drops under reversing flow conditions  

SciTech Connect (OSTI)

This paper examines pressure-drop data from the Reversing Flow Test Facility (RFTF) at Argonne National Laboratory (ANL). The data comprise part of an initial series of measurements conducted with pressurized helium gas under reversing flow conditions. The characteristics of fluid pressure drops in compressible, reversing flows are discussed in the paper and compared with pressure-drop measurements for steady, incompressible flows. The methodology used to calculate instantaneous mass flows in the test section of the RFTF is summarized. The measured pressure drops are analyzed in terms of their frictional and inertial components. Pressure-drop data are presented for both tubes and wire mesh regenerators over a range of flow reversal frequencies. The results are discussed with reference to other experimental data and analytical models available in the literature. 10 refs., 6 figs., 2 tabs.

Krazinski, J.L.; Holtz, R.E.; Uherka, K.L.; Lottes, P.A.

1986-01-01T23:59:59.000Z

4

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

E-Print Network [OSTI]

THE INTERACTION BETWEEN A TWO SLOTTED PLATE FLOW METER UNDER ONE, TWO, OR THREE COMPONENT FLOW CONDITIONS A Thesis by SANG HYUN PARK Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2004 Major Subject: Mechanical Engineering THE INTERACTION BETWEEN A TWO SLOTTED PLATE FLOW METER UNDER ONE, TWO, OR THREE COMPONENT FLOW...

Park, Sang Hyan

2005-02-17T23:59:59.000Z

5

Inhibition of slug front corrosion in multiphase flow conditions  

SciTech Connect (OSTI)

Corrosion at the slug front at the bottom of a pipeline is identified as one of the worst cases of corrosion occurring in the pipeline which carries unprocessed multiphase production with a high level of CO{sub 2} gas. One objective of the study in recommending a subsea completion to shore was to determine if commercial corrosion inhibitors can control this type of corrosion using carbon steel pipeline. Thus, inhibitors which showed excellent performance in the lab using the Rotating Cylinder Electrode system (RCE) were further evaluated to confirm their performance in a flow loop simulating the test conditions predicted from the flow modeling for the proposed pipeline. The performance profile of two commercial inhibitors were determined in a 4 in. flow loop at 7O C, 100 psig CO{sub 2} partial pressure in corrosive brines with or without ethylene glycol and/or light hydrocarbon. Results showed that the carbon steel pipeline could be adequately protected at low temperature using a commercial corrosion inhibitor to meet the designed life of the pipeline. Ethylene glycol, which is used in the pipeline to prevent hydrate formation, reduces the corrosivity of the brine and gives no effect on inhibitor performance under the slug flow conditions. A good agreement in inhibitor performance was observed between the flow loop and the RCE testing. The uninhibited corrosion rate of the test brine in this study is in good agreement with the predicted value using deWaard and Williams correlation for CO{sub 2} corrosion.

Chen, H.J. [Chevron Petroleum Technology Co., La Habra, CA (United States); Jepson, W.P. [Ohio Univ., Athens, OH (United States)

1998-12-31T23:59:59.000Z

6

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

SciTech Connect (OSTI)

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

7

The gradient flow running coupling with twisted boundary conditions  

E-Print Network [OSTI]

We study the gradient flow for Yang-Mills theories with twisted boundary conditions. The perturbative behavior of the energy density $\\langle E(t)\\rangle$ is used to define a running coupling at a scale given by the linear size of the finite volume box. We compute the non-perturbative running of the pure gauge $SU(2)$ coupling constant and conclude that the technique is well suited for further applications due to the relatively mild cutoff effects of the step scaling function and the high numerical precision that can be achieved in lattice simulations. We also comment on the inclusion of matter fields.

A. Ramos

2014-09-04T23:59:59.000Z

8

Revisiting Johnson and Jackson boundary conditions for granular flows  

SciTech Connect (OSTI)

In this article, we revisit Johnson and Jackson boundary conditions for granular flows. The oblique collision between a particle and a flat wall is analyzed by adopting the classic rigid-body theory and a more realistic semianalytical model. Based on the kinetic granular theory, the input parameter for the partial-slip boundary conditions, specularity coefficient, which is not measurable in experiments, is then interpreted as a function of the particle-wall restitution coefficient, the frictional coefficient, and the normalized slip velocity at the wall. An analytical expression for the specularity coefficient is suggested for a flat, frictional surface with a low frictional coefficient. The procedure for determining the specularity coefficient for a more general problem is outlined, and a working approximation is provided.

Li, Tingwen; Benyahia, Sofiane

2012-07-01T23:59:59.000Z

9

Elliptic Flow from Nonequilibrium Color Glass Condensate Initial Conditions  

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.

Ruggieri, M; Plumari, S; Greco, V

2013-01-01T23:59:59.000Z

10

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

11

On stability condition for bifluid flows with surface tension : application to microfluidics  

E-Print Network [OSTI]

On stability condition for bifluid flows with surface tension : application to microfluidics C immiscible bifluid flows with surface tension are here considered. Since Brackbill, Kothe and Zemach (J mixing dynamics inside microdroplets. Key words: surface tension, curvature, stability condition, bifluid

Paris-Sud XI, Université de

12

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

SciTech Connect (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

13

Flow conditions of fresh mortar and concrete in different pipes  

SciTech Connect (OSTI)

The variation in fresh concrete flow rate over the pipe cross section was investigated on differently coloured and highly flowable concrete mixes flowing through pipes of different materials (rubber, steel, acryl). First, uncoloured (gray) concrete was poured through the pipe and the pipe blocked. Similar but coloured (black) concrete was then poured into the pipe filled with gray concrete, flowing after the gray concrete for a while before being blocked and hardened. The advance of the colouring along the pipe wall (showing boundary flow rate) was observed on the moulded concrete surface appearing after removing the pipe from the hardened concrete. The shapes of the interfaces between uncoloured and coloured concrete (showing variation of flow rate over the pipe cross section) were observed on sawn surfaces of concrete half cylinders cut along the length axes of the concrete-filled pipe. Flow profiles over the pipe cross section were clearly seen with maximum flow rates near the centre of the pipe and low flow rate at the pipe wall (typically rubber pipe with reference concrete without silica fume and/or stabilizers). More plug-shaped profiles, with long slip layers and less variation of flow rate over the cross section, were also seen (typically in smooth acrylic pipes). Flow rate, amount of concrete sticking to the wall after flow and SEM-images of pipe surface roughness were observed, illustrating the problem of testing full scale pumping.

Jacobsen, Stefan, E-mail: stefan.jacobsen@ntnu.n [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway); Haugan, Lars; Hammer, Tor Arne [SINTEF Byggforsk AS Building and Infrastructure, Trondheim (Norway); Kalogiannidis, Evangelos [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway)

2009-11-15T23:59:59.000Z

14

Numerical study of the effects of upstream flow condition upon orifice flow meter performance  

SciTech Connect (OSTI)

Recent experimental work has shown that when the mean velocity profile upstream of an orifice plate has a deficit on the centerline and higher velocities at the outer edges of the pipe, the pressure drop across the orifice is greater than if the flow upstream is fully developed. It is proposed that this increase in [Delta]P is directly correlated with the radial distribution of momentum upstream of the orifice plate. In an effort to investigate how the upstream flow condition affects the pressure distribution along the pipe wall and to determine if the hypothesis is correct, Creare.X Inc. 's FLUENT numerical analysis program was used to simulate the effects. Two [beta] ratios (0.50 and 0.75) have been considered with various mean velocity inlet profiles. Inlet profiles include the 1/16th, 1/7th, 1/8th, 1/9th and 1/10th power law power law, uniform flow, and two linear distributions. The results indicate that there is a correlation between the second and third-order moments of momentum and the value of the discharge coefficient. This empirical correlation, after being fully verified by experimental data, can be used to estimate the change in the coefficient of discharge given the inlet velocity profile.

Morrison, G.L.; Panak, D.L.; DeOtte, R.E. Jr. (Texas A and M Univ., College Station, TX (United States). Mechanical Engineering Dept.)

1993-11-01T23:59:59.000Z

15

Diagnosis of Fracture Flow Conditions with Acoustic Sensing  

E-Print Network [OSTI]

that this turbulent flow can generate sound as fluid flows from the fracture into the well. According to Testud et al. (2009) it is widely known that industry pipe systems, valves, taps and orifices whistle when fluid flows through them. Lacombe et al. (2013... of the fluid downstream of the shear layer (Lacombe et al. 2013). During this process there is a transfer of energy from the fluid moving to vortices that create sound. Poldervaart et al. (1974) illustrated how vortices can act as an acoustic source in Fig...

Martinez, Roberto

2014-07-10T23:59:59.000Z

16

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...

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

2006-01-01T23:59:59.000Z

17

Spatial and temporal analysis and experiments of annular two-phase flow under microgravity conditions  

E-Print Network [OSTI]

, sounding rockets, the Shuttle or the future Space Station. Under zero-g conditions the time average base state geometry of gas-liquid flow in cylindrical channels should be axisymmetric (as in vertical flow on Earth) because buoyancy does not act.../16/86. 62 23 Experimental set-up of 1987. 24 Experimental set-up of 1990. 65 66 25 Different flow conditions for the 1987 flights, from top to bottom: wavy turbulent, two bubbles touching each other or annular, wavy turbulent- laminar, slug flow. . 67...

Carron, Igor

1992-01-01T23:59:59.000Z

18

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

E-Print Network [OSTI]

ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus Yanping Zhou Jingyi..., especially for those who ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 show some interest about high-efficiency systems like VRF, it becomes of interest to compare the VRF to other systems and evaluate VRF?s performance...

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

2006-01-01T23:59:59.000Z

19

On fluid flow in a heterogeneous medium under nonisothermal conditions  

SciTech Connect (OSTI)

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

20

Three-Dimensional Nonreflecting Boundary Conditions for Swirling Flow in Turbomachinery  

E-Print Network [OSTI]

Three-Dimensional Nonreflecting Boundary Conditions for Swirling Flow in Turbomachinery Pierre turbomachinery problems. Based on the use of precalculated far-field acoustic eigenmodes for a mean flow THERE are different approaches to analyze turbomachinery unsteadiness. These methods vary from the use of linearized

Giles, Mike

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

On stability condition for bifluid flows with surface tension: Application to microfluidics  

E-Print Network [OSTI]

On stability condition for bifluid flows with surface tension: Application to microfluidics Ce simulations of microfluidic flows using a Level Set method, namely the exploration of different mixing-vol- umes; Microfluidics; Droplets 1. Introduction Analysis and algorithms derived herein are the result

Frey, Pascal

22

FLOW CONDITIONING DESIGN IN THICK LIQUID PROTECTION S.G. Durbin  

E-Print Network [OSTI]

issuing downwards from nozzles of thickness (small dimension) = 1 cm into ambient air for Reynolds conditioner was studied. As the flow conditioning element immediately upstream of the nozzle inlet, fine, and that free-surface fluctuations are strongly affected by changes in flow conditioner design, even in the near

California at San Diego, University of

23

Development of a flow-condition-based interpolation 9-node element for incompressible flows  

E-Print Network [OSTI]

The Navier-Stokes equations are widely used for the analysis of incompressible laminar flows. If the Reynolds number is increased to certain values, oscillations appear in the finite element solution of the Navier-Stokes ...

Banijamali, Bahareh

2006-01-01T23:59:59.000Z

24

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

SciTech Connect (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

25

Fluctuating initial condition and smoothening effect on elliptic and triangular flow  

E-Print Network [OSTI]

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. Generally, one uses Monte-Carlo Glauber model to obtain the participating nucleon positions. To use in a hydrodynamic model, the positions needs to be smoothened. We study the effect of smoothening of Glauber Monte-Carlo initial conditions on elliptic and triangular flow. It is shown that integrated as well as differential elliptic and triangular flow remain largely unaltered, irrespective of functional form of the smoothening function, or the smoothening parameter

Haque, Md Rihan; Chaudhuri, A K

2012-01-01T23:59:59.000Z

26

Fluctuating initial condition and smoothening effect on elliptic and triangular flow  

E-Print Network [OSTI]

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. Generally, one uses Monte-Carlo Glauber model to obtain the participating nucleon positions. To use in a hydrodynamic model, the positions needs to be smoothened. We study the effect of smoothening of Glauber Monte-Carlo initial conditions on elliptic and triangular flow. It is shown that integrated as well as differential elliptic and triangular flow remain largely unaltered, irrespective of functional form of the smoothening function, or the smoothening parameter

Md. Rihan Haque; Victor Roy; A. K. Chaudhuri

2012-04-13T23:59:59.000Z

27

Two-phase stratified flow regime transition analysis for low gravity conditions  

E-Print Network [OSTI]

liquid, and dispersed bubble. This study lends well to stratified flow analysis because Taitel and Dukler [23] assumed an equilibrium stratified condition and developed transition models to the slug and annular regimes from this initial state. Also... This thesis follows the style of the A~lh~EllItlg. concentrated on low gravity conditions other than zero-g, such as moon gravity (1/6 g) or Mars gravity (1/3 g). This work concerns the development of a stratified flow regime transition model which...

Miller, Kathryn M.

1990-01-01T23:59:59.000Z

28

Artificial boundary conditions for stationary Navier-Stokes flows past bodies in the half-plane  

E-Print Network [OSTI]

We discuss artificial boundary conditions for stationary Navier-Stokes flows past bodies in the half-plane, for a range of low Reynolds numbers. When truncating the half-plane to a finite domain for numerical purposes, artificial boundaries appear. We present an explicit Dirichlet condition for the velocity at these boundaries in terms of an asymptotic expansion for the solution to the problem. We show a substantial increase in accuracy of the computed values for drag and lift when compared with results for traditional boundary conditions. We also analyze the qualitative behavior of the solutions in terms of the streamlines of the flow. The new boundary conditions are universal in the sense that they depend on a given body only through one constant, which can be determined in a feed-back loop as part of the solution process.

Boeckle, Christoph

2012-01-01T23:59:59.000Z

29

CO[sub 2] flow patterns under multiphase flow: Heterogeneous field-scale conditions  

SciTech Connect (OSTI)

A finite-difference, equation-of-state (EOS), compositional simulator has been used to study CO[sub 2] flooding. First, unstable first-contact-miscible (FCM) displacements were simulated with a fine mesh to investigate the transition from gravity override to viscous fingering. Next, a direct comparison was made for FCM and multiple-contact-miscible (MCM) displacements under the same conditions to investigate effects of phase behavior on the growth of viscous fingers. Then, the effects of gravity, physical dispersion, capillary pressure, phase behavior, and heterogeneity were combined and simulated for CO[sub 2] flooding on a field scale with stochastic permeability fields.

Chang, Y.B.; Lim, M.T.; Pope, G.A.; Sepehrnoori, K. (Univ. of Texas, Austin, TX (United States))

1994-08-01T23:59:59.000Z

30

IMPACT OF BOUNDARY-LAYER CUTTING AND FLOW CONDITIONING ON FREE-SURFACE BEHAVIOR IN TURBULENT LIQUID SHEETS  

E-Print Network [OSTI]

IMPACT OF BOUNDARY-LAYER CUTTING AND FLOW CONDITIONING ON FREE-SURFACE BEHAVIOR IN TURBULENT LIQUID dimension) = 1 cm into ambient air are compared with empirical correlations at a nearly prototypical term, for a well- conditioned jet but is not a substitute for well-designed flow conditioning. I

California at San Diego, University of

31

Permeability-dependent propagation of polyacrylamides under near-wellbore flow conditions  

SciTech Connect (OSTI)

A new type of polyacrylamide flow-induced retention has been observed in core experiments simulating near-wellbore flow conditions. The retention is due to the bridging of pore throats by adsorbed macromolecules previously stretched under elongational flow. It occurs in low-to-medium permeability granular packs (up to k = 1,000 mD in the test conditions) and leads to progressive but severe plugging. The present paper shows that polymer placement in the reservoir surrounding the wellbore can be very different from what is predicted from stable values of polymer mobility. In heterogeneous reservoirs, polymer penetration in low-permeability layers is expected to be strongly reduced, thus allowing a deeper penetration into higher permeability zones. The polymer can thus improve reservoir conformance around the wellbore when injected directly through the entire opened interval. Near-wellbore polymer or gel treatments may thus not require zone isolation to be efficient.

Zitha, P.; Chauveteau, G.; Zaitoun, A. [Inst. Francais du Petrole, Rueil-Malmaison (France)

1995-11-01T23:59:59.000Z

32

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...

Shukla, Shashank

2009-05-15T23:59:59.000Z

33

MULTIPHASE FLOW SIMULATION WITH VARIOUS BOUNDARY CONDITIONS Z. CHEN, R. E. EWING, and M. ESPEDAL  

E-Print Network [OSTI]

commonly used boundary conditions for groundwater hydrology and petroleum engineering problems can­ water hydrology and petroleum engineering is considered. The phase flow equations are given be incorporated into the pressure­saturation formu­ lation. INTRODUCTION In petroleum reservoir simulation

Ewing, Richard E.

34

Turbulent heat transfer in parallel flow boundary layers with streamwise step changes in surface conditions  

SciTech Connect (OSTI)

This paper examines the convective heat/mass transfer behavior of a turbulent boundary layer with parallel streamlines. The most notable example of such flow is an atmospheric boundary layer with a steady mean wind in the absence of topography. The classic, two-dimensional problem involves the surface boundary condition of a finite-length step change in temperature/concentration in the streamwise direction of an atmospheric flow. In the literature on geophysical evapotranspiration, this problem is known as Sutton's problem (cf. Sutton, 1934, and Brutsaert, 1984). This flow situation is equally applicable to heat/mass transfer in solar ponds, ground solar collectors, and heated roadways, as examples. The present note revisits the Sutton problem, with the can Driest eddy diffusivity model, and expands the types of boundary conditions that are examined to include surface changes in temperature/concentration and fluxes. The parallel streamline condition allows for Graetz-type solutions, with boundary conditions at the surface and in the far flow field. The predicted results are presented as a series of power law correlations of the relevant nondimensional parameters.

Lindberg, W.R.; Lee, R.C.; Smathers, L.B. (Univ. of Wyoming, Laramie (United States))

1989-11-01T23:59:59.000Z

35

Sampling Point Compliance Tests for 325 Building at Set-Back Flow Conditions  

SciTech Connect (OSTI)

The stack sampling system at the 325 Building (Radiochemical Processing Laboratory [RPL]) was constructed to comply with the American National Standards Institutes (ANSIs) Guide to Sampling Airborne Radioactive Materials in Nuclear Facilities (ANSI N13.1-1969). This standard provided prescriptive criteria for the location of radionuclide air-sampling systems. In 1999, the standard was revised (Sampling and Monitoring Releases of Airborne Radioactive Substances From the Stacks and Ducts of Nuclear Facilities [ANSI/Health Physics Society [HPS] 13.1-1999]) to provide performance-based criteria for the location of sampling systems. Testing was conducted for the 325 Building stack to determine whether the sampling system would meet the updated criteria for uniform air velocity and contaminant concentration in the revised ANSI/HPS 13.1-1999 standard under normal operating conditions (Smith et al. 2010). Measurement results were within criteria for all tests. Additional testing and modeling was performed to determine whether the sampling system would meet criteria under set-back flow conditions. This included measurements taken from a scale model with one-third of the exhaust flow and computer modeling of the system with two-thirds of the exhaust flow. This report documents the results of the set-back flow condition measurements and modeling. Tests performed included flow angularity, uniformity of velocity, gas concentration, and particle concentration across the duct at the sampling location. Results are within ANSI/HPS 13.1-1999 criteria for all tests. These tests are applicable for the 325 Building stack under set-back exhaust flow operating conditions (980 - 45,400 cubic feet per minute [cfm]) with one fan running. The modeling results show that criteria are met for all tests using a two-fan configuration exhaust (flow modeled at 104,000 cfm). Combined with the results from the earlier normal operating conditions, the ANSI/HPS 13.1-1999 criteria for all tests are met for all configurations: one, two, or three fans (normal).

Ballinger, Marcel Y.; Glissmeyer, John A.; Barnett, J. M.; Recknagle, Kurtis P.; Yokuda, Satoru T.

2011-05-31T23:59:59.000Z

36

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...

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

2006-01-01T23:59:59.000Z

37

Identification of the Flow Resistance Coefficient and Validation of a Building Air Conditioning System  

E-Print Network [OSTI]

for HRC estimation is investigated in this paper. And some conclusions can be got as follows: 1) The MGO method is applicable for S value identification. The method is based on the principle for multi goal optimization. The process can be widely used...ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency, Vol. IV-11-2 Zhijian Hou Identification of the Flow Resistance Coefficient and Validation of a Building Air Conditioning System Zhiwei Lian...

Hou, Z.; Lian, Z.

2006-01-01T23:59:59.000Z

38

Inflow performance relationship curves in two-phase and three-phase flow conditions  

SciTech Connect (OSTI)

This research investigates inflow performance relationship IPR curves for two and three-phase flow conditions, using a one-dimensional, three-phase cylindrical reservoir simulator. Using the simulator, a new method for predicting future IPR curves was developed. IPR curves for two-phase flow conditions from a well producing from low permeability formations are also presented. The purpose of this investigation is to predict the IPR curves at pseudo-steady state conditions using flowing test data obtained during the transient period. The new equations have also been applied to data from the simulator with good agreement. Three-phase IPR curves are also determined by using the simulator, and seven different hypothetical three-phase reservoir cases were studied. Three-hundred and eighty five data points were collected using 5 different values of water cut. Regression analysis techniques were applied to the data points and the new equations for predicting the three-phase IPR curves were developed. Comparison of the new equations to results from the simulator show excellent agreement.

Sukarno, P.

1986-01-01T23:59:59.000Z

39

Pore-Scale Characterization of Biogeochemical Controls on Iron and Uranium Speciation under Flow Conditions  

SciTech Connect (OSTI)

Etched silicon microfluidic pore network models (micromodels) with controlled chemical and redox gradients, mineralogy, and microbiology under continuous flow conditions are used for the incremental development of complex microenvironments that simulate subsurface conditions. We demonstrate the colonization of micromodel pore spaces by an anaerobic Fe(III)-reducing bacterial species (Geobacter sulfurreducens) and the enzymatic reduction of a bioavailable Fe(III) phase within this environment. Using both X-ray Microprobe and X-ray Absorption Spectroscopy, we investigate the combined effects of the precipitated Fe(III) phases and the microbial population on uranium biogeochemistry under flow conditions. Precipitated Fe(III) phases within the micromodel were most effectively reduced in the presence of an electron shuttle (AQDS), and Fe(II) ions adsorbed onto the precipitated mineral surface without inducing any structural change. In the absence of Fe(III), U(VI) was effectively reduced by the microbial population to insoluble U(IV), which was precipitated in discrete regions associated with biomass. In the presence of Fe(III) phases, however, both U(IV) and U(VI) could be detected associated with biomass, suggesting re-oxidation of U(IV) by localized Fe(III) phases. These results demonstrate the importance of the spatial localization of biomass and redox active metals, and illustrate the key effects of pore-scale processes on contaminant fate and reactive transport.

Pearce, Carolyn I.; Wilkins, Michael J.; Zhang, Changyong; Heald, Steve M.; Fredrickson, Jim K.; Zachara, John M.

2012-09-17T23:59:59.000Z

40

Experimental analysis of the vorticity and turbulent flow dynamics of a pitching airfoil at realistic flight (helicopter) conditions  

E-Print Network [OSTI]

was improved understanding of the fundamental vorticity and turbulent flow physics for a dynamically stalling airfoil at realistic helicopter flight conditions. An experimental program was performed on a large-scale (C = 0.45 m) dynamically pitching NACA 0012...

Sahoo, Dipankar

2008-10-10T23:59:59.000Z

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

Low-Flow Liquid Desiccant Air-Conditioning: Demonstrated Performance and Cost Implications  

SciTech Connect (OSTI)

Cooling loads must be dramatically reduced when designing net-zero energy buildings or other highly efficient facilities. Advances in this area have focused primarily on reducing a building's sensible cooling loads by improving the envelope, integrating properly sized daylighting systems, adding exterior solar shading devices, and reducing internal heat gains. As sensible loads decrease, however, latent loads remain relatively constant, and thus become a greater fraction of the overall cooling requirement in highly efficient building designs, particularly in humid climates. This shift toward latent cooling is a challenge for heating, ventilation, and air-conditioning (HVAC) systems. Traditional systems typically dehumidify by first overcooling air below the dew-point temperature and then reheating it to an appropriate supply temperature, which requires an excessive amount of energy. Another dehumidification strategy incorporates solid desiccant rotors that remove water from air more efficiently; however, these systems are large and increase fan energy consumption due to the increased airside pressure drop of solid desiccant rotors. A third dehumidification strategy involves high flow liquid desiccant systems. These systems require a high maintenance separator to protect the air distribution system from corrosive desiccant droplet carryover and so are more commonly used in industrial applications and rarely in commercial buildings. Both solid desiccant systems and most high-flow liquid desiccant systems (if not internally cooled) add sensible energy which must later be removed to the air stream during dehumidification, through the release of sensible heat during the sorption process.

Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.; Lowenstein, A.

2014-09-01T23:59:59.000Z

42

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

E-Print Network [OSTI]

SPE 30975 Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow, 163245 SPEUT. Abstract Pressure drop prediction in pipes is an old petroleum engineering problem. There is a long history of attempts to develop empirical correlations to predict the pressure drop in pipes. Some

Mohaghegh, Shahab

43

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor  

SciTech Connect (OSTI)

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m{sup 3}/hr.

Polzin, Kurt A.; Godfroy, Thomas J. [NASA Marshall Space Flight Center Propulsion Research and Technology Applications Branch/ER24, MSFC, AL 35812 (United States)

2008-01-21T23:59:59.000Z

44

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

SciTech Connect (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

45

Thermalization, Isotropization and Elliptic Flow from Nonequilibrium Initial Conditions with a Saturation Scale  

E-Print Network [OSTI]

In this article we report on our results about the computation of the elliptic flow of the quark-gluon-plasma produced in relativistic heavy ion collisions, simulating the expansion of the fireball by solving the relativistic Boltzmann equation for the parton distribution function tuned at a fixed shear viscosity to entropy density ratio $\\eta/s$. Our main goal is to put emphasis on the role of a saturation scale in the initial gluon spectrum, which makes the initial distribution far from a thermalized one. We find that the presence of the saturation scale reduces the efficiency in building-up the elliptic flow, even if the thermalization process is quite fast $\\tau_{therm} \\approx 0.8 \\,\\rm fm/c$ and the pressure isotropization even faster $\\tau_{isotr} \\approx 0.3 \\,\\rm fm/c$. The impact of the non-equilibrium implied by the saturation scale manifests for non-central collisions and can modify the estimate of the viscosity respect to the assumption of full thermalization in $p_T$-space. We find that the estimate of $\\eta/s$ is modified from $\\eta/s \\approx 2/4\\pi$ to $\\eta/s \\approx 1/4\\pi$ at RHIC and from $\\eta/s \\approx 3/4\\pi$ to $\\eta/s \\approx 2/4\\pi$ at LHC. We complete our investigation by a study of the thermalization and isotropization times of the fireball for different initial conditions and values of $\\eta/s$ showing how the latter affects both isotropization and thermalization. Lastly, we have seen that the range of values explored by the phase-space distribution function $f$ is such that at $p_T<0.5\\, \\rm GeV$ the inner part of the fireball stays with occupation number significantly larger than unity despite the fast longitudinal expansion, which might suggest the possibility of the formation of a transient Bose-Einstein Condensate.

Marco Ruggieri; Francesco Scardina; Salvatore Plumari; Vincenzo Greco

2014-07-09T23:59:59.000Z

46

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

SciTech Connect (OSTI)

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

47

Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions  

E-Print Network [OSTI]

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.

Nikolai V. Priezjev

2012-08-27T23:59:59.000Z

48

Second order adaptive boundary conditions for exterior flow problems: non-symmetric stationary flows in two dimensions  

E-Print Network [OSTI]

called "artificial boundary conditions" to replace the boundary conditions at infinity. To solve this problem we construct -- by combining results from dynamical systems theory with matched asymptotic field depending explicitly on drag and lift and describing the solution to second and dominant third

49

Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii (I) aerobic conditions  

E-Print Network [OSTI]

Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii (I, requires the production of ATP and NADPH in a ratio of 3:2. The oxygenic photosynthetic chain can function following two different modes: the linear electron flow which produces reducing power and ATP

50

Groundwater flow and salt transport in a subterranean estuary2 driven by intensified wave conditions3  

E-Print Network [OSTI]

groundwater discharge, aquifer-ocean exchange, coastal45 aquifer, numerical modeling.46 #12;1. Introduction47 A numerical study, based on a density-dependent variably saturated groundwater flow model,26 was conducted1 Groundwater flow and salt transport in a subterranean estuary2 driven by intensified wave

Candea, George

51

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

SciTech Connect (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

52

Second law analysis of water flow through smooth microtubes under adiabatic conditions  

SciTech Connect (OSTI)

In the study, a second law analysis for a steady-laminar flow of water in adiabatic microtubes has been conducted. Smooth microtubes with the diameters between 50 and 150 {mu}m made of fused silica were used in the experiments. Considerable temperature rises due to viscous dissipation and relatively high pressure losses of flow were observed in experiments. To identify irreversibility of flow, rate of entropy generation from the experiments have been determined in the laminar flow range of Re = 20-2200. The second law of thermodynamics was applied to predict the entropy generation. The results of model taken from the literature, proposed to predict the temperature rise caused by viscous heating, correspond well with the experimental data. The second law analysis results showed that the flow characteristics in the smooth microtubes distinguish substantially from the conventional theory for flow in the larger tubes with respect to viscous heating/dissipation (temperature rise of flow) total entropy generation rate and lost work. (author)

Parlak, Nezaket; Guer, Mesut; Ari, Vedat; Kuecuek, Hasan; Engin, Tahsin [The University of Sakarya, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, 54187 Sakarya (Turkey)

2011-01-15T23:59:59.000Z

53

Measurement of two-phase flow at the core upper plenum interface under simulated reflood conditions  

SciTech Connect (OSTI)

Objectives of the Instrument Development Loop program were to simulate flows at the core/upper plenum interface during the reflood phase of a LOCA and to develop instruments for measuring mass-flows at this interface. A tie plate drag body was developed and tested successfully, and the data obtained were shown to be equivalent to pressure drops. The tie-plate drag body gave useful measurements in pure downflow, and the drag/turbine combination correlates with mass flow for high upflow. (DLC)

Thomas, D.G.; Combs, S.K.; Bagwell, M.E.

1980-01-01T23:59:59.000Z

54

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

SciTech Connect (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

55

Vertical Flow Dynamics in Kelp Forests: Implications for Nutrient Uptake, Condition and Survival  

E-Print Network [OSTI]

change and ENSO impacts on kelp forests. As yet, we areVertical Flow Dynamics in Kelp Forests: Implications forof ocean waves on giant kelp fronds results in the vertical

Edwards, Matthew S.

2008-01-01T23:59:59.000Z

56

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 out of borosilicate glass, and flown on NASA's KC-135 reduced gravity airplane...

Westheimer, David Thomas

2000-01-01T23:59:59.000Z

57

Nonlocal and localized analyses of conditional mean transient flow in bounded, randomly heterogeneous  

E-Print Network [OSTI]

TERMS: 1829 Hydrology: Groundwater hydrology; 1869 Hydrology: Stochastic processes; 3210 Mathematical Geophysics: Modeling; 3230 Mathematical Geophysics: Numerical solutions; KEYWORDS: transient flow.1029/2003WR002099. 1. Introduction [2] Hydraulic parameters vary randomly in space and are therefore often

Tartakovsky, Daniel M.

58

23.11.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/36 7. Air conditioning, cooling towers  

E-Print Network [OSTI]

23.11.2014?bo Akademi Univ - Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/36 7. Air conditioning, cooling towers Ron Zevenhoven ?bo Akademi University Thermal and Flow Engineering Laboratory Engineering Piispankatu 8, 20500 Turku 2/36 7.1 Humid air #12;23.11.2014 ?bo Akademi Univ - Thermal and Flow

Zevenhoven, Ron

59

Ice stream basal conditions from block-wise surface data inversion and simple regression models of ice stream flow: Application to  

E-Print Network [OSTI]

Ice stream basal conditions from block-wise surface data inversion and simple regression models of ice stream flow: Application to Bindschadler Ice Stream O. V. Sergienko,1 R. A. Bindschadler,2 P. L; published 4 December 2008. [1] Widespread basal conditions controlling ice stream flows are still beyond

Boyce, C. Kevin

60

INVESTIGATION OF PERIODIC BOUNDARY CONDITIONS IN MULTIPASSAGE CASCADE FLOWS USING OVERSET GRIDS  

E-Print Network [OSTI]

. Computational results are presented for two and four passage, subsonic and tran­ sonic flows through a turbine and a compressor cascade. The overset grid solutions over the multi­passage periodic domains agree well in Refers to inflow exit Refers to outflow a Acoustic speed A Max. amplitude of the plunging motion c Blade

Tuncer, Ismail H.

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

Susceptibility and predictability of conditions for preferential flow Zhi Wang1 and Jan Feyen  

E-Print Network [OSTI]

Institute for Land and Water Management, Katholieke Universiteit Leuven, Leuven, Belgium Coen J. Ritsema DLO Winand Staring Centre for Integrated Land, Soil and Water Research, Wageningen, Netherlands Abstract unstable preferen- tial flow) in porous media affects the efficiency of oil recovery from a reservoir

Wang, Zhi "Luke"

62

Real time monitoring of multiple wells flowing under pseudosteady state condition by using Kalman filtering  

E-Print Network [OSTI]

This work develops a method for the real time monitoring of well performance by using Kalman filtering. A system of two or more wells draining the same reservoir under pseudo steady state condition is monitored simultaneously to estimate both...

Jacob, Suresh

2002-01-01T23:59:59.000Z

63

Numerical simulation of the flow over a coastal structure in depth-limited conditions  

E-Print Network [OSTI]

of detailed measurements of irregular wave transformation in front of the structure in depth-limited conditions. The second data set consists of several test runs to study the irregular wave reflection and runup on the coastal structure in depth...

Ginting, Victor Eralingga

1998-01-01T23:59:59.000Z

64

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

SciTech Connect (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

65

Low-Flow Liquid Desiccant Air Conditioning: General Guidance and Site Considerations  

SciTech Connect (OSTI)

Dehumidification or latent cooling in buildings is an area of growing interest that has been identified as needing more research and improved technologies for higher performance. Heating, ventilating, and air-conditioning (HVAC) systems typically expend excessive energy by using overcool-and-reheat strategies to dehumidify buildings. These systems first overcool ventilation air to remove moisture and then reheat the air to meet comfort requirements. Another common strategy incorporates solid desiccant rotors that remove moisture from the air more efficiently; however, these systems increase fan energy consumption because of the high airside pressure drop of solid desiccant rotors and can add heat of absorption to the ventilation air. Alternatively, liquid desiccant air-conditioning (LDAC) technology provides an innovative dehumidification solution that: (1) eliminates the need for overcooling and reheating from traditional cooling systems; and (2) avoids the increased fan energy and air heating from solid desiccant rotor systems.

Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.

2014-09-01T23:59:59.000Z

66

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

E-Print Network [OSTI]

character of the solution), each of the existing approximate solutions does have disadvantages. The purpose of this work is to provide a solution mechanism for the case of timedependent real gas flow which contains as few "limitations" as possible...

Zhakupov, Mansur

2006-08-16T23:59:59.000Z

67

WATER-QUALITY CONDITIONS DURING LOW FLOW IN THE LOWER YOUGHIOGHENY RIVER BASIN, PENNSYLVANIA, OCTOBER 5-7, 1998  

SciTech Connect (OSTI)

In October 1998, a chemical synoptic survey was conducted by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, National Energy Technology Laboratory, in the Lower Youghiogheny River Basin in Pennsylvania to give a snap-shot of present (1998) water quality during low-flow conditions. Water samples from 38 sites--12 mainstem sites, 22 tributaries, and 4 mine discharges that discharge directly to the Youghiogheny River--were used to identify sources of contaminants from mining operations. Specific conductance, water temperature, pH, and dissolved oxygen were measured in the field at each site and concentrations of major ions and trace elements were measured in the laboratory. Unaccounted for gains and losses in streamflow were measured during the study. Unaccounted for losses in streamflow might be attributed to water loss through streambed fractures. Extensive mine tunnels are present in the basin and loss of water to these tunnels seems likely. Unaccounted for gains in streamflow may be from unmeasured tributaries or surface seeps, but most of the gains are suspected to come from artesian flow through fractures in the streambed from underground mine pools. Influent flows of rust-colored water were noted in some river sections. The pH values for all the samples collected during this survey were above 5.8, and most (33 of 38 samples) were above 7.0. Samples from the four mine-discharge sites also had pH values between 6.3 and 6.7. The lowest pH (5.8) was in a tributary, Galley Run. All 38 sampling sites had net alkalinity. The alkalinity load in the Youghiogheny River increased between Connellsville and McKeesport from 35 to 79 tons per day. Above Smithton, the measured alkalinity load in the Lower Youghiogheny River agreed well with the estimated alkalinity load. Below Smithton, measured alkalinity loads in the Lower Youghiogheny River are greater than calculated loads, resulting in unaccounted for gains in alkalinity. These gains are believed to be from seeps in the streambed. Approximately one-third of the load of total alkalinity in the Youghiogheny River at McKeesport is attributed to Sewickley Creek, which contributes 14 tons per day. Sulfate concentrations in the Youghiogheny River steadily increase from 33 milligrams per liter at Connellsville to 77 milligrams per liter near McKeesport. The measured concentrations of sulfate exceeded Pennsylvania water-quality standards at four tributary sites (Galley Run, Hickman Run, Sewickley Creek, and Gillespie Run) and all four mine-discharge sites but not at any main-stem sites. A large increase in sulfate load between West Newton and Sutersville can be attributed almost entirely to the contribution from Sewickley Creek (49 tons per day). Approximately 25 percent of the load measured between Connellsville and McKeesport is unaccounted for. These gains are believed to be from seeps in the streambed from underground mine pools. Similar patterns also were observed for loads of sodium, calcium, and magnesium. Unmeasured inputs from mine rainage are believed to be the source of these loads. Elevated concentrations (above background levels) of chemicals associated with drainage from coal-mining operations were measured in samples from tributaries, especially from Galley Run, Gillespie Run, and Sewickley Creek, and from the mine-discharge sites. The synoptic survey conducted for this study was successful in identifying generalized reaches of the Youghiogheny River where unaccounted for loads of constituents associated with mining activities are entering the river. However, the survey was not able to pinpoint the location of these loads. Remote-sensing techniques, such as thermal infrared imaging by the National Energy Technology Laboratory, could be useful for determining the precise locations of these inputs.

James I. Sams, III, Karl T. Schroeder; Terry E. Ackman; J. Kent Crawford; Kim L. Otto

2001-01-01T23:59:59.000Z

68

Climatological conditions for the subpolar North Atlantic during the field campaign of the Greenland Flow Distortion Experiment  

E-Print Network [OSTI]

of the Greenland Flow Distortion Experiment G.W.K. Moore Department of Physics University of Toronto R.S. Pickart January 21, 2009 #12; 2 Abstract: Due to its high topography, Greenland results in significant to help document this flow distortion as part of the international research project called the Greenland

Pickart, Robert S.

69

The effect of velocity boundary conditions on the heat transfer and flow topology in two-dimensional Rayleigh-B\\'enard convection  

E-Print Network [OSTI]

The effect of various velocity boundary condition is studied in two-dimensional Rayleigh-B\\'enard convection. Combinations of no-slip, stress-free and periodic boundary conditions are used on both the sidewalls and the horizontal plates. For the studied Rayleigh numbers Ra between $10^8$ and $10^{11}$ the heat transport is lower for $\\Gamma = 0.33$ than for $\\Gamma = 1$ in case of no-slip sidewalls. This is surprisingly opposite for stress-free sidewalls, where the heat transport increases for lower aspect-ratio. In wider cells the aspect-ratio dependence is observed to disappear for $\\text{Ra} \\ge 10^{10}$. Two distinct flow types with very different dynamics can be seen, mostly dependent on the plate velocity boundary condition, namely roll-like flow and horizontal zonal flow, which have a substantial effect on the dynamics and heat transport in the system. The predominantly horizontal zonal flow suppresses heat flux and is observed for stress-free and asymmetric plates. Low aspect-ratio periodic sidewall s...

van der Poel, Erwin P; Verzicco, Roberto; Lohse, Detlef

2015-01-01T23:59:59.000Z

70

Electrochemical study of multi-electrode microbial fuel cells under fed-batch and continuous flow conditions  

E-Print Network [OSTI]

Electrochemical study of multi-electrode microbial fuel cells under fed-batch and continuous flow November 2013 Available online 18 December 2013 Keywords: Multi-electrode Microbial fuel cells Hydraulic connected microbial fuel cells (MFCs) was compared with the reactors operated using individual electrical

71

Investigating the changes in matrix and fracture properties and fluid flow under different stress-state conditions  

E-Print Network [OSTI]

pressure of 500 psi................................................................33 3.16 The average flow rate comparison between laboratory and simulation results at 5 cc/min and each different overburden pressure.............................35... .........................................................................................................87 xiii FIGURE Pa ge 5.28 Sample scans taken along the length of the core with 500 psi overburden pressure...

Muralidharan, Vivek

2004-11-15T23:59:59.000Z

72

A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California  

SciTech Connect (OSTI)

In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.

D'Agnese, F.A.; O'Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma

2002-11-22T23:59:59.000Z

73

Assessment of the application of acoustic emission technology for monitoring the presence of sand under multiphase flow condition  

SciTech Connect (OSTI)

The monitoring of multiphase flow is an established process that has spanned several decades. This paper demonstrates the use of acoustic emission (AE) technology to investigate sand transport characteristic in three-phase (air-water-sand) flow in a horizontal pipe where the superficial gas velocity (VSG) had a range of between 0.2 ms{sup ?1} to 2.0 ms{sup ?1} and superficial liquid velocity (VSL) had a range of between 0.2 ms{sup ?1} to 1.0 ms{sup ?1}. The experimental findings clearly show a correlation exists between AE energy levels, sand concentration, superficial gas velocity (VSG) and superficial liquid velocity (VSL)

El-Alej, M., E-mail: m.elalej@cranfield.ac.uk; Mba, D., E-mail: m.elalej@cranfield.ac.uk; Yeung, H., E-mail: m.elalej@cranfield.ac.uk [School of Engineering, Cranfield University, Cranfield, Bedfordshire, MK43 OAL (United Kingdom)

2014-04-11T23:59:59.000Z

74

A computational study of ultrasonic film thickness measurements in annular two-phase flows under microgravity conditions  

E-Print Network [OSTI]

wave equation: 11 V p(x, t) ? z z' = S(x, t), o p(x, t) c'(x) cl' (2. 1) where p(x, t) is the sound pressure, c(x) is the sound speed of propagation, and S(x, t) is a time-dependent source. Equation (2. 1) is derived from conservation laws... of level liquid film with epoxy layer, 2D approximation . . . . . 55 4. 13 Return signal of level liquid film with epoxy layer, 2D approximation . . . . . . . . . . . . . 56 5. 1 Maximum return amplitude vs. interfacial slope for smooth annular flow...

Pautz, Shawn Daniel

1995-01-01T23:59:59.000Z

75

129 Iodine: A New Hydrologic Tracer for Aquifer Recharge Conditions Influenced by River Flow Rate and Evapotranspiration  

E-Print Network [OSTI]

analogy to chloride ? Long term database Chloride: Analogy for Iodide y = 5.27x -0.32 R 2 = 0.53 R = 0.73 0 1 2 3 4 5 6 0 20 40 60 80 100 120 SARPD Monthly Flow m 3 s -1 S ARP D [ C l - ] m e q / L Monthly values INSET: Annual median values.... GW y = 0.46x + 1.27 R 2 = 0.96 -2 -1 0 1 2 -3 -2 -1 0 log [Cl - GW ] or log [Cl - SARPD ] meq/L lo g [ C l - PP T ] m e q/ L ...

Schwehr, K. A.; Santschi, P. H.; Moran, J. E.

2003-01-01T23:59:59.000Z

76

Simulation of steady-state and transient sodium boiling experiments in a seven-pin bundle under flow rundown conditions by using BODYFIT-1FE code  

SciTech Connect (OSTI)

A seven-pin rod bundle under flow rundown conditions was simulated by using the computer code BODYFIT-1FE (BOunDarY-FITted Coordinate System - 1 phase, Fully-Elliptic). In this code, the complicated rod bundle configuration is first transformed into rectangular geometry with uniform meshes. The transformed governing equations for all the thermal-hydraulic variables are then solved. The results of the simulation are presented here. All the predicted values agree favorably with the measured data. 7 refs., 20 figs.

Chen, B.C.J.; Sha, W.T.

1981-01-01T23:59:59.000Z

77

Sufficient condition for a finite-time singularity in a high-symmetry Euler flow: Analysis and statistics  

E-Print Network [OSTI]

City, Iowa 52242 Received 20 March 1995 A sufficient condition is obtained for the development that for fixed total energy, pxxxx is predominantly positive with the average value growing with the numbers spontaneously, dissipa- tion intervenes, and the dynamical balance between the two processes determines

Ng, Chung-Sang

78

Uncertainty and sensitivity analysis for two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant: Undisturbed conditions  

SciTech Connect (OSTI)

Uncertainty and sensitivity analysis results obtained in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented for two-phase flow the vicinity of the repository under undisturbed conditions. Techniques based on Latin hypercube sampling, examination of scatterplots, stepwise regression analysis, partial correlation analysis and rank transformation are used to investigate brine inflow, gas generation repository pressure, brine saturation and brine and gas outflow. Of the variables under study, repository pressure is potentially the most important due to its influence on spallings and direct brine releases, with the uncertainty in its value being dominated by the extent to which the microbial degradation of cellulose takes place, the rate at which the corrosion of steel takes place, and the amount of brine that drains from the surrounding disturbed rock zone into the repository.

HELTON,JON CRAIG; BEAN,J.E.; ECONOMY,K.; GARNER,J.W.; MACKINNON,ROBERT J.; MILLER,JOEL D.; SCHREIBER,JAMES D.; VAUGHN,PALMER

2000-05-19T23:59:59.000Z

79

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

SciTech Connect (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

80

FLOW CONDITIONING DESIGN IN TURBULENT  

E-Print Network [OSTI]

/L) · Free surface = interface between fluorescing (bright) water and (dark) air · Image obliquely with B-Injection Fusion Energy) #12;3 Motivation · Effective protection Minimize clearance between edge of liquid sheet) at FWHM · Positioning controlled by two linear stages · Water seeded with TiO2 particles (typical dia. 0

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

Environmental Conditions Environmental Conditions  

E-Print Network [OSTI]

Environmental Conditions Environmental Conditions Appendix II The unique geology, hydrology and instream habitat. This chapter examines how environmental conditions in the Deschutes watershed affect, the discussion characterizes the environmental conditions within three watershed areas: the Lower Deschutes

82

Low volume flow meter  

DOE Patents [OSTI]

The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

Meixler, Lewis D. (East Windsor, NJ)

1993-01-01T23:59:59.000Z

83

Numerical analysis of hypersonic continuum and rarefied gas flows near blunt probes is presented under conditions of intensive gas blowing from the surface.  

E-Print Network [OSTI]

1 Abstract Numerical analysis of hypersonic continuum and rarefied gas flows near blunt probes injection, hydrogen combustion, hypersonic flow, exponential box-scheme, direct-simulation Monte-Carlo method. 1 Introduction Numerical and experimental studies [1, 2] of aerothermodynamics of hypersonic

Riabov, Vladimir V.

84

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

85

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

86

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

SciTech Connect (OSTI)

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

87

Measurement of two-phase flow at the core/upper plenum interface for a PWR geometry under simulated reflood conditions  

SciTech Connect (OSTI)

The Instrument Development Loop (IDL) Program is part of the International 2D/3D Refill and Reflood Experimental and Analytical Research Program. Among the objectives of the International Program are: the study of the steam binding effect during reflood flow distribution (chimney effect) in a heated core; and the study of flow hydrodynamics in the core, downcomer and upper plenum during refill and reflood. Three experimental facilities were used in these studies: a one-bundle air/water loop, a three-bundle air/water loop, and a one-bundle steam/water loop. The loops represent full-scale vertical sections of the UPTF, extending from spray nozzles to the top of the upper plenum and including a short length of dummy fuel rods, upper end boxes, core support plate and control rod guide tubes. Three flow regimes were identified and studied: (1) all liquid down; (2) countercurrent flow in which gas (or vapor) goes up and liquid goes both up and down; and (3) cocurrent flow in which both gas (or vapor) and liquid go up.

Thomas, D.G.; Combs, S.K.

1983-08-01T23:59:59.000Z

88

Development of a Well Intervention Toolkit to Analyze Initial Wellbore Conditions and Evaluate Injection Pressures, Flow Path, Well Kill, and Plugging Procedures  

E-Print Network [OSTI]

Target Well ?? Bubble velocity, m/sec ?? Mean gas velocity ?? Homogeneous velocity ?? Gas-bubble slip velocity Vgas Gas volume in standard condition, scf Xg Influx volume, ft 3 Xm Mud volume, ft 3 Voil Oil volume in stock tank condition...; ?? = ???? ???? , ................................................................................................................. (2.32) Where; Rs = solution gas-oil ratio, scf/stb Vgas = gas volume in standard condition, scf Voil = Oil volume in stock tank condition, stb At pressures above the bubble point, the solution GOR remains constant. Below the bubble point...

Paknejad, Amir S

2009-08-03T23:59:59.000Z

89

Numerical simulation of the fluid flow and heat transfer processes during scavenging in a two-stroke engine under steady-state conditions  

SciTech Connect (OSTI)

A numerical simulation of the scavenging process in a two-stroke flat-piston model engine has been developed. Air enters the cylinder circumferentially, inducting a three-dimensional turbulent swirling flow. The problem was modeled as a steady-state axisymmetric flow through a cylinder with uniform wall temperature. The steady-state regime was simulated by assuming the piston head fixed at the bottom dead center. The calculation was performed employing the {kappa}-{epsilon} model of turbulence. A comparison of the results obtained for the flow field with available experimental data showed very good agreement, and a comparison with an available numerical solution revealed superior results. The effects of the Reynolds number, inlet port angles, and engine geometry on the flow and in-cylinder heat transfer characteristics were investigated. The Nusselt number substantially increases with larger Reynolds numbers and a smaller bore-to-stroke ratio. It is shown that the positioning of the exhaust value(s) is the main parameter to control the scavenging process.

Castro Gouveia, M. de; Reis Parise, J.A. dos; Nieckele, A.O. (Pontificia Univ. Catolica, Rio de Janeiro (Brazil))

1992-05-01T23:59:59.000Z

90

Combined effects of Reynolds number, turbulence intensity and periodic unsteady wake flow conditions on boundary layer development and heat transfer of a low pressure turbine blade  

E-Print Network [OSTI]

.18 (S R =80 mm)........................................103 Figure 11.1. Static pressure distributions at Re=110,000 and reduced frequencies S=0, 1.59, 3.18 (no rod, 160 mm, 80 mm), SS=Separation start, SE= Separation end...................................................110 Figure 11.2. Time-averaged hot-film distributions at Re=110,000 and reduced frequencies S=0, 1.59, 3.18 (no rod, 160 mm, 80 mm)...........................112 Figure 11.3. Ensemble averaged velocity as a function for (a) steady flow case S=0 (S R...

Ozturk, Burak

2009-05-15T23:59:59.000Z

91

Flow Distances on Open Flow Networks  

E-Print Network [OSTI]

Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...

Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

2015-01-01T23:59:59.000Z

92

Elliptic and Hexadecapole flow of charged hadron in viscous hydrodynamics with Glauber and Color Glass Condensate initial conditions for Pb-Pb collision at $\\sqrt{s_{NN}}$=2.76 TeV  

E-Print Network [OSTI]

The experimentally measured elliptic ($v_{2}$) and hexadecapole ($v_{4}$) flow of charged particles as a function of transverse momentum ($p_{T}$) at midrapidity in Pb-Pb collisions at $\\sqrt{s_{\\mathrm NN}}$ = 2.76 TeV are compared with the relativistic viscous hydrodynamic model simulations. The simulations are carried out for two different initial energy density profiles obtained from (i) Glauber model, and (ii) Color Glass Condensate (CGC) model. Comparison to experimental data for 10-20% to 40-50% centrality, shows that a centrality dependent shear viscosity to entropy density ($\\eta/s$) ratio with values ranging between 0.0 to 0.12 are needed to explain the $v_{2}$ data for simulations with the Glauber based initial condition. Whereas for the CGC based initial conditions a slightly higher value of $\\eta/s$ is preferred, around 0.08 to 0.16. From the comparison of the $v_{4}$ simulated results to the corresponding experimental measurements we observe that for the centralities 20-30% to 40-50% the $\\eta/s...

Roy, Victor; Chaudhuri, A K

2012-01-01T23:59:59.000Z

93

MHD duct flows under hydrodynamic slip condition  

E-Print Network [OSTI]

9. Morley, N.B. , Medina, A. , Abdou, M.A. : Measurements ofSmolentsev, S. , Moreau, R. , Abdou, M. : Characterization

Smolentsev, S.

2009-01-01T23:59:59.000Z

94

Cotton flow  

E-Print Network [OSTI]

Using the conformally invariant Cotton tensor, we define a geometric flow, the "Cotton flow", which is exclusive to three dimensions. This flow tends to evolve the initial metrics into conformally flat ones, and is somewhat orthogonal to the Yamabe flow, the latter being a flow within a conformal class. We define an entropy functional, and study the flow of nine homogeneous spaces both numerically and analytically. In particular, we show that the arbitrarily deformed homogeneous 3-sphere flows into the round 3-sphere. Two of the nine homogeneous geometries, which are degenerated by the Ricci flow, are left intact by the Cotton flow.

Ali Ulas Ozgur Kisisel; Ozgur Sarioglu; Bayram Tekin

2008-06-17T23:59:59.000Z

95

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

96

UZ Flow Models and Submodels  

SciTech Connect (OSTI)

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

97

Security Conditions  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

This Notice ensures that DOE uniformly meets the requirements of the Homeland Security Advisory System outlined in Homeland Security Presidential Directive-3, Threat Conditions and Associated Protective Measures, dated 3-11-02, and provides responses specified in Presidential Decision Directive 39, U.S. Policy on Counterterrorism (U), dated 6-21-95. It cancels DOE N 473.8, Security Conditions, dated 8-7-02. Extended until 7-7-06 by DOE N 251.64, dated 7-7-05 Cancels DOE N 473.8

2004-07-08T23:59:59.000Z

98

Flow chamber  

DOE Patents [OSTI]

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

Morozov, Victor (Manassas, VA)

2011-01-18T23:59:59.000Z

99

CX-010826: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

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

100

Classification of Two-Phase Flow Patterns by Ultrasonic Sensing  

E-Print Network [OSTI]

in addition to several other factors such as the bulk flow rate, fluid properties, and flow boundary conditions [1]. Characterization of flow patterns and identification of the associ- ated flow regimes instrumentation, both for void fraction identification and flow pattern classification. High-speed photog- raphy

Ray, Asok

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

Geological flows  

E-Print Network [OSTI]

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

Yu. N. Bratkov

2008-11-19T23:59:59.000Z

102

Cooling Flows or Heating Flows?  

E-Print Network [OSTI]

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.

James Binney

2003-10-08T23:59:59.000Z

103

E-Print Network 3.0 - artificial boundary conditions Sample Search...  

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

obtained from satellite (above) and GPS mea- surements 1 as boundary conditions. The ice... by Glen's flow law: Boundary conditions are ... Source: Langhorne, Pat - Department...

104

Constraints on flow regimes in wide-aperture fractures  

SciTech Connect (OSTI)

In recent years, significant advances have been made in our understanding of the complex flow processes in individual fractures, aided by flow visualization experiments and conceptual modeling efforts. These advances have led to the recognition of several flow regimes in individual fractures subjected to different initial and boundary conditions. Of these, the most important regimes are film flow, rivulet flow, and sliding of droplets. The existence of such significantly dissimilar flow regimes has been a major hindrance in the development of self-consistent conceptual models of flow for single fractures that encompass all the flow regimes. The objective of this study is to delineate the existence of the different flow regimes in individual fractures. For steady-state flow conditions, we developed physical constraints on the different flow regimes that satisfy minimum energy configurations, which enabled us to segregate the wide range of fracture transmissivity (volumetric flow rate per fracture width) into several flow regimes. These are, in increasing order of flow rate, flow of adsorbed films, flow of sliding drops, rivulet flow, stable film flow, and unstable (turbulent) film flow. The scope of this study is limited to wide-aperture fractures with the flow on the opposing sides of fracture being independent.

Ghezzehei, Teamrat A.

2004-02-28T23:59:59.000Z

105

Comment on Velocity boundary conditions at a tokamak resistive wall [Phys. Plasmas 21, 032506 (2014)  

SciTech Connect (OSTI)

The paper gives the derivation of the MHD boundary condition for the plasma flow to the wall during disruptions.

Zakharov, Leonid E. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Li, Xujing [Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing (China)

2014-09-15T23:59:59.000Z

106

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

107

Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands  

E-Print Network [OSTI]

Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands D, Lyngby Abstract. Two-dimensional unsaturated flow and transport through heterogeneous sand was investigated under controlled laboratory conditions. The unsaturated hydraulic conductivity of five homogeneous

Wildenschild, Dorthe

108

SFTEL: Flow Cell | EMSL  

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

Flow Cell EMSL's Subsurface Flow and Transport Experimental Laboratory offers several meter-scale flow cells and columns for research in saturated and unsaturated porous media....

109

Interpretation of Array Production Logging Measurements in Horizontal Wells for Flow Profile  

E-Print Network [OSTI]

and possible back flow of denser phases result in misinterpretation of the inflow distribution. To assess the downhole flow conditions more accurately, logging tools have been developed to overcome the flow regime related issues. Multiple-sensor array tools...

Liao, Lulu

2013-12-12T23:59:59.000Z

110

Some hydrodynamic characteristics of bubbly mixtures flowing vertically upward in tubes  

E-Print Network [OSTI]

An investigation of bubbly flow has been conducted in vertical plexiglass tubes using air and water at atmospheric pressure. The bubbly flow pattern is an entrance condition or a non-fully developed flow. A spontaneous ...

Rose, Sewell C.

1964-01-01T23:59:59.000Z

111

Dissipation flow-frames: particle, energy, thermometer  

E-Print Network [OSTI]

We associate the following physical co-mover conditions of to different frame choices: i) Eckart: particle flow, ii) Landau-Lifshitz: energy flow, iii) J\\"uttner: moving thermometer frame. The role of fixing a flow-frame is analysed with respect to local equilibrium concentrating on dissipative currents and forces in single component relativistic fluids. The special role of a "J\\"uttner frame" is explored and contrasted to the more common Eckart and Landau-Lifshitz choices.

Vn, P

2013-01-01T23:59:59.000Z

112

Dissipation flow-frames: particle, energy, thermometer  

E-Print Network [OSTI]

We associate the following physical co-mover conditions of to different frame choices: i) Eckart: particle flow, ii) Landau-Lifshitz: energy flow, iii) J\\"uttner: moving thermometer frame. The role of fixing a flow-frame is analysed with respect to local equilibrium concentrating on dissipative currents and forces in single component relativistic fluids. The special role of a "J\\"uttner frame" is explored and contrasted to the more common Eckart and Landau-Lifshitz choices.

P. Vn; T. S. Bir

2013-05-14T23:59:59.000Z

113

Integrable magnetic geodesic flows on Lie groups  

E-Print Network [OSTI]

Right-invariant geodesic flows on manifolds of Lie groups associated with 2-cocycles of corresponding Lie algebras are discussed. Algebra of integrals of motion for magnetic geodesic flows is considered and necessary and sufficient condition of integrability in quadratures is formulated. Canonic forms for 2-cocycles of all 4-dimensional Lie algebras are given and integrable cases among them are separated.

Alexey A. Magazev; Igor V. Shirokov; Yuriy Y. Yurevich

2011-11-03T23:59:59.000Z

114

Microstructure and Rheology of a Flow-Induced Structured Phase...  

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

salt concentration. In our work, by introducing external flow conditions via microfluidics, these micellar structures can follow very different trajectories on the phase map...

115

Theoretical uncertainty of orifice flow measurement  

SciTech Connect (OSTI)

Orifice meters are the most common meters used for fluid flow measurement, especially for measuring hydrocarbons. Meters are rugged, mechanically simple, and well suited for field use under extreme weather conditions. Because of their long history of use and dominance in the fluid flow measurement, their designs, installation requirements, and equations for flow rate calculation have been standardized by different organizations in the United States and internationally. These standards provide the guideline for the users to achieve accurate flow measurement. and minimize measurement uncertainty. This paper discusses different factors that contribute to the measurement inaccuracy and provide an awareness to minimize or eliminate these errors. Many factors which influence the overall measurement uncertainty are associated with the orifice meter application. Major contributors to measurement uncertainty include the predictability of flow profile, fluid properties at flowing condition, precision of empirical equation for discharge coefficient, manufacturing tolerances in meter components, and the uncertainty associated with secondary devices monitoring the static line pressure, differential pressure across the orifice plate, flowing temperature, etc. Major factors contributing to the measurement uncertainty for a thin, concentric, square-edged orifice flowmeter are as follows: (a) Tolerances in prediction of coefficient of discharge, (b) Predictability in defining the physical properties of the flowing fluid, (c) Fluid flow condition, (d) Construction tolerances in meter components, (e) Uncertainty of secondary devices/instrumentation, and (f) Data reduction and computation. Different factors under each of the above areas are discussed with precautionary measures and installation procedures to minimize or eliminate measurement uncertainty.

Husain, Z.D. [Daniel Flow Products, Inc., Houston, TX (United States)

1995-12-01T23:59:59.000Z

116

On the Geodesic Nature of Wegner's Flow  

E-Print Network [OSTI]

Wegner's method of flow equations offers a useful tool for diagonalizing a given Hamiltonian and is widely used in various branches of quantum physics. Here, generalizing this method, a condition is derived, under which the corresponding flow of a quantum state becomes geodesic in a submanifold of the projective Hilbert space, independently of specific initial conditions. This implies the geometric optimality of the present method as an algorithm of generating stationary states. The result is illustrated by analyzing some physical examples.

Yuichi Itto; Sumiyoshi Abe

2012-02-08T23:59:59.000Z

117

Modeling of bubbly and slug flow behavior under microgravity conditions  

E-Print Network [OSTI]

. 31 4. 1 Time dependent pressure gradient for parabola 2, set 2 on day 7/10/92. . 40 4. 2 Comparison between 0-g experimental friction factor pressure gradient for test section 1 and test section 2. . 45 4. 3 Comparison between the theoretical (fw... I I I I I I I I I I I I I I I I I I I I I I I 1 I I a/' (~i oi/I I I 'I I I I I I I I 'I I I I I I I I I I I I I I I oo Vl ct w ac oo t oa t oo oo oa ot vl t ao t v1 ata cI R S oa oa ta 't u1...

Longeot, Matthieu Jean-Sebastien

1995-01-01T23:59:59.000Z

118

ORIGINAL PAPER Conditional simulations of wateroil flow in heterogeneous porous  

E-Print Network [OSTI]

water standards. Thus, a small amount of NAPL can contaminate large volumes of groundwater over a long period of time. Therefore, it is very important to understand the processes associated with contaminant is a complicated mixture of hydrocarbon fluids, brine, porous rock and fractures. The structure of the void space

Lu, Zhiming

119

On fluid flow in a heterogeneous medium under nonisothermal conditions  

E-Print Network [OSTI]

aver- age of the heat capacity of the liquid and the heatthe volumetric heat capacity of the liquid, and K T = ?K l

D.W., Vasco

2011-01-01T23:59:59.000Z

120

Original article Influence of heating conditions in continuous-flow  

E-Print Network [OSTI]

, holding and cooling phases. When milk was heated in a continuous microwave heating system, at 90 C and cooling times. vitamin B1 / vitamin B2 / milk / microwave heating Rsum -- tude de l'effet des exchange systems on the vitamin B1 and B2 content of milk Isabel SIERRA, Concepcin VIDAL

Paris-Sud XI, Universit de

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

A survey of air flow models for multizone structures  

SciTech Connect (OSTI)

Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 50 multizone air flow models, all developed since 1966, two of which are still under development. All these programs use similar flow equations for crack flow but differ in the versatility to describe the full range of flow phenomena and the algorithm provided for solving the set of nonlinear equations. This literature review was found that newer models are able to describe and simulate the ventilation systems and interrelation of mechanical and natural ventilation. 27 refs., 2 figs., 1 tab.

Feustel, H.E.; Dieris, J.

1991-03-01T23:59:59.000Z

122

Propeller Flow Meter  

E-Print Network [OSTI]

Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....

Enciso, Juan; Santistevan, Dean; Hla, Aung K.

2007-10-01T23:59:59.000Z

123

Dispersed flow film boiling  

E-Print Network [OSTI]

Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

Yoder, Graydon L.

1980-01-01T23:59:59.000Z

124

Bacteria in shear flow  

E-Print Network [OSTI]

Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

Marcos, Ph.D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

125

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

126

New boundary conditions for granular fluids  

E-Print Network [OSTI]

We present experimental evidence, which contradicts the the standard boundary conditions used in continuum theories of non-cohesive granular flows for the velocity normal to a boundary u.n=0, where n points into the fluid. We propose and experimentally verify a new boundary condition for u.n, based on the observation that the boundary cannot exert a tension force Fb on the fluid. The new boundary condition is u.n=0 if Fb.n>=0 else n.P.n=0, where P is the pressure tensor. This is the analog of cavitation in ordinary fluids, but due the lack of attractive forces and dissipation it occurs frequently in granular flows.

Mark D. Shattuck

2007-03-22T23:59:59.000Z

127

Seal inlet disturbance boundary conditions for rotordynamic models and influence of some off-design conditions on labyrinth rotordynamic instability  

E-Print Network [OSTI]

Systematic parametric studies were performed to better understand seal-inlet rotordynamics. A CFD-perturbation model was employed to compute the seal-inlet flow disturbance quantities. Seal inlet disturbance boundary condition correlations were...

Xi, Jinxiang

2007-04-25T23:59:59.000Z

128

Nonlinear model-based control of two-phase flow in risers by feedback linearization  

E-Print Network [OSTI]

conditions at offshore oilfields. The slugging flow constitutes an unstable and highly nonlinear system and flow rates (Storkaas (2005), Storkaas and Skogestad (2007)). The oscillatory flow condition in offshore disturbances or plant changes. We aim to find a robust control solution for anti-slug control systems

Skogestad, Sigurd

129

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation  

E-Print Network [OSTI]

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions)" #12;Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions, cavitation, fluid flow load, CFD. Abstract: The evaluation of fluid forces on the stem is important for wear

Paris-Sud XI, Université de

130

Prediction of flow rates through an orifice at pressures corresponding to the transition between molecular and isentropic flow  

SciTech Connect (OSTI)

A model of compressible flow through an orifice, in the region of transition from free molecular to isentropic expansion flow, has been developed and tested for accuracy. The transitional or slip regime is defined as the conditions where molecular interactions are too many for free molecular flow modeling, yet not great enough for isentropic expansion flow modeling. Due to a lack of literature establishing a well-accepted model for predicting transitional flow, it was felt such work would be beneficial. The model is nonlinear and cannot be satisfactorily linearized for a linear regression analysis. Consequently, a computer routine was developed which minimized the sum of the squares of the residual flow for the nonlinear model. The results indicate an average accuracy within 15% of the measured flow throughout the range of test conditions. Furthermore, the results of the regression analysis indicate that the transitional regime lies between Knudsen numbers of approximately 2 and 45. 4 refs., 3 figs., 1 tab.

DeMuth, S.F.; Watson, J.S.

1985-01-01T23:59:59.000Z

131

Grid sensitivity in low Reynolds number hypersonic continuum flows  

SciTech Connect (OSTI)

A computational scheme is presented to solve the unsteady Navier-Stokes equations over a blunt body at high altitude, high Mach number atmospheric reentry flow conditions. This continuum approach is directed to low Reynolds/low density hypersonic flows by accounting for non-zero bulk viscosity effects in near frozen flow conditions. A significant difference from previous studies is the inclusion of the capability to model non-zero bulk viscosity effects. The grid definition for these low Reynolds number, viscous dominated flow fields is especially important in terms of numerical stability and accurate heat transfer solutions. 11 refs., 15 figs.

Rutledge, W.H. (Sandia National Labs., Albuquerque, NM (USA)); Hoffmann, K.A. (Wichita State Univ., KS (USA). Dept. of Aerospace Engineering)

1991-01-01T23:59:59.000Z

132

Terms and Conditions  

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

Testbed Results Current Testbed Research Proposal Process Terms and Conditions Dark Fiber Testbed Performance (perfSONAR) Software & Tools Development Partnerships...

133

Variational bounds on the energy dissipation rate in body-forced shear flow  

E-Print Network [OSTI]

, the bulk (space and time averaged) dissipation rate per unit mass is proportional to the power required applied to many flows driven by boundary conditions, including shear flows and a variety of thermal

Petrov, Nikola

134

Interpreting Horizontal Well Flow Profiles and Optimizing Well Performance by Downhole Temperature and Pressure Data  

E-Print Network [OSTI]

be used to obtain downhole flow conditions, which is key information to control and optimize horizontal well production. However, the fluid flow in the reservoir is often multiphase and complex, which makes temperature and pressure interpretation very...

Li, Zhuoyi

2011-02-22T23:59:59.000Z

135

Recirculation on a single stage of vertical flow constructed wetland: treatment limits and operation modes  

E-Print Network [OSTI]

1 Recirculation on a single stage of vertical flow constructed wetland: treatment limits French vertical flow constructed wetlands (VFCWs) plant comprises two stages of treatment which the first and treatment performances in different operating conditions. Results showed good performances

Paris-Sud XI, Université de

136

Flow Split Venturi, Axially-Rotated Valve  

SciTech Connect (OSTI)

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)

2000-02-22T23:59:59.000Z

137

When Does Aid Conditionality Work?  

E-Print Network [OSTI]

institutions may tailor conditions for success because theytailor their conditions for success, and they are especially

Montinola, Gabriella R.

2010-01-01T23:59:59.000Z

138

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

139

Elbow mass flow meter  

DOE Patents [OSTI]

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

140

Bypass flow computations on the LOFA transient in a VHTR  

SciTech Connect (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 [National Tsing Hua Univ., Hsinchu (Taiwan). Inst. of Nuclear Engineering and Science; Richard W. Johnson [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Yuh-Ming Ferng [National Tsing Hua Univ., Hsinchu (Taiwan). Inst. of Nuclear Engineering and Science; Ching-Chang Chieng [City Univ. of Hong Kong, Kowloon (Hong Kong). Dept. of Mechanical and Biomedical Engineering

2014-01-01T23:59:59.000Z

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

Site-Scale Saturated Zone Flow Model  

SciTech Connect (OSTI)

The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca Mountain using FEHM V 2.20 are being carried out in the model report, ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The velocity fields are calculated by the flow model, described herein, independent of the transport processes, and are then used as inputs to the transport model. Justification for this abstraction is presented in the model report, ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021 (BSC 2003 [164870]).

G. Zyvoloski

2003-12-17T23:59:59.000Z

142

A new precision flow calorimeter  

E-Print Network [OSTI]

differences. With no sample fluid flowing, a supply of electrical power is fed to the inner calorimeter. The reference fluid is evaporated with this electrical power and the thermo-syphon system is brought to controlled steady-state conditions of pressure... calorimeter is kept cooler than the inner calorimeter for reasons discussed in chapter 4. Thus the above mentioned procedure is essential to avoid condensation in Freon@-11 vapor lines. The thermo-syphon ensures a saturated Freon&-11 vapor phase in the top...

Johnson, Mark Gezer

1984-01-01T23:59:59.000Z

143

A New Approach to Computing Max Flows using Electrical Flows  

E-Print Network [OSTI]

A New Approach to Computing Max Flows using Electrical Flows Yin Tat Lee (MIT) Satish Rao (UC-Kelner-Madry-Spielman-Teng'11]: approximate flow in time Uses electrical flows. 7 #12;Electrical Flows 3 1 S t 8 #12;Electrical Flows Identify Graph with Resistor Network R(e)=1/w(e) 1/3 S t 1 9 #12;Electrical Flows Electrical flow

Rajamani, Sriram K.

144

Low flow fume hood  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

145

Laminar Entrained Flow Reactor (Fact Sheet)  

SciTech Connect (OSTI)

The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

Not Available

2014-02-01T23:59:59.000Z

146

Investigation of flow in centrifugal impeller with tandem inducer  

E-Print Network [OSTI]

resulted in significantly increased interest in flow problems related to centrifugal compressors. This is because a centrifugal compressor has a reasonably high efficiency, and can be compactly designed for a high pressure ratio per stage, also a... line rotating with impeller Kinematic viscosity Pressure ratio referred to stagnation conditions Density Shear stress at the wall Flow coefficient = meridional flow velocity at impeller inlet / UZ Pressure rise coefficient = stagnation...

Nishida, Akira

1976-01-01T23:59:59.000Z

147

Conditional data watchpoint management  

DOE Patents [OSTI]

A method, system and computer program product for managing a conditional data watchpoint in a set of instructions being traced is shown in accordance with illustrative embodiments. In one particular embodiment, the method comprises initializing a conditional data watchpoint and determining the watchpoint has been encountered. Upon that determination, examining a current instruction context associated with the encountered watchpoint prior to completion of the current instruction execution, further determining a first action responsive to a positive context examination; otherwise, determining a second action.

Burdick, Dean Joseph (Austin, TX); Vaidyanathan, Basu (Austin, TX)

2010-08-24T23:59:59.000Z

148

Flow reversal power limit for the HFBR  

SciTech Connect (OSTI)

The High Flux Beam Reactor (HFBR) undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Uncertainties about the afterheat removal capability during the flow reversal has limited the reactor operating power to 30 MW. An experimental and analytical program to address these uncertainties is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW.

Cheng, Lap Y.; Tichler, P.R.

1995-10-01T23:59:59.000Z

149

Method for use of hydraulically or electrically controlled solenoids under failed on conditions  

DOE Patents [OSTI]

A method to operate a clutch device in an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and at least one electric machine includes, in response to a failure condition detected within a flow control device configured to facilitate flow of hydraulic fluid for operating the clutch device, selectively preventing the flow of hydraulic fluid from entering the flow control device and feeding the clutch device. Synchronization of the clutch device is initiated when the clutch device is intended for activation, and only if the clutch device is synchronized, the flow of hydraulic fluid is selectively permitted to enter the flow control device to activate the clutch device.

Bolenbaugh, Jonathan M.; Naqi, Syed

2014-07-08T23:59:59.000Z

150

IPR Conditions, 25 January 2006 1 Intellectual Property Rights Conditions  

E-Print Network [OSTI]

IPR Conditions, 25 January 2006 1 Intellectual Property Rights Conditions for Collaborative Research Projects (IPR Conditions) I. GENERAL PRINCIPLES These rules should promote the protection guarantee the protection of the participants' intellectual assets. These IPR Conditions establish rules

De Cindio, Fiorella

151

E-Print Network 3.0 - applying dynamic flow-density Sample Search...  

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

Collection: Energy Storage, Conversion and Utilization 17 Dynamic Origin-Destination Demand Flow Estimation under Congested Traffic Conditions Xuesong Zhou Summary: for the...

152

Modeling multiphase flow for high viscosity liquids: a study of vertical/inclined zero net liquid flow  

E-Print Network [OSTI]

This experimental study investigates the effects of inclination angle and fluid viscosity on zero net liquid flow (ZNLF). Predicting liquid holdup under ZNLF conditions is necessary in several types of petroleum industry operations. These include...

Rodriguez, Jose Ramon

2001-01-01T23:59:59.000Z

153

CX-005689: Categorical Exclusion Determination | Department of...  

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

Exclusion Determination Joint Inversion of Electrical and Seismic Data for Fracture Characterization and Imaging of Fluid Flow in Geothermal Systems CX(s) Applied: A9,...

154

CX-010020: Categorical Exclusion Determination | Department of...  

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

Determination CX-010020: Categorical Exclusion Determination F-08 Industrial Wastewater Outfall Flow Measurement Improvements CX(s) Applied: B3.1 Date: 01282013...

155

Flow focusing in unsaturated fracture networks: A numerical investigation  

SciTech Connect (OSTI)

A numerical modeling study is presented to investigate flow-focusing phenomena in a large-scale fracture network, constructed using field data collected from the unsaturated zone of Yucca Mountain, Nevada, the proposed repository site for high-level nuclear waste. The two-dimensional fracture network for an area of 100 m x 150 m contains more than 20,000 fractures. Steady-state unsaturated flow in the fracture network is investigated for different boundary conditions and rock properties. Simulation results indicate that flow paths are generally vertical, and that horizontal fractures mainly provide pathways between neighboring vertical paths. In addition to fracture properties, flow-focusing phenomena are also affected by rock-matrix permeability, with lower matrix permeability leading to a high degree of flow focusing. The simulation results further indicate that the average spacing between flow paths in a layered system tends to increase and flow tends to becomes more focused, with depth.

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.; Liu, Hui-Hai

2003-04-17T23:59:59.000Z

156

Cyclotron resonance in plasma flow  

SciTech Connect (OSTI)

This paper is devoted to the mechanism of particle acceleration via resonant interaction with the electromagnetic circular wave propagating along the inhomogeneous background magnetic field in the presence of a plasma flow. We consider the system where the plasma flow velocity is large enough to change the direction of wave propagation in the rest frame. This system mimics a magnetic field configuration typical for inner structure of a quasi-parallel shock wave. We consider conditions of gyroresonant interaction when the force corresponding to an inhomogeneity of the background magnetic field is compensated by the Lorentz force of the wave-magnetic field. The wave-amplitude is assumed to be about 10% of the background magnetic field. We show that particles can gain energy if kv{sub sw}>?>kv{sub sw}??{sub c} where k is the wave number, v{sub sw} is a plasma flow velocity, and ? and ?{sub c} are the wave frequency and the particle gyrofrequency, respectively. This mechanism of acceleration resembles the gyrosurfing mechanism, but the effect of the electrostatic field is replaced by the effect of the magnetic field inhomogeneity.

Artemyev, A. V.; Agapitov, O. V.; Krasnoselskikh, V. V. [LPC2E/CNRS-University of Orleans, Orleans (France)] [LPC2E/CNRS-University of Orleans, Orleans (France)

2013-12-15T23:59:59.000Z

157

Flow dynamics and solute transport in unsaturated rock fractures  

SciTech Connect (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

158

Process for retarding fluid flow  

SciTech Connect (OSTI)

A process is described for retarding the flow of fluid in a subterranean formation, comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean formation, the gel-forming composition being operable when gelled in the formation for retarding the flow of fluid therein. The gel-forming composition consists of: i. a first substance dissolved in water to form an aqueous solution, the first substance being selected from the group consisting of polyvivyl alcohols, and mixtures thereof, wherein the gel-forming composition contains an amount of the first substance of from about 0.5 to about 5 weight percent of the gel-forming composition, and ii. an effective amount of glutaraldehyde which is operable for forming a weakly acidic condition having a pH from about 5.5 to less than 7 in the gel-forming composition and also operable for promoting crosslinking of the first substance and glutaraldehyde and for forming a gel from the gel-forming composition under the weakly acidic condition within a period of time no greater than about 5 days without adding an acidic catalyst to the gel-forming composition to lower the pH of the gel-forming composition below about 5.5.

Sandford, B.B.; Zillmer, R.C.

1989-01-10T23:59:59.000Z

159

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

2010-06-05T23:59:59.000Z

160

Mineralogy under extreme conditions  

SciTech Connect (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

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

Flow Partitioning in Fully Saturated Soil Aggregates  

SciTech Connect (OSTI)

Microbes play an important role in facilitating organic matter decomposition in soils, which is a major component of the global carbon cycle. Microbial dynamics are intimately coupled to environmental transport processes, which control access to labile organic matter and other nutrients that are needed for the growth and maintenance of microorganisms. Transport of soluble nutrients in the soil system is arguably most strongly impacted by preferential flow pathways in the soil. Since the physical structure of soils can be characterized as being formed from constituent micro aggregates which contain internal porosity, one pressing question is the partitioning of the flow among the inter-aggregate and intra-aggregate pores and how this may impact overall solute transport within heterogeneous soil structures. The answer to this question is particularly important in evaluating assumptions to be used in developing upscaled simulations based on highly-resolved mechanistic models. We constructed a number of diverse multi-aggregate structures with different packing ratios by stacking micro-aggregates containing internal pores and varying the size and shape of inter-aggregate pore spacing between them. We then performed pore-scale flow simulations using computational fluid dynamics methods to determine the flow patterns in these aggregate-of-aggregates structures and computed the partitioning of the flow through intra- and inter-aggregate pores as a function of the spacing between the aggregates. The results of these numerical experiments demonstrate that soluble nutrients are largely transported via flows through inter-aggregate pores. Although this result is consistent with intuition, we have also been able to quantify the relative flow capacity of the two domains under various conditions. For example, in our simulations, the flow capacity through the aggregates (intra-aggregate flow) was less than 2% of the total flow when the spacing between the aggregates was larger than 18 micron. Inter-aggregate pores continued to be the dominant flow pathways even at much smaller spacing; intra-aggregate flow was less than 10% of the total flow when the inter- and intra-aggregate pore sizes were comparable. Such studies are making it possible to identify which model upscaling assumptions are realistic and what computational methods are required for detailed numerical investigation of microbial carbon cycling dynamics in soil systems.

Yang, Xiaofan; Richmond, Marshall C.; Scheibe, Timothy D.; Perkins, William A.; Resat, Haluk

2014-03-30T23:59:59.000Z

162

Towards improved methods for determining porous media multiphase flow functions  

E-Print Network [OSTI]

to the empirical relation by using the three-dimensional saturation and relaxation data. 7 CHAPTER II ESTIMATION OF POROUS MEDIA FLOW FUNCTIONS Multiphase flow functions are required to simulate the flow of multiple fluid phases through porous media....3) Snw + Sw = 1: (2.4) Together with boundary and initial conditions, Eqs. (2.1)-(2.4) provide a mathemat- ical model of three-dimensional, two-phase fluid flow in porous media. Several properties have to be specified in the above model. The densities...

Xue, Song

2004-09-30T23:59:59.000Z

163

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 <= 2 particles switches from in-plane to out-of-plane enhancement at around 100 MeV per nucleon, in good agreement with the result reported by the FOPI Collaboration. The 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.

Lukasik, J; Begemann-Blaich, M L; Bellaize, N; Bittiger, R; Bocage, F; Borderie, B; Bougault, R; Bouriquet, B; Charvet, J L; Chbihi, A; Dayras, R; Durand, D; Frankland, J D; Galchet, E; Gourio, D; Guinet, D; Hudan, S; Lautesse, P; Lavaud, F; Lefvre, A; Legrain, R; Lpez, O; Lynen, U; Mller, W F J; Nalpas, L; Orth, H; Plagnol, E; Rosato, E; Saija, A; Schwarz, C; Sfienti, C; Tamain, B; Trautmann, W; Trzcinski, A; Turz, K; Vient, E; Vigilante, M; Volant, C; Zwieglinski, B

2004-01-01T23:59:59.000Z

164

Productivity & Energy Flow  

E-Print Network [OSTI]

1 Productivity & Energy Flow Ecosystem approach, focuses: on flow of energy, water, and nutrients (capture) of energy by autotrophs Gross (total) Net (total ­ costs) Secondary productivity- capture of energy by herbivores http://sciencebitz.com/?page_id=204 What Controls the Primary Productivity

Mitchell, Randall J.

165

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

166

Microelectromechanical flow control apparatus  

DOE Patents [OSTI]

A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.

Okandan, Murat (NE Albuquerque, NM)

2009-06-02T23:59:59.000Z

167

Air conditioning system  

DOE Patents [OSTI]

An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.

Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael

2005-02-01T23:59:59.000Z

168

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

SciTech Connect (OSTI)

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

169

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

170

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

171

Momentum rate probe for use with two-phase flows S. G. Bush,a)  

E-Print Network [OSTI]

of flows including nuclear reactor coolant streams, refrigerants in heating-ventilating air flow rates of these flows span a wide range of values, from those in nuclear power plant cooling systems, through supercritical diesel fuel injection, heating-ventilating and air-conditioning HVAC

Panchagnula, Mahesh

172

Domain decomposition for coupled Stokes and Darcy flows q Danail Vassilev a  

E-Print Network [OSTI]

and fluid flow Stokes­Darcy flow Beavers­Joseph­Saffman condition Mixed finite element a b s t r a c t A non iteration. Finite element techniques appropriate for the type of each subdomain problem are used-overlapping domain decomposition method is presented to solve a coupled Stokes­ Darcy flow problem in parallel

Yotov, Ivan

173

Elliptic flow phenomenon at ATLAS  

E-Print Network [OSTI]

We summarize measurements of elliptic flow and higher order flow harmonics performed by the ATLAS experiment at the LHC. Results on event-averaged flow measurements and event-plane correlations in Pb+Pb collisions are discussed along with the event-by-event flow measurements. Further, we summarize results on flow in p+Pb collisions.

Martin Spousta

2014-06-20T23:59:59.000Z

174

PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW  

E-Print Network [OSTI]

1 PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW F.K. Lu,* C.M. Roseberry, J.M. Meyers and D arc pyrolysis of methane at supersonic conditions, representative of conditions in the reformer- cate the feasibility of arc pyrolysis of methane. Introduction he high specific enthalpy of combustion

Texas at Arlington, University of

175

Instabilities of uniform filtration flows with phase transition  

SciTech Connect (OSTI)

New mechanisms of instability are described for vertical flows with phase transition through horizontally extended two-dimensional regions of a porous medium. A plane surface of phase transition becomes unstable at an infinitely large wavenumber and at zero wavenumber. In the latter case, the unstable flow undergoes reversible subcritical bifurcations leading to the development of secondary flows (which may not be horizontally uniform). The evolution of subcritical modes near the instability threshold is governed by the Kolmogorov-Petrovskii-Piskunov equation. Two examples of flow through a porous medium are considered. One is the unstable flow across a water-bearing layer above a layer that carries a vapor-air mixture under isothermal conditions in the presence of capillary forces at the phase transition interface. The other is the vertical flow with phase transition in a high-temperature geothermal reservoir consisting of two high-permeability regions separated by a low-permeability stratum.

Il'ichev, A. T. [Russian Academy of Sciences, Steklov Institute of Mathematics (Russian Federation)], E-mail: ilichev@mi.ras.ru; Tsypkin, G. G. [Russian Academy of Sciences, Institute for Problems in Mechanics (Russian Federation)

2008-10-15T23:59:59.000Z

176

Nonlinear model-based control of two-phase flow in risers by feedback linearization  

E-Print Network [OSTI]

conditions at offshore oilfields. The slugging flow constitutes an unstable and highly nonlinear system systems, stabilizing control. 1. INTRODUCTION The oscillatory flow condition in offshore multi systems tend to become unstable after some time, because of large inflow disturbances or plant changes

Skogestad, Sigurd

177

Evolution of flow disturbances in cocurrent gas-liquid flows  

SciTech Connect (OSTI)

Studies of interfacial waves in horizontal gas-liquid flows, close to neutral stability, suggest that the rate of evolution of the interface may be linked to nonlinear interactions between the fundamental mode and the subharmonic -- even if the subharmonic is linearly stable. The rate of evolution increases as the subharmonic becomes more unstable. A comparison of linear stability techniques used to predict the initial behavior of waves reveals similar predictions of growth rates and almost identical speeds between a two layer laminar Orr-Sommerfeld theory and an Orr-Sommerfeld theory when the effect of the (turbulent) gas flow enters as boundary conditions on the liquid layer. However, there is disagreement at small wavenumbers as to the point at which the growth curve crosses 0. This is a significant problem because longwave disturbances, in our case roll waves, form by growth of (initially) small amplitude waves that have frequencies which are 0.5 to 1 Hz, which is in the range where the two theories disagree about the sign of the growth rate. While nonlinear effects are probably involved in the formation of the peak (at least while its amplitude is small), the linear growth rate must play an important role when the amplitude is small.

McCready, M.J.

1992-10-01T23:59:59.000Z

178

Shroud leakage flow discouragers  

DOE Patents [OSTI]

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

179

Bypass Flow Study  

SciTech Connect (OSTI)

The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

Richard Schultz

2011-09-01T23:59:59.000Z

180

Magnetically stimulated fluid flow patterns  

ScienceCinema (OSTI)

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

Martin, Jim; Solis, Kyle

2014-08-06T23:59:59.000Z

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

Conditions of Employment Modern Apprentice  

E-Print Network [OSTI]

Conditions of Employment Modern Apprentice 1. GENERAL CONDITIONS Members of staff are subject. Modern Apprentices are required under this agreement to undertake training, attend courses and carry out

Strathclyde, University of

182

Summary on the depressurization from supercritical pressure conditions  

SciTech Connect (OSTI)

When a fluid discharges from a high pressure and temperature system, a 'choking' or critical condition occurs, and the flow rate becomes independent of the downstream pressure. During a postulated loss of coolant accident (LOCA) of a water reactor the break flow will be subject to this condition. An accurate estimation of the critical flow rate is important for the evaluation of the reactor safety, because this flow rate controls the loss of coolant inventory and energy from the system, and thus has a significant effect on the accident consequences[1]. In the design of safety systems for a super critical water reactor (SCWR), postulated LOCA transients are particularly important due to the lower coolant inventory compared to a typical PWR for the same power output. This lower coolant inventory would result in a faster transient response of the SCWR, and hence accurate prediction of the critical discharge is mandatory. Under potential two-phase conditions critical flow is dominated by the vapor content or quality of the vapor, which is closely related with the onset of vaporization and the interfacial interaction between phases [2]. This presents a major challenge for the estimation of the flow rate due to the lack of the knowledge of those processes, especially under the conditions of interest for the SCWR. According to the limited data of supercritical fluids, the critical flows at conditions above the pseudo-critical point seem to be fairly stable and consistent with the subcritical homogeneous equilibrium model (HEM) model predictions, while having a lower flow rate than those in the two-phase region. Thus the major difficulty in the prediction of the depressurization flow rates remains in the region where two phases co-exist at the top of the vapor dome. In this region, the flow rate is strongly affected by the nozzle geometry and tends to be unstable. Various models for this region have been developed with different assumptions, e.g. the HEM and Moody model [3], and the Henry-Fauske non-equilibrium model [4], and are currently used in subcritical pressure reactor safety design[5]. It appears that some of these models could be reasonably extended to above the thermodynamic pseudo-critical point. The more stable and lower discharge flow rates observed in conditions above the pseudo-critical point suggests that even though SCWR's have a smaller coolant inventory, the safety implications of a LOCA and the subsequent depressurization may not be as severe as expected, this however needs to be confirmed by a rigorous evaluation of the particular event and further evaluation of the critical flow rate. This paper will summarize activities on critical flow models, experimental data and numerical modeling during blowdown from supercritical pressure conditions under the International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on 'Heat Transfer Behaviour and Thermo-hydraulics Code testing for SCWRs'. (authors)

Anderson, M. [Univ. of Wisconsin Madison, 1500 Engineering Dr., Madison, WI 53706 (United States); Chen, Y. [Dept. of Reactor Engineering, Research and Design, Reactor Thermal-Hydraulic Lab., China Inst. of Atomic Energy, P.O.Box 275 59, 102413 Beijing (China); Ammirable, L. [JRC/Inst. for Energy and Transport (Netherlands); Novog, D. [Dept. of Engineering Physics, McMaster Univ., 1280 Main Street, ON (Canada); Yamada, K. [International Atomic Energy Agency, Vienna International Centre, P.O. Box 100, 1400 Vienna (Austria)

2012-07-01T23:59:59.000Z

183

High-density turbidity currents: Are they sandy debris flows?  

SciTech Connect (OSTI)

Conventionally, turbidity currents are considered as fluidal flows in which sediment is supported by fluid turbulence, whereas debris flows are plastic flows in which sediment is supported by matrix strength, dispersive pressure, and buoyant lift. The concept of high-density turbidity current refers to high-concentration, commonly non-turbulent, flows of fluids in which sediment is supported mainly by matrix strength, dispersive pressure, and buoyant lift. The conventional wisdom that traction carpets with entrained turbulent clouds on top represent high-density turbidity currents is a misnomer because traction carpets are neither fluidal nor turbulent. Debris flows may also have entrained turbulent clouds on top. The traction carpet/debris flow and the overriding turbulent clouds are two separate entities in terms of flow rheology and sediment-support mechanism. In experimental and theoretical studies, which has linked massive sands and floating clasts to high-density turbidity currents, the term high-density turbidity current has actually been used for laminar flows. In alleviating this conceptual problem, sandy debris flow is suggested as a substitute for high-density turbidity current. Sandy debris flows represent a continuous spectrum of processes between cohesive and cohesionless debris flows. Commonly they are rheologically plastic. They may occur with or without entrained turbulent clouds on top. Their sediment-support mechanisms include matrix strength, dispersive pressure, and buoyant lift. They are characterized by laminar flow conditions, a moderate to high grain concentration, and a low to moderate mud content. Although flows evolve and transform during the course of transport in density-stratified flows, the preserved features in a deposit are useful to decipher only the final stages of deposition. At present, there are no established criteria to decipher transport mechanism from the depositional record.

Shanmugam, G. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

1996-01-01T23:59:59.000Z

184

Optical flow switching  

E-Print Network [OSTI]

Present-day networks are being challenged by dramatic increases in bandwidth demand of emerging applications. We will explore a new transport, ldquooptical flow switchingrdquo, that will enable significant growth and ...

Chan, Vincent W. S.

185

Olefin Autoxidation in Flow  

E-Print Network [OSTI]

Handling hazardous multiphase reactions in flow brings not only safety advantages but also significantly improved performance, due to better mass transfer characteristics. In this paper, we present a continuous microreactor ...

Neuenschwander, Ulrich

186

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

187

Influence of shear viscosity on the correlation between the triangular flow and initial spatial triangularity  

E-Print Network [OSTI]

In a hydrodynamic model, with fluctuating initial conditions, the correlation between triangular flow and initial spatial triangularity is studied. The triangular flow, even in ideal fluid, is only weakly correlated with the initial triangularity. The correlation is largely reduced in viscous fluid. Elliptic flow on the other hand appears to be strongly correlated with initial eccentricity. Weak correlation between triangular flow and initial triangularity indicate that a part of triangular flow is unrelated to initial triangularity. Triangularity acquired during the fluid evolution also contributes to the triangular flow.

A. K. Chaudhuri

2011-12-06T23:59:59.000Z

188

Influence of shear viscosity on the correlation between the triangular flow and initial spatial triangularity  

E-Print Network [OSTI]

In a hydrodynamic model, with fluctuating initial conditions, the correlation between triangular flow and initial spatial triangularity is studied. The triangular flow, even in ideal fluid, is only weakly correlated with the initial triangularity. The correlation is largely reduced in viscous fluid. Elliptic flow on the other hand appears to be strongly correlated with initial eccentricity. Weak correlation between triangular flow and initial triangularity indicate that a part of triangular flow is unrelated to initial triangularity. Triangularity acquired during the fluid evolution also contributes to the triangular flow.

Chaudhuri, A K

2011-01-01T23:59:59.000Z

189

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

190

Initial Cladding Condition  

SciTech Connect (OSTI)

The purpose of this analysis is to describe the condition of commercial Zircaloy clad fuel as it is received at the Yucca Mountain Project (YMP) site. Most commercial nuclear fuel is encased in Zircaloy cladding. This analysis is developed to describe cladding degradation from the expected failure modes. This includes reactor operation impacts including incipient failures, potential degradation after reactor operation during spent fuel storage in pool and dry storage and impacts due to transportation. Degradation modes include cladding creep, and delayed hydride cracking during dry storage and transportation. Mechanical stresses from fuel handling and transportation vibrations are also included. This Analysis and Model Report (AMR) does not address any potential damage to assemblies that might occur at the YMP surface facilities. Ranges and uncertainties have been defined. This analysis will be the initial boundary condition for the analysis of cladding degradation inside the repository. In accordance with AP-2.13Q, ''Technical Product Development Planning'', a work plan (CRWMS M&O 2000c) was developed, issued, and utilized in the preparation of this document. There are constraints, caveats and limitations to this analysis. This cladding degradation analysis is based on commercial Pressurized Water Reactor (PWR) fuel with Zircaloy cladding but is applicable to Boiling Water Reactor (BWR) fuel. Reactor operating experience for both PWRs and BWRs is used to establish fuel reliability from reactor operation. It is limited to fuel exposed to normal operation and anticipated operational occurrences (i.e. events which are anticipated to occur within a reactor lifetime), and not to fuel that has been exposed to severe accidents. Fuel burnup projections have been limited to the current commercial reactor licensing environment with restrictions on fuel enrichment, oxide coating thickness and rod plenum pressures. The information provided in this analysis will be used in evaluating the post-closure performance of the Monitored Geologic Repository (MGR) in relation to waste form degradation.

E. Siegmann

2000-08-22T23:59:59.000Z

191

Section 13: Flow control 1 Section 13: Flow control  

E-Print Network [OSTI]

Geometries for Energyefficient Flow Around Bodies Abstract 14:30 14:50: Elfriede Friedmann (Universitt

Kohlenbach, Ulrich

192

Binary fish passage models for uniform and nonuniform flows  

SciTech Connect (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

193

On specification of initial conditions in turbulence models  

SciTech Connect (OSTI)

Recent research has shown that initial conditions have a significant influence on the evolution of a flow towards turbulence. This important finding offers a unique opportunity for turbulence control, but also raises the question of how to properly specify initial conditions in turbulence models. We study this problem in the context of the Rayleigh-Taylor instability. The Rayleigh-Taylor instability is an interfacial fluid instability that leads to turbulence and turbulent mixing. It occurs when a light fluid is accelerated in to a heavy fluid because of misalignment between density and pressure gradients. The Rayleigh-Taylor instability plays a key role in a wide variety of natural and man-made flows ranging from supernovae to the implosion phase of Inertial Confinement Fusion (ICF). Our approach consists of providing the turbulence models with a predicted profile of its key variables at the appropriate time in accordance to the initial conditions of the problem.

Rollin, Bertrand [Los Alamos National Laboratory; Andrews, Malcolm J [Los Alamos National Laboratory

2010-12-01T23:59:59.000Z

194

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

195

Monte Carlo Simulations of the Dissolution of Borosilicate Glasses in Near-Equilibrium Conditions  

SciTech Connect (OSTI)

Monte Carlo simulations were performed to investigate the mechanisms of glass dissolution as equilibrium conditions are approached in both static and flow-through conditions. The glasses studied are borosilicate glasses in the compositional range (80 x)% SiO2 (10 + x / 2)% B2O3 (10 + x / 2)% Na2O, where 5 < x < 30%. In static conditions, dissolution/condensation reactions lead to the formation, for all compositions studied, of a blocking layer composed of polymerized Si sites with principally 4 connections to nearest Si sites. This layer forms atop the altered glass layer and shows similar composition and density for all glass compositions considered. In flow-through conditions, three main dissolution regimes are observed: at high flow rates, the dissolving glass exhibits a thin alteration layer and congruent dissolution; at low flow rates, a blocking layer is formed as in static conditions but the simulations show that water can occasionally break through the blocking layer causing the corrosion process to resume; and, at intermediate flow rates, the glasses dissolve incongruently with an increasingly deepening altered layer. The simulation results suggest that, in geological disposal environments, small perturbations or slow flows could be enough to prevent the formation of a permanent blocking layer. Finally, a comparison between predictions of the linear rate law and the Monte Carlo simulation results indicates that, in flow-through conditions, the linear rate law is applicable at high flow rates and deviations from the linear rate law occur under low flow rates (e.g., at near-saturated conditions with respect to amorphous silica). This effect is associated with the complex dynamics of Si dissolution/condensation processes at the glass water interface.

Kerisit, Sebastien [Pacific Northwest National Laboratory (PNNL); Pierce, Eric M [ORNL

2012-01-01T23:59:59.000Z

196

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

197

CX-003354: Categorical Exclusion Determination | Department of...  

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

State Energy Program American Recovery and Reinvestment Act - Heating, Ventilating, and Air Conditioning and Window Replacement in Administration Building CX(s) Applied: B5.1...

198

CX-010139: Categorical Exclusion Determination | Department of...  

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

Determination Permanent Power for MCU Sampling Building Heating, Ventilation and Air Conditioning and Ancillary CX(s) Applied: B2.5 Date: 03072013 Location(s): South...

199

CX-000061: Categorical Exclusion Determination | Department of...  

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

CX-000061: Categorical Exclusion Determination Greenville's Heating, Ventilating, and Air Conditioning and Boiler Retrofit CX(s) Applied: B2.5, B5.1 Date: 11122009...

200

CX-006351: Categorical Exclusion Determination | Department of...  

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

CX-006351: Categorical Exclusion Determination Retrofit Heating, Ventilation and Air Conditioning and Control Systems in Parks and Recreation Facilities CX(s) Applied:...

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

CX-006628: Categorical Exclusion Determination | Department of...  

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

Categorical Exclusion Determination 221-F Canyon Truckwell Heating, Ventilation, and Air Conditioning System CX(s) Applied: B1.5 Date: 08012011 Location(s): Aiken, South...

202

CX-003856: Categorical Exclusion Determination | Department of...  

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

Exclusion Determination Road Prison Geothermal Earth Coupled Heating, Ventilation and Air Conditioning (HVAC) Upgrade CX(s) Applied: B5.1 Date: 09072010 Location(s): Escambia...

203

CX-001671: Categorical Exclusion Determination | Department of...  

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

and Conservation Block Grant (EECBG) Health Department Heating, Ventilating, and Air Conditioning (HVAC) RetrofitUpgrade and Revolving Loan Fund (RLF) (S) CX(s) Applied:...

204

CX-009282: Categorical Exclusion Determination | Department of...  

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

Categorical Exclusion Determination Big 8 - 922, 920, 921 Heating, Ventilation and Air Conditioning Upgrades; 921, 74 Roof Replacement; HPSB Upgrades CX(s) Applied: B2.1,...

205

CX-004909: Categorical Exclusion Determination | Department of...  

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

Categorical Exclusion Determination University of Notre Dame - Compact, Efficient Air Conditioning with Ionic Liquid Based Refrigerant CX(s) Applied: B3.6 Date: 08032010...

206

CX-006625: Categorical Exclusion Determination | Department of...  

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

Categorical Exclusion Determination 221-F Canyon Truckwell Heating, Ventilation, and Air Conditioning System CX(s) Applied: B1.5 Date: 07292011 Location(s): Aiken, South...

207

CX-008732: Categorical Exclusion Determination | Department of...  

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

(INL) Administration Building (IAB) Communication Room Heating, Ventilation, and Air Conditioning (HVAC) Upgrade CX(s) Applied: B1.31 Date: 05212012 Location(s): Idaho...

208

CX-002821: Categorical Exclusion Determination | Department of...  

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

Teutopolis Community Unit School District 50 - Geothermal Heating, Ventilating, and Air Conditioning Project CX(s) Applied: B5.1 Date: 06242010 Location(s): Teutopolis,...

209

CX-000870: Categorical Exclusion Determination | Department of...  

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

Exclusion Determination CX-000870: Categorical Exclusion Determination West Hackberry Air ConditioningHeating Repairs CX(s) Applied: B1.3 Date: 02052010 Location(s): West...

210

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

SciTech Connect (OSTI)

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

211

Evaluation of flow hood measurements for residential register flows  

SciTech Connect (OSTI)

Flow measurement at residential registers using flow hoods is becoming more common. These measurements are used to determine if the HVAC system is providing adequate comfort, appropriate flow over heat exchangers and in estimates of system energy losses. These HVAC system performance metrics are determined by using register measurements to find out if individual rooms are getting the correct airflow, and in estimates of total air handler flow and duct air leakage. The work discussed in this paper shows that commercially available flow hoods are poor at measuring flows in residential systems. There is also evidence in this and other studies that flow hoods can have significant errors even when used on the non-residential systems they were originally developed for. The measurement uncertainties arise from poor calibrations and the sensitivity of exiting flow hoods to non-uniformity of flows entering the device. The errors are usually large--on the order of 20% of measured flow, which is unacceptably high for most applications. Active flow hoods that have flow measurement devices that are insensitive to the entering airflow pattern were found to be clearly superior to commercially available flow hoods. In addition, it is clear that current calibration procedures for flow hoods may not take into account any field application problems and a new flow hood measurement standard should be developed to address this issue.

Walker, I.S.; Wray, C.P.; Dickerhoff, D.J.; Sherman, M.H.

2001-09-01T23:59:59.000Z

212

Piezoelectric axial flow microvalve  

SciTech Connect (OSTI)

This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

2007-01-09T23:59:59.000Z

213

Importance of Design Conditions for Sizing Air-Conditioning Plant  

E-Print Network [OSTI]

. 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...

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

2000-01-01T23:59:59.000Z

214

Ground validation of an intermittent flow visualization system  

E-Print Network [OSTI]

the smoke from one exit port to another, and one in which the valve is used to completely block the flow of smoke. In addition, a model of the system has been developed and validated. It can be used to predict the pressure build-up in the system when... Flow Visualization System. . . . . DESIGN DEVELOPMENT System Requirements . Preliminary Design . Detailed Design. . Instrumentation . Data Collection . . . Signal Conditioning Cartridge Ignition. . . . . . . . Valve Control. PRESSURE...

Myatt, James Harold

1991-01-01T23:59:59.000Z

215

SATURATED-SUBCOOLED STRATIFIED FLOW IN HORIZONTAL PIPES  

SciTech Connect (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

216

Semiclassical energy conditions and wormholes  

E-Print Network [OSTI]

We consider the nonlinear energy conditions and their quantum extensions. These new energy conditions behave much better than the usual pointwise energy conditions in the presence of semiclassical quantum effects. Analogous quantum extensions for the linear energy conditions are not always satisfied as one enters the quantum realm, but they can be used to constrain the violation of the classical conditions. Thus, the existence of wormholes supported by a fluid which violates the null energy condition in a controlled way is of particular interest.

Prado Martin-Moruno

2014-11-17T23:59:59.000Z

217

Electrocapturing flow cell  

DOE Patents [OSTI]

A flow cell for electrophoretically-assisted capturing analytes from a flow. The flow cell includes a specimen chamber, a first membrane, a second membrane, a first electrode chamber, and a second electrode chamber. The specimen chamber may have a sample inlet and a sample outlet. A first portion of the first membrane may be coupled to a first portion of the specimen chamber. A first portion of the second membrane may be coupled to a second portion of the specimen chamber. The first electrode chamber may be configured to accept a charge. A portion of the first electrode chamber may be coupled to a second portion of the first membrane. A second electrode chamber may be configured to accept an opposite charge. A portion of the second electrode chamber may be coupled to a second portion of the second membrane.

Morozov, Victor (Manassas, VA)

2011-04-05T23:59:59.000Z

218

Workshop on hypersonic flow  

SciTech Connect (OSTI)

An overview is given of research activity on the application of computational fluid dynamics (CDF) for hypersonic propulsion systems. After the initial consideration of the highly integrated nature of air-breathing hypersonic engines and airframe, attention is directed toward computations carried out for the components of the engine. A generic inlet configuration is considered in order to demonstrate the highly three dimensional viscous flow behavior occurring within rectangular inlets. Reacting flow computations for simple jet injection as well as for more complex combustion chambers are then discussed in order to show the capability of viscous finite rate chemical reaction computer simulations. Finally, the nozzle flow fields are demonstrated, showing the existence of complex shear layers and shock structure in the exhaust plume. The general issues associated with code validation as well as the specific issue associated with the use of CFD for design are discussed. A prognosis for the success of CFD in the design of future propulsion systems is offered.

Povinelli, L.A.

1990-01-01T23:59:59.000Z

219

Multiphase cooling flows  

E-Print Network [OSTI]

I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide strong constraints on the mass distribution within the cooling radius.

Peter A. Thomas

1996-08-20T23:59:59.000Z

220

Friction and the oscillatory motion of granular flows  

E-Print Network [OSTI]

This contribution reports on numerical simulations of 2D granular flows on erodible beds. The broad aim is to investigate whether simple flows of model granular matter exhibits spontaneous oscillatory motion in generic flow conditions, and in this case, whether the frictional properties of the contacts between grains may affect the existence or the characteristics of this oscillatory motion. The analysis of different series of simulations show that the flow develops an oscillatory motion with a well-defined frequency which increases like the inverse of the velocity's square root. We show that the oscillation is essentially a surface phenomena. The amplitude of the oscillation is higher for lower volume fractions, and can thus be related to the flow velocity and grains friction properties. The study of the influence of the periodic geometry of the simulation cell shows no significant effect. These results are discussed in relation to sonic sands.

Lydie Staron

2012-11-26T23:59:59.000Z

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

Topologically Massive Gravity and Ricci-Cotton Flow  

E-Print Network [OSTI]

We consider Topologically Massive Gravity (TMG), which is three dimensional general relativity with a cosmological constant and a gravitational Chern-Simons term. When the cosmological constant is negative the theory has two potential vacuum solutions: Anti-de Sitter space and Warped Anti-de Sitter space. The theory also contains a massive graviton state which renders these solutions unstable for certain values of the parameters and boundary conditions. We study the decay of these solutions due to the condensation of the massive graviton mode using Ricci-Cotton flow, which is the appropriate generalization of Ricci flow to TMG. When the Chern-Simons coupling is small the AdS solution flows to warped AdS by the condensation of the massive graviton mode. When the coupling is large the situation is reversed, and warped AdS flows to AdS. Minisuperspace models are constructed where these flows are studied explicitly.

Nima Lashkari; Alexander Maloney

2010-09-14T23:59:59.000Z

222

Topologically Massive Gravity and Ricci-Cotton Flow  

E-Print Network [OSTI]

We consider Topologically Massive Gravity (TMG), which is three dimensional general relativity with a cosmological constant and a gravitational Chern-Simons term. When the cosmological constant is negative the theory has two potential vacuum solutions: Anti-de Sitter space and Warped Anti-de Sitter space. The theory also contains a massive graviton state which renders these solutions unstable for certain values of the parameters and boundary conditions. We study the decay of these solutions due to the condensation of the massive graviton mode using Ricci-Cotton flow, which is the appropriate generalization of Ricci flow to TMG. When the Chern-Simons coupling is small the AdS solution flows to warped AdS by the condensation of the massive graviton mode. When the coupling is large the situation is reversed, and warped AdS flows to AdS. Minisuperspace models are constructed where these flows are studied explicitly.

Lashkari, Nima

2010-01-01T23:59:59.000Z

223

Condition Monitoring System for Reinforced  

E-Print Network [OSTI]

containing dissolved ionic species such as chlorides. Since concrete is a porous material, with timeCondition Monitoring System for Reinforced Concrete Structures PROBLEM THIS TECHNOLOGY SOLVES: Patent pending concrete condition monitoring system providing `real-time' information on temperature

Painter, Kevin

224

Fission product release from irradiated LWR fuel under accident conditions  

SciTech Connect (OSTI)

Fission product release from irradiated LWR fuel is being studied by heating fuel rod segments in flowing steam and an inert carrier gas to simulate accident conditions. Fuels with a range of irradiation histories are being subjected to several steam flow rates over a wide range of temperatures. Fission product release during each test is measured by gamma spectroscopy and by detailed examination of the collection apparatus after the test has been completed. These release results are complemented by a detailed posttest examination of samples of the fuel rod segment. Results of release measurements and fuel rod characterizations for tests at 1400 through 2000/sup 0/C are presented in this paper.

Strain, R.V.; Sanecki, J.E.; Osborne, M.F.

1984-01-01T23:59:59.000Z

225

The kinematics of debris flow transport down a canyon  

E-Print Network [OSTI]

in the spring during snowmelt. The elevated ground-water conditions at East Layton are shown by the muddy runoff which began several days before the May 14 debris flow, and the clear water which ran after the debris flow and continued flowing until the middle...), and plasticity index is 5 (Standard Deviation =1)(Figure 6, Table 1). The Atterberg Limits were determined on material passing the ?40 sieve (about 20'/o of the total material). Since there is a great amount of coarse material, much of it relatively "inert...

Santi, Paul M.

1988-01-01T23:59:59.000Z

226

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

227

Twilight for the energy conditions?  

E-Print Network [OSTI]

Twilight for the energy conditions? Matt Visser Physics Department Washington University Saint;#16;s (CAB, Madrid) Marcel Grossmann 9 Roma July 2000 #12; Abstract: The energy conditions of general relativity per- mit one to deduce very powerful and general theorems. However, the energy conditions are now

Visser, Matt

228

ENERGY FLOWS CLIMATE CHANGE  

E-Print Network [OSTI]

ENERGY FLOWS FORCINGS CLIMATE CHANGE A REALLY TOUGH PROBLEM Stephen E. Schwartz, BNL, 7-20-11 www average temperature 15°C or 59°F #12;ATMOSPHERIC RADIATION Power per area Energy per time per area Unit" temperature to radiative flux. #12;GLOBAL ENERGY BALANCE Global and annual average energy fluxes in watts per

Schwartz, Stephen E.

229

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

230

AGN and Cooling Flows  

E-Print Network [OSTI]

For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. A small number of enthusiasts have argued for a radically different interpretation of the data, but had little impact on prevailing opinion because the unsteady heating picture that they advocate is extremely hard to work out in detail. Here I explain why it is difficult to extract robust observational predictions from the heating picture. Major problems include the variability of the sources, the different ways in which a bi-polar flow can impact on X-ray emission, the weakness of synchrotron emission from sub-relativistic flows, and the sensitivity of synchrotron emission to a magnetic field that is probably highly localized.

James Binney

2001-03-23T23:59:59.000Z

231

Prediction of annular liquid-gas flow with entrainment: cocurrent vertical pipe flow with no gravity  

SciTech Connect (OSTI)

A fully developed and adiabatic two-phase annular model with liquid entrainment is derived for flow in a pipe with negligible gravity effects. The model subdivides the flow cross section into three regions: a liquid film, a gas core of constant density, and a transition wavy layer between them. The combination of a constant velocity and a density varying exponentially with distance from the wall is employed in the transition layer. Extensive comparisons of the model are made with air-water and steam-water test data, and the results generally are satisfactory over a wide range of conditions and for all the important characteristics of this flow pattern. A simplified model is developed to permit rapid and approximate calculations.

Levy, S.; Healzer, J.M.

1980-05-01T23:59:59.000Z

232

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

233

Colloidal particle deposition in turbulent flow  

SciTech Connect (OSTI)

A theoretical analysis is presented which describes the initial deposition of monodispersed spherical colloidal particles from a steady fully developed turbulent flow onto conduit walls. When the net particle-conduit electrical interaction potential is attractive, particle deposition is shown to be often governed by turbulent hydrodynamics. When the net particle-conduit electrical interaction potential possess a repulsive maximum, particle deposition to first order is uniform and depends solely on electrical interaction effects. The developed theoretical model specialized to orifice deposition with the use of Harwell Flow3D turbulence modelling software qualitatively described the deposition of 0.5 {mu}m silica particles onto glass orifices from an aqueous suspension. The effect of the electrical double layer on the rate of colloidal particle deposition in laminar flow has been described by Spielman and Friedlander (1), Dahneke (2), Bowen et al. (3) and Bowen and Epstein (4). This article describes the extension of their work to colloidal particle deposition under steady fully developed turbulent flow conditions. This article also reports the results of orifice particle deposition experiments which were conducted to qualitatively investigate the developed theoretical model.

Morton, D.S.

1994-05-01T23:59:59.000Z

234

Theoretical and experimental studies of churn flow in vertical tubes. Final technical report  

SciTech Connect (OSTI)

The pattern known as churn flow is a highly unsteady pattern with stochastic features and is extremely complex. However, calculations show that for many geothermal wells the condition of churn flow consists over much of the length of the two phase zone. Furthermore, it frequently exists at the surface so that design of separation equipment and surface piping depends on the accurate modelling of this type of flow. It has been the long term purpose of this project to develop physically based models for churn flow which can be used as a basis for predicting holdup, frictional loss and heat transfer rates for this flow pattern in geothermal systems. To achieve this end, it was necessary to develop new methods for measuring the time dependent characteristics of the flow and thus be able to uncover the basic physics of the flow. Models can then be developed based on this understanding which characterizes the flow and equations for holdup, friction and heat transfer evolved.

Not Available

1986-01-27T23:59:59.000Z

235

Analysis of flow patterns and flow mechanisms in soils  

E-Print Network [OSTI]

Analysis of flow patterns and flow mechanisms in soils Dissertation Co-directed by the University of paths, varying flow mechanism or changing soil physical properties (stratification). Thus, in stratified-28Jan2010 #12;This doctoral thesis was prepared at the Department of Soil Physics, University

Paris-Sud XI, Université de

236

Data-flow graphs as a model of parallel complexity  

SciTech Connect (OSTI)

A new model of parallel computation based on data-flow graphs is introduced, which is specifically oriented towards complexity theory. Data-flow graphs are capable of illustrating properties of synchronous, asynchronous, and nondeterministic computations. Sufficient conditions are derived for asynchronous data-flow graphs to be determinate, i.e., all possible computations are finite and yield the same result. For determinate graphs, it is shown that the synchronous computation is as fast as any asynchronous computation. An algorithm is presented that transforms a nondeterminate data-flow graphs into a synchronous determinate one. The basic data-flow graph idea is extended into a model with greater potential parallelism, called the Uniform Data Flow Graph Family (UDFGF) Model. It is proved that time and space for the UDFGF model are polynomially related to reversal and space for the Turing Machine model, in both the deterministic and nondeterministic cases. In addition to forming an abstract computational model, data-flow graphs are parallel programs for real multiprocessors. Given a data flow graph program and a multiprocessor, each node of the graph must be assigned to one of the processors. It is proved that this problem is intractable, and a practical algorithm to find approximate solutions for it is presented.

Campbell, M.L.

1987-01-01T23:59:59.000Z

237

Flow and evaporation in single micrometer and nanometer scale pipes  

SciTech Connect (OSTI)

We report measurements of pressure driven flow of fluids entering vacuum through a single pipe of micrometer or nanometer scale diameter. Nanopores were fabricated by etching a single ion track in polymer or mica foils. A calibrated mass spectrometer was used to measure the flow rates of nitrogen and helium through pipes with diameter ranging from 10??m to 31?nm. The flow of gaseous and liquid nitrogen was studied near 77?K, while the flow of helium was studied from the lambda point (2.18?K) to above the critical point (5.2?K). Flow rates were controlled by changing the pressure drop across the pipe in the range 031 atm. When the pressure in the pipe reached the saturated vapor pressure, an abrupt flow transition was observed. A simple viscous flow model is used to determine the position of the liquid/vapor interface in the pipe. The observed mass flow rates are consistent with no slip boundary conditions.

Velasco, A. E.; Yang, C.; Siwy, Z. S.; Taborek, P. [Department of Physics and Astronomy, University of California, Irvine 92697 (United States); Toimil-Molares, M. E. [Department of Materials Science, GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany)

2014-07-21T23:59:59.000Z

238

X-ray photon correlation spectroscopy under flow  

E-Print Network [OSTI]

X-ray photon correlation spectroscopy was used to probe the diffusive dynamics of colloidal particles in a shear flow. Combining X-ray techniques with microfluidics is an experimental strategy that reduces the risk of x-ray induced beam damage and also allows time-resolved studies of processes taking place in flowcells. The experimental results and theoretical predictions presented here, show that in the low shear limit, for a ``transverse flow'' scattering geometry (scattering wave vector q perpendicular to the direction of flow) the measured relaxation times are independent of the flow rate and determined only by the diffusive motion of the particles. This is not generally valid and in particular, for a ``longitudinal flow'' (q || flow) scattering geometry, the relaxation times are strongly affected by the flow-induced motion of the particles. Our results show that the Brownian diffusion of colloidal particles can be measured in a flowing sample and that, up to flux limitations, the experimental conditions under which this is possible are easier to achieve at higher values of q.

Andrei Fluerasu; Abdellatif Moussaid; Henri Gleyzolle; Peter Falus; Anders Madsen

2008-03-10T23:59:59.000Z

239

Monte Carlo Simulations of the Dissolution of Borosilicate Glasses in Near-Equilibrium Conditions  

SciTech Connect (OSTI)

Monte Carlo simulations were performed to investigate the mechanisms of glass dissolution as equilibrium conditions are approached in both static and flow-through conditions. The glasses studied are borosilicate glasses in the compositional range (80-x)% SiO2 (10+x/2)% B2O3 (10+x/2)% Na2O, where 5 < x < 30%. In static conditions, dissolution/condensation reactions lead to the formation, for all compositions studied, of a blocking layer composed of polymerized Si sites with principally 4 connections to nearest Si sites. This layer forms atop the altered glass layer and shows similar composition and density for all glass compositions considered. In flow-through conditions, three main dissolution regimes are observed: at high flow rates, the dissolving glass exhibits a thin alteration layer and congruent dissolution; at low flow rates, a blocking layer is formed as in static conditions but the simulations show that water can occasionally break through the blocking layer causing the corrosion process to resume; and, at intermediate flow rates, the glasses dissolve incongruently with an increasingly deepening altered layer. The simulation results suggest that, in geological disposal environments, small perturbations or slow flows could be enough to prevent the formation of a permanent blocking layer.

Kerisit, Sebastien N.; Pierce, Eric M.

2012-05-15T23:59:59.000Z

240

Brine flow in heated geologic salt.  

SciTech Connect (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

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

A void distribution model-flashing flow  

SciTech Connect (OSTI)

A new model for flashing flow based on wall nucleations is proposed here and the model predictions are compared with some experimental data. In order to calculate the bubble number density, the bubble number transport equation with a distributed source from the wall nucleation sites was used. Thus it was possible to avoid the usual assumption of a constant bubble number density. Comparisons of the model with the data shows that the model based on the nucleation site density correlation appears to be acceptable to describe the vapor generation in the flashing flow. For the limited data examined, the comparisons show rather satisfactory agreement without using a floating parameter to adjust the model. This result indicated that, at least for the experimental conditions considered here, the mechanistic predictions of the flashing phenomenon is possible on the present wall nucleation based model.

Riznic, J.; Ishii, M.; Afgan, N.

1987-01-01T23:59:59.000Z

242

Radial flow pulse jet mixer  

DOE Patents [OSTI]

The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

VanOsdol, John G.

2013-06-25T23:59:59.000Z

243

The Big Flow  

E-Print Network [OSTI]

The late infall of cold dark matter onto an isolated galaxy, such as our own, produces streams and caustics in its halo. The outer caustics are topological spheres whereas the inner caustics are rings. The self-similar model of galactic halo formation predicts that the caustic ring radii $a_n$ follow the approximate law $a_n \\sim 1/n$. In a study of 32 extended and well-measured external galactic rotation curves evidence was found for this law. In the case of the Milky Way, the locations of eight sharp rises in the rotation curve fit the prediction of the self-similar model at the 3% level. Moreover, a triangular feature in the IRAS map of the galactic plane is consistent with the imprint of a ring caustic upon the baryonic matter. These observations imply that the dark matter in our neighborhood is dominated by a single flow. Estimates of that flow's density and velocity vector are given.

P. Sikivie

2001-12-04T23:59:59.000Z

244

Structural power flow measurement  

SciTech Connect (OSTI)

Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

Falter, K.J.; Keltie, R.F.

1988-12-01T23:59:59.000Z

245

Neutrino Factory Mercury Flow Loop  

E-Print Network [OSTI]

Neutrino Factory Mercury Flow Loop V. GravesV. Graves C. Caldwell IDS-NF Videoconference March 9, 2010 #12;Flow Loop Review · 1 cm dia nozzle, 20 m/s jet requires 1.57 liter/sec mercury flow (94 2 liter/min 24 9 gpm)mercury flow (94.2 liter/min, 24.9 gpm). · MERIT experiment showed that a pump

McDonald, Kirk

246

Detection and effects of pump low-flow operation  

SciTech Connect (OSTI)

Operating experience and previous studies have shown that a significant cause of pump problems and failures can result from low- flow operation. Operation at low-flow rates can create unstable flows within the pump impeller and casing. This condition can result in an increased radial and axial thrust on the rotor, which in turn causes higher shaft stresses, increased shaft deflection, and potential bearing and mechanical seal problems. Two of the more serious results of low-flow pump operation are cavitation and recirculation. Cavitation is the formation and subsequent collapse of vapor bubbles in any flow that is at an ambient pressure less than the vapor pressure of the liquid medium. It is the collapse of these vapor bubbles against the metal surfaces of the impeller or casing that causes surface pitting, erosion, and deterioration. Pump recirculation more damaging than cavitation. If located at the impeller eye, recirculation damages the inlet areas of the casing. At the impeller tips, recirculation alters the outside diameter of the impeller. If recirculation occurs around impeller shrouds, it damages thrust bearings. Recirculation also erodes impellers, diffusers, and volutes and causes failure of mechanical seals and bearings. This paper reports on a utility pump failure caused by low-flow induced phenomena. ORNL is investigating the results of low-flow pump operations by evaluating the types of measurements and diagnostic techniques that are currently used by licensees to detect pump degradation. A new, enhanced application of motor current and power data analysis has been developed that uses a signal comparison methodology to produce an instability ratio indicative of normal or unstable flow conditions. Examples of this type of low-flow detection technique are presented in this paper along with a brief discussion of the various types of technologies currently being used by licensees to evaluate pump operation and determine possible degradation.

Casada, D.A.; Greene, R.H.

1993-12-01T23:59:59.000Z

247

Orifice flow measurement uncertainty  

SciTech Connect (OSTI)

A computer program is now available from Union Carbide that evaluates the total flow uncertainty of orifice flowmeter systems. Tolerance values for every component in the system and the sensitivity of the measured flowrate to each component can be established using historical data and published hardware specifications. Knowing the tolerance and sensitivity values, a total measurement uncertainty can be estimated with a 95% confidence level. This computer program provides a powerful design tool to ensure correct component matching and total metering system optimization.

Samples, C.R.

1984-04-01T23:59:59.000Z

248

Variation of hydraulic conductance of some adult conifers under natural conditions  

E-Print Network [OSTI]

Variation of hydraulic conductance of some adult conifers under natural conditions A. Granier, N; in the liquid phase, the flow depends upon water potential gradients and hydraulic conductance from the soil present here some evaluations of hydraulic conductance of trees growing under natural conditions. Data

Paris-Sud XI, Universit de

249

Gas-surface interaction and boundary conditions for the Boltzmann equation  

E-Print Network [OSTI]

Gas-surface interaction and boundary conditions for the Boltzmann equation St´ephane Brull, Pierre Equation. The interaction between the wall atoms and the gas molecules within a thin surface layer of the gas in the bulk flow. Boundary conditions are formally derived from this model by using classical

Mieussens, Luc

250

THE ONE-DIMENSIONAL SHALLOW WATER EQUATIONS WITH TRANSPARENT BOUNDARY CONDITIONS  

E-Print Network [OSTI]

THE ONE-DIMENSIONAL SHALLOW WATER EQUATIONS WITH TRANSPARENT BOUNDARY CONDITIONS MADALINA PETCU the question of the local in time well-posedness of the one-dimensional Shallow Water on an interval, these equations being supplemented with suitable boundary conditions. The flows considered are subcritical

Temam, Roger

251

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

252

Extremality conditions for generalized channels  

E-Print Network [OSTI]

A generalized channel is a completely positive map that preserves trace on a given subspace. We find conditions under which a generalized channel with respect to a positively generated subspace J is an extreme point in the set of all such generalized channels. As a special case, this yields extremality conditions for quantum protocols. In particular, we obtain new extremality conditions for quantum 1-testers with 2 outcomes, which correspond to yes/no measurements on the set of quantum channels.

Anna Jencova

2012-04-12T23:59:59.000Z

253

Belief Revision through Forgetting Conditionals in Conditional Probabilistic Logic Programs  

E-Print Network [OSTI]

of probabilistic belief revising, most research focuses on revising a single probabilistic distribution [5, 1, 8, 4Belief Revision through Forgetting Conditionals in Conditional Probabilistic Logic Programs Anbu Yue 1 and Weiru Liu 1 Abstract. In this paper, we present a revision strategy of revis- ing

Liu, Weiru

254

Numerical Investigations of Magnetohydrodynamic Hypersonic Flows.  

E-Print Network [OSTI]

??Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow are presented for both laminar and turbulent flow over a cylinder and flow entering a scramjet inlet. ANSYS (more)

Guarendi, Andrew N

2013-01-01T23:59:59.000Z

255

Radial Inflow Gas Turbine Flow Path Design  

E-Print Network [OSTI]

Abstract:- A new method for radial inflow gas turbine flow paths design based on a unique integrated conceptual design environment AxSTREAM is presented in this paper. This integrated environment is a seamless and swift processing scheme that incorporates stages aerodynamic analysis and preliminary design/sizing based on the one dimensional method. The environment makes possible to find number of different designs with inverse task solver, basing on initially specified boundary conditions, closing conditions and design variables. Design space explorer provides easy and visual comparison for range of obtained design in customizable coordinate axes. Solution filtering on different parameters, such as meridional and axial dimensions, maximal blades weight, saving the time to choose from thousands obtained solutions the only one right design. Flexibility of presented approach allows to built-up complete gas turbine flow path from consequence of individual elements: stationary and rotating elements, ducts, heat exchangers, and analyze it in common environment. Complete control of all aspects of aerodynamic flow path quality, structural reliability, and integral performances on design and offdesign conditions is performing throughout all design process. This gives full interaction between user and system for immediate correction and enhancement of current design data using various optimization capabilities to feel the impact of changes on each design step. Integrated system AxSTREAM significantly shortening the design cycle time from initial machine concept to finalized design with all offdesign performances details. The design process is demonstrated for a 25kW radial inflow gas turbine. Keywords:- Radial Inflow Turbine, Performance Maps, AxSTREAM I.

Samip Shah; Gaurang Chaudhri; Digvijay Kulshreshtha; S. A. Channiwalla

256

A study of grout flow pattern analysis  

SciTech Connect (OSTI)

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

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

2013-01-10T23:59:59.000Z

257

A Holistic Framework for Environmental Flows Determination in Hydropower Contexts  

SciTech Connect (OSTI)

Among the ecological science community, the consensus view is that the natural flow regime sustains the ecological integrity of river systems. This prevailing viewpoint by many environmental stakeholders has progressively led to increased pressure on hydropower dam owners to change plant operations to affect downstream river flows with the intention of providing better conditions for aquatic biological communities. Identifying the neccessary magnitude, frequency, duration, timing, or rate of change of stream flows to meet ecological needs in a hydropower context is challenging because the ecological responses to changes in flows may not be fully known, there are usually a multitude of competing users of flow, and implementing environmental flows usually comes at a price to energy production. Realistically, hydropower managers must develop a reduced set of goals that provide the most benefit to the identified ecological needs. As a part of the Department of Energy (DOE) Water Power Program, the Instream Flow Project (IFP) was carried out by Oak Ridge National Laboratory (ORNL), Pacific Northwest National Laboratory (PNNL), and Argon National Laboratory (ANL) as an attempt to develop tools aimed at defining environmental flow needs for hydropower operations. The application of these tools ranges from national to site-specific scales; thus, the utility of each tool will depend on various phases of the environmental flow process. Given the complexity and sheer volume of applications used to determine environmentally acceptable flows for hydropower, a framework is needed to organize efforts into a staged process dependent upon spatial, temporal, and functional attributes. By far, the predominant domain for determining environmental flows related to hydropower is within the Federal Energy Regulatory Commission (FERC) relicensing process. This process can take multiple years and can be very expensive depending on the scale of each hydropower project. The utility of such a framework is that it can expedite the environmental flow process by 1) organizing data and applications to identify predictable relationships between flows and ecology, and 2) suggesting when and where tools should be used in the environmental flow process. In addition to regulatory procedures, a framework should also provide the coordination for a comprehensive research agenda to guide the science of environmental flows. This research program has further reaching benefits than just environmental flow determination by providing modeling applications, data, and geospatial layers to inform potential hydropower development. We address several objectives within this document that highlight the limitations of existing environmental flow paradigms and their applications to hydropower while presenting a new framework catered towards hydropower needs. Herein, we address the following objectives: 1) Provide a brief overview of the Natural Flow Regime paradigm and existing environmental flow frameworks that have been used to determine ecologically sensitive stream flows for hydropower operations. 2) Describe a new conceptual framework to aid in determining flows needed to meet ecological objectives with regard to hydropower operations. The framework is centralized around determining predictable relationships between flow and ecological responses. 3) Provide evidence of how efforts from ORNL, PNNL, and ANL have filled some of the gaps in this broader framework, and suggest how the framework can be used to set the stage for a research agenda for environmental flow.

McManamay, Ryan A [ORNL; Bevelhimer, Mark S [ORNL

2013-05-01T23:59:59.000Z

258

Plastic flow in solids with interfaces  

E-Print Network [OSTI]

A non-equilibrium theory of isothermal and diffusionless evolution of incoherent interfaces within a plastically deforming solid is developed. The irreversible dynamics of the interface are driven by its normal motion, incoherency (slip and misorientation), and an intrinsic plastic flow; and purely by plastic deformation in the bulk away from the interface. Using the continuum theory for defect distribution (in bulk and over the interface) we formulate a general kinematical framework, derive relevant balance laws and jump conditions, and prescribe a thermodynamically consistent constitutive/kinetic structure for interface evolution.

Anurag Gupta; David Steigmann

2011-11-25T23:59:59.000Z

259

Collective flow measured with the Plastic Ball  

SciTech Connect (OSTI)

The experimental results from the Plastic Ball detector have contributed vastly to the understanding of the reaction mechanism of nuclear collisions at several hundred MeV per nucleon. The discovery of the collective flow phenomena (bounce-off of spectator fragments, side-splash in the reaction plane, and squeeze-out out of the reaction plane), as they were predicted by hydrodynamical models, has led to the experimental observation of compressed nuclear matter, which is a necessary condition before one can study the equation of state in detail and search for phase transitions at higher energies. 39 refs., 9 figs., 1 tab.

Ritter, H.G.; Gutbrod, H.H.; Kampert, K.H.; Kolb, B.; Poskanzer, A.M.; Schicker, R.; Schmidt, H.R.; Siemiarczuk, T.

1989-08-01T23:59:59.000Z

260

Thermal Energy Measurement with Tangential Paddlewheel Flow Meters: Summary of Experimental Results and in-situ Diagnostics  

E-Print Network [OSTI]

paddlewheel flow meters, and several new methods for in-situ diagnostic measures for ascertaining whether or not a flow meter is experiencing fluctuating flow conditions or if a flow meter is suffering a degraded signal due to shaft wear. INTRODUCTION Flow... section where it passes across the candidate sensor that is placed in the inter-changeable test section, through the orifice plate and finally into the is combined with Btu meter the threshold can be much higher than the published threshold of the flow...

Haberl, J. S.; Watt, J. B.

1994-01-01T23:59:59.000Z

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

Speed-up of combustion fronts in shear flows  

E-Print Network [OSTI]

This paper is concerned with the analysis of speed-up of reaction-diffusion-advection traveling fronts in infinite cylinders with periodic boundary conditions. The advection is a shear flow with a large amplitude and the reaction is nonnegative, with either positive or zero ignition temperature. The unique or minimal speeds of the traveling fronts are proved to be asymptotically linear in the flow amplitude as the latter goes to infinity, solving an open problem from \\cite{b}. The asymptotic growth rate is characterized explicitly as the unique or minimal speed of traveling fronts for a limiting degenerate problem, and the convergence of the regular traveling fronts to the degenerate ones is proved for positive ignition temperatures under an additional H{\\"{o}}rmander-type condition on the flow.

Hamel, Francois

2011-01-01T23:59:59.000Z

262

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

263

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.

Weimer, Robert F. (Allentown, PA)

1987-01-01T23:59:59.000Z

264

Analysis of Transient Processes in a Radiophysical Flow System  

E-Print Network [OSTI]

Transient processes in a third-order radiophysical flow system are studied and a map of the transient process duration versus initial conditions is constructed and analyzed. The results are compared to the arrangement of submanifolds of the stable and unstable cycles in the Poincare section of the system studied.

E. N. Egorov; A. A. Koronovskii; A. E. Hramov

2006-01-31T23:59:59.000Z

265

RATIONALE FOR MEASURING DUCT LEAKAGE FLOWS IN LARGE COMMERCIAL BUILDINGS  

E-Print Network [OSTI]

. Some duct sections operate at high static pressures (e.g., 100 to 2,500 Pa), but other sections leakage flows is to assume that an average duct static pressure applies to every leak. A third important2 ), central HVAC systems continuously supply heated or cooled air to conditioned spaces through

Diamond, Richard

266

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.

267

ISFV14 -14th International Symposium on Flow Visualization  

E-Print Network [OSTI]

FLOWS: HVAC-BOS Michael J. Hargather and Gary S. Settles Gas Dynamics Laboratory, Mechanical & Nuclear airflow patterns in the heating, ventilation, and air-conditioning (HVAC) field. We propose background-dimensional. Finally, BOS lends itself well to certain HVAC chores such as the diagnosis of commercial kitchen

Settles, Gary S.

268

COMPARISON OF VARIOUS FORMULATIONS OF THREEPHASE FLOW IN POROUS MEDIA  

E-Print Network [OSTI]

permeability and capillary pressure curves satisfy a so­called total differential condition, the pseudo­global, oil, and gas) flow in porous media, including phase, global, and pseudo­global pressure and numerically presented for the first time. It is shown that the global pressure­saturation formulation

269

Two-Phase Flow of HCFC-22 and HFC-134a through Short Tube Orifices  

E-Print Network [OSTI]

and pressure conditions were those typically found in air-conditioner and heat pump applications. Effects of each operating parameters and short tube geometry on the flow rate were discussed and included in the modeling. Both an analytical and semi...

Yongchan, K.

2008-01-23T23:59:59.000Z

270

Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications...  

Open Energy Info (EERE)

caldera was cooled to normal thermal conditions by vigorous hydrothermal activity in the past, and that a present-day hot water flow system is responsible for local hot anomalies,...

271

Green Water Flow Kinematics and Impact Pressure on a Three Dimensional Model Structure  

E-Print Network [OSTI]

Flow kinematics of green water due to plunging breaking waves interacting with a simplified, three-dimensional model structure was investigated in laboratory. Two breaking wave conditions were tested: one with waves impinging and breaking...

Ariyarathne, Hanchapola Appuhamilage Kusalika Suranjani

2011-10-21T23:59:59.000Z

272

Computer discovery of the mechanism of flow-induced sloshing  

SciTech Connect (OSTI)

A novel numerical method called physical component boundary fitted coordinate method (PC-BFC method) was applied to a recently discovered flow instability called in-vessel flow-induced sloshing. Then, with a spirit of computer discovery, a general procedure was developed and applied for solving the mechanism and condition for the occurrence of this sloshing. As a result, a nonlinear wave that never reflects at the wall was singled out numerically and was demonstrated to be the cause of the sloshing. In-vessel circulated free surface flow characterizes the flow of coolant in liquid metal cooled fast breeder reactor (LMFBR) during power generation; finding of the criteria for the occurrence of this sloshing has crucial importance for the safety operation of LMFBR.

Takizawa, Akihiko [Tokyo Electric Power Co., Yokohama (Japan). Nuclear Power R and D Center; Kondo, Shunsuke [Univ. of Tokyo (Japan). Dept. of Quantum Engineering and Systems Science

1995-11-01T23:59:59.000Z

273

Report on Hydrologic Flow in Low-Permeability Media  

SciTech Connect (OSTI)

We demonstrate that under normal conditions (under which there are no intersections between tunnels/drifts and conductive geological structures, such as faults), the water flow velocity in the damage zone, as a result of non-Darcian flow behavior, is extremely small such that solute transport is dominated by diffusion, rather than advection. We show that unless non-Darcian flow behavior is considered, significant errors can occur in the measured relative-permeability values. We propose a hypothesis to consider the temperature impact based on limited test results from the petroleum literature. To consider the bedding effects, we present an empirical relationship between water flux and hydraulic gradient for non-Darcian water flow in anisotropic cases.

Liu, Hui-Hai; Birkholzer, Jens

2013-11-13T23:59:59.000Z

274

The effect of anchoring on nematic flow in channels  

E-Print Network [OSTI]

Understanding the flow of liquid crystals in microfluidic environments plays an important role in many fields, including device design and microbiology. We perform hybrid lattice-Boltzmann simulations of a nematic liquid crystal flowing under an applied pressure gradient in two-dimensional channels with various anchoring boundary conditions at the substrate walls. We investigate the relation between flow rate and pressure gradient and the corresponding profile of the nematic director, and find significant departures from the linear Poiseuille relation. We also identify a morphological transition in the director profile and explain this in terms of an instability in the dynamical equations. We examine the qualitative and quantitative effects of changing the type and strength of the anchoring. Understanding such effects may provide a useful means of quantifying the anchoring of a substrate by measuring its flow properties.

V. M. O. Batista; M. L. Blow; M. M. Telo da Gama

2014-09-18T23:59:59.000Z

275

Nonstationary flow for the Navier-Stokes equations in a cylindrical pipe  

E-Print Network [OSTI]

In cylindrical domain, we consider the nonstationary flow with prescribed inflow and outflow, modelled with Navier-Stokes equations under the slip boundary conditions. Using smallness of some derivatives of inflow function, external force and initial velocity of the flow, but with no smallness restrictions on the inflow, initial velocity neither force, we prove existence of solutions in $W^{2,1}_2.$

Joanna Renclawowicz; Wojciech M. Zajaczkowski

2011-03-21T23:59:59.000Z

276

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS  

E-Print Network [OSTI]

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS Keh-Ming Shyue Department tracking approach for the numerical simulation of one-dimensional elastic- plastic flow in solids, and the von Mises condition for the elastic-plastic phase change. To characterize the cavitation

Shyue, Keh-Ming

277

Energy-Efficient Variable-Flow Liquid Cooling in 3D Stacked Architectures  

E-Print Network [OSTI]

1 Energy-Efficient Variable-Flow Liquid Cooling in 3D Stacked Architectures Ayse K. Coskun , David not fully utilized. Thus, it is not energy-efficient to adjust the coolant flow rate based on the worst-case conditions, as this would cause an excess in pump power. For energy-efficient cooling, we propose a novel

Simunic, Tajana

278

Experimental study of turbulent unconfined groundwater flow in a single fracture  

E-Print Network [OSTI]

Experimental study of turbulent unconfined groundwater flow in a single fracture Jiazhong Qiana groundwater flow in a single fracture under the conditions of different surface roughness and apertures. We found that the gradient of the Reynolds number versus the average velocity in a single fracture

Zhan, Hongbin

279

The last Scandinavian Ice Sheet in northwestern Russia: ice flow patterns and decay dynamics  

E-Print Network [OSTI]

U N C O R R EC TED PR O O F The last Scandinavian Ice Sheet in northwestern Russia: ice flow Sheet in northwestern Russia: ice flow patterns and decay dynamics. Boreas, Vol. 35, pp. xxxÁxxx. Oslo) in northwestern Russia took place after a period of periglacial conditions. Till of the last SIS, Bobrovo till

Ingólfsson, ?lafur

280

In-Situ Calibration for Feedwater Flow Measurement  

SciTech Connect (OSTI)

With the approval by the Nuclear Regulatory Commission (NRC), of the Appendix K power up-rates, it has become important to provide an accurate measurement of the feedwater flow. Failure to meet documented requirements can now more easily lead to plant operations above their analyzed safety limits. Thus, the objective of flow instrumentation used in Appendix K up-rates, becomes one of providing precise measurements of the feedwater mass flow that will not allow the plant to be overpowered, but will still assure that maximum licensed thermal output is achieved. The NRC has licensed two technologies that meet these standards. Both are based on ultrasonic measurements of the flow. The first of these technologies, which is referred to as transit-time, relies on the measurement of differences in time for multiple ultrasonic beams to pass up and downstream in the fluid stream. These measurements are then coupled with a numerical integration scheme to compensate for distortions in the velocity profile due to upstream flow disturbances. This technology is implemented using a spool piece that is inserted into the feedwater pipe. The second technology relies on the measurement of the velocity of eddies within the fluid using a numerical process called cross-correlation. This technology is implemented by attaching the ultrasonic flow meter to the external surface of the pipe. Because of the ease in installation, for atypical situations, distortions in the velocity profile can be accounted for by attaching a second ultrasonic flow meter to the same pipe or multiple meters to a similar piping configuration, where the flow is fully developed. The additional meter readings are then used for the calibration of the initial set-up. Thus, it becomes possible to provide an in-situ calibration under actual operating conditions that requires no extrapolation of laboratory calibrations to compensate for distortions in the velocity profile. This paper will focus on the cross-correlation method of flow measurement, starting with the theoretical bases for the velocity profile correction factor and its reliance on only the Reynolds number to produce an accurate measurement of the flow, when the flow is fully developed. The method of laboratory calibration and the verification of these calibrations under actual plant operating conditions will be discussed. This will be followed by a discussion of how this technology is being used today to support the Appendix K up-rates. Various examples will be presented of piping configurations, where in-situ calibrations have or will be used to provide an accurate measurement of the feedwater flow at a specific location. (authors)

Peyvan, David [Entergy Nuclear Generating Company (United States); Gurevich, Yuri [Advanced Measurement and Analysis Group, Mississauga, ON (Canada); French, Charles T. [Westinghouse Electric Company (United States)

2002-07-01T23:59:59.000Z

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

The distortion of a uniform flow field due to a finite flat plate  

E-Print Network [OSTI]

Advantages of the Application of the Complete Navier-Stokes Equations Synopsis II ANALYSIS The Physical Model The Mathematical Model Governing Differential Fquations Initial and Boundary Conditions 10 III METHOD OF SOLUTION 19 General Method... INTRODUCTION Pur ose and Sco e The purpose of this study is to apply numerical methods to solve the exact partial differential equations governing viscous fluid flow past a finite flat plate. The flow condition studied is that of time-dependent, two...

Zull, Lawrence Michael

1970-01-01T23:59:59.000Z

282

Fluid flow monitoring device  

DOE Patents [OSTI]

A flow meter and temperature measuring device are described 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. 7 figures.

McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.

1993-11-30T23:59:59.000Z

283

Fluid flow monitoring device  

DOE Patents [OSTI]

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, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)

1993-01-01T23:59:59.000Z

284

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

285

Annular flow diverter valve  

DOE Patents [OSTI]

A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

Rider, Robert L. (Walkersville, MD)

1980-01-01T23:59:59.000Z

286

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

287

Energetic materials at extreme conditions  

E-Print Network [OSTI]

In order to effectively model the behaviour of energetic materials under operational conditions it is essential to obtain detailed structural information for these compounds at elevated temperature and/or pressures. The ...

Millar, David Iain Archibald

2011-06-27T23:59:59.000Z

288

Spectral conditions for positive maps  

E-Print Network [OSTI]

We provide a partial classification of positive linear maps in matrix algebras which is based on a family of spectral conditions. This construction generalizes celebrated Choi example of a map which is positive but not completely positive. It is shown how the spectral conditions enable one to construct linear maps on tensor products of matrix algebras which are positive but only on a convex subset of separable elements. Such maps provide basic tools to study quantum entanglement in multipartite systems.

Dariusz Chruscinski; Andrzej Kossakowski

2008-09-29T23:59:59.000Z

289

Active combustion flow modulation valve  

DOE Patents [OSTI]

A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

2013-09-24T23:59:59.000Z

290

Differential probes aid flow measurement  

SciTech Connect (OSTI)

Nonconstricting differential pressure flow probes which help solve the problems of clogging, wear, and pressure loss at the Seawater Filtration Facility in Saudi Arabia are described. Treated seawater is pumped into oil-bearing formations for secondary recovery. Figures showing principle of operation for probes, installation schematic and long-term accuracy results (flow probes vs. orifice meters) are presented. The new diamond-shaped design flow sensor offers accurate flow measurement with low permanent pressure loss, which translates into cost savings for the operator.

Mesnard, D.R.

1982-07-01T23:59:59.000Z

291

Liquid and liquidgas flows at all speeds  

SciTech Connect (OSTI)

All speed flows and in particular low Mach number flow algorithms are addressed for the numerical approximation of the Kapila et al. [1] multiphase flow model. This model is valid for fluid mixtures evolving in mechanical equilibrium but out of temperature equilibrium and is efficient for material interfaces computation separating miscible and non-miscible fluids. In this context, the interface is considered as a numerically diffused zone, captured as well as all present waves (shocks, expansion waves). The same flow model can be used to solve cavitating and boiling flows [2]. Many applications occurring with liquidgas interfaces and cavitating flows involve a very wide range of Mach number, from 10{sup ?3} to supersonic (and even hypersonic) conditions with respect to the mixture sound speed. It is thus important to address numerical methods free of restrictions regarding the Mach number. To do this, a preconditioned Riemann solver is built and embedded into the Godunov explicit scheme. It is shown that this method converges to exact solutions but needs too small time steps to be efficient. An implicit version is then derived, first in one dimension and second in the frame of 2D unstructured meshes. Two-phase flow preconditioning is then addressed in the frame of the Saurel et al. [3] algorithm. Modifications of the preconditioned Riemann solver are needed and detailed. Convergence of both single phase and two-phase numerical solutions are demonstrated with the help of single phase and two-phase steady nozzle flow solutions. Last, the method is illustrated by the computation of real cavitating flows in Venturi nozzles. Vapour pocket size and instability frequencies are reproduced by the model and method without using any adjustable parameter.

LeMartelot, S., E-mail: sebastien.lemartelot@polytech.univ-mrs.fr [Polytech'Marseille, Aix-Marseille University, UMR CNRS 7343 IUSTI, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France); Nkonga, B., E-mail: boniface.nkonga@unice.fr [RS2N, Bastidon de la Caou, 13360 Roquevaire (France); University of Nice, LJAD UMR CNRS 7351, Parc Valrose, 06108 Nice Cedex (France); Saurel, R., E-mail: richard.saurel@polytech.univ-mrs.fr [Polytech'Marseille, Aix-Marseille University, UMR CNRS 7343 IUSTI, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France); RS2N, Bastidon de la Caou, 13360 Roquevaire (France); University Institute of France, 5 rue E. Fermi, 13453 Marseille Cedex 13 (France)

2013-12-15T23:59:59.000Z

292

Droplet sizes, dynamics and deposition in vertical annular flow  

SciTech Connect (OSTI)

The role of droplets in vertical upwards annular flow is investigated, focusing on the droplet size distributions, dynamics, and deposition phenomena. An experimental program was performed based on a new laser optical technique developed in these laboratories and implemented here for annular flow. This permitted the simultaneous measurement of droplet size, axial and radial velocity. The dependence of droplet size distributions on flow conditions is analyzed. The Upper-Log Normal function proves to be a good model for the size distribution. The mechanism controlling the maximum stable drop size was found to result from the interaction of the pressure fluctuations of the turbulent flow of the gas core with the droplet. The average axial droplet velocity showed a weak dependence on gas rates. This can be explained once the droplet size distribution and droplet size-velocity relationship are analyzed simultaneously. The surprising result from the droplet conditional analysis is that larger droplet travel faster than smaller ones. This dependence cannot be explained if the drag curves used do not take into account the high levels of turbulence present in the gas core in annular flow. If these are considered, then interesting new situations of multiplicity and stability of droplet terminal velocities are encountered. Also, the observed size-velocity relationship can be explained. A droplet deposition is formulated based on the particle inertia control. This permitted the calculation of rates of drop deposition directly from the droplet size and velocities data.

Lopes, J C.B.; Dukler, A E

1985-10-01T23:59:59.000Z

293

Section 11: Interfacial flows 1 Section 11: Interfacial flows  

E-Print Network [OSTI]

Abstract 15:10 ­ 15:30: Martin Lübke, Olaf Wünsch (Universität Kassel): Two-Phase Flow in Single- Screw Extruders Abstract S11.4: Capillary Flows Wed, 16:00­18:00 Chair: Dieter Bothe S1|03­123 16:00 ­ 16:20: K

Kohlenbach, Ulrich

294

Analysis of flow patterns and flow mechanisms in soils  

E-Print Network [OSTI]

Analysis of flow patterns and flow mechanisms in soils Dissertation Co-directed by the University mechanism or changing soil physical properties (stratification). Thus, in stratified soil, we restricted was prepared at the Department of Soil Physics, University of Bayreuth, and at the Hydrogeological Laboratory

Avignon et des Pays de Vaucluse, Université de

295

Parameter Estimation of Dynamic Air-conditioning Component Models Using Limited Sensor Data  

E-Print Network [OSTI]

.1). ?? , is the area of orifice opening and ?? is the coefficient of discharge of the expansion valve at that specific condition. Coefficient of discharge is a dependent on the EEV geometry and the thermal?fluid properties of the refrigerant flowing through... Area of application of bulb pressure ?2 Area of application of evaporator pressure ?? External surface area of the TEV bulb ??? Area of heat conduction between the refrigerant and the bulb ?? Area of opening for refrigerant flow in expansion...

Hariharan, Natarajkumar

2011-08-08T23:59:59.000Z

296

Conditioned changes in pain reactivity: conditioned stimuli elicit hypoalgesia under a wide range of test conditions  

E-Print Network [OSTI]

conditioned hypoalgesia, two recent reports suggest that a conditioned stimulus (CS) which has been paired with an aversive event may sometimes produce an increase in pain reactivity, or "hyperalgesia" rather than hypoalgesia (Davis & Henderson, 1985...-Evans hooded rats) (Davis & Henderson, 1985; Lysle & Fowler, 1988). Currently, it is not clear what determines whether a stimulus which has been paired with an aversive event will elicit either an increase or decrease in pain reactivity. In the present...

Illich, Paul Anthony

1990-01-01T23:59:59.000Z

297

Effect of flow fluctuations and nonflow on elliptic flow methods  

SciTech Connect (OSTI)

We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_2,PP elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_2,RP in the reaction plane. Thus, the 20percent spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.

Ollitrault, Jean-Yves; Poskanzer, Arthur M.; Voloshin, Sergei A.

2009-04-16T23:59:59.000Z

298

Some observations on Goldberg-Trajan's Maximum Flow algorithm on Bipartite Graphs  

E-Print Network [OSTI]

) is a direct graph with two distinguished vertices s (the source) and t (the sink). Each edge [u, v] in G is associated with a positive integer cap(u, v), called the capacity of the edge. If there is no edge from vertex u to vertex v. then we define... cap(u, v) = 0. Intuitively, a flow in a flow network should satisfy the following three conditions: (1) the amount of flow along an edge should not exceed the capacity of the edge (capacity constraint); (2) a flow from a vertex u to a vertex v can...

Yang, Bencai

1997-01-01T23:59:59.000Z

299

Experimental and theoretical studies of the effects of nonuniformities in nonequilibrium magnetohydrodynamic flows  

SciTech Connect (OSTI)

A study of wake nonuniformities in a nonequilibrium magnetohydrodynamic plasma is described. Experimental results are presented from an electrodeless disk-shaped channel in both radial flow and swirl flow configurations. The experimental conditions are analyzed with a nonequilibrium plasma model that accounts for variations in the wake gas properties and wake width. The results show that the wake nonuniformities in the radial flow channel are weak, but in the swirl flow channel they are strong because of an instability. This instability is a consequence of the wake orientation. Furthermore, the intensity of the nonuniformity in an unstable plasma is dependent upon the wake gas velocity and wake width.

Lytle, J.K.; Louis, J.F.

1984-07-01T23:59:59.000Z

300

Flume studies of sediment transportation in shallow flow with simulated rainfall  

E-Print Network [OSTI]

force exerted on a particle by flowing water, which according to Newton, was equal to Trr V 2 where s is a shape factor (0. 79 for spheres), g is the specific weight s of the particle, r is its radius, and V is the critical bottom velocity. cr... water pipe flow . Turbulent flow can be visualized as being divided into sheets of fluid having one velocity. These sheets are traversed by eddies, and in this manner the flow tends to establish a condition of equilibrium by a mixing process...

Nail, Frank Mitchell

2012-06-07T23:59:59.000Z

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

Thermonuclear Fusion with the Sheared Flow Stabilized Z-Pinch  

E-Print Network [OSTI]

Two basic approaches to producing thermonuclear fusion with a sheared flow stabilized z-pinch are considered. One consists of heating the entire length of the z-pinch column to the required temperatures. The other basic approach considered here involves the concept of fast ignition. A localized "hot-spot" is produced under the proper conditions to ignite a thermonuclear burn wave in the z-pinch plasma. Here we demonstrate that sheared flow stabilization is more efficient in the fast-ignition method with isentropic compression then in a z-pinch where the entire plasma column is heated.

Winterberg, F

2008-01-01T23:59:59.000Z

302

Laminar and turbulent nozzle-jet flows and their acoustic near-field  

SciTech Connect (OSTI)

We investigate numerically the effects of nozzle-exit flow conditions on the jet-flow development and the near-field sound at a diameter-based Reynolds number of Re{sub D} = 18?100 and Mach number Ma = 0.9. Our computational setup features the inclusion of a cylindrical nozzle which allows to establish a physical nozzle-exit flow and therefore well-defined initial jet-flow conditions. Within the nozzle, the flow is modeled by a potential flow core and a laminar, transitional, or developing turbulent boundary layer. The goal is to document and to compare the effects of the different jet inflows on the jet flow development and the sound radiation. For laminar and transitional boundary layers, transition to turbulence in the jet shear layer is governed by the development of Kelvin-Helmholtz instabilities. With the turbulent nozzle boundary layer, the jet flow development is characterized by a rapid changeover to a turbulent free shear layer within about one nozzle diameter. Sound pressure levels are strongly enhanced for laminar and transitional exit conditions compared to the turbulent case. However, a frequency and frequency-wavenumber analysis of the near-field pressure indicates that the dominant sound radiation characteristics remain largely unaffected. By applying a recently developed scaling procedure, we obtain a close match of the scaled near-field sound spectra for all nozzle-exit turbulence levels and also a reasonable agreement with experimental far-field data.

Bhler, Stefan; Obrist, Dominik; Kleiser, Leonhard [Institute of Fluid Dynamics, ETH Zurich, 8092 Zurich (Switzerland)

2014-08-15T23:59:59.000Z

303

Network Flow Optimization under Uncertainty  

E-Print Network [OSTI]

Network model in words Minimize the cost of satisfying demands for electric energy By: imports, exports and electricity Subject to: conservation of energy flows (net after losses), lower and upper bounds on flows is a reactive approach: how would the optimal solution have changed if I'd only known? · Proactive approaches

Tesfatsion, Leigh

304

Redox Flow Batteries, a Review  

SciTech Connect (OSTI)

Redox flow batteries 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 redox flow batteries with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.

U. Tennessee Knoxville; U. Texas Austin; McGill U; Weber, Adam Z.; Mench, Matthew M.; Meyers, Jeremy P.; Ross, Philip N.; Gostick, Jeffrey T.; Liu, Qinghua

2011-07-15T23:59:59.000Z

305

Conditions for successful data assimilation  

E-Print Network [OSTI]

We show, using idealized models, that numerical data assimilation can be successful only if an effective dimension of the problem is not excessive. This effective dimension depends on the noise in the model and the data, and in physically reasonable problems it can be moderate even when the number of variables is huge. We then analyze several data assimilation algorithms, including particle filters and variational methods. We show that well-designed particle filters can solve most of those data assimilation problems that can be solved in principle, and compare the conditions under which variational methods can succeed to the conditions required of particle filters. We also discuss the limitations of our analysis.

Alexandre J. Chorin; Matthias Morzfeld

2014-10-22T23:59:59.000Z

306

Extreme Conditions Modeling Workshop Report  

SciTech Connect (OSTI)

Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

2014-07-01T23:59:59.000Z

307

The magnetic flywheel flow meter: Theoretical and experimental contributions  

SciTech Connect (OSTI)

The development of contactless flow meters is an important issue for monitoring and controlling of processes in different application fields, like metallurgy, liquid metal casting, or cooling systems for nuclear reactors and transmutation machines. Shercliff described in his book The Theory of Electromagnetic Flow Measurement, Cambridge University Press, 1962 a simple and robust device for contact-less measurements of liquid metal flow rates which is known as magnetic flywheel. The sensor consists of several permanent magnets attached on a rotatable soft iron plate. This arrangement will be placed closely to the liquid metal flow to be measured, so that the field of the permanent magnets penetrates into the fluid volume. The flywheel will be accelerated by a Lorentz force arising from the interaction between the magnetic field and the moving liquid. Steady rotation rates of the flywheel can be taken as a measure for the mean flow rate inside the fluid channel. The present paper provides a detailed theoretical description of the sensor in order to gain a better insight into the functional principle of the magnetic flywheel. Theoretical predictions are confirmed by corresponding laboratory experiments. For that purpose, a laboratory model of such a flow meter was built and tested on a GaInSn-loop under various test conditions.

Buchenau, D., E-mail: d.buchenau@hzdr.de; Galindo, V.; Eckert, S. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstrae 400, 01328 Dresden (Germany)

2014-06-02T23:59:59.000Z

308

Modelling of multiphase flow in ironmaking blast furnace  

SciTech Connect (OSTI)

A mathematical model for the four-phase (gas, powder, liquid, and solids) flow in a two-dimensional ironmaking blast furnace is presented by extending the existing two-fluid flow models. The model describes the motion of gas, solid, and powder phases, based on the continuum approach, and implements the so-called force balance model for the flow of liquids, such as metal and slag in a blast furnace. The model results demonstrate a solid stagnant zone and dense powder hold-up region, as well as a dense liquid flow region that exists in the lower part of a blast furnace, which are consistent with the experimental observations reported in the literature. The simulation is extended to investigate the effects of packing properties and operational conditions on the flow and the volume fraction distribution of each phase in a blast furnace. It is found that solid movement has a significant effect on powder holdup distribution. Small solid particles and low porosity distribution are predicted to affect the fluid flow considerably, and this can cause deterioration in bed permeability. The dynamic powder holdup in a furnace increases significantly with the increase of powder diameter. The findings should be useful to better understand and control blast furnace operations.

Dong, X.F.; Yu, A.B.; Burgess, J.M.; Pinson, D.; Chew, S.; Zulli, P. [University of New South Wales, Sydney, NSW (Australia). School for Material Science and Engineering

2009-01-15T23:59:59.000Z

309

Reversing Flow Test Facility. Technical report, March 1986  

SciTech Connect (OSTI)

The Reversing Flow Test Facility (RFTF) is intended for the study of fluid flow and heat transfer under the reversing-flow conditions that occur in Stirling engines. the facility consists of four major parts: (1) Mechanical Drive - two cylinders with cam-driven pistons which generate the reversing gas flow, (2) Test Section - a U-shaped section containing instrumented test pieces, (3) Instruments -l high-speed transducers for measuring gas pressure and temperature, piston positions, and other system parameters, and (4) Data Acquisition System - a computer-based system able to acquire, store, display and analyze the data from the instruments. The RFTF can operate at pressures up to 8.0 MPa, hot-side temperatures to 800/sup 0/C, and flow-reversal frequencies to 50 Hz. Operation to data has used helium as the working gas at pressures of 3.0 and 6.0 MPa, at ambient temperature, and at frequencies from 1 to 50 Hz. The results show that both frictional and inertial parts of the pressure drop are significant in the heater, coolers and connecting tubes; the inertial part is negligible in the regenerators. In all cases, the frictional part of the pressure drop is nearly in phase with the mass flow. 18 refs., 22 figs., 13 tabs.

Roach, P.D.

1986-04-01T23:59:59.000Z

310

Vertical flow chemical detection portal  

DOE Patents [OSTI]

A portal apparatus is described for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow. 3 figs.

Linker, K.L.; Hannum, D.W.; Conrad, F.J.

1999-06-22T23:59:59.000Z

311

Wavy flow cooling concept for turbine airfoils  

DOE Patents [OSTI]

An airfoil including an outer wall and a cooling cavity formed therein. The cooling cavity includes a leading edge flow channel located adjacent a leading edge of the airfoil and a trailing edge flow channel located adjacent a trailing edge of the airfoil. Each of the leading edge and trailing edge flow channels define respective first and second flow axes located between pressure and suction sides of the airfoil. A plurality of rib members are located within each of the flow channels, spaced along the flow axes, and alternately extending from opposing sides of the flow channels to define undulating flow paths through the flow channels.

Liang, George (Palm City, FL)

2010-08-31T23:59:59.000Z

312

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

313

hal-00145315,version3-2Aug2007 Viscous potential free-surface flows in a fluid layer of finite depth  

E-Print Network [OSTI]

´equations. Key words: potential flow, free-surface flow, viscosity, dissipation, water waves, wave damping-surface elevation. A new predominant nonlocal viscous term is derived in the bottom kinematic boundary condition potential flow theories [7]. Corresponding long wave model equations are derived. R´esum´e Ecoulements

Paris-Sud XI, Université de

314

Investigation of Swirling Flow in Rod Bundle Subchannels Using Computational Fluid Dynamics  

SciTech Connect (OSTI)

The fluid dynamics for turbulent flow through rod bundles representative of those used in pressurized water reactors is examined using computational fluid dynamics (CFD). The rod bundles of the pressurized water reactor examined in this study consist of a square array of parallel rods that are held on a constant pitch by support grids spaced axially along the rod bundle. Split-vane pair support grids are often used to create swirling flow in the rod bundle in an effort to improve the heat transfer characteristics for the rod bundle during both normal operating conditions and in accident condition scenarios. Computational fluid dynamics simulations for a two subchannel portion of the rod bundle were used to model the flow downstream of a split-vane pair support grid. A high quality computational mesh was used to investigate the choice of turbulence model appropriate for the complex swirling flow in the rod bundle subchannels. Results document a central swirling flow structure in each of the subchannels downstream of the split-vane pairs. Strong lateral flows along the surface of the rods, as well as impingement regions of lateral flow on the rods are documented. In addition, regions of lateral flow separation and low axial velocity are documented next to the rods. Results of the CFD are compared to experimental particle image velocimetry (PIV) measurements documenting the lateral flow structures downstream of the split-vane pairs. Good agreement is found between the computational simulation and experimental measurements for locations close to the support grid. (authors)

Holloway, Mary V. [United States Naval Academy, 117 Decatur Road, Annapolis, MD 21402-5018 (United States); Beasley, Donald E. [Clemson University, Clemson, S.C. 29634 (United States); Conner, Michael E. [Westinghouse Nuclear Fuel (United States)

2006-07-01T23:59:59.000Z

315

Conditionally Independent Generalized Competing Risks  

E-Print Network [OSTI]

is subjected to corrective maintenance (CM) and condition-based preventive maintenance (PM) actions. In order into a state in which it can perform its function again. Preventive maintenance (PM) is carried out when whether the maintenance is preventive or correc- tive. 2. Characterization of the PM-CM process Let Ht

Paris-Sud XI, Université de

316

Introduction Simulation of Pathological conditions  

E-Print Network [OSTI]

Reference Survey of the Modeling Brain Energy Metabolism and Function -- Report of the work by Larisa. V et State University MATH 690P, Dec. 1. 06 Wen Zhou Modeling Brain Energy #12;Outline Introduction Modeling Simulation of Pathological conditions Conclusion and Discussion Reference Introduction Modeling Energy

Willson, Stephen J.

317

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

SciTech Connect (OSTI)

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

318

Turbine blade tip flow discouragers  

DOE Patents [OSTI]

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

319

Self-Control of Traffic Lights and Vehicle Flows in Urban Road Networks  

E-Print Network [OSTI]

Based on fluid-dynamic and many-particle (car-following) simulations of traffic flows in (urban) networks, we study the problem of coordinating incompatible traffic flows at intersections. Inspired by the observation of self-organized oscillations of pedestrian flows at bottlenecks [D. Helbing and P. Moln\\'ar, Phys. Eev. E 51 (1995) 4282--4286], we propose a self-organization approach to traffic light control. The problem can be treated as multi-agent problem with interactions between vehicles and traffic lights. Specifically, our approach assumes a priority-based control of traffic lights by the vehicle flows themselves, taking into account short-sighted anticipation of vehicle flows and platoons. The considered local interactions lead to emergent coordination patterns such as ``green waves'' and achieve an efficient, decentralized traffic light control. While the proposed self-control adapts flexibly to local flow conditions and often leads to non-cyclical switching patterns with changing service sequences ...

Lmmer, Stefan

2008-01-01T23:59:59.000Z

320

Multiscale Simulations for Polymeric Flow  

E-Print Network [OSTI]

Multiscale simulation methods have been developed based on the local stress sampling strategy and applied to three flow problems with different difficulty levels: (a) general flow problems of simple fluids, (b) parallel (one-dimensional) flow problems of polymeric liquids, and (c) general (two- or three-dimensional) flow problems of polymeric liquids. In our multiscale methods, the local stress of each fluid element is calculated directly by performing microscopic or mesoscopic simulations according to the local flow quantities instead of using any constitutive relations. For simple fluids (a), such as the Lenard-Jones liquid, a multiscale method combining MD and CFD simulations is developed based on the local equilibrium assumption without memories of the flow history. (b), the multiscale method is extended to take into account the memory effects that arise in hydrodynamic stress due to the slow relaxation of polymer-chain conformations. The memory of polymer dynamics on each fluid element is thus resolved by performing MD simulations in which cells are fixed at the mesh nodes of the CFD simulations.For general (two- or three-dimensional) flow problems of polymeric liquids (c), it is necessary to trace the history of microscopic information such as polymer-chain conformation, which carries the memories of past flow history, along the streamline of each fluid element. A Lagrangian-based CFD is thus implemented to correctly advect the polymer-chain conformation consistently with the flow. On each fluid element, coarse-grained polymer simulations are carried out to consider the dynamics of entangled polymer chains that show extremely slow relaxation compared to microscopic time scales.

Takahiro Murashima; Takashi Taniguchi; Ryoichi Yamamoto; Shugo Yasuda

2011-01-06T23:59:59.000Z

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

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

322

Flow distribution channels to control flow in process channels  

DOE Patents [OSTI]

The invention describes features that can be used to control flow to an array of microchannels. The invention also describes methods in which a process stream is distributed to plural microchannels.

Tonkovich, Anna Lee; Arora, Ravi; Kilanowski, David

2014-10-28T23:59:59.000Z

323

Gas flow characterization of restrictive flow orifice devices  

SciTech Connect (OSTI)

A restrictive flow orifice (RFO) can be used to limit the uncontrolled release of system media upon component or line failure in a gas handling system and can thereby enhance the system safety. This report describes a new RFO product available from the Swagelok Companies and specifies the gas flow characteristics of this device. A family of four different sizes of RFO devices is documented.

Shrouf, R.G. [Sandia National Labs., Albuquerque, NM (United States). Safety Engineering Dept.; Page, S.R. [Albuquerque Valve and Fitting Co., NM (United States)

1997-07-01T23:59:59.000Z

324

Turbulent patterns in wall-bounded flows: a Turing instability?  

E-Print Network [OSTI]

In their way to/from turbulence, plane wall-bounded flows display an interesting transitional regime where laminar and turbulent oblique bands alternate, the origin of which is still mysterious. In line with Barkley's recent work about the pipe flow transition involving reaction-diffusion concepts, we consider plane Couette flow in the same perspective and transform Waleffe's classical four-variable model of self-sustaining process into a reaction-diffusion model. We show that, upon fulfillment of a condition on the relative diffusivities of its variables, the featureless turbulent regime becomes unstable against patterning as the result of a Turing instability. A reduced two-variable model helps us to delineate the appropriate region of parameter space. An {\\it intrinsic} status is therefore given to the pattern's wavelength for the first time. Virtues and limitations of the model are discussed, calling for a microscopic support of the phenomenological approach.

Manneville, Paul

2012-01-01T23:59:59.000Z

325

Insertable fluid flow passage bridgepiece and method  

DOE Patents [OSTI]

A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.

Jones, Daniel O. (Glenville, NV)

2000-01-01T23:59:59.000Z

326

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

327

Evaluation of Wall Boundary Condition Parameters for Gas-Solids Fluidized Bed Simulations  

SciTech Connect (OSTI)

Wall boundary conditions for the solids phase have significant effects on numerical predictions of various gas-solids fluidized beds. Several models for the granular flow wall boundary condition are available in the open literature for numerical modeling of gas-solids flow. In this study, a model for specularity coefficient used in Johnson and Jackson boundary conditions by Li and Benyahia (AIChE Journal, 2012, 58, 2058-2068) is implemented in the open-source CFD code-MFIX. The variable specularity coefficient model provides a physical way to calculate the specularity coefficient needed by the partial-slip boundary conditions for the solids phase. Through a series of 2-D numerical simulations of bubbling fluidized bed and circulating fluidized bed riser, the model predicts qualitatively consistent trends to the previous studies. Furthermore, a quantitative comparison is conducted between numerical results of variable and constant specularity coefficients to investigate the effect of spatial and temporal variations in specularity coefficient.

Li, Tingwen; Benyahia, Sofiane

2013-10-01T23:59:59.000Z

328

Analytical methods under emergency conditions  

SciTech Connect (OSTI)

This lecture discusses methods for the radiochemical determination of internal contamination of the body under emergency conditions, here defined as a situation in which results on internal radioactive contamination are needed quickly. The purpose of speed is to determine the necessity for medical treatment to increase the natural elimination rate. Analytical methods discussed include whole-body counting, organ counting, wound monitoring, and excreta analysis. 12 references. (ACR)

Sedlet, J.

1983-01-01T23:59:59.000Z

329

A Primer on Energy Conditions  

E-Print Network [OSTI]

An energy condition, in the context of a wide class of spacetime theories (including general relativity), is, crudely speaking, a relation one demands the stress-energy tensor of matter satisfy in order to try to capture the idea that "energy should be positive". The remarkable fact I will discuss in this paper is that such simple, general, almost trivial seeming propositions have profound and far-reaching import for our understanding of the structure of relativistic spacetimes. It is therefore especially surprising when one also learns that we have no clear understanding of the nature of these conditions, what theoretical status they have with respect to fundamental physics, what epistemic status they may have, when we should and should not expect them to be satisfied, and even in many cases how they and their consequences should be interpreted physically. Or so I shall argue, by a detailed analysis of the technical and conceptual character of all the standard conditions used in physics today, including examination of their consequences and the circumstances in which they are believed to be violated.

Erik Curiel

2014-04-30T23:59:59.000Z

330

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 (OSTI)

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

331

Shear flow effects on ion thermal transport in tokamaks  

SciTech Connect (OSTI)

From various laboratory and numerical experiments, there is clear evidence that under certain conditions the presence of sheared flows in a tokamak plasma can significantly reduce the ion thermal transport. In the presence of plasma fluctuations driven by the ion temperature gradient, the flows of energy and momentum parallel and perpendicular to the magnetic field are coupled with each other. This coupling manifests itself as significant off-diagonal coupling coefficients that give rise to new terms for anomalous transport. The authors derive from the gyrokinetic equation a set of velocity moment equations that describe the interaction among plasma turbulent fluctuations, the temperature gradient, the toroidal velocity shear, and the poloidal flow in a tokamak plasma. Four coupled equations for the amplitudes of the state variables radially extended over the transport region by toroidicity induced coupling are derived. The equations show bifurcations from the low confinement mode without sheared flows to high confinement mode with substantially reduced transport due to strong shear flows. Also discussed is the reduced version with three state variables. In the presence of sheared flows, the radially extended coupled toroidal modes driven by the ion temperature gradient disintegrate into smaller, less elongated vortices. Such a transition to smaller spatial correlation lengths changes the transport from Bohm-like to gyrobohm-like. The properties of these equations are analyzed. The conditions for the improved confined regime are obtained as a function of the momentum-energy deposition rates and profiles. The appearance of a transport barrier is a consequence of the present theory.

Tajima, T.; Horton, W.; Dong, J.Q. [Univ. of Texas, Austin, TX (United States). Institute for Fusion Studies; Kishimoto, Y. [JAERI (Japan). Naka Fusion Research

1995-03-01T23:59:59.000Z

332

Hanford Tank Farms Waste Certification Flow Loop Test Plan  

SciTech Connect (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 Laboratorys 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

333

Vertical Flow Dynamics in Kelp Forests: Implications for Nutrient Uptake, Condition and Survival  

E-Print Network [OSTI]

Dynamics in Kelp Forests: Implications for Nutrient Uptake,on the temperature/nutrient regime around giant kelp will benutrient-rich water results in increased Nitrogen uptake by giant kelp and

Edwards, Matthew S.

2008-01-01T23:59:59.000Z

334

E-Print Network 3.0 - annular flow conditions Sample Search Results  

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

Collection: Environmental Sciences and Ecology ; Geosciences 88 225Noise Control Eng. J. 52 (5), 2004 SeptOct Determination of sound radiation from a simplified disk-brake...

335

Estimation of Hydraulic Parameters under Unsaturated Flow Conditions in Heap Leaching  

E-Print Network [OSTI]

experi- mental results from the Chilean copper mining industry and related works, and we obtain better is a widely used extraction method for low-grade minerals as well as copper, gold, silver, and uranium. Copper

Sepúlveda, Mauricio

336

Modeling of Multiphase Flow in the Near-Wellbore Region of the Reservoir under Transient Conditions  

E-Print Network [OSTI]

/ft ? porosity ? viscosity, cp ? angle, degree Subscripts c condensate g gas m neighboring gridblock to gridblock n n gridblock o oil r relative sg solution gas w water Superscripts n old timestep n+1 current timestep viii TABLE OF CONTENTS...) ...................................... 81 Fig. 6.13 Relative permeability vs. wetting phase saturation ........................... 83 Fig. 6.14 Plots for the pressure and saturation of the three phases along the distance ............................................... 84...

Zhang, He

2010-07-14T23:59:59.000Z

337

Analysis of alternatives for computing backwater at bridges for free-surface, subcritical flow conditions  

E-Print Network [OSTI]

Downsville, Louisiana Profde Computation Results . . 46 Flagon Bayou near Libuse, Louisiana Site Characteristics . . . 51 Flagon Bayou near Libuse, Louisiana Profile Computation Results 52 Alexander Creek near St. Francisville, Louisiana Site... Characteristics . 56 Alexander Creek near St. Francisville, Louisiana Flood of September 17, 1971 Profile Computation Results . . . . . . . . . . . . . . . . . . 57 Tenmile Creek near Elizabeth, Louisiana Site Characteristics . 62 10 Tenmile Creek near...

Kaatz, Kelly Jay

1993-01-01T23:59:59.000Z

338

Use of tritium and helium to define groundwater flow conditions in Everglades National Park  

E-Print Network [OSTI]

and tem- perature as tracers of the seawater intrusion into coastal aquifers [Back et al., 1970; Kohout

Swart, Peter K.

339

Energy-Saving Design for Pressure Difference Control in Variable Flow Air Conditioning Systems  

E-Print Network [OSTI]

) [2] Zhaoyu SHI. Adjustment and Control of Operation of Heat Supply System. Beijing: Tsinghua University Press, 1994. (In Chinese) [3] Junliang SHI. Selection of Control Valves. Beijing: China Architecture & Building Press, 1986. (In Chinese...

Chen, Y.; Zhang, Z.

2006-01-01T23:59:59.000Z

340

The rapid synthesis of oxazolines and their heterogeneous oxidation to oxazoles under flow conditions  

E-Print Network [OSTI]

. Microfluidics are known to provide a highly efficient static mixing23- 26 and therefore the cyclodehydration of ?-hydroxy amides 1b and 1i was attempted on a 1 L (Labtrix Start) microchip (Scheme 2).27 It was found that both substrates could...

Glckner, Steffen; Tran, Duc N.; Ingham, Richard J.; Fenner, Sabine; Wilson, Zoe E.; Battilocchio, Claudio; Ley, Steven V.

2014-10-28T23:59:59.000Z

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

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, John P. (1204 Woodbine Rd., Aiken, SC 29803)

1993-01-01T23:59:59.000Z

342

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

343

Capillary flows in flexible structures  

E-Print Network [OSTI]

Interactions between capillary and elastic effects are relevant to a variety of applications, from micro- and nano-scale manufacturing to biological systems. In this thesis, we investigate capillary flows in extremely ...

Hoberg, Theresa B. (Theresa Blinn)

2013-01-01T23:59:59.000Z

344

2007 Estimated International Energy Flows  

SciTech Connect (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

345

particle flow for nonlinear filters  

E-Print Network [OSTI]

particle flow for nonlinear filters Fred Daum 19 June 2012 Copyright © 2012 Raytheon Company. All rights reserved. Customer Success Is Our Mission is a trademark of Raytheon Company. 1 #12;discrete time

Dobigeon, Nicolas

346

Fluid Flow Modeling in Fractures  

E-Print Network [OSTI]

In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...

Sarkar, Sudipta

2004-01-01T23:59:59.000Z

347

Mechanical design of flow batteries  

E-Print Network [OSTI]

The purpose of this research is to investigate the design of low-cost, high-efficiency flow batteries. Researchers are searching for next-generation battery materials, and this thesis presents a systems analysis encompassing ...

Hopkins, Brandon J. (Brandon James)

2013-01-01T23:59:59.000Z

348

Field Flows of Dark Energy  

E-Print Network [OSTI]

Field Flows of Dark Energy Robert N. Cahn, Roland de Putter,July 8, 2008) Scalar ?eld dark energy evolving from a longthe key aspects of the dark energy evolution during much of

Cahn, Robert N.

2010-01-01T23:59:59.000Z

349

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

350

Pipe Flow System Holly Guest  

E-Print Network [OSTI]

numbers #12;Pipe Flow System Form #12;Components Form Fitting Loss Coefficient, k Globe valve, fully open 10 Angle valve, fully open 5 Swing check valve, fully open 2.5 Gate valve, fully open .2 Shortradius

Clement, Prabhakar

351

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

352

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

353

Minimum Stream Flow Standards (Connecticut)  

Broader source: Energy.gov [DOE]

These regulations apply to all dams and structures which impound or divert waters on rivers or their tributaries, with some exceptions. The regulations set standards for minimum flow (listed in the...

354

Automation of radiochemical analysis by applying flow  

E-Print Network [OSTI]

of detection systems, including scintillation counting, a-spectrometers, proportional counters, mass spectrometry and spectrophotometry. 2010 Published by Elsevier Ltd. Keywords: Flow-analysis technique; Flow

Snchez, David

355

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER  

E-Print Network [OSTI]

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

Lahey, Richard T.

356

Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow...  

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

Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer, Longer-lasting Batteries Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer,...

357

Geometry of Power Flows in Tree Networks  

E-Print Network [OSTI]

We investigate the problem of power flow and its relationship to optimization in tree networks by looking at the injection regions of the networks. The injection region is the set of all vectors of bus power injections that satisfy the network and operation constraints. The geometrical object of interest is the set of Pareto-optimal points of the injection region, since they are the solutions to the minimization of increasing functions. If the voltage magnitudes are fixed, the injection region of a tree network can be written as a linear transformation of the product of two-bus injection regions, one for each line in the network. Using this decomposition, we show that under the practical condition that the angle difference across each line is not too large, the set of Pareto-optimal points of the injection region remains unchanged by taking the convex hull. Therefore, the optimal power flow problem can be convexified and efficiently solved. This result improves upon earlier works by removing the assumptions o...

Lavaei, Javad; Zhang, Baosen

2012-01-01T23:59:59.000Z

358

Equidistribution results for geodesic flows  

E-Print Network [OSTI]

Using the works of Ma\\~n\\'e \\cite{Ma} and Paternain \\cite{Pat} we study the distribution of geodesic arcs with respect to equilibrium states of the geodesic flow on a closed manifold, equipped with a $\\mathcal{C}^{\\infty}$ Riemannian metric. We prove large deviations lower and upper bounds and a contraction principle for the geodesic flow in the space of probability measures of the unit tangent bundle. We deduce a way of approximating equilibrium states for continuous potentials.

Abdelhamid Amroun

2011-09-15T23:59:59.000Z

359

Subcritical dynamos in shear flows  

E-Print Network [OSTI]

Identifying generic physical mechanisms responsible for the generation of magnetic fields and turbulence in differentially rotating flows is fundamental to understand the dynamics of astrophysical objects such as accretion disks and stars. In this paper, we discuss the concept of subcritical dynamo action and its hydrodynamic analogue exemplified by the process of nonlinear transition to turbulence in non-rotating wall-bounded shear flows. To illustrate this idea, we describe some recent results on nonlinear hydrodynamic transition to turbulence and nonlinear dynamo action in rotating shear flows pertaining to the problem of turbulent angular momentum transport in accretion disks. We argue that this concept is very generic and should be applicable to many astrophysical problems involving a shear flow and non-axisymmetric instabilities of shear-induced axisymmetric toroidal velocity or magnetic fields, such as Kelvin-Helmholtz, magnetorotational, Tayler or global magnetoshear instabilities. In the light of several recent numerical results, we finally suggest that, similarly to a standard linear instability, subcritical MHD dynamo processes in high-Reynolds number shear flows could act as a large-scale driving mechanism of turbulent flows that would in turn generate an independent small-scale dynamo.

F. Rincon; G. I. Ogilvie; M. R. E. Proctor; C. Cossu

2008-05-09T23:59:59.000Z

360

Parametric effects of glass reaction under unsaturated conditions  

SciTech Connect (OSTI)

Eventual liquid water contact of high-level waste glass stored under the unsaturated conditions anticipated at the Yucca Mountain site will be by slow intrusion of water into a breached container/canister assembly. The water flow patterns under these unsaturated conditions will vary, and the Unsaturated Test method has been developed by the YMP to study glass reaction. The results from seven different sets of tests done to investigate the effect of systematically varying parameters, such as glass composition, composition and degree of sensitization of 304L stainless steel, water input volume, and the interval of water contact are discussed. Glass reaction has been monitored over a period of five years, and the parametric effects can result in up to a ten-fold variance in the degree of glass reaction.

Bates, J.K.; Gerding, T.J.; Woodland, A.B.

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.


361

Pressure and flow characteristics of restrictive flow orifice devices.  

SciTech Connect (OSTI)

A Restrictive Flow Orifice (RFO) can be used to enhance the safe design of a pressure system in several ways. Pressure systems frequently incorporate a regulator and relief valve to protect the downstream equipment from accidental overpressure caused by regulator failure. Analysis frequently shows that in cases of high-flow regulator failure, the downstream pressure may rise significantly above the set pressure of the relief valve. This is due to limited flow capacity of the relief valve. A different regulator or relief valve may need to be selected. A more economical solution to this problem is to use an RFO to limit the maximum system flow to acceptable limits within the flow capacity of the relief valve, thereby enhancing the overpressure protection of laboratory equipment. An RFO can also be used to limit the uncontrolled release of system fluid (gas or liquid) upon component or line failure. As an example, potential asphyxiation hazards resultant from the release of large volumes of inert gas from a 'house' nitrogen system can be controlled by the use of an RFO. This report describes a versatile new Sandia-designed RFO available from the Swagelok Company and specifies the gas flow characteristics of this device. Two sizes, 0.010 and 0.020 inch diameter RFOs are available. These sizes will allow enhanced safety for many common applications. This new RFO design are now commercially available and provide advantages over existing RFOs: a high pressure rating (6600 psig); flow through the RFO is equal for either forward or reverse directions; they minimize the potential for leakage by incorporating the highest quality threaded connections; and can enhance the safety of pressure systems.

Shrouf, Roger D.

2003-06-01T23:59:59.000Z

362

Admissibility Conditions for Degenerate Cyclotomic BMW Algebras  

E-Print Network [OSTI]

We study admissibility conditions for the parameters of degenerate cyclotomic BMW algebras. We show that the u-admissibility condition of Ariki, Mathas and Rui is equivalent to a simple module theoretic condition.

Goodman, Frederick M

2009-01-01T23:59:59.000Z

363

Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning...  

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

highlighted in the video series. Addthis Related Articles National Renewable Energy Laboratory engineer Eric Kozubal examines a prototype air flow channel of the DEVAP, a...

364

Two-dimensional flows of foam: drag exerted on circular obstacles and dissipation  

E-Print Network [OSTI]

A Stokes experiment for foams is proposed. It consists in a two-dimensional flow of a foam, confined between a water subphase and a top plate, around a fixed circular obstacle. We present systematic measurements of the drag exerted by the flowing foam on the obstacle, \\emph{versus} various separately controlled parameters: flow rate, bubble volume, solution viscosity, obstacle size and boundary conditions. We separate the drag into two contributions, an elastic one (yield drag) at vanishing flow rate, and a fluid one (viscous coefficient) increasing with flow rate. We quantify the influence of each control parameter on the drag. The results exhibit in particular a power-law dependence of the drag as a function of the solution viscosity and the flow rate with two different exponents. Moreover, we show that the drag decreases with bubble size, increases with obstacle size, and that the effect of boundary conditions is small. Measurements of the streamwise pressure gradient, associated to the dissipation along the flow of foam, are also presented: they show no dependence on the presence of an obstacle, and pressure gradient depends on flow rate, bubble volume and solution viscosity with three independent power laws.

Benjamin Dollet; Florence Elias; Catherine Quilliet; Arnaud Huillier; Miguel Aubouy; Francois Graner

2004-11-22T23:59:59.000Z

365

Flow-Through Microfluidic Device for High-Efficiency Transfection of Mammalian Cells through Combined Microelectroporation and Sonoporation  

E-Print Network [OSTI]

In this study we are presenting a proof-of-concept microfluidic device that simultaneously applies the conditions required for microelectroporation and micro-sonoporation in a flow-through fashion that allows for high throughput, high efficiency...

Longsine, Whitney Leigh

2012-07-16T23:59:59.000Z

366

Kinematics of geodesic flows in stringy black hole backgrounds  

E-Print Network [OSTI]

We study the kinematics of timelike geodesic congruences in two and four dimensions in spacetime geometries representing stringy black holes. The Raychaudhuri equations for the kinematical quantities (namely, expansion, shear and rotation) characterising such geodesic flows are written down and subsequently solved analytically (in two dimensions) and numerically (in four dimensions) for specific geodesics flows. We compare between geodesic flows in dual (electric and magnetic) stringy black hole backgrounds in four dimensions, by showing the differences that arise in the corresponding evolutions of the kinematic variables. The crucial role of initial conditions and the spacetime curvature on the evolution of the kinematical variables is illustrated. Some novel general conclusions on geodesic focusing are obtained from the analytical and numerical findings. We also propose new quantifiers in terms of (a) the time (affine parameter) of approach to a singularity and (b) the location of extrema in the functional evolution of the kinematic variables, which may be used to distinguish between flows in different geometries. In summary, our quantitative findings bring out hitherto unknown features of the kinematics of geodesic flows, which, otherwise, would have remained overlooked, if we confined ourselves to only a qualitative analysis.

Anirvan Dasgupta; Hemwati Nandan; Sayan Kar

2009-06-12T23:59:59.000Z

367

Modeling for Free Surface Flow with Phase Change  

SciTech Connect (OSTI)

The development of predictive capability for free surface flow with phase change is essential to evaluate liquid wall protection schemes for various fusion chambers in IFE and MFE. This paper presents a numerical methodology for free surface flow with heat and mass transfer to help resolve feasibility issues encountered in the aforementioned fusion engineering fields. The numerical methodology is conducted within the framework of the incompressible flow with the heat and mass transfer model. We present a new second-order projection method, in conjunction with Approximate-Factorization techniques (AF method) for incompressible Navier-Stokes equations. The level set method was used to capture the free surface of the flow and the deformation of the droplets accurately. This numerical investigation identifies the physics characterizing transient heat and mass transfer of the droplet and the free surface flow. The preliminary results show that the numerical methodology is successful in modeling the free surface with heat and mass transfer, though some severe deformation such as breaking and merging occurs. The versatility of the numerical methodology shows that the work can easily handle complex physical conditions in fusion science and engineering.

Luo Xiaoyong; Ni Mingjiu; Ying, Alice; Abdou, M. [University of California, Los Angeles (United States)

2005-05-15T23:59:59.000Z

368

Building America Webinar: High Performance Space Conditioning...  

Energy Savers [EERE]

Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried Ducts Building America Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried...

369

Space Conditioning Standing Technical Commitee Presentation ...  

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

Commitee Presentation Space Conditioning Standing Technical Commitee Presentation This presentation outlines the goals of the Space Conditioning Standing Technical ommittee, as...

370

Building America Webinar: High Performance Space Conditioning...  

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

II - Design Options for Locating Ducts within Conditioned Space Building America Webinar: High Performance Space Conditioning Systems, Part II - Design Options for Locating Ducts...

371

AnalyzeHOLE: An Integrated Wellbore Flow Analysis Tool  

SciTech Connect (OSTI)

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

372

A one-way coupled, EulerLagrangian simulation of bubble coalescence in a turbulent pipe flow  

E-Print Network [OSTI]

modifies the speed of sound in the bubbly mixture, which has implications for marine acoustic signatures. Gas­liquid flow at microgravity conditions ­ I. Dispersed bubble and slug flow. Int. J. Multiphase- ical in many heat transfer problems where liquid water contacting a hot surface boils and the resulting

Mahesh, Krishnan

373

Energy density is an important mea-sure of fish nutritional condition and  

E-Print Network [OSTI]

indices, energy density integrates and reflects the history of fish feed- ing environments before the time218 Energy density is an important mea- sure of fish nutritional condition and is used to assess growth, construct energy budgets, and measure energy flow in ecosystems (Brett et al., 1969; Jobling

374

On the current conditions along the Ormen Lange pipeline path during an extreme, idealized storm  

E-Print Network [OSTI]

On the current conditions along the Ormen Lange pipeline path during an extreme, idealized storm-shore for processing by means of a pipeline. Due to the abrupt topography this pipeline will have many long free spans along a possible path for the pipeline, and in a simulation study the effects on the flow due

Avlesen, Helge

375

Integrated Simulations for Multi-Component Analysis of Gas Turbines : RANS Boundary Conditions  

E-Print Network [OSTI]

More recently the coupling method has also been applied to a Pratt & Whitney gas turbine.7 The RANSIntegrated Simulations for Multi-Component Analysis of Gas Turbines : RANS Boundary Conditions 94305, U.S.A The aero-thermal computation of the flow path of an entire gas turbine engine can

Kim, Sangho

376

Hot conditioning equipment conceptual design report  

SciTech Connect (OSTI)

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

377

An evaluation of pressure and flow measurement in the Molten Salt Test Loop (MSTL) system.  

SciTech Connect (OSTI)

The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL allows customers and researchers to test components in flowing, molten nitrate salt at plant-like conditions for pressure, flow, and temperature. An important need in thermal storage systems that utilize molten salts is for accurate flow and pressure measurement at temperatures above 535%C2%B0C. Currently available flow and pressure instrumentation for molten salt is limited to 535%C2%B0C and even at this temperature the pressure measurement appears to have significant variability. It is the design practice in current Concentrating Solar Power plants to measure flow and pressure on the cold side of the process or in dead-legs where the salt can cool, but this practice won't be possible for high temperature salt systems. For this effort, a set of tests was conducted to evaluate the use of the pressure sensors for flow measurement across a device of known flow coefficient Cv. To perform this task, the pressure sensors performance was evaluated and was found to be lacking. The pressure indicators are severely affected by ambient conditions and were indicating pressure changes of nearly 200psi when there was no flow or pressure in the system. Several iterations of performance improvement were undertaken and the pressure changes were reduced to less than 15psi. The results of these pressure improvements were then tested for use as flow measurement. It was found that even with improved pressure sensors, this is not a reliable method of flow measurement. The need for improved flow and pressure measurement at high temperatures remains and will need to be solved before it will be possible to move to high temperature thermal storage systems with molten salts.

Gill, David Dennis; Kolb, William J.; Briggs, Ronald J.

2013-07-01T23:59:59.000Z

378

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

SciTech Connect (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

379

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

SciTech Connect (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

380

Effects of abnormal conditions on accuracy of orifice measurement  

SciTech Connect (OSTI)

The orifice meter is a remarkable paradox. Despite its incredible longevity and simple appearance, we`ve only begun to truly understand how its installation affects its performance. Hundreds of thousands of orifice meters are used for custody transfer around the world and every resulting transaction implies a base level of trust in the technology. Over the last 10 to 15 years we`ve learned more about the physics of flow measurement in {open_quotes}ideal{close_quotes} and {open_quotes}non-ideal{close_quotes} flow conditions. In many cases, the laboratory work confirms the experience of industry but there have been a few interesting surprises, too. The intended audience of this paper are users and/or designers of orifice meter facilities who want to know more about the contemporary issues, terminology, and results of research into abnormal metering conditions. Because of its introductory nature, this paper doesn`t attempt to squeeze twenty years if scientific data into five pages, but may lead the measurement aficionado toward specific areas of interest.

Peterson, W.B. [NOVA Gas Transmission Ltd., Calgary (Canada)

1995-12-01T23:59:59.000Z

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.


381

Stochastic models for turbulent reacting flows  

SciTech Connect (OSTI)

The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

382

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

Flow Duration Curve Load Duration Curve 1. Develop Flow Duration Curve 2. Estimate load given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve What are they? How do you make one? Describes the percent of time a flow rate

383

SHORT-TUBE SUBCRITICAL FLOW Enerag Division  

E-Print Network [OSTI]

#12;SHORT-TUBE SUBCRITICAL FLOW Y. C. Mei Enerag Division Oak Ridge National Laboratory Oak Ridge-tube subcritical flow. For short tubes used as refrigerant expansion devices, the orifice model is found inadequate-TUBE SUBCRITICAL FLOW INTRODUCTION Much theoretical and experimental work regarding short tube fluid flow has

Oak Ridge National Laboratory

384

Mach flow angularity probes for scramjet engine flow path diagnostics  

SciTech Connect (OSTI)

Mach-flow angularity (MFA) probes were developed for use in scramjet flow path probe rakes. Prototype probes were fabricated to demonstrate the assembly processes (numerical control machining, furnace brazing, and electron beam welding). Tests of prototype probes confirmed the thermal durability margins and life cycle. Selected probes were calibrated in air at Mach numbers from 1.75 to 6.0. Acceptance criteria for the production probes stressed thermal durability and pressure (and, consequently, Mach number) measurement quality. This new water-cooled MFA probe has 0.397-cm shaft diameter and is capable of withstanding heat fluxes of 2.724 kW/sq cm.

Jalbert, P.A.; Hiers, R.S. Jr. [Sverdrup Technology, Inc., Arnold AFS, TN (United States)

1993-12-31T23:59:59.000Z

385

Application of a Hydrodynamic Model for Assessing the Hydraulic Capacity and Flow Field at Willamette Falls Dam, Oregon  

SciTech Connect (OSTI)

The Willamette Falls Hydroelectric Power Dam, operated by Portland General Electric (PGE), is located on the Willamette River, Oregon. The Project site consists of T.W. Sullivan Power Plant and a 2,950-ft-long spillway located on the top of the Willamette Falls Dam. As part of the effort of protection and enhancement of environmental resources, a flow control structure at the dam was proposed to improve the flow field and enhance the downstream juvenile fish passage in the region just upstream of the forebay (pre-forebay). The flow in the pre-forebay of Willamette Falls Dam is affected by the complex geometry and bathymetry, powerhouse flow, fish ladder flow and the spillway around the dam. The expectation was that the flow would be sensitive to the proposed flow control structures and could be modified to enhance downstream migration. In this study, a three-dimensional, free-surface hydrodynamic model (EFDC) was developed for the pre-forebay region of Willamette Falls to evaluate the feasibility of the proposed alternative and its effect on the flow field in two different flow regimes (low and high river flow), as well as to assess the hydraulic capacity of flow control structures. One of the key challenges in this modeling study was to properly specify the free open boundary conditions along the 2,950-feet-long spillway. In this study, a pressure boundary condition based on hydraulic head rating curves was applied to the free spillway boundary. The numerical model was calibrated with ADP velocity measurements at 17 stations for the existing low flow condition. Good agreements between model results and measured data were obtained, indicating the successful application of pressure boundary condition on the free spillway boundary. The calibrated model was applied to simulate the flow field and free surface elevation in the high flow region near the control flow structures under different alternative conditions. The model results were used to evaluate the effectiveness of flow control structure alternative for downstream fish passage. The model was also used to estimate the hydraulic capacity based on the water surface head drops upstream of the structures. This model application demonstrated that a free surface coastal model can be used successfully to examine free surface hydraulic problems near high velocity regions upstream of spillways at dams.

Lee, Cheegwan; Yang, Zhaoqing; Khangaonkar, Tarang P.; Divers, Arya-Behbehani

2006-08-03T23:59:59.000Z

386

Conditions for Successful Extended Inflation  

E-Print Network [OSTI]

We investigate, in a model-independent way, the conditions required to obtain a satisfactory model of extended inflation in which inflation is brought to an end by a first-order phase transition. The constraints are that the correct present strength of the gravitational coupling is obtained, that the present theory of gravity is satisfactorily close to general relativity, that the perturbation spectra from inflation are compatible with large scale structure observations and that the bubble spectrum produced at the phase transition doesn't conflict with the observed level of microwave background anisotropies. We demonstrate that these constraints can be summarized in terms of the behaviour in the conformally related Einstein frame, and can be compactly illustrated graphically. We confirm the failure of existing models including the original extended inflation model, and construct models, albeit rather contrived ones, which satisfy all existing constraints.

Anne M Green; Andrew R Liddle

1996-06-10T23:59:59.000Z

387

CONMOW: Condition Monitoring for Offshore Wind Farms  

E-Print Network [OSTI]

practice the European project CONMOW (Condition Monitoring for Offshore Wind Farms) was started in November

Edwin Wiggelinkhuizen; Theo Verbruggen; Henk Braam; Luc Rademakers; Miguel Catalin Tipluica; Andrew Maclean; Axel Juhl Christensen; Edwin Becker; Pr?ftechnik Cm Gmbh (d; Dirk Scheffler; Nordex Energy Gmbh (d

388

Wind Turbine Drivetrain Condition Monitoring (Presentation)  

SciTech Connect (OSTI)

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

Sheng, S.

2011-10-01T23:59:59.000Z

389

Mirrored serpentine flow channels for fuel cell  

DOE Patents [OSTI]

A PEM fuel cell having serpentine flow field channels wherein the input/inlet legs of each channel border the input/inlet legs of the next adjacent channels in the same flow field, and the output/exit legs of each channel border the output/exit legs of the next adjacent channels in the same flow field. The serpentine fuel flow channels may be longer, and may contain more medial legs, than the serpentine oxidant flow channels.

Rock, Jeffrey Allan (Rochester, NY)

2000-08-08T23:59:59.000Z

390

Downward flow of water with entrained air in a nonuniformaly heated subdivided annulus  

SciTech Connect (OSTI)

This paper describes an experimental study in which water was fed to a vertical annulus, entraining air in downward flow. The annulus was subdivided by longitudinal fins into four subchannels and was heated with an azimuthally varying heat flux. A bypass was provided to simulate flow in parallel channels. For steady liquid flow, inlet temperature, and pressure boundary conditions, the power was increased until critical heat flux was reached. Overheating characteristics were grouped according to the prevailing flow pattern. In annular flows (j{sub L} < 0.3 m/s) overheating of the whole test section occurs when steam production causes countercurrent flooding. In intermittent flows (0.3 < j{sub L} < 0.9 m/s) the overheating is confined to a portion of the hot subchannel. The mechanism is postulated to be stagnation of a large bubble. In bubble flows (0.9 m/s < j{sub L}) overheating occurs by diverting inlet flow to the bypass and again involves the whole test section. Except at the very lowest flow rates, critical heat flux occurs when the effluent liquid temperature is below saturation.

Johnston, B.S.; May, C.P.

1992-10-01T23:59:59.000Z

391

Downward flow of water with entrained air in a nonuniformaly heated subdivided annulus  

SciTech Connect (OSTI)

This paper describes an experimental study in which water was fed to a vertical annulus, entraining air in downward flow. The annulus was subdivided by longitudinal fins into four subchannels and was heated with an azimuthally varying heat flux. A bypass was provided to simulate flow in parallel channels. For steady liquid flow, inlet temperature, and pressure boundary conditions, the power was increased until critical heat flux was reached. Overheating characteristics were grouped according to the prevailing flow pattern. In annular flows (j{sub L} < 0.3 m/s) overheating of the whole test section occurs when steam production causes countercurrent flooding. In intermittent flows (0.3 < j{sub L} < 0.9 m/s) the overheating is confined to a portion of the hot subchannel. The mechanism is postulated to be stagnation of a large bubble. In bubble flows (0.9 m/s < j{sub L}) overheating occurs by diverting inlet flow to the bypass and again involves the whole test section. Except at the very lowest flow rates, critical heat flux occurs when the effluent liquid temperature is below saturation.

Johnston, B.S.; May, C.P.

1992-01-01T23:59:59.000Z

392

Two-phase flow instability and dryout in parallel channels in natural circulation  

SciTech Connect (OSTI)

The unique feature of parallel channel flows is that the pressure drop or driving head for the flow is maintained constant across any given channel by the flow in all the others, or by having a large downcomer or bypass in a natural circulation loop. This boundary condition is common in all heat exchangers, reactor cores and boilers, it is well known that the two-phase flow in parallel channels can exhibit both so-called static and dynamic instability. This leads to the question of the separability of the flow and pressure drop boundary conditions in the study of stability and dryout. For the areas of practical interest, the flow can be considered as incompressible. The dynamic instability is characterized by density (kinematic) or continuity waves, and the static instability by inertial (pressure drop) or manometric escalations. The static has been considered to be the zero-frequency or lowest mode of the dynamic case. We briefly review the status of the existing literature on both parallel channel static and dynamic instability, and the latest developments in theory and experiment. The difference between the two derivations lies in the retention of the time-dependent terms in the conservation equations. The effects and impact of design options are also discussed. Since dryout in parallel systems follows instability, it has been traditional to determine the dryout power for a parallel channel by testing a single channel with a given (inlet) flow boundary condition without particular regard for the pressure drop. Thus all modern dryout correlations are based on constant or fixed flow tests, a so-called hard inlet, and subchannel and multiple bundle effects are corrected for separately. We review the thinking that lead to this approach, and suggest that for all multiple channel and natural circulation systems close attention should be paid to the actual (untested) pressure drop conditions. A conceptual formulation is suggested as a basis for discussion.

Duffey, R.B.; Rohatgi, U.S. [Brookhaven National Lab., Upton, NY (United States); Hughes, E.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1993-06-01T23:59:59.000Z

393

RESEARCH ARTICLE Effectiveness of pulse flows in a regulated river for inducing  

E-Print Network [OSTI]

) in a reach of the Puntledge River where water is diverted for power generation, resulting in stable low flows (i.e., turbine out flows), and/or the presence of non-optimal environmental conditions (i.e., cold, Courtenay, BC V9N 2Z5, Canada B. Mossop BC Hydro, 6911 Southpoint Drive, Burnaby, BC V3N 4X8, Canada S. G

Hinch, Scott G.

394

Integration of geodesic flows on homogeneous spaces: the case of a wild lie group  

E-Print Network [OSTI]

We obtain necessary and sufficient conditions for the integrability in quadratures of geodesic flows on homogeneous spaces $M$ with invariant and central metrics. The proposed integration algorithm consists in using a special canonical transformation in the space $T^*M$ based on constructing the canonical coordinates on the orbits of the coadjoint representation and on the simplectic sheets of the Poisson algebra of invariant functions. This algorithm is applicable to integrating geodesic flows on homogeneous spaces of a wild Lie group.

A. A. Magazev; I. V. Shirokov

2007-03-21T23:59:59.000Z

395

A field example of a gas orifice meter with debris-ridden liquid in mist flow  

SciTech Connect (OSTI)

A field example of debris-ridden liquids in an orifice meter is presented in this paper. Flow conditions in gas pipelines containing hydrocarbon liquids and particulate matter are discussed. Known effects on measurement of the presence of these materials in orifice meters is presented. By definition, gas measurement is accurate if performed on a clean and dry flow stream. This paper demonstrates the importance of removing as much liquid and debris as possible prior to measurement.

Chisholm, J.L.; Mooney, C.V. [Texas A and M Univ., Kingsville, TX (United States); Datta-Barua, L.; Feldmann, R.J.

1995-12-31T23:59:59.000Z

396

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

SciTech Connect (OSTI)

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

397

Pressure compensated flow control valve  

DOE Patents [OSTI]

The invention is an air flow control valve which is capable of maintaining a constant flow at the outlet despite changes in the inlet or outlet pressure. The device consists of a shell assembly with an inlet chamber and outlet chamber separated by a separation plate. The chambers are connected by an orifice. Also located within the inlet chamber is a port controller assembly. The port controller assembly consists of a differential pressure plate and port cap affixed thereon. The cap is able to slide in and out of the orifice separating the inlet and outlet chambers. When the pressure differential is sufficient, the differential pressure plate rises or falls to maintain a constant air flow. Movement of the port controller assembly does not require the use of seals, diaphragms, tight tolerances, bushings, bearings, hinges, guides, or lubricants.

Minteer, Daniel J. (West Richland, WA)

1999-01-01T23:59:59.000Z

398

Advanced tomographic flow diagnostics for opaque multiphase fluids  

SciTech Connect (OSTI)

This report documents the work performed for the ``Advanced Tomographic Flow Diagnostics for Opaque Multiphase Fluids`` LDRD (Laboratory-Directed Research and Development) project and is presented as the fulfillment of the LDRD reporting requirement. Dispersed multiphase flows, particularly gas-liquid flows, are industrially important to the chemical and applied-energy industries, where bubble-column reactors are employed for chemical synthesis and waste treatment. Due to the large range of length scales (10{sup {minus}6}-10{sup 1}m) inherent in real systems, direct numerical simulation is not possible at present, so computational simulations are forced to use models of subgrid-scale processes, the accuracy of which strongly impacts simulation fidelity. The development and validation of such subgrid-scale models requires data sets at representative conditions. The ideal measurement techniques would provide spatially and temporally resolved full-field measurements of the distributions of all phases, their velocity fields, and additional associated quantities such as pressure and temperature. No technique or set of techniques is known that satisfies this requirement. In this study, efforts are focused on characterizing the spatial distribution of the phases in two-phase gas-liquid flow and in three-phase gas-liquid-solid flow. Due to its industrial importance, the bubble-column geometry is selected for diagnostics development and assessment. Two bubble-column testbeds are utilized: one at laboratory scale and one close to industrial scale. Several techniques for measuring the phase distributions at conditions of industrial interest are examined: level-rise measurements, differential-pressure measurements, bulk electrical impedance measurements, electrical bubble probes, x-ray tomography, gamma-densitometry tomography, and electrical impedance tomography.

Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Jackson, N.B.; Shollenberger, K.A.

1997-05-01T23:59:59.000Z

399

Connectivity due to preferential flow controls water flow and solute transport at the hillslope scale  

E-Print Network [OSTI]

feedback, flow through the fractured bedrock, kinematic wave routing and flow through discrete preferentialConnectivity due to preferential flow controls water flow and solute transport at the hillslope the major controls on water flow and solute transport at the hillslope scale remains a major topic

Weiler, Markus

400

Rheo-optical determination of flow birefringence and flow dichroism with the pulsed laser method  

E-Print Network [OSTI]

Rheo-optical determination of flow birefringence and flow dichroism with the pulsed laser method online 29 August 2006 Rheo-optical measurements of the flow birefringence, flow dichroism systems under flow. However, the standard setup of an optical train, using phase modulation for the rheo-optical

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

Interfacial flows in corrugated microchannels: flow regimes, transitions and hysteresis  

E-Print Network [OSTI]

, 1266-1276 (2011), doi:10.1016/j.ijmultiphaseflow.2011.08.003 #12;model, microfluidics, porous media 1 of displacing oil by water in enhanced oil recovery (Marle, 1981; Lenormand et al., 1988). More recently on hy- drodynamic principles and concrete flow mechanisms. In fact, conflicting assumptions have been

Feng, James J.

402

Nuclear reactor downcomer flow deflector  

DOE Patents [OSTI]

A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

Gilmore, Charles B. (Greensburg, PA); Altman, David A. (Pittsburgh, PA); Singleton, Norman R. (Murrysville, PA)

2011-02-15T23:59:59.000Z

403

High gas flow alpha detector  

DOE Patents [OSTI]

An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors. 4 figs.

Bolton, R.D.; Bounds, J.A.; Rawool-Sullivan, M.W.

1996-05-07T23:59:59.000Z

404

High gas flow alpha detector  

DOE Patents [OSTI]

An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors.

Bolton, Richard D. (Los Alamos, NM); Bounds, John A. (Los Alamos, NM); Rawool-Sullivan, Mohini W. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

405

Non-Newtonian fluid flow  

E-Print Network [OSTI]

zero and unity. The Ostwald- de Waele Equation (4), commonly known as the power law, is sometimes used to describe fluid behavior of this type. The rheological equation is (4) where the parameters "k" and "n" are constant for a particular fluid... be extended to include Reynolds numbers and the type of flow determined to be laminar and/or turbulent. It is assumed that the transition from laminar to turbulent flow occurs at a Reynolds number of 2100, the numeric distribution of Reynolds numbers...

Osinski, Charles Anthony

1963-01-01T23:59:59.000Z

406

Dynamo action in flows with  

E-Print Network [OSTI]

Dynamo action in flows with cat's eyes A l i c e C o u r v o i s i e r A n d r e w G i l b e r t Y of k for R = 500 and the flow (2.4) and (2.5). nts k = 2.5 and k = 5 are highlighted. Magnetic field). In (a) k = 2.5 and we have 0.5 max Bz (with max Bz 0.6 max |B|), and in (b) k = 5 and the levels .65 max

Li, Yi

407

CX-008772: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Buried Flow Line from 32-A-34 to 34-AX-34 CX(s) Applied: B2.5, B5.2, B5.4 Date: 07/17/2012 Location(s): Wyoming Offices(s): RMOTC

408

CX-010968: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Novel Flow Sheet for Low Energy Carbon Dioxide (CO2) Capture Enabled by Biocatalyst Delivery System CX(s) Applied: A9 Date: 09/16/2013 Location(s): Pennsylvania Offices(s): National Energy Technology Laboratory

409

CX-010204: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Nalco / Total Flow Loop Polymer Test CX(s) Applied: B1.6, B1.13, B1.18 Date: 02/07/2013 Location(s): Wyoming Offices(s): RMOTC

410

CX-012166: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Perform Hydrant Flushing, Maintenance, Prove Curb Valves, and Flow Test in C-Area CX(s) Applied: B1.3 Date: 04/23/2014 Location(s): South Carolina Offices(s): Savannah River Operations Office

411

CX-012287: Categorical Exclusion Determination | Department of...  

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

Determination CX-012287: Categorical Exclusion Determination Development of Reduced-Order Model for Gas-Solid Flow Using Proper Orthogonal Decomposition CX(s) Applied: A9 Date: 06...

412

CX-012288: Categorical Exclusion Determination | Department of...  

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

Determination CX-012288: Categorical Exclusion Determination Development of Reduced-Order Model for Gas-Solid Flow Using Proper Orthogonal Decomposition CX(s) Applied: A9 Date: 06...

413

CX-011410: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Scalable Low-head Axial-type Venturi-flow Energy Scavenger CX(s) Applied: B5.24 Date: 11/05/2013 Location(s): New Mexico Offices(s): Golden Field Office

414

CX-008917: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Application of Crunch-Flow to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites CX(s) Applied: A9 Date: 08/29/2012 Location(s): Oregon Offices(s): National Energy Technology Laboratory

415

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect (OSTI)

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

416

Persistent energy flow for a stochastic wave equation model in nonequilibrium statistical mechanics  

E-Print Network [OSTI]

We consider a one-dimensional partial differential equation system modeling heat flow around a ring. The system includes a Klein-Gordon wave equation for a field satisfying spatial periodic boundary conditions, as well as Ornstein-Uhlenbeck stochastic differential equations with finite rank dissipation and stochastic driving terms modeling heat baths. There is an energy flow around the ring. In the case of a linear field with different (fixed) bath temperatures, the energy flow can persist even when the interaction with the baths is turned off. A simple example is given.

Lawrence E. Thomas

2012-04-29T23:59:59.000Z

417

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

SciTech Connect (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

418

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

SciTech Connect (OSTI)

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

419

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

SciTech Connect (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

420

Data Flow Testing Neelam Gupta  

E-Print Network [OSTI]

Data Flow Testing Neelam Gupta The University of Arizona, Tucson, Arizona and Rajiv Gupta The University of Arizona, Tucson, Arizona Software testing techniques are designed to execute a program on a set of test cases that provide su?cient coverage under some speci#12;c well-de#12;ned test coverage criterion

Gupta, Rajiv

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

Rinse trough with improved flow  

DOE Patents [OSTI]

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. 5 figs.

O`Hern, T.J.; Grasser, T.W.

1998-08-11T23:59:59.000Z

422

Comments on "Microscale flow visualization"  

E-Print Network [OSTI]

We make comments on the presentation of Sinton's paper (Microfluidics and Nanofluidics {\\bf 1}: 2, 2004) about the microscale flow visualization since the effects of the roughness along the microfabricated wall upon the current macroflow visualization methods could be significant and cannot be neglected in microdomain and even nanodomain.

A. Kwang-Hua Chu

2005-10-22T23:59:59.000Z

423

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

424

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

425

Flow preconditioner for electrostatic precipitator  

SciTech Connect (OSTI)

A flow preconditioner for an electrostatic precipitator removes particulate matter from a stream of polluted gas immediately after it passes through a tangential inlet at the lower end of a vertical cylindrical housing and straightens and divides the stream into laminations parallel to the axis of the housing. It comprises an annular ledge or choke ring extending inwardly from said housing above the inlet and an assembly of vanes above said ledge extending radially from the axis of the housing and angularly spaced apart. Each of said vanes has a flow receiving edge directed toward said inlet, a curved portion extending upwardly and away from said inlet, and a flat portion extending upwardly from said curved portion in a plane parallel to the housing axis. The curved portion of each vane defines a trough having a camber which gradually decreases along its span from the outer end of the vane towards the axis of the housng, together with means to vary the centrifugal flow distribution relative to the housing to render the preconditioner adjustable for various flow capacities.

Honacker, H.; Drlik, R.J.

1980-01-01T23:59:59.000Z

426

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

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference...

427

Effect of charged particle's multiplicity fluctuations on flow harmonics in even-by-event hydrodynamics  

E-Print Network [OSTI]

In nucleon-nucleon collisions, charged particle's multiplicity fluctuates. We have studied the effect of multiplicity fluctuation on flow harmonics in nucleus-nucleus collision in event-by-event hydrodynamics. Assuming that the charged particle's multiplicity fluctuations are governed by the negative binomial distribution, the Monte-Carlo Glauber model of initial condition is generalised to include the fluctuations. Explicit simulations with the generalised Monte-Carlo Glauber model initial conditions indicate that the multiplicity fluctuations do not have large effect on the flow harmonics.

Chaudhuri, A K

2012-01-01T23:59:59.000Z

428

Effect of charged particle's multiplicity fluctuations on flow harmonics in even-by-event hydrodynamics  

E-Print Network [OSTI]

In nucleon-nucleon collisions, charged particle's multiplicity fluctuates. We have studied the effect of multiplicity fluctuation on flow harmonics in nucleus-nucleus collision in event-by-event hydrodynamics. Assuming that the charged particle's multiplicity fluctuations are governed by the negative binomial distribution, the Monte-Carlo Glauber model of initial condition is generalised to include the fluctuations. Explicit simulations with the generalised Monte-Carlo Glauber model initial conditions indicate that the multiplicity fluctuations do not have large effect on the flow harmonics.

A. K. Chaudhuri

2013-03-19T23:59:59.000Z

429

Liquid metal Flow Meter - Final Report  

SciTech Connect (OSTI)

Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

Andersen C, Hoogendoom S, Hudson B, Prince J, Teichert K, Wood J, Chase K

2007-01-30T23:59:59.000Z

430

Laminar-turbulent separatrix in a boundary layer flow  

E-Print Network [OSTI]

The transitional boundary layer flow over a flat plate is investigated. The boundary layer flow is known to develop unstable Tollmien-Schlichting waves above a critical value of the Reynolds number. However, it is also known that this transition can be observed for sub-critical Reynolds numbers. In that case, the basin of attraction of the laminar state coexists with the sustained turbulence. In this article, the trajectory on the separatrix between these two states is simulated. The state on the separatrix is independent from the initial condition and is dynamically connected to both the laminar flow and the turbulence. Such an edge state provides information regarding the basic features of the transitional flow. The solution takes the form of a low speed streak, flanked by two quasi-streamwise sinuous vortices. The shape of the streaks is close to that simulated with the linear optimal perturbation method. This solution is compared to existing results concerning streak breakdown. The simulations are realize...

Biau, Damien

2013-01-01T23:59:59.000Z

431

Flow calculations for Yucca Mountain groundwater travel time (GWTT-95)  

SciTech Connect (OSTI)

In 1983, high-level radioactive waste repository performance requirements related to groundwater travel time were defined by NRC subsystem regulation 10 CFR 60.113. Although DOE is not presently attempting to demonstrate compliance with that regulation, understanding of the prevalence of fast paths in the groundwater flow system remains a critical element of any safety analyses for a potential repository system at Yucca Mountain, Nevada. Therefore, this analysis was performed to allow comparison of fast-path flow against the criteria set forth in the regulation. Models developed to describe the conditions for initiation, propagation, and sustainability of rapid groundwater movement in both the unsaturated and saturated zones will form part of the technical basis for total- system analyses to assess site viability and site licensability. One of the most significant findings is that the fastest travel times in both unsaturated and saturated zones are in the southern portion of the potential repository, so it is recommended that site characterization studies concentrate on this area. Results support the assumptions regarding the importance of an appropriate conceptual model of groundwater flow and the incorporation of heterogeneous material properties into the analyses. Groundwater travel times are sensitive to variation/uncertainty in hydrologic parameters and in infiltration flux at upper boundary of the problem domain. Simulated travel times are also sensitive to poorly constrained parameters of the interaction between flow in fractures and in the matrix.

Altman, S.J.; Arnold, B.W.; Barnard, R.W.; Barr, G.E.; Ho, C.K.; McKenna, S.A.; Eaton, R.R.

1996-09-01T23:59:59.000Z

432

Soluble Lead Flow Battery: Soluble Lead Flow Battery Technology  

SciTech Connect (OSTI)

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 todays 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

433

A New Approach to Industrial Air Conditioning  

E-Print Network [OSTI]

-dryer Systems Division, has marketed industrial drying machinery. These heat reactivated dryers can handle latent loads in industrial air conditioning systems. Through waste heat conservation, air conditioning costs can be reduced 25 to 50%, with applications...

Gravenstreter, T.

1982-01-01T23:59:59.000Z

434

Wind Turbine Drivetrain Condition Monitoring - An Overview  

SciTech Connect (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

435

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

SciTech Connect (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 Laboratorys (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

436

Building America Webinar: Retrofitting Central Space Conditioning...  

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

Control strategies to improve hydronic space heating performance Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Control...

437

Building America Webinar: Retrofitting Central Space Conditioning...  

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

Introduction Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Introduction This presentation serves as the introduction to...

438

Building America Webinar: High Performance Space Conditioning...  

Energy Savers [EERE]

Strategies for Affordable Housing Building America Webinar: High Performance Space Conditioning Systems, Part II - Air Distribution Retrofit Strategies for Affordable...

439

Test and evaluation of constant-flow devices for use in SSN AFFF proportioning systems. Interim report, January-May 1986  

SciTech Connect (OSTI)

Constant flow devices, which deliver a constant flow of liquid over a range of upstream and downstream pressures, have been suggested as an alternative to orifice plates for proportioning AFFF in SSN 21 fire-suppression systems. Operational and performance characteristics of two lightweight, inexpensive, commercially available constant-flow devices have significant advantages over orifice plates. Both models tested, however, showed performance degradation when subjected to simulated service conditions. A constant flow device with improved resistance to wear and to AFFF exposure is desirable. Since the constant-flow control devices tested improves proportioning efficiency but do not have optimum characteristics, investigation of improved devices or methods is recommended.

Williams, F.W.; Back, G.G.; Burns, R.E.; Quellette, R.J.; Scheffey, J.L.

1986-11-04T23:59:59.000Z

440

MAXIMAL CONDITIONAL EFFICIENCY SUCCESSIVE INTERFERENCE CANCELLATION  

E-Print Network [OSTI]

MAXIMAL CONDITIONAL EFFICIENCY SUCCESSIVE INTERFERENCE CANCELLATION Ananya Sen Gupta, Andrew C that maximizes the asymp- totic conditional efficiency at each stage of successive de- tection is also derived Urbana, IL 61801, USA ABSTRACT Conditional asymptotic multi-user efficiency is introduced

Singer, Andrew C

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.


441

Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT  

E-Print Network [OSTI]

Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT Yan Zhan, Foluso Ladeinde Stony Brook University thSep.21th , 2010 #12;OutlineOutline · Straight Pipe flowStraight Pipe flow · Curved pipe flow #12;OutlineOutline · Straight Pipe flowStraight Pipe flow · Curved pipe flow #12

McDonald, Kirk

442

Plugging of intersubassembly gaps by downward flowing molten steel. [LMFBR  

SciTech Connect (OSTI)

In the assessment of the meltout phase of an LMFBR hypothetical core disruptive accident, a pathway for the escape of molten fuel from the disrupted core is provided by the narrow channels separating adjacent subassemblies. However, the removal of fuel through intersubassembly gaps might be impeded by steel blockage formation, if molten steel is postulated to enter the gap network ahead of disrupted fuel. Reported here are the results of an analysis of the conduction freezing controlled penetration behavior of molten steel flowing downward through the voided (of sodium) gap channels nominally separating adjacent subassemblies below the active core region. The objective is to determine the range of conditions under which the steel is predicted to be deposited as a thin crust on the channel walls leaving an open pathway remaining for subsequent fuel flow instead of forming a complete plug which closes off the gap channel and obstructs fuel removal immediately thereafter.

Sienicki, J.J.; Spencer, B.W.

1984-01-01T23:59:59.000Z

443

An Inverted Co-Flow Diffusion Flame for Producing Soot  

SciTech Connect (OSTI)

We developed an inverted, co-flow, methane/air/nitrogen burner that generates a wide range of soot particles sizes and concentrations. By adjusting the flow rates of air, methane, and nitrogen in the fuel, the mean electric mobility diameter and number concentration are varied. Additional dilution downstream of the flame allows us to generate particle concentrations spanning those produced by spark-ignited and diesel engines: particles with mean diameters between 50 and 250 nm and number concentrations from 4.7 {center_dot} 10{sup 4} to 10{sup 7} cm{sup -3}. The range of achievable number concentrations, and therefore volume concentrations, can be increased by a factor of 30 by reducing the dilution ratio. These operating conditions make this burner valuable for developing and calibrating diagnostics as well as for other studies involving soot particles.

Stipe, Christopher B.; Higgins, Brian S.; Lucas, Donald; Koshland, Catherine P.; Sawyer, Robert F.

2005-06-21T23:59:59.000Z

444

Analysis of oscillating flow cooled SMA actuator  

E-Print Network [OSTI]

literature, most of the cooling mechanisms involve unidirectional forced convection. This may not be the most effective method. Oscillating flow in a channel can sometimes enhance heat transfer over a unidirectional flow. One possible explanation...

Pachalla Seshadri, Rajagopal

2005-11-01T23:59:59.000Z

445

A quasionedimensional approach for hypersonic stagnationpoint flows  

E-Print Network [OSTI]

A quasi­onedimensional approach for hypersonic stagnation­point flows Arno Klomfass 1 Lehr­ und An approximate method for the efficient calculation of stagnation streamline quantities in hypersonic flows about

446

GUI for Hypersonic flow solver Master Project  

E-Print Network [OSTI]

GUI for Hypersonic flow solver Master Project Student : Enrique Guzman concerns the design of a GUI for commanding hypersonic flow applications using CFD techniques, as well as its potential applications. These problems are quite complex, since the called hypersonic regime

Diggavi, Suhas

447

Smokeless Control of Flare Steam Flow Rate  

E-Print Network [OSTI]

measurement of mass flow rate of flare gas, in spite of the hostile environment. Its use for initiating control of flare steam flow rate and the addition of molecular weight compensation, using specific gravity (relative density) measurement to achieve...

Agar, J.; Balls, B. W.

1979-01-01T23:59:59.000Z

448

Decentralized information flow control on a cluster  

E-Print Network [OSTI]

Information flow control security models can prevent programs from divulging sensitive information in unexpected ways. There has been significant work on tracking information flow between processes in the same computer at ...

Cliffer, Natan Tsvi Cohen

2007-01-01T23:59:59.000Z

449

Electromagnetically Induced Flows Michiel de Reus  

E-Print Network [OSTI]

Electromagnetically Induced Flows in Water Michiel de Reus 8 maart 2013 () Electromagnetically Conclusion and future research () Electromagnetically Induced Flows 2 / 56 #12;1 Introduction 2 Maxwell Navier Stokes equations 5 Simulations 6 Conclusion and future research () Electromagnetically Induced

Vuik, Kees

450

Numerical simulation of electrokinetically driven micro flows  

E-Print Network [OSTI]

Spectral element based numerical solvers are developed to simulate electrokinetically driven flows for micro-fluidic applications. Based on these numerical solvers, basic phenomena and devices for electrokinetic applications in micro and nano flows...

Hahm, Jungyoon

2005-11-01T23:59:59.000Z

451

gtp_flow_power_estimator.xlsx  

Broader source: Energy.gov [DOE]

This simple spreadsheet model estimates either the flow rate required to produce a specified level of power output, or the power output that can be produced from a specified flow rate.

452

High Energy Efficiency Air Conditioning  

SciTech Connect (OSTI)

This project determined the performance of a new high efficiency refrigerant, Ikon B, in a residential air conditioner designed to use R-22. The refrigerant R-22, used in residential and small commercial air conditioners, is being phased out of production in developed countries beginning this year because of concerns regarding its ozone depletion potential. Although a replacement refrigerant, R-410A, is available, it operates at much higher pressure than R-22 and requires new equipment. R-22 air conditioners will continue to be in use for many years to come. Air conditioning is a large part of expensive summer peak power use in many parts of the U.S. Previous testing and computer simulations of Ikon B indicated that it would have 20 - 25% higher coefficient of performance (COP, the amount of cooling obtained per energy used) than R-22 in an air-cooled air conditioner. In this project, a typical new R-22 residential air conditioner was obtained, installed in a large environmental chamber, instrumented, and run both with its original charge of R-22 and then with Ikon B. In the environmental chamber, controlled temperature and humidity could be maintained to obtain repeatable and comparable energy use results. Tests with Ikon B included runs with and without a power controller, and an extended run for several months with subsequent analyses to check compatibility of Ikon B with the air conditioner materials and lubricant. Baseline energy use of the air conditioner with its original R-22 charge was measured at 90 deg F and 100 deg F. After changeover to Ikon B and a larger expansion orifice, energy use was measured at 90 deg F and 100 deg F. Ikon B proved to have about 19% higher COP at 90 deg F and about 26% higher COP at 100 deg F versus R-22. Ikon B had about 20% lower cooling capacity at 90 deg F and about 17% lower cooling capacity at 100 deg F versus R-22 in this system. All results over multiple runs were within 1% relative standard deviation (RSD). All of these values agree well with previous results and computer simulations of Ikon B performance versus R-22. The lower cooling capacity of Ikon B is not a concern unless a particular air conditioner is near its maximum cooling capacity in application. Typically, oversized A/C systems are installed by contractors to cover contingencies. In the extended run with Ikon B, which lasted about 4.5 months at 100 deg F ambient temperature and 68% compressor on time, the air conditioner performed well with no significant loss of energy efficiency. Post-run analysis of the refrigerant, compressor lubricant oil, compressor, compressor outlet tubing, and the filter/dryer showed minor effects but nothing that was considered significant. The project was very successful. All objectives were achieved, and the performance of Ikon B indicates that it can easily be retrofitted into R-22 air conditioners to give 15 - 20% energy savings and a 1 - 3 year payback of retrofit costs depending on location and use. Ikon B has the potential to be a successful commercial product.

Edward McCullough; Patrick Dhooge; Jonathan Nimitz

2003-12-31T23:59:59.000Z

453

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

SciTech Connect (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

454

Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited)  

SciTech Connect (OSTI)

A new coherence imaging Doppler spectroscopy diagnostic has been deployed on the UKs Mega Amp Spherical Tokamak for scrape-off-layer and divertor impurity flow measurements. The system has successfully obtained 2D images of C III, C II, and He II line-of-sight flows, in both the lower divertor and main scrape-off-layer. Flow imaging has been obtained at frame rates up to 1 kHz, with flow resolution of around 1 km/s and spatial resolution better than 1 cm, over a 40 field of view. C III data have been tomographically inverted to obtain poloidal profiles of the parallel impurity flow in the divertor under various conditions. In this paper we present the details of the instrument design, operation, calibration, and data analysis as well as a selection of flow imaging results which demonstrate the diagnostic's capabilities.

Silburn, S. A., E-mail: s.a.silburn@durham.ac.uk; Sharples, R. M. [Centre for Advanced Instrumentation, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Harrison, J. R.; Meyer, H.; Michael, C. A. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Howard, J. [Plasma Research Laboratory, Australian National University, Canberra, ACT 0200 (Australia); Gibson, K. J. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2014-11-15T23:59:59.000Z

455

Cascade redox flow battery systems  

DOE Patents [OSTI]

A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

2014-07-22T23:59:59.000Z

456

Gas flow in barred potentials  

E-Print Network [OSTI]

We use a Cartesian grid to simulate the flow of gas in a barred Galactic potential and investigate the effects of varying the sound speed in the gas and the resolution of the grid. For all sound speeds and resolutions, streamlines closely follow closed orbits at large and small radii. At intermediate radii shocks arise and the streamlines shift between two families of closed orbits. The point at which the shocks appear and the streamlines shift between orbit families depends strongly on sound speed and resolution. For sufficiently large values of these two parameters, the transfer happens at the cusped orbit as hypothesised by Binney et al. over two decades ago. For sufficiently high resolutions the flow downstream of the shocks becomes unsteady. If this unsteadiness is physical, as appears to be the case, it provides a promising explanation for the asymmetry in the observed distribution of CO.

Sormani, Mattia C; Magorrian, John

2015-01-01T23:59:59.000Z

457

Zonal Flow as Pattern Formation  

E-Print Network [OSTI]

In this section, we examine the transition from statistically homogeneous turbulence to inhomogeneous turbulence with zonal flows. Statistical equations of motion can be derived from the quasilinear approximation to the Hasegawa-Mima equation. We review recent work that finds a bifurcation of these equations and shows that the emergence of zonal flows mathematically follows a standard type of pattern formation. We also show that the dispersion relation of modulational instability can be extracted from the statistical equations of motion in a certain limit. The statistical formulation can thus be thought to offer a more general perspective on growth of coherent structures, namely through instability of a full turbulent spectrum. Finally, we offer a physical perspective on the growth of large-scale structures.

Parker, Jeffrey B

2015-01-01T23:59:59.000Z

458

Internat. Congress on Science & Technology of Steelmaking, Charlotte, NC, May 9-12, AIST, Warrendale, PA, 2005, pp. 847-861. Modeling of Continuous-Casting Defects Related to Mold Fluid Flow  

E-Print Network [OSTI]

that is neither too cold nor too turbulent. In addition, the flow conditions should minimize exposure to air optimization. Fluid flow in the mold is controlled by many design parameters and operating conditions. Nozzle geometry is the most important, and includes the bore size, port angle, port opening size, nozzle wall

Thomas, Brian G.

459

Conditional averaging on volumetric velocity fields for analysis of the pseudo-periodic organization of jet-in-crossflow vortices  

E-Print Network [OSTI]

Volumetric velocimetry measurements have been performed on a round jet in crossflow (JICF). Two kind of conditional averaging process are presented : a global conditional average (GCA) and a local conditional average (LCA). Vortices crossing the JICF symmetry plane are used to quantify the jet pseudo-periodicity leading to the GCA and LCA definitions. Because they make possible to improve the velocity field resolution as well as to significantly reduce the experimental noise, these conditional averages are an interesting and efficient way to study the instantaneous swirling structures of this instantaneous flow.

Cambonie, Tristan

2014-01-01T23:59:59.000Z

460

Flow Imaging Using MRI: Quantification and Analysis  

E-Print Network [OSTI]

&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Jim Ji Committee Members, Andrew K. Chan Deepa Kundur Yoonsuck Choe Mary P. McDougall Head of Department, Costas N... Committee: Dr. Jim Ji A complex and challenging problem in flow study is to obtain quantitative flow information in opaque systems, for example, blood flow in biological systems and flow channels in chemical reactors. In this regard, MRI is superior...

Jiraraksopakun, Yuttapong

2010-07-14T23:59:59.000Z

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

A theory for radial jet reattachment flow  

E-Print Network [OSTI]

, the velocity profile and mass entrainment are given accordrng to Goertler's t. wo- dimensional free jet theory. His analysrs of a free jet also assumes that. the turbulent eddy viscosity is constant ar ross the jet. (6) For the case of laminar flow... of total jet momentum. Laminar jet flow is approximated using Schlichting's velocity profile, whereas turbulent flow calculations are made assuming Goertler's velocity profile. Momentum integral principles are applied to the flow at reattachment...

Hadden, Lynne Loise

2012-06-07T23:59:59.000Z

462

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

2011-06-30T23:59:59.000Z

463

Building up the elliptic flow: analytical insights  

E-Print Network [OSTI]

In this paper, we present a fully analytical description of the early-stage formation of elliptic flow in relativistic viscous hydrodynamics. We first construct an elliptic deformation of Gubser flow which is a boost invariant solution of the Navier-Stokes equation with a nontrivial transverse profile. We then analytically calculate the momentum anisotropy of the flow as a function of time and discuss the connection with the empirical formula by Bhalerao {\\it et al.} regarding the viscosity dependence of elliptic flow.

Yoshitaka Hatta; Bo-Wen Xiao

2014-07-15T23:59:59.000Z

464

The Cotton tensor and the Ricci flow  

E-Print Network [OSTI]

We compute the evolution equation of the Cotton tensor under the Ricci flow of a three dimensional Riemannian manifold.

Mantegazza, Carlo

2012-01-01T23:59:59.000Z

465

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

466

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.

Wilkinson, William H. (Columbus, OH)

1984-01-01T23:59:59.000Z

467

Microgravity Flow Regime Transition Modeling  

E-Print Network [OSTI]

apparatus have been used in past flow regime mapping experiments such as Venturi, perforated pipe, annular, and t-junction mixers. The mixing apparatus used in a particular experiment determines the bubble size distribution at the inlet... pressure of 80 kPa was reported, however, the temperature was not. The orientation and location of the test section with respect to the aircraft are unknown. The mixing apparatus used in the experiment was a Venturi mixer. This data set does...

Shephard, Adam M.

2010-07-14T23:59:59.000Z

468

Incompressible flow over delta wings  

E-Print Network [OSTI]

&M University. vi TABLE OF CONTENTS ~Pa e INTRODUCTION REVIEW OF LITERATURE THEORY 12 NUMERICAL APPLICATIONS AND RESULTS Attached Flow Model Calculation of Pressure Distribution Fixed-Wake Model Free-Wake Model CONCLUSIONS 21 21 24 26 32 52...- lation. This theory has been expanded to include spanwise velocity effects and the leading-edge separation associated with delta wings. The numerical technique has made use of both fixed and free wakes. In the fixed-wake model the analytical results...

Nathman, James Kirwin

1976-01-01T23:59:59.000Z

469

Direct numerical simulation of turbulent reacting flows  

SciTech Connect (OSTI)

The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

470

Structural stability of cooling flows  

E-Print Network [OSTI]

Three-dimensional hydrodynamical simulations are used to investigate the structural stability of cooling flows that are episodically heated by jets from a central AGN. The radial profile of energy deposition is controlled by (a) the power of the jets, and (b) the pre-outburst density profile. A delay in the ignition of the jets causes more powerful jets to impact on a more centrally concentrated medium. The net effect is a sufficient increase in the central concentration of energy deposition to cause the post-outburst density profile to be less centrally concentrated than that of an identical cluster in which the outburst happened earlier and was weaker. These results suggest that the density profiles of cooling flows oscillate around an attracting profile, thus explaining why cooling flows are observed to have similar density profiles. The possibility is raised that powerful FR II systems are ones in which this feedback mechanism has broken down and a runaway growth of the source parameters has occurred.

Henrik Omma; James Binney

2003-12-31T23:59:59.000Z

471

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

#12;Flow Duration Curve Load Duration Curve #12;1. Develop Flow Duration Curve 2. Estimate load given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve #12;What are they? How do you make one? #12;Describes

472

A quasionedimensional approach for hypersonic stagnationpoint flows  

E-Print Network [OSTI]

A quasi­onedimensional approach for hypersonic stagnation­point flows Arno Klomfass 1 Lehr­ und An approximate method for the efficient calculation of stagnation streamline quantities in hypersonic flows about­conduction coefficient [W=mK] 2 Introduction The hypersonic flow about a spacecraft entering the atmosphere at orbital

473

Optimal Power Flow Incorporating Voltage Collapse Constraints  

E-Print Network [OSTI]

Optimal Power Flow Incorporating Voltage Collapse Constraints William Rosehart Claudio Ca on the current operating con- ditions is presented. Second, an Optimal Power Flow formulation that incorporates: Voltage Collapse, Optimal Power Flow, Bifur- cations. I. Introduction As open-access market principles

Cañizares, Claudio A.

474

(Preview Draft) Chapter 3. Stocks and Flows  

E-Print Network [OSTI]

the state over time. It will take some time for the flows to have their effect on the stocks, so the stocks(Preview Draft) Chapter 3. Stocks and Flows: The Building Blocks of System Dynamics Models The best way to construct a model is to start with the stocks, add the flows and then use converters to explain

Ford, Andrew

475

Progress in Grid Scale Flow Batteries  

E-Print Network [OSTI]

Progress in Grid Scale Flow Batteries IMRE GYUK, PROGRAM MANAGER ENERGY STORAGE RESEARCH, DOE Flow;LogMW Renewables (not capacity factor adjusted) 9 8 7 6 5 4 3 Wind Wind (proj) Solar PV Solar PV 2011Year #12;Flow Battery Research at PNNL and Sandia #12

476

Managing talent flow. 2006 Energy and Resources  

E-Print Network [OSTI]

Managing talent flow. 2006 Energy and Resources Talent Pulse Survey Report Consulting #12;Executive ................................................................ 13 Contents #12;1 Managing talent flow 2006 Energy and Resources Talent Pulse Survey Report 2006 strategy. 1 #12;2 Managing talent flow 2006 Energy and Resources Talent Pulse Survey Report Key findings

477

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-Print Network [OSTI]

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. II CO2 is separated from natural

Santos, Juan

478

Setup of Particle Image Velocimetry (PIV) in Hypersonic Flows.  

E-Print Network [OSTI]

??The accuracy of numerical methods in calculating the flow of backward facing steps in turbulent hypersonic flows is limited due to a lack of flow (more)

Anwar, Moazzam

2008-01-01T23:59:59.000Z

479

WHICH HYDRAULIC MODEL TO USE IN VERTICAL FLOW CONSTRUCTED WETLANDS?  

E-Print Network [OSTI]

WHICH HYDRAULIC MODEL TO USE IN VERTICAL FLOW CONSTRUCTED WETLANDS? Ania Morvannoua , Nicolas-equilibrium model, preferential flow path, vertical flow constructed wetlands INTRODUCTION Constructed wetlands (CWs

Paris-Sud XI, Université de

480

Organized Oscillations of Initially-Turbulent Flow Past a Cavity  

SciTech Connect (OSTI)

Flow past an open cavity is known to give rise to self-sustained oscillations in a wide variety of configurations, including slotted-wall, wind and water tunnels, slotted flumes, bellows-type pipe geometries, high-head gates and gate slots, aircraft components and internal piping systems. These cavity-type oscillations are the origin of coherent and broadband sources of noise and, if the structure is sufficiently flexible, flow-induced vibration as well. Moreover, depending upon the state of the cavity oscillation, substantial alterations of the mean drag may be induced. In the following, the state of knowledge of flow past cavities, based primarily on laminar inflow conditions, is described within a framework based on the flow physics. Then, the major unresolved issues for this class of flows will be delineated. Self-excited cavity oscillations have generic features, which are assessed in detail in the reviews of Rockwell and Naudascher, Rockwell, Howe and Rockwell. These features, which are illustrated in the schematic of Figure 1, are: (i) interaction of a vorticity concentration(s) with the downstream corner, (ii) upstream influence from this corner interaction to the sensitive region of the shear layer formed from the upstream corner of the cavity; (iii) conversion of the upstream influence arriving at this location to a fluctuation in the separating shear layer; and (iv) amplification of this fluctuation in the shear layer as it develops in the streamwise direction. In view of the fact that inflow shear-layer in the present investigation is fully turbulent, item (iv) is of particular interest. It is generally recognized, at least for laminar conditions at separation from the leading-corner of the cavity, that the disturbance growth in the shear layer can be described using concepts of linearized, inviscid stability theory, as shown by Rockwell, Sarohia, and Knisely and Rockwell. As demonstrated by Knisely and Rockwell, on the basis of experiments interpreted with the aid of linearized theory, not only the fundamental component of the shear layer instability may be present, but a number of additional, primarily lower frequency components can exist as well. In fact, the magnitude of these components can be of the same order as the fundamental component. These issues have not been addressed for the case of a fully-turbulent in-flow and its separation from the leading corner of the cavity.

J.C. Lin; D. Rockwell

2002-09-17T23:59:59.000Z

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481

Numerical study of transition to supersonic flows in the edge plasma  

SciTech Connect (OSTI)

The plasma scrape-off layer (SOL) in a tokamak is characterized by ion flow down a long narrow flux tube terminating on a solid surface. The ion flow velocity along a magnetic field line can be equal to or greater than sonic at the entrance of a Debye sheath or upstream in the presheath. This paper presents a numerical study of the transition between subsonic and supersonics flows. A quasineutral one-dimensional (1D) fluid code has been used for modeling of plasma transport in the SOL along magnetic field lines, both in steady state and under transient conditions. The model uses coupled equations for continuity, momentum, and energy balance with ionization, radiation, charge exchange, and recombination processes. The recycled neutrals are described in the diffusion approximation. Standard Bohm sheath criterion is used as boundary conditions at the material surface. Three conditions conducive for the generation of supersonic flows in SOL plasmas have been explored. It is found that in steady state high (attached) and low (detached) divertor temperatures cases, the role of particle, momentum, and energy loss is critical. For attached case, the appearance of shock waves in the divertor region if the incoming plasma flow is supersonic and its effect on impurity retention is presented. In the third case, plasma expansion along the magnetic field can yield time-dependent supersonic solutions in the quasineutral rarefaction wave. Such situations can arise in the parallel transport of intermittent structures such as blobs and edge localized mode filaments along field lines.

Goswami, Rajiv, E-mail: rajiv@ipr.res.in; Artaud, Jean-Franois; Imbeaux, Frdric [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar382428 (India)

2014-07-15T23:59:59.000Z

482

Field-Flow Fractionation of Carbon Nanotubes and Related Materials  

SciTech Connect (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

483

Transport bifurcation induced by sheared toroidal flow in tokamak plasmas  

SciTech Connect (OSTI)

First-principles numerical simulations are used to describe a transport bifurcation in a differentially rotating tokamak plasma. Such a bifurcation is more probable in a region of zero magnetic shear than one of finite magnetic shear, because in the former case the component of the sheared toroidal flow that is perpendicular to the magnetic field has the strongest suppressing effect on the turbulence. In the zero-magnetic-shear regime, there are no growing linear eigenmodes at any finite value of flow shear. However, subcritical turbulence can be sustained, owing to the existence of modes, driven by the ion temperature gradient and the parallel velocity gradient, which grow transiently. Nonetheless, in a parameter space containing a wide range of temperature gradients and velocity shears, there is a sizeable window where all turbulence is suppressed. Combined with the relatively low transport of momentum by collisional (neoclassical) mechanisms, this produces the conditions for a bifurcation from low to high temperature and velocity gradients. A parametric model is constructed which accurately describes the combined effect of the temperature gradient and the flow gradient over a wide range of their values. Using this parametric model, it is shown that in the reduced-transport state, heat is transported almost neoclassically, while momentum transport is dominated by subcritical parallel-velocity-gradient-driven turbulence. It is further shown that for any given input of torque, there is an optimum input of heat which maximises the temperature gradient. The parametric model describes both the behaviour of the subcritical turbulence (which cannot be modelled by the quasi-linear methods used in current transport codes) and the complicated effect of the flow shear on the transport stiffness. It may prove useful for transport modelling of tokamaks with sheared flows.

Highcock, E. G.; Barnes, M. [Rudolph Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Parra, F. I.; Schekochihin, A. A. [Rudolph Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Roach, C. M.; Cowley, S. C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2011-10-15T23:59:59.000Z

484

Two-dimensional flow of foam around an obstacle: force measurements  

E-Print Network [OSTI]

A Stokes experiment for foams is proposed. It consists in a two-dimensional flow of a foam, confined between a water subphase and a top plate, around a fixed circular obstacle. We present systematic measurements of the drag exerted by the flowing foam on the obstacle, \\emph{versus} various separately controlled parameters: flow rate, bubble volume, bulk viscosity, obstacle size, shape and boundary conditions. We separate the drag into two contributions, an elastic one (yield drag) at vanishing flow rate, and a fluid one (viscous coefficient) increasing with flow rate. We quantify the influence of each control parameter on the drag. The results exhibit in particular a power-law dependence of the drag as a function of the bulk viscosity and the flow rate with two different exponents. Moreover, we show that the drag decreases with bubble size, and increases proportionally to the obstacle size. We quantify the effect of shape through a dimensioned drag coefficient, and we show that the effect of boundary conditions is small.

Benjamin Dollet; Florence Elias; Catherine Quilliet; Christophe Raufaste; Miguel Aubouy; Francois Graner

2004-10-13T23:59:59.000Z

485

Thermal/chemical degradation of ceramic cross-flow filter materials  

SciTech Connect (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

486

PROBABILISTIC SIMULATION OF SUBSURFACE FLUID FLOW: A STUDY USING A NUMERICAL SCHEME  

SciTech Connect (OSTI)

There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.

Buscheck, Timothy Eric

1980-03-01T23:59:59.000Z

487

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

488

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; Graldine Pichot

2006-12-20T23:59:59.000Z

489

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

490

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

491

Effect of bulk viscosity in low density, hypersonic blunt body flows  

SciTech Connect (OSTI)

A computational fluids dynamics scheme is presented to solve the unsteady Thin-Layer Navier-Stokes (TLNS) equations over a blunt body at high altitude, high Mach number atmospheric reentry flow conditions. This continuum approach is directed to low density hypersonic flows by accounting for non-zero bulk viscosity effects in near frozen flow conditions. The TLNS equations are solved over an axisymmetric body at zero incidence relative to the free stream. The time dependent axisymmetric governing equations are transformed into a computational plane, then cast into weak conservative form and solved using a first-order fully implicit scheme in time with second-order flux vector splitting for spatial derivatives. The physical domain is defined over representative sphere and sphere/cone geometries using a body-fitted clustered algebraic grid within a fixed domain (i.e., shock capturing). At the present time, nonequilibrium thermo-chemistry effects are not modeled. Catalytic wall, ionization and radiation effects are also excluded from the current analysis. However, the significant difference from previous studies is the inclusion of the capability to model non-zero bulk viscosity effects. The importance of bulk viscosity is reviewed and blunt body flow field solutions are presented to illustrate the potential contribution of this phenomena at high altitude hypersonic conditions. The current technique is compared with experimental data and other approximate continuum solutions. A variety of test cases are also presented for a wide range of free stream Mach conditions. 18 refs., 42 figs.

Rutledge, W.H. (Sandia National Labs., Albuquerque, NM (USA)); Hoffmann, K.A. (Texas Univ., Austin, TX (USA))

1991-01-01T23:59:59.000Z

492

An experimental study of flow boiling characteristics of carbon dioxide in multiport mini channels  

E-Print Network [OSTI]

& Technology, Clear Water Bay, Kowloon, Hong Kong, China d Aluminum Technology Center, Showa Denko K.K. Oyama of CO2 flowing in a multi-port extruded aluminum test section, which had 10 circular channels, each. The promising applications of CO2 refrigeration systems include automotive air conditioning, heat pumps

Zhao, Tianshou

493

Verification of flow processes in soils with combined sprinkling and dye tracer experiments  

E-Print Network [OSTI]

1 Verification of flow processes in soils with combined sprinkling and dye tracer experiments with sprinkling experiments and dye tracing under different rainfall intensities and soil moisture conditions. The dye tracer was continuously applied with the sprinkling water on 1 m2 plots. After the sprinkling

Weiler, Markus

494

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...

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

495

MatrixFree SecondOrder Methods in Implicit Time Integration for Compressible Flows Using  

E-Print Network [OSTI]

as a design tool reducing the number of expensive wind tunnel experiments. The three­dimensional simulation of the flow field around an aircraft requires accurate and e#cient numerical methods in order to resolve all of high­capacity aircraft in transonic conditions, such as deformation of airplane wings and wake vortices