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1

FLOW CONDITIONING DESIGN IN TURBULENT  

E-Print Network [OSTI]

for HYLIFE-II · Measure loss coefficient across the flow conditioner / nozzle assembly for different flow conditioner configurations #12;5 Flow Loop A Pump H 400 gal tank B Bypass line I Butterfly valve C Flow meter

2

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

3

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

4

Flow boundary conditions for chain-end adsorbing polymer blends  

E-Print Network [OSTI]

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the surface defects. In response to the increase of the number of the adsorbed additives the surface layer becomes thinner and solidifies. This results in a gradual transition from the slip to the no-slip boundary condition for the melt flow, with a non-monotonic dependence of the slip length on the surface concentration of the adsorbed ends.

X. Zhou; D. Andrienko; L. Delle Site; K. Kremer

2005-07-18T23:59:59.000Z

5

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

6

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

7

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

8

Multiphase Flow in Complex Fracture Apertures Under a Wide Range of Flow Conditions  

SciTech Connect (OSTI)

The summary below is an update of our previous progress report of June, 2003. That previous progress report, which was submitted as a PDF document, is not recorded on the RIMS website but will appear on the EMSP website. Our recent results are in the following areas: (1) Single-component flow through a rough-walled fracture to validate our methods, we have simulated slow single-component fluid flow through a geometry taken from analogous laboratory experiments. The permeability of this fracture is studied as the direction of the driving force is changed. We find that the lattice-Boltzmann method agrees with the experimental data and with previous numerical efforts. Additionally, flow enhancement compared to the well-known cubic law is observed in certain directions, i.e., the direction in which channels are most strongly correlated. Conversely, flow inhibition is observed in the perpendicular direction. Fluid flow appears to follow the correlated channels. We are currently extending these studies to higher Reynolds numbers where classical approximations based on assumptions of slow creeping flow are no longer valid. (2) Capillary rise in simple and complex geometries Capillary rise is studied using the lattice-Boltzmann method. The geometries used are a circular tube, a rectangular tube, and a fracture between two rough walls. The capillary rise height and the shape of the interface is studied as a function of the size of the tube, the wetting tendency of the walls, the surface tension, and the magnitude of an applied body force. In performing this study we discovered a technical problem with the lattice-Boltzmann method: it exhibited lattice pinning. This pinning created two significant problems: the entrapment of small bubbles and a history dependence of the contact angle. We solved these problems by modifying our algorithm so that it now allows interfaces to move at a smaller velocity. The new method practically removes all effects of lattice pinning. For the case of rectangular tubes, we have shown that the shape of the interface follows theoretical predictions and that the pressure drop across the interface obeys Laplace's law. Consequently our improved method solves a significant problem encountered in lattice-Boltzmann simulations of drainage and imbibition. We are presently pursuing analogous studies in more complex geometries. (3) Macroscopic laws for two-component fluid flow through rough fractures. Macroscopic two-phase flow through porous media is commonly approximated by a generalization of Darcy's law, wherein ''relative permeability's'' represent the mobility of wetting and non-wetting fluids. We have recently begun studying the applicability of this approximation for two-phase flow through rough-walled fractures. We find that when the nonwetting fluid is unconnected it can become trapped in tight geometries. Once forcing exceeds a certain capillary threshold the non-wetting fluid starts to move again. This capillary threshold depends on the roughness of the fracture surface and the size of the fracture aperture. Further simulations are being performed to better specify these dependencies along with the relationship of relative permeability to fracture roughness. (4) Multiple relaxation-time lattice-Boltzmann method. We are exploring ways to use the lattice-Boltzmann method in a rectangular lattice with different spacing in one direction. This idea is motivated by the fact that self-affine fracture surfaces exhibit different scaling perpendicular to the plane of the fracture than they exhibit in the plane. Therefore, allowing different lattice spacing in the different directions should greatly increase the efficiency of our simulations. We also seek a practical way of solving a well-known problem that derives from using the ''bounce-back'' method to approximate no-slip boundary conditions. We are pursuing a new generalization of the ''multiple relaxation time generalized lattice-Boltzmann method'' and are in the process of implementing it. (5) Study of thermal fluctuations of fluid-fluid interfaces. We hav

Rothman, Daniel H.

2003-06-01T23:59:59.000Z

9

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

E-Print Network [OSTI]

As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new...

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

2006-01-01T23:59:59.000Z

10

Diagnosis of Fracture Flow Conditions with Acoustic Sensing  

E-Print Network [OSTI]

processing techniques and quantitative analysis are used to measure flow rates in a simulated fractured well. Production into a 5-œ inch OD well was simulated by injecting fluid through packed bed of 16/30 mesh, 20/40 mesh and 30/50 mesh proppant. Gas...

Martinez, Roberto

2014-07-10T23:59:59.000Z

11

Variational necessary and sufficient stability conditions for inviscid shear flow  

Science Journals Connector (OSTI)

...University of Texas at Austin, , Austin, TX 78712, USA A necessary and sufficient condition...where the velocity profile is assumed to be monotonic and analytic. It is shown...for continuous spectra and is applicable to other stability problems of infinite-dimensional...

2014-01-01T23:59:59.000Z

12

Heat transfer in an MHD channel flow with boundary conditions of the third kind  

Science Journals Connector (OSTI)

The heat transfer equation for a two-dimensional magnetohydrodynamic channel flow has been solved using boundary conditions of the third kind considering a discontinuity in the “ambient” temperature. The bound...

Sergio Cuevas; Eduardo Ramos

1991-01-01T23:59:59.000Z

13

Dependence of thermal destabilization of electric-arc plasma in an air flow on discharge conditions  

Science Journals Connector (OSTI)

The effect of the conditions of electric-arc burning in an air flow on the ... processes in the development of instability in an arc-discharge column is shown.

V. N. Borisyuk; S. V. Goncharik…

1997-03-01T23:59:59.000Z

14

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

15

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

16

Inverse Prediction and Optimization of Flow Control Conditions for Confined Spaces using a CFD-Based Genetic Algorithm  

E-Print Network [OSTI]

temperature and velocity. In order to identify the best flow control conditions, conventional approach function to optimize the inlet boundary conditions (e.g., supply velocity, temperature, and angle of critical flow control conditions such as flow inlet temperature, velocity and angle. In order to identify

Chen, Qingyan "Yan"

17

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

18

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

19

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

20

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.

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

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

22

Study on Performance and Internal Flow Condition of Mini Turbo?Pump  

Science Journals Connector (OSTI)

Mini turbo?pumps which have a diameter smaller than 100mm are utilized in many fields; automobile radiator pump artificial heart pump cooling pump for electric devices washing machine pump and so on. And the needs for the mini turbo?pumps would become larger with the increase of the application of it for electrical machines. It is desirable that the mini turbo?pump design is as simple as possible due to the limitation of the precision for manufacture. But the design method for the mini turbo?pump is not established because the internal flow condition for these small?sized fluid machineries is not clarified and conventional theory is not conductive for small?sized pumps because of the low Reynolds number and the size effects. Therefore we started the research of the mini turbo?pump for the purpose of development of high performance mini turbo?pump with simple structure. As a first step of this research mini turbo?pump with the 46mm rotor diameter was designed based on the conventional design method in order to clarify the problems for the application of conventional method for mini turbo?pump in details. The three dimensional steady numerical flow analysis was conducted with the commercial code (Fluent6.3). The numerical flow analysis was also performed under the condition with and without a tip clearance because the tip clearance influence on the performance and internal flow condition is extremely large for mini turbo?pumps. It was clarified from the numerical results that head of the mini turbo?pump at the designed point without the tip clearance satisfied the designed value head H?=?1.2 m and the efficiency is about ??=?60% which is acceptable value for the centrifugal pump. On the other hand head and efficiency decreased drastically with the increase of the tip clearance. The flow condition near the tip region was influenced by the leakage flow from the blade tip. And it is observed by the results of the total pressure distributions that the total pressure loss near the tip is considerably large. In the present paper the performance of the mini turbo?pump is shown and the internal flow condition is clarified with the results of the numerical flow analysis. Furthermore the effects of the tip clearance on the performance are investigated and high performance rotor design for mini turbo?pump would be considered.

Toru Shigemitsu; Junichiro Fukutomi; Ryoichi Nasada

2010-01-01T23:59:59.000Z

23

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 Institute’s (ANSI’s) 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

24

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

25

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

26

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

27

Influence of speed and frequency towards the automotive turbocharger turbine performance under pulsating flow conditions  

Science Journals Connector (OSTI)

Abstract The ever-increasing demand for low carbon applications in automotive industry has intensified the development of highly efficient engines and energy recovery devices. Even though there are significant developments in the alternative powertrains such as full electric, their full deployment is hindered by high costing and unattractive life-cycle energy and emission balance. Thus powertrain based on highly efficient internal combustion engines are still considered to be the mainstream for years to come. Traditionally, turbocharger has been an essential tool to boost the engine power, however in recent years it is seen as an enabling technology for engine downsizing. It is a well-known fact that a turbocharger turbine in an internal combustion engine operates in a highly pulsating exhaust flow. There are numerous studies looking into the complex interaction of the pulsating exhaust gas within the turbocharger turbine, however the phenomena is still not fully integrated into the design stage. Industry practice is still to design and match the turbine to an engine based on steady performance maps. The current work is undertaken with the mind to move one step closer towards fully integrating the pulsating flow performance into the turbocharger turbine design. This paper presents the development efforts and results from a full 3-D CFD model of a turbocharger turbine stage. The simulations were conducted at 30,000 rpm and 48,000 rpm (50% and 80% design speed respectively) for both 20 Hz and 80 Hz pulsating flow inlet conditions. Complete validation procedure using cold-flow experimental data is also described. The temporal and spatial resolutions of the incidence angle at the rotor leading edge suggest that the circumference variation is little (7%) as compared to its variation in time as the pulse progresses. The primary aim of this paper is to investigate the relationship of the turbine speed, as well as the pulsating flow frequency to its performance. It was found that there are no direct instantaneous relationship between the pulsating pressure at the turbine inlet and the turbine efficiency, except when one considers an additional parameter, namely the incidence angle. This paper also intends to investigate the potential loss of information if the performance parameters are simply averaged without considering the instantaneous effects.

M.H. Padzillah; S. Rajoo; R.F. Martinez-Botas

2014-01-01T23:59:59.000Z

28

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

29

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

30

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

31

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

32

Free Flow Energy (TRL 1 2 3 Component)- Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion  

Broader source: Energy.gov [DOE]

Free Flow Energy (TRL 1 2 3 Component) - Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion

33

Exergy analysis of second-generation micro heat sinks under single-phase and flow boiling conditions  

Science Journals Connector (OSTI)

A parametric study of exergy efficiency was conducted for five micro pin fin heat sinks of different spacing and shapes. Of the four micro pin fin heat sinks tested under single-phase flow conditions, those with better heat transfer performance yielded superior exergy efficiencies. The use of R-123 in place of water as working fluid was found to enhance exergetic performance at the expense of reduced heat transfer performance. The exergy analysis was also extended to the flow boiling of R-123 in an additional hydrofoil-based micro pin fin heat sink. It was found that exergy efficiencies decreased with mass velocity.

Ali Kosar

2010-01-01T23:59:59.000Z

34

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

35

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

E-Print Network [OSTI]

of calcium carbonate/silica in place of an aqueous work up; d total flow rate = 10 mL min-1 with 2.6 eq. of Deoxo-Fluorź. Such a dependence on the flow rate suggested that the mixing efficiency was a significant factor affecting the rate of cyclisation... ) ppm. Data match those reported in: A. I. Meyers and F. X. Tavares J. Org. Chem. 1996, 61, 8207-8215. General protocol for the preparation of 2-alkyl-oxazoles in flow: a solution of oxazoline (0.125 mmol) in DME (2 mL) was loaded into a 2 mL loop...

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

2014-10-28T23:59:59.000Z

36

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

E-Print Network [OSTI]

Zhang Senior Engineer Postgraduate Wuhan Architectural Design Institute, Wuhan, China, 430014 Chenyh918@263.net Abstract: This paper analyzes energy-saving design for pressure-difference control in a variable flow air...

Chen, Y.; Zhang, Z.

2006-01-01T23:59:59.000Z

37

Performance characterisation and energy savings of uncovered swimming pool solar collectors under reduced flow rate conditions  

Science Journals Connector (OSTI)

The effects of reduced flow rates on the performance and effectiveness of domestic unglazed, uninsulated pool solar collector heaters are investigated. The study shows electrical energy savings in excess of 80% are achievable for typical solar collectors operating at flow rates reduced by up to 75% while collector efficiency is only reduced by approximately 10–15%. The reduction of electrical energy required for pumping and the increased COP of reduced flow through typical pool solar thermal collectors is shown to far outweigh the small loss of collector performance attributable to the change in flow rates. The ratio of thermal energy delivered to the electrical energy supplied was improved in the order of 400% for the collector tested.

L.N. Cunio; A.B. Sproul

2012-01-01T23:59:59.000Z

38

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

E-Print Network [OSTI]

creating unique visual and quantitative data. These data were then analyzed using a resistance type heat transfer model and five different zero gravity flow regime maps. Results from this analysis included: (i) presenting zero gravity data that correlated...

Westheimer, David Thomas

2012-06-07T23:59:59.000Z

39

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

E-Print Network [OSTI]

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

Zevenhoven, Ron

40

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.


41

A new view of flow topology and conditional statistics in turbulence  

Science Journals Connector (OSTI)

...simulation data, the statistics of the shape parameters...asymmetry of the joint probability density function of...segments. Conditional statistics based on these newly...asymmetry of the joint probability density function of...segments. Conditional statistics based on these newly...

2013-01-01T23:59:59.000Z

42

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

2012-06-07T23:59:59.000Z

43

Experimental investigation of supersonic low pressure air plasma flows obtained with different arc-jet operating conditions  

SciTech Connect (OSTI)

A stationary arc-jet plasma flow at low pressure is used to simulate some properties of the gas flow surrounding a vehicle during its entry into celestial body's atmospheres. This paper presents an experimental study concerning plasmas simulating a re-entry into our planet. Optical measurements have been carried out for several operating plasma conditions in the free stream, and in the shock layer formed in front of a flat cylindrical plate, placed in the plasma jet. The analysis of the spectral radiation enabled the identification of the emitting species, the determination of the rotational and vibrational temperatures in the free-stream and in the shock layer and the determination of the distance of the shock to the flat plate face. Some plasma fluid parameters like, stagnation pressure, specific enthalpy and heat flux have been determined experimentally along the plasma-jet axis.

Lago, Viviana; Ndiaye, Abdoul-Aziz [Laboratoire ICARE CNRS, 1C Av. de la Recherche Scientifique 45071 Orleans Cedex 2 (France)

2012-11-27T23:59:59.000Z

44

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

SciTech Connect (OSTI)

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

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

2012-08-29T23:59:59.000Z

45

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

46

A Refined Model of Stationary Heat Transfer in Composite Bodies Reinforced with Pipes Containing a Heat-Transfer Fluid Moving in Laminar Flow Conditions  

Science Journals Connector (OSTI)

Equations describing the stationary heat conduction of composite bodies spatially reinforced with ... of smooth pipes, through which an incompressible heat-transfer fluid is pumped in laminar flow conditions, are...

A. P. Yankovskii

2014-03-01T23:59:59.000Z

47

Simulations of long column flow experiments related to geologic carbon sequestration: Effects of outer wall boundary condition on upward flow and formation of liquid CO2  

E-Print Network [OSTI]

did not occur. Rock-fluid heat transfer is minimized by thePruess K. On CO 2 fluid flow and heat transfer behavior inthe fluid could cool into the single digits if heat transfer

Oldenburg, C.M.

2014-01-01T23:59:59.000Z

48

Computational Fluid Dynamics Simulation of Open-Channel Flows Over Bridge-Decks Under Various Flooding Conditions  

E-Print Network [OSTI]

. This study simulates limited scaled experimental data conducted elsewhere for bridge flooding in open channel simulation, Computational fluid dynamics, Flooding flows, Turbulence modeling, VOF modeling. 1. IntroductionComputational Fluid Dynamics Simulation of Open-Channel Flows Over Bridge-Decks Under Various

Kostic, Milivoje M.

49

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

50

Mean and Turbulent Flow Downstream of a Low-Intensity Fire: Influence of Canopy and Background Atmospheric Conditions  

Science Journals Connector (OSTI)

This study examines the sensitivity of mean and turbulent flow in the planetary boundary layer (PBL) and roughness sub-layer to a low-intensity fire and evaluates whether the sensitivity is dependent on canopy and background atmospheric ...

Michael T. Kiefer; Warren E. Heilman; Shiyuan Zhong; Joseph J. Charney; Xindi Bian

51

Studies into the Initial Conditions, Flow Rate, and Containment System of Oil Field Leaks in Deep Water  

E-Print Network [OSTI]

height measurements to determine flow rate using an integral model. Plume width and temperature were determined to have little sensitivity. Separately, a containment dome was tested in the laboratory to determine if a full scale dome can be used...

Holder, Rachel

2013-07-22T23:59:59.000Z

52

Effects of geometry/dimensions of gas flow channels and operating conditions on high-temperature PEM fuel cells  

Science Journals Connector (OSTI)

In order to accomplish the objective of studying and optimizing the flow channel geometries and dimensions for high-temperature proton-exchange-membrane (PEM) fuel cells (with operating temperatures above 120 °C)...

Hong Liu; Peiwen Li; Alexandra Hartz…

2014-11-01T23:59:59.000Z

53

Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. II. Electron Heating Efficiency as a Function of Flow Conditions  

E-Print Network [OSTI]

In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the electrons. This paradigm assumes that Coulomb collisions are the only channel for transferring the ion energy to the electrons. In this work, the second of a series, we assess the efficiency of electron heating by ion velocity-space instabilities in collisionless accretion flows. The instabilities are seeded by the pressure anisotropy induced by magnetic field amplification, coupled to the adiabatic invariance of the particle magnetic moments. Using two-dimensional (2D) particle-in-cell (PIC) simulations, we showed in Paper I that if the electron-to-ion temperature ratio is cyclotron instability is the dominant mode for values of ion beta_i ~ 5-30 (here, beta_i is the ratio of ion thermal pressure to magnetic pressure), as appropriate for the midplane of low-lumin...

Sironi, Lorenzo

2014-01-01T23:59:59.000Z

54

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

SciTech Connect (OSTI)

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

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

2010-08-01T23:59:59.000Z

55

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

56

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

57

The microcanonical thermodynamics of finite systems: The microscopic origin of condensation and phase separations, and the conditions for heat flow from lower to higher temperatures  

Science Journals Connector (OSTI)

Microcanonical thermodynamics [D. H. E. Gross Microcanonical Thermodynamics Phase Transitions in “Small” Systems (World Scientific Singapore 2001)] allows the application of statistical mechanics both to finite and even small systems and also to the largest self-gravitating ones. However one must reconsider the fundamental principles of statistical mechanics especially its key quantity entropy. Whereas in conventional thermostatistics the homogeneity and extensivity of the system and the concavity of its entropy are central conditions these fail for the systems considered here. For example at phase separation the entropy S ( E ) is necessarily convex to make e S ( E ) ? E ? T bimodal in E . Particularly as inhomogeneities and surface effects cannot be scaled away one must be careful with the standard arguments of splitting a system into two subsystems or bringing two systems into thermal contact with energy or particle exchange. Not only the volume part of the entropy must be considered; the addition of any other external constraint [A. Wehrl Rev. Mod. Phys.50 221 (1978)] such as a dividing surface or the enforcement of gradients of the energy or particle profile reduce the entropy. As will be shown here when removing such constraints in regions of a negative heat capacity the system may even relax under a flow of heat (energy) against a temperature slope. Thus the Clausius formulation of the second law: “Heat always flows from hot to cold ” can be violated. Temperature is not a necessary or fundamental control parameter of thermostatistics. However the second law is still satisfied and the total Boltzmannentropy increases. In the final sections of this paper the general microscopic mechanism leading to condensation and to the convexity of the microcanonical entropy at phase separation is sketched. Also the microscopic conditions for the existence (or nonexistence) of a critical end point of the phase separation are discussed. This is explained for the liquid-gas and the solid-liquidtransition.

D. H. E. Gross; J. F. Kenney

2005-01-01T23:59:59.000Z

58

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

59

Heat transfer during the flow of an incompressible fluid in a circular tube, allowing for axial heat flow, with boundary conditions of the first and second kind at the tube surface  

Science Journals Connector (OSTI)

An examination is made of heat transfer in a hydraulically stabilized laminar stream and in a two-layer dynamic flow model.

V. V. Shapovalov

1966-09-01T23:59:59.000Z

60

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

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

Optimal power flow under both normal and contingent operation conditions using the hybrid fuzzy particle swarm optimisation and Nelder-Mead algorithm (HFPSO-NM)  

Science Journals Connector (OSTI)

In this paper, we solve the optimal power flow problem using by the new hybrid fuzzy particle swarm optimisation and Nelder-Mead (NM) algorithm (HFPSO-NM). The goal of combining the NM simplex method and the particle swarm optimisation (PSO) method is ... Keywords: Fuzzy logic, HFPSO-NM, Nelder-Mead method, Optimal power flow, Particle swarm optimisation, Voltage stability

Mahmood Joorabian; Ehsan Afzalan

2014-01-01T23:59:59.000Z

62

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.

63

Portable wastewater flow meter  

DOE Patents [OSTI]

A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under 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

64

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

65

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

66

Effect of flow and physical parameters on the wax deposition of Middle East crude oil under subsea condition: heat transfer viewpoint  

Science Journals Connector (OSTI)

Change in pressure, temperature, flow rate and concentration of oil causes precipitation and deposition of wax particles in the pipelines which has become a major problem for ... reserves increases. Change in tem...

Reza Gooya; Mehdy Gooya; Bahram Dabir

2013-08-01T23:59:59.000Z

67

Single crystal flow reactor for studying reactivities on metal oxide model catalysts at atmospheric pressure to bridge the pressure gap to the adsorption properties determined under UHV conditions  

Science Journals Connector (OSTI)

A flow reactor for the investigation of heterogeneous catalytic reactions on single crystalline metal oxide model catalysts has been designed. It is located in a high pressure cell attached to an UHV analysis cha...

C. Kuhrs; M. Swoboda; W. Weiss

2001-01-01T23:59:59.000Z

68

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

69

Identification of boundary conditions for elements of the flow-through part of a turbine in a gas-turbine engine  

Science Journals Connector (OSTI)

A method is proposed for identifying boundary conditions on the basis of analytical solution of the inverse heat conduction problem and use of the rules governing the displacement of isotherms.

Yu. Yu. Rykachev; N. M. Tsirel'man

1989-03-01T23:59:59.000Z

70

Effects of alternating seawater flow and stagnant layup conditions on the general and localized corrosion resistance of CuNi and NiCu alloys in marine service  

SciTech Connect (OSTI)

From time-to-time seawater handling systems are subjected to lay-up which can produce chemical and biological changes, and conceivably alter the corrosion resistance of metals used in piping and other equipment. In the case of reverse osmosis/membrane technology type desalination equipment, sanitizing agents may be introduced after draining. Simulation tests were conducted to determine any effect of a bisulfite sanitizing treatment when used between periods of normal seawater flow. Corresponding tests were conducted with lay-up comprising non-refreshed seawater which ultimately stagnated. Test results for CuNi alloy C71500 indicted that repeated cycling between seawater exposure and bisulfite treatments was detrimental in reducing that alloy`s resistance to general corrosion, and to a lesser degree its crevice corrosion resistance. The typical pitting and crevice corrosion behavior of NiCu alloy N04400, found upon exposure to slowly moving, aerated seawater was neither diminished or accelerated by cyclic lay-up with either stagnant seawater or the candidate bisulfite-containing solution. However, some increase in general corrosion was observed.

Kain, R.M. [LaQue Corrosion Services, Wrightsville Beach, NC (United States); Weber, B.E. [NAWC-Aircraft Div., Patuxent River, MD (United States)

1997-12-01T23:59:59.000Z

71

Air Conditioning  

Science Journals Connector (OSTI)

Air Conditioning ... CHEMISTS and engineers use air conditioning as a valuable tool in more than two hundred industries. ... Air conditioning is a tool with many facets. ...

MARGARET INGELS

1938-02-10T23:59:59.000Z

72

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

73

Running Boundary Condition  

E-Print Network [OSTI]

In this paper we argue that boundary condition may run with energy scale. As an illustrative example, we consider one-dimensional quantum mechanics for a spinless particle that freely propagates in the bulk yet interacts only at the origin. In this setting we find the renormalization group flow of U(2) family of boundary conditions exactly. We show that the well-known scale-independent subfamily of boundary conditions are realized as fixed points. We also discuss the duality between two distinct boundary conditions from the renormalization group point of view. Generalizations to conformal mechanics and quantum graph are also discussed.

Ohya, Satoshi; Tachibana, Motoi

2010-01-01T23:59:59.000Z

74

Running Boundary Condition  

E-Print Network [OSTI]

In this paper we argue that boundary condition may run with energy scale. As an illustrative example, we consider one-dimensional quantum mechanics for a spinless particle that freely propagates in the bulk yet interacts only at the origin. In this setting we find the renormalization group flow of U(2) family of boundary conditions exactly. We show that the well-known scale-independent subfamily of boundary conditions are realized as fixed points. We also discuss the duality between two distinct boundary conditions from the renormalization group point of view. Generalizations to conformal mechanics and quantum graph are also discussed.

Satoshi Ohya; Makoto Sakamoto; Motoi Tachibana

2010-05-25T23:59:59.000Z

75

Information Flow in Ensemble Weather Predictions  

Science Journals Connector (OSTI)

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

Richard Kleeman

2007-03-01T23:59:59.000Z

76

MHD duct flows under hydrodynamic “slip” condition  

E-Print Network [OSTI]

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

Smolentsev, S.

2009-01-01T23:59:59.000Z

77

Initial Conditions  

Science Journals Connector (OSTI)

Before we can run a transient analysis, we must find the appropriate set of initial conditions for the variables. The most important requirement of initial conditions is that they do not contradict any of the ...

Michael Tiller Ph.D.

2001-01-01T23:59:59.000Z

78

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

79

Attractor Flows from Defect Lines  

E-Print Network [OSTI]

Deforming a two dimensional conformal field theory on one side of a trivial defect line gives rise to a defect separating the original theory from its deformation. The Casimir force between these defects and other defect lines or boundaries is used to construct flows on bulk moduli spaces of CFTs. It turns out, that these flows are constant reparametrizations of gradient flows of the g-functions of the chosen defect or boundary condition. The special flows associated to supersymmetric boundary conditions in N=(2,2) superconformal field theories agree with the attractor flows studied in the context of black holes in N=2 supergravity.

Ilka Brunner; Daniel Roggenkamp

2010-02-12T23:59:59.000Z

80

Pouring flows  

Science Journals Connector (OSTI)

Free surface flows of a liquid poured from a container are calculated numerically for various configurations of the lip. The flow is assumed to be steady two dimensional and irrotational; the liquid is treated as inviscid and incompressible; and gravity is taken into account. It is shown that there are jetlike flows with two free surfaces and other flows with one free surface which follow along the underside of the lip or spout. The latter flows occur in the well?known ‘‘teapot effect ’’ which was treated previously without including gravity. Some of the results are applicable also to flows over weirs and spillways.

Jean?Marc Vanden?Broeck; Joseph B. Keller

1986-01-01T23:59:59.000Z

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.


81

Connecting the second exhaust-heat boiler to the operating first one under the conditions of flow circuits of combined-cycle plants with two gas-turbine units and one steam turbine  

Science Journals Connector (OSTI)

Problems arising with connecting the second exhaust-heat boiler to the first exhaust-heat boiler under load in the case of flow circuits of combined-cycle plants of type PGU-450 are considered. Similar problem...

Yu. A. Radin; I. A. Grishin; T. S. Kontorovich…

2006-03-01T23:59:59.000Z

82

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

83

UZ Flow Models and Submodels  

SciTech Connect (OSTI)

The purpose of this Model Report is to document the unsaturated zone (UZ) fluid flow and tracer transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain (UZ Model), Nevada. This work was planned in ''Technical Work Plan (TWP) for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819], Section 1.10, Work Package AUZM06). The UZ Model has revised, updated, and enhanced the previous UZ Flow Model REV 00 ICN 01 (BSC 2001 [158726]) by incorporation of the conceptual 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 3-D UZ flow fields are used directly by Performance Assessment (PA). 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 conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. In addition, this Model Report supports several PA activities, including abstractions, particle-tracking transport simulations, and the UZ Radionuclide Transport Model.

P. Dixon

2004-02-11T23:59:59.000Z

84

Evaluation of low flow characteristics of the Vermont Yankee plant  

SciTech Connect (OSTI)

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

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

1997-12-01T23:59:59.000Z

85

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

86

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

87

Slug flow  

E-Print Network [OSTI]

Introduction: When two phases flow concurrently in a pipe, they can distribute themselves in a number of different configurations. The gas could be uniformly dispersed throughout the liquid in the form of small bubbles. ...

Griffith, P.

1959-01-01T23:59:59.000Z

88

Lattice Boltzmann boundary conditions via singular forces: irregular expansion analysis  

E-Print Network [OSTI]

Lattice Boltzmann boundary conditions via singular forces: irregular expansion analysis. We benchmark the method on lattice Boltzmann flows past a rigid disk, comparing its numerical performances with standard boundary condition approaches. Key words: lattice Boltzmann method, boundary

89

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

90

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....

91

Shear instabilities in granular flows  

Science Journals Connector (OSTI)

... of sizes were also tested, but these never produced interfacial waves under any conditions. Roughening either side wall by attaching sandpaper had a minimal effect on the flow, indicating ... to 28°. (The shear itself varied by less than 20%.) Second, we roughened the last 10?cm of the chute bottom, thus artificially retarding downstream particles and ...

David J. Goldfarb; Benjamin J. Glasser; Troy Shinbrot

2002-01-17T23:59:59.000Z

92

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.

Ván, P

2013-01-01T23:59:59.000Z

93

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. Ván; T. S. Biró

2013-05-14T23:59:59.000Z

94

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

95

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

96

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

97

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

98

Solutions and procedures to assure the flow in deepwater conditions  

SciTech Connect (OSTI)

Petrobras has been developing deep water oil fields located in Campos Basin, a vanguard subsea project which faces big challenges, one of them wax deposition in production flowlines. So, since 1990, Petrobras has been studying methods to prevent and remove paraffin-wax deposits. Tests of techniques based on chemical inhibition of crystal growth, thermo-chemical cleaning (SGN), mechanical cleaning (pigging), electrical heating and thermal insulation were done and the main results obtained at CENPES (Petrobras R and D Center) started to be used in the field in 1993. This paper presents solutions and procedures which has been used to minimize oil production losses at Campos Basin -- Brazil.

Gomes, M.G.F.M.; Pereira, F.B.; Lino, A.C.F.

1996-12-31T23:59:59.000Z

99

Theory of free surface flow over rough seeping beds  

Science Journals Connector (OSTI)

...horizontal bed is assumed to be rough consisting of sediment...the other hand, in the rough flow regime (Re *70...the introduction, the set of equations (3.2...turbulent flow over a rough planar sand bed. The...The flow conditions were set in such a way that sediment...

2007-01-01T23:59:59.000Z

100

Theoretical and numerical studies on the flow multiplicity phenomenon for gas–solids two-phase flows in CFB risers  

Science Journals Connector (OSTI)

The dependence of the fully-developed flow profiles on the inlet flow conditions for gas–solids two-phase flows, i.e. the flow multiplicity phenomenon, in circulating fluidized bed (CFB) risers was proposed and discussed in this article. The flow multiplicity phenomenon for gas–solids two-phase flows was first proved mathematically based on the conservation equations of mass and momentum. Then the CFD model using Eulerian–Eulerian approach with k–? turbulence model for each phase was further adopted to analyze the details of this flow multiplicity phenomenon. It is theoretically and numerically revealed that for gas–solids two-phase flows, the flow profiles in the fully-developed region are always dominated by the flow profiles at the inlet. The solids concentration profile is closely coupled with the velocity profile, and the inlet solids concentration and velocity profiles can largely influence the fully-developed concentration and velocity profiles.

B. Peng; C. Zhang; J. Zhu

2011-01-01T23:59:59.000Z

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.


101

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

102

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

103

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

104

An investigation into flow regimes for two-phase helium flow  

SciTech Connect (OSTI)

The Tevatron accelerator at Fermilab incorporates long two-phase helium passages. During magnet design, the generalized flow map of Baker was used to predict homogeneous flow. Longer than expected magnet time constants led to this investigation. The importance of predicting the flow regime has been amplified with the advent of non-horizontal accelerator designs. A test setup was constructed at Fermilab to investigate two-phase helium flow regimes for conditions practical in accelerator designs. The setup consisted of a standard Tevatron satellite refrigerator, subcooling dewar, heater, 35 m long transfer line, and a specialized end box. A knife blade on the midplane of the transfer line diverted the flow from the upper and lower halves of the pipe to separate vessels in the end box. The amount of liquid above and below the plane was measured at various total mass flow rates and liquid percentages. The results show that stratified flow occurs at much higher liquid percentages than predicted by the Baker diagram (several orders of magnitude). We were not able to produce high enough steady state flows to find a boundary to a homogenous flow regime. Stratified flow occurred over all practical conditions for long accelerator magnet systems.

Theilacker, J.C.; Rode, C.H.

1987-10-01T23:59:59.000Z

105

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

106

Numerical Study of Geometry and Rotation Dependence on the Flow in Labyrinth Seals  

E-Print Network [OSTI]

for a given flow boundary condition. This formation of SRZ's is more evident in incompressible flow and occur at prohibitively high rotational speeds in case of air (compressible flow). It is also observed that flow with teeth on rotor are characterized...

Yamsani, Vamshi Krishna

2011-10-21T23:59:59.000Z

107

Terms and Conditions  

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

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

108

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

109

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

110

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...

111

Development of Next Generation Multiphase Pipe Flow Prediction Tools  

SciTech Connect (OSTI)

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

Tulsa Fluid Flow

2008-08-31T23:59:59.000Z

112

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

113

Simplified Space Conditioning  

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

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

114

Foamy Oil Flow and its Role in Heavy Oil Production  

Science Journals Connector (OSTI)

Two?phase oil?gas flow in porous media is often encountered during oil production from oil bearing sedimentary rocks. Traditionally such flow is modeled by extending the Darcy’s law to two?phase flow by employing the concept of saturation dependent relative permeability. This model is remarkably successful as long as the fluid distribution within the porous medium is controlled by capillary forces. Under this condition the two fluids appear to flow in their own continuous flow channels. This flow description is applicable to most reservoir flow scenarios encountered in light oil production. However in primary production of heavy oil under solution?gas drive this flow model often fails to provide a satisfactory match of the observed behaviour.

Brij B. Maini; Bashir Busahmin

2010-01-01T23:59:59.000Z

115

Inhomogeneity of fluid flow in Stirling engine regenerators  

SciTech Connect (OSTI)

The literature relating to inhomogeneity of flow regenerators is briefly reviewed. It is noted that, in contrast to other applications of regenerators, relatively little attention has been paid to the consequences of flow inhomogeneity for thermal regeneration in Stirling cycle machines. The construction of regenerator capsules for a large stationary Stirling engine is described. A test rig is developed to measure the gas velocity profile across the face of the packed regenerator capsules under steady flow conditions. Measured flow profiles for a number of different matrix materials and construction techniques are presented, and it is noted that stacked-mesh regenerator matrices tend to display marked inhomogeneities of flow. The consequences of flow inhomogeneity for flow friction and regenerator effectiveness are analyzed theoretically, and approximate formulae deduced. One method for reducing flow inhomogeneity in stacked-screen matrice

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

1989-10-01T23:59:59.000Z

116

Plastic Flow in Glass  

Science Journals Connector (OSTI)

...1964 research-article Plastic Flow in Glass D. M. Marsh The classical brittle fracture...account for the mechanical properties of glasses, but the widespread evidence of plastic flow in all glass fracture phenomena even at room temperature...

1964-01-01T23:59:59.000Z

117

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

118

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

119

ARM - Measurement - Surface condition  

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

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

120

Terms and Conditions  

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

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

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


121

Bypass flow computations on the LOFA transient in a VHTR  

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

122

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

123

Entrainment measurements in annular flow  

SciTech Connect (OSTI)

Air/water and vapor/freon were utilized to scale and simulate annular two-phase flow for high pressure steam/water conditions. A unique vapor/liquid Freon loop was built to obtain the high pressure data. The results were compared with two correlations available in the open literature. The Ishii and Mishima dimensionless group was able to scale the data remarkably well even for vapor/liquid Freon. However, the correlation needs to be adjusted for high Weber numbers of the gas phase.

Assad, A.; Jan, C.; Bertodano, M. de [Purdue Univ., West Lafayette, IN (United States); Beus, S.G. [Bettis Atomic Power Lab., West Mifflin, PA (United States)

1997-07-01T23:59:59.000Z

124

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

125

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.

126

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

127

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

128

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

129

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

130

Slurry fired heater cold-flow modelling  

SciTech Connect (OSTI)

This report summarizes the experimental and theoretical work leading to the scale-up of the SRC-I Demonstration Plant slurry fired heater. The scale-up involved a theoretical model using empirical relations in the derivation, and employed variables such as flow conditions, liquid viscosity, and slug frequency. Such variables have been shown to affect the heat transfer characteristics ofthe system. The model assumes that, if all other variables remain constant, the heat transfer coefficient can be scaled up proportional to D/sup -2/3/ (D = inside diameter of the fired heater tube). All flow conditions, liquid viscosities, and pipe inclinations relevant to the demonstration plant have indicated a slug flow regime in the slurry fired heater. The annular and stratified flow regimes should be avoided to minimize the potential for excessive pipe erosion and to decrease temperature gradients along the pipe cross section leading to coking and thermal stresses, respectively. Cold-flow studies in 3- and 6.75-in.-inside-diameter (ID) pipes were conducted to determine the effect of scale-up on flow regime, slug frequency, and slug dimensions. The developed model assumes that conduction heat transfer occurs through the liquid film surrounding the gas slug and laminar convective heat transfer to the liquid slug. A weighted average of these two heat transfer mechanisms gives a value for the average pipe heat transfer coefficient. The cold-flow work showed a decrease in the observed slug frequency between the 3- and 6.75-ID pipes. Data on the ratio of gas to liquid slug length in the 6.75-in. pipe are not yet complete, but are expected to yield generally lower values than those obtained in the 3-in. pipe; this will probably affect the scale-up to demonstration plant conditions. 5 references, 15 figures, 7 tables.

Moujaes, S.F.

1983-07-01T23:59:59.000Z

131

The Polishing, Surface Flow and Wear of Diamond and Glass  

Science Journals Connector (OSTI)

...Polishing, Surface Flow and Wear of Diamond and Glass F. P. Bowden H. G. Scott It has been shown that a diamond sliding on glass can under suitable conditions induce surface flow of the glass. The speed (v) and load (W) necessary to cause...

1958-01-01T23:59:59.000Z

132

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...

133

Application of continuous flow and alternative energy devices for 5-hydroxymethylfurfural production  

Science Journals Connector (OSTI)

Dehydration of fructose and glucose in dipolar, aprotic solvents leads to formation of 5-hydroxymethylfurfural. Conditions for continuous flow reactions using a...

Michael Schön; Michael Schnürch; Marko D. Mihovilovic

2011-08-01T23:59:59.000Z

134

ECWEBTermsandConditions.doc  

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

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

135

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

136

Development of Next Generation Multiphase Pipe Flow Prediction Tools  

SciTech Connect (OSTI)

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

Cem Sarica; Holden Zhang

2006-05-31T23:59:59.000Z

137

NETL: Gasifipedia - Entrained Flow Gasifiers  

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

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

138

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

139

Energy Loss Distribution in the Taylor-Couette Flow between Concentric Rotating Cylinders  

E-Print Network [OSTI]

The distribution of energy loss due to viscosity friction in plane Couette flow and Taylor-Couette Flow between concentric rotating cylinders are studied in detail for various flow conditions. The energy loss is related to the industrial processes in some fluid delivery devices and has significant influence on the flow efficiency, flow stability, turbulent transition, mixing, and heat transfer behaviours, etc. Therefore, it is very helpful to know about the energy loss distribution in the flow domain and to know its influence on the flow for understanding the flow physics. The calculation method of the energy loss distribution in the Taylor-Couette Flow between concentric rotating cylinders has not been found in open literature. In this note, the principle and the calculation are given for single cylinder rotating of inner or outer cylinder, and counter and same direction rotating of two cylinders. For comparison, the distribution of energy loss in a plane Couette flow is also derived for various flow conditi...

Dou, H S; Phan-Thien, N; Yeo, K S; Dou, Hua-Shu; Khoo, Boo Cheong; Phan-Thien, Nhan; Yeo, Khoon Seng

2005-01-01T23:59:59.000Z

140

Turbulent flow in graphene  

E-Print Network [OSTI]

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

Kumar S. Gupta; Siddhartha Sen

2009-11-03T23:59:59.000Z

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

Muffler Theory Considering Flow  

Science Journals Connector (OSTI)

The effect of a steady subsonic flow component upon the acoustical properties of pipes and of laminar and turbulent flow resistances is accounted for in an elementary fashion. The effect of the alternating or acoustic component upon the steady?flow properties is treated likewise. Acoustic transmission loss referred to the end radiation from a pipe is related to back pressure (increase in steady pressure due to the muffler). Equivalent circuits and diagrams of transmission loss vs back pressure are presented for some simple arrangements of pipes volumes irises and flow resistances.

Ewald Eichler

1962-01-01T23:59:59.000Z

142

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

143

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

144

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

145

Instream Flow Project  

Broader source: Energy.gov [DOE]

As a part of the Department of Energy’s Water Power Program, the Instream Flow Project was carried out by Oak Ridge National Laboratory, Pacific Northwest National Laboratory, and Argonne National Laboratory to develop tools aimed at defining environmental flow needs for hydropower operations.

146

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.

147

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

148

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

149

Effect of heat transfer on the plane-channel poiseuille flow of a thermo-viscous fluid  

Science Journals Connector (OSTI)

A steady-state plane channel flow of viscous incompressible fluid with no-slip and heat transfer boundary conditions is considered. The flow is ... induced by a fixed pressure difference and the fluid viscosity d...

S. N. Aristov; V. G. Zelenina

150

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

151

Rationale for Measuring Duct Leakage Flows in Large Commercial Buildings  

SciTech Connect (OSTI)

Industry-wide methods of assessing duct leakage are based on duct pressurization tests, and focus on ''high pressure'' ducts. Even though ''low pressure'' ducts can be a large fraction of the system and tend to be leaky, few guidelines or construction specifications require testing these ducts. We report here on the measured leakage flows from ten large commercial duct systems at operating conditions: three had low leakage (less than 5% of duct inlet flow), and seven had substantial leakage (9 to 26%). By comparing these flows with leakage flows estimated using the industry method, we show that the latter method by itself is not a reliable indicator of whole-system leakage flow, and that leakage flows need to be measured.

Wray, Craig P.; Diamond, Richard C.; Sherman, Max H.

2005-07-01T23:59:59.000Z

152

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

153

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

154

The Measured Energy Impact of Infiltration Under Dynamic Conditions  

E-Print Network [OSTI]

, the heat transfer process is a complicated non-linear process, and neither the temperature nor the air flow rate is constant. Therefore, the validity of the steady-state methodology should be proved for dynamic condition. As a preliminary step, dynamic...

Liu, M.; Claridge, D. E.

155

Multiphase Flow Modeling Research  

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

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

156

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

157

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

158

Lattice Boltzmann model for traffic flow  

Science Journals Connector (OSTI)

Mesoscopic models for traffic flows are usually difficult to be employed because of the appearance of integro-differential terms in the models. In this work, a lattice Boltzmann model for traffic flow is introduced on the basis of the existing kinetics models by using the Bhatnagar-Gross-Krook-type approximation interaction term in the Boltzmann equation and discretizing it in time and phase space. The so-obtained model is simple while the relevant parameters are physically meaningful. Together with its discrete feature, the model can be easily used to investigate numerically the behavior of traffic flows. In consequence, the macroscopic dynamics of the model is derived using the Taylor and Chapman-Enskog expansions. For validating the model, numerical simulations are conducted under the periodic boundary conditions. It is found that the model could reasonably reproduce the fundamental diagram. Moreover, certain interesting physical phenomena can be captured by the model, such as the metastability and stop-and-go phenomena.

Jianping Meng; Yuehong Qian; Xingli Li; Shiqiang Dai

2008-03-06T23:59:59.000Z

159

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

160

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

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

RMOTC - Testing - Flow Assurance  

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

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

162

Holographic supersymmetric membrane flows  

Science Journals Connector (OSTI)

The M-theory lift of SU(3) ? U(1)R-invariant RG flow via a combinatorical use of the four-dimensional flow and 11-dimensional Einstein–Maxwell equations was found previously. By taking the three internal coordinates differently and preserving only the SU(3) symmetry from the CP2 space, we find a new 11-dimensional solution of the SU(3)-invariant RG flow interpolating from the SO(8)-invariant UV fixed point to the SU(3) ? U(1)R-invariant IR fixed point in four dimensions. We describe how the corresponding three-dimensional superconformal Chern–Simons matter theory deforms. By replacing the above CP2 space with the Einstein–Kahler twofold, we also find out a new 11-dimensional solution of the SU(2) ? U(1)-invariant RG flow connecting the above two fixed points in four dimensions.

Changhyun Ahn; Kyungsung Woo

2010-01-01T23:59:59.000Z

163

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.

164

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

165

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

166

Multi-Domain Modeling and Simulation of Automotive Air Conditioning System Based On Modelica  

Science Journals Connector (OSTI)

The automotive air conditioning (AC) systems are complex systems where two-phase flow, pneumatic, mechanical and electrical components are coupled. Such systems coupled with various physical domains have great...

Jing Li; Yunqing Zhang…

2013-01-01T23:59:59.000Z

167

E-Print Network 3.0 - air conditioning heat Sample Search Results  

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

water. FIND... : Determine which condition feels colder. Contrast these results with a heat loss of 30 Wm2 under ormal room... in the case f air flow.o ANALYSIS: The hand will...

168

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

169

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

170

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

171

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.

Martin-Moruno, Prado

2014-01-01T23:59:59.000Z

172

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

173

Two-phase flow studies  

SciTech Connect (OSTI)

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

Hanold, R.J.

1983-12-01T23:59:59.000Z

174

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

175

Flow Test | Open Energy Information  

Open Energy Info (EERE)

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

176

Solar Heating and Air Conditioning  

Science Journals Connector (OSTI)

...given of the status of solar fired air conditioning...to an approach to cool storage in solar air conditioning systems...an assessment of cool storage for reducing peak electrical...rolling cylinder thermal energy storage device for compact...

1980-01-01T23:59:59.000Z

177

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

178

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

179

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

180

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

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

MHK Technologies/Uppsala Cross flow Turbine | Open Energy Information  

Open Energy Info (EERE)

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

182

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

183

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

184

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

185

Two-phase fluid flow through nozzles and abrupt enlargements  

SciTech Connect (OSTI)

The behavior of a fluid undergoing a phase change from liquid to vapor while flowing through a duct is of interest to engineers in many practical situations. For the case of interest to us, geothermal hot water flowing through various channels (well bores, surface pipes, equipment, etc.) may reach its flash point and choke point under appropriate conditions. The proper design of energy conversion systems depends on the ability of the engineer to predict this behavior with an acceptable degree of accuracy. The present study was in part motivated by the task of designing the blow-down, two-phase fluid flow test facility at Brown University. In that facility, a refrigerant (dichlorotetrafluoroethane or R-114) is boosted to a selected stagnation state and allowed to flow through a nozzle orifice into a long straight tube. The operation relies on the fluid being choked at the inlet section, and under certain circumstances, at the downstream section as well. A simple schematic of the test section is shown. This paper treats the problem generically and analytically, making use of the basic laws of fluid mechanics and thermodynamics. Specific calculations have been performed using R-114 as the flowing medium. They attempt to identify and describe all possible flow conditions in and downstream of the nozzle for all possible stagnation conditions.

Olia, H.; Maeder, P.F.; DiPippo, R.; Dickinson, D.A.

1983-10-01T23:59:59.000Z

186

Transonic throat flow in radial or nearly radial supersonic nozzles  

E-Print Network [OSTI]

general non- symmetric, inclined radial nozzle with n =2. 0, ( inward flow) 37 4 Mach number contours with n=0. 0 and Rc/D=1. 0 . . 42 5 Mach number contours with n=1. 0 and Rc/D=1. 0 6 Mach number contours with n=2. 0 and R /D=1. 0 7 Mach number... are taken as the irrotat ional ity condition U - VR ? 0 (6) and the gas dynamic equation 2 (U ? a')U + (V ? a )V + 2UVU ? = 0 2 2 va V z R R R where m=0 for planar flow and ~=1 for axisymmetric flow. The subscripts denote partial differentiation...

Carroll, Bruce Frederick

2012-06-07T23:59:59.000Z

187

Planetary heat flow measurements  

Science Journals Connector (OSTI)

...ESA's Rosetta mission towards comet Churyumov-Gerasimenko. It...Heat flow measurements on comets have a different motivation...penetrator is by no means limited to comets; it has also been tested in...measurement. Currently, a landing on Mercury within the framework...

2005-01-01T23:59:59.000Z

188

The Flow of Water  

Science Journals Connector (OSTI)

... for ice-covered streams become of very great importance wlieii a stream is required for hydroelectric power production. An appendix is attached of fifty - two well- selected problems relating ... The remaining chapters dealing with flow in pipes and channels and with centrifugal pumps and turbines call for no particular comment. It is of interest to find a chapter dealing ...

1927-12-31T23:59:59.000Z

189

ENERGY FLOWS CLIMATE CHANGE  

E-Print Network [OSTI]

absorption of solar radiation. #12;AEROSOLS AS SEEN FROM SPACE Fire plumes from southern Mexico transportedENERGY 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

Schwartz, Stephen E.

190

US energy flow, 1991  

SciTech Connect (OSTI)

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

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

1992-06-01T23:59:59.000Z

191

Matter Under Extreme Conditions: The Early Years  

E-Print Network [OSTI]

Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex forces induce a non-turbulent kinetic energy cascade to Planck-Kolmogorov scales where vorticity is produced, overcoming 10^113 Pa Planck-Fortov pressures. The spinning, expanding fireball has a slight deficit of Planck antiparticles. Space and mass-energy powered by gluon viscous stresses expand exponentially at speeds >10^25 c. Turbulent temperature and spin fluctuations fossilize at scales larger than ct, where c is light speed and t is time. Because â??dark-energyâ? antigravity forces vanish when inflation ceases, and because turbulence produces entropy, the universe is closed and will collapse and rebound. Density and spin fossils of big bang turbulent mixing trigger structure formation in the plasma epoch. Fragmenting protosuperclustervoids and protoclustervoi...

Keeler, R Norris

2010-01-01T23:59:59.000Z

192

Self-Organized Network Flows  

E-Print Network [OSTI]

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

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

2007-01-01T23:59:59.000Z

193

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

194

Flow reversal power limit for the HFBR  

SciTech Connect (OSTI)

The High Flux Beam Reactor (HFBR) is a pressurized heavy water moderated and cooled research reactor that began operation at 40 MW. The reactor was subsequently upgraded to 60 MW and operated at that level for several years. The reactor undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Questions which were raised about the afterheat removal capability during the flow reversal transition led to a reactor shutdown and subsequent resumption of operation at a reduced power of 30 MW. An experimental and analytical program to address these questions 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. Direct use of the experimental results and an understanding of the governing phenomenology supports this conclusion.

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

1997-01-01T23:59:59.000Z

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.

Kerisit, Sebastien N.; Pierce, Eric M.

2012-05-15T23:59:59.000Z

196

Thermal photon $v_3$ at LHC from fluctuating initial conditions  

E-Print Network [OSTI]

We calculate the triangular flow parameter $v_3$ of thermal photons for 0--40\\% central collisions of Pb nuclei at LHC using an event-by-event hydrodynamic model with fluctuating initial conditions. Thermal photon $v_3$ with respect to the the participant plane angle is found to be positive and significant compared to the elliptic flow parameter $v_2$ of thermal photons. In addition, photon $v_3$ as a function of $p_T$ shows similar qualitative nature to photon $v_2$ in the region $1< p_T <6$ GeV/$c$. We argue that while $v_3$ originates from $\\epsilon_3$ deformations of the initial state density distribution, fast buildup of radial flow due to fluctuations is the main driving mechanism for the observed large value.

Rupa Chatterjee; Dinesh K. Srivastava; Thorsten Renk

2014-07-31T23:59:59.000Z

197

Investor Flows and the 2008 Boom/Bust in Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

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

198

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

199

LFS Exhibit B Special Conditions  

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

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

200

CPFFS Exhibit A General Conditions  

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

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

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

EFS Exhibit A General Conditions  

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

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

202

EFS Exhibit A General Conditions  

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

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

203

AES Exhibit A General Conditions  

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

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

204

SFS Exhibit A General Conditions  

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

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

205

SFS Exhibit A General Conditions  

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

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

206

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

207

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

208

Gas-surface interaction and boundary conditions for the Boltzmann equation  

E-Print Network [OSTI]

Gas-surface interaction and boundary conditions for the Boltzmann equation StÂŽephane 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

209

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

210

An experimental study on flow resistance of regenerator wire meshes in oscillatory flow  

SciTech Connect (OSTI)

Stirling engine is considered as an important energy system for utilizing Biomass energy. Regenerator is a very important element of the Stirling engine as it determines thermal efficiency and its flow resistance determines output power. This paper describes the experimental results on fluid motion in regenerator wire meshes of a Stirling engine in a oscillatory flow. Theoretical analysis on laminar flow in a circular pipe is described for a comparison. Simultaneous measurements of velocity nearby the mesh layer in the test section, pressure drops between entree and exit point of mesh layer and photo signal of top position of the piston were carried out in oscillatory flow condition. Experimental results shows that variation of pressure drops slightly advances toward velocity variation as is clarified in the theoretical analysis on laminar oscillatory flow in a circular pipe. Friction factors defined by adjusting phase angle shift between pressure drops and velocity variations show that it appears bigger in the accelerating period than in the decelerating period. This phenomenon seems to be explained because fluid motion requires more energy to make eddy structure in the accelerating period, while fluid motion in the decelerating period requires less energy as streamwise eddy structure is already developed.

Isshiki, Seita; Takasaki, Yousuke, Ushiyama, Izumi [Ashikaga Inst. of Tech., Tochigiken (Japan); Isshiki, Naotsugu [Nihon Univ., Setagayaku, Tokyo (Japan)

1997-12-31T23:59:59.000Z

211

Ising model conformal boundary conditions from open string field theory  

E-Print Network [OSTI]

Given a consistent choice of conformally invariant boundary conditions in a two dimensional conformal field theory, one can construct new consistent boundary conditions by deforming with a relevant boundary operator and flowing to the infrared, or by a marginal deformation. Open string field theory provides a very universal tool to discover and study such new boundary theories. Surprisingly, it also allows one to go in the reverse direction and to uncover solutions with higher boundary entropy. We will illustrate our results on the well studied example of Ising model.

Kudrna, Matej; Schnabl, Martin

2014-01-01T23:59:59.000Z

212

flow_loop.indd  

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

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

213

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

214

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

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

215

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

216

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

217

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

218

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

219

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

220

Subsidiary Conditions in Covariant Theories  

Science Journals Connector (OSTI)

We have investigated the effect that coordinate conditions and similar conditions will have on the formal properties of covariant theories. Two distinct types of coordinate conditions were included, those involving first derivatives of the field variables (such as the gauge condition of Lorentz and the coordinate conditions of De Donder) and those algebraic in the field variables (of which the Coulomb gauge is an example).We have found that with either type of coordinate condition we can construct a variational principle, or a Hamiltonian formalism, which leads to physically meaningful field equations if associated with appropriate initial conditions on a space-like hypersurface. Thus the existence of a properly set Cauchy problem is always assured.It had been found previously that the infinitesimal invariant transformations of covariant theories form a group and that the coordinate (and similar) transformations represent a normal subgroup. The members of the resulting factor group are in one-to-one correspondence with the true observables of the theory, those dynamical variables which alone possess intrinsic significance without reference to a particular frame of description and whose commutator algebra is presumably reflected in the commutators of the corresponding Hilbert operators of the quantized theory. In this paper we have established the appropriate transformation groups (and their subgroups and factor groups) of a theory with either type of coordinate conditions. We have found that in any of these versions the theory will yield the same observables with the same commutator algebra. One may therefore hope that a quantization scheme based on a theory with subsidiary conditions will be free of the arbitrariness involved in the choice of particular conditions.

Peter G. Bergmann and Allen I. Janis

1958-08-15T23:59:59.000Z

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

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

222

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

223

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

224

Importance of Design Conditions for Sizing Air-Conditioning Plant  

E-Print Network [OSTI]

Design conditions based on the meteorological data collected at two weather stations located less than 10 km away from each other within Kuwait City are presented for dry-bulb temperature (DBT) and web-bulb temperature (WBT) prioritization...

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

2000-01-01T23:59:59.000Z

225

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

226

Lattice-Boltzmann accuracy in pore-scale flow simulation  

Science Journals Connector (OSTI)

We investigate the possibility of using nominally second-order-accurate techniques for resolving flow about solid boundaries as a means of improving accuracy and reducing grid resolution requirements in pore-scale simulations. An LBGK method is used ... Keywords: Boundary condition, Lattice-Boltzmann, Pore-scale simulation, Porous media

R. S. Maier; R. S. Bernard

2010-01-01T23:59:59.000Z

227

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

228

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

229

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.

230

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.

231

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

232

Analysis of Compressible and Incompressible Flows Through See-through Labyrinth Seals  

E-Print Network [OSTI]

effect on the discharge coefficient. In particular, for compressible fluid under certain flow and seal geometric conditions, the discharge coefficient did not increase with an increase in the Reynolds number. It was correlated to the pressure ratio, g...1842g1870. Moreover, it was also related to the fact that the flow of the fluid through the constriction became compressible and the flow eventually became choked. At low pressure ratios (less than 0.7), Saikishan?s incompressible model deviated from...

Woo, Jeng Won

2011-08-08T23:59:59.000Z

233

Simulation of Turbulent Flow Inside and Above Wind Farms: Model Validation and Layout Effects  

Science Journals Connector (OSTI)

A recently-developed large-eddy simulation framework is validated and used to investigate turbulent flow within and above wind farms under neutral conditions. Two different layouts are considered, consisting of t...

Yu-Ting Wu; Fernando Porté-Agel

2013-02-01T23:59:59.000Z

234

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

235

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

236

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

237

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

238

CFD Simulation of Open Channel Flooding Flows and Scouring Around Bridge Structures  

E-Print Network [OSTI]

CFD Simulation of Open Channel Flooding Flows and Scouring Around Bridge Structures B. D. ADHIKARYKalb, IL 60115 U.S.A. Email: kostic@niu.edu; Web: http://www.kostic.niu.edu Abstract: - Simulation of scour caused by flooding and pressure flow conditions, is of significant interest nowadays to computational

Kostic, Milivoje M.

239

Development of CFD Simulation for 3-D Flooding Flow and Scouring Around a Bridge Structure  

E-Print Network [OSTI]

Development of CFD Simulation for 3-D Flooding Flow and Scouring Around a Bridge Structure B of bridge failure during storms and floods. Simulation of scour-hole formation under the bridge deck and around the bridge piers, due to sediment entrainment and transport caused by flooding flow conditions

Kostic, Milivoje M.

240

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

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

Drift-flux analysis of two-phase flow in microgravity  

E-Print Network [OSTI]

-phase phenomena such as flow regime transitions and void fraction at microgravity conditions is greatly limited and its development is still in its infancy. A Texas A&M University two-phase flow loop was tested aboard NASA's KC-135 aircraft to collect two...

Braisted, Jonathan David

2012-06-07T23:59:59.000Z

242

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

IngĂłlfsson, Ă?lafur

243

The Continuous Spectrum of Linear Couette Flow with the Beta Effect  

Science Journals Connector (OSTI)

The previously known analytic solution for the unbounded plane Couette flow [i.e., a mean flow U(y)=Sy, S constant] is extended by 1) inclusion of the beta effect, and 2) more general initial conditions. It is shown that the beta effect and ...

John P. Boyd

1983-09-01T23:59:59.000Z

244

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

245

Economizer control assembly for regulating the volume flow of outdoor ambient air  

SciTech Connect (OSTI)

An economizer assembly is disclosed wherein a sliding door is utilized for covering an outdoor ambient air opening allowing outdoor ambient air flow into a space to be conditioned. A motor shaft arrangement connected via a rotating drive rod is utilized to slidably displace the door to any position necessary to effectively regulate air flow. The utilization of this economizer control arrangement with a rooftop type air conditioning unit is further disclosed.

Michaels, D.D. Jr.

1984-10-23T23:59:59.000Z

246

Fuzzy Systems for Condition Monitoring  

Science Journals Connector (OSTI)

The chapter presents the application of Fuzzy Set Theory (FST) and fuzzy ARTMAP (Adaptive Resonance Theory Mapping) to diagnose the condition of high voltage bushings. The diagnosis uses Dissolved Gas Analysis...

Tshilidzi Marwala

2012-01-01T23:59:59.000Z

247

Natural Air-Conditioning Systems  

Science Journals Connector (OSTI)

Recent research in summer air conditioning utilizing natural sources of coolness* are discussed. These systems are classified according to the sources of coolness, the modes of heat transfer and airflow, and t...

Mehdi N. Bahadori

1986-01-01T23:59:59.000Z

248

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

249

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

250

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

251

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

252

Hack's law of debris-flow basins  

Science Journals Connector (OSTI)

Hack's law was originally derived from basin statistics for varied spatial scales and regions. The exponent value of the law has been shown to vary between 0.47 and 0.70, causing uncertainty in its application. This paper focuses on the emergence of Hack's law from debris-flow basins in China. Over 5,000 debris-flow basins in different regions of China with drainage areas less than 100km2 are included in this study. Basins in the different regions are found to present similar distributions. Hack's law is derived from maximum probability and conditional distributions, suggesting that the law should describe some critical state of basin evolution. Results suggest the exponent value is approximately 0.5. Further analysis indicates that Hack's law is related to other scaling laws underlying the evolution of a basin and that the exponent is not dependent on basin shape but rather on the evolutionary stage. A case study of a well known debris-flow basin further confirms Hack's law and its implications in basin evolution.

Yong LI; Z.Q. YUE; C.F. LEE; R.E. BEIGHLEY; Xiao-Qing CHEN; Kai-Heng HU; Peng CUI

2009-01-01T23:59:59.000Z

253

Lattice Boltzmann models for nonequilibrium gas flows  

Science Journals Connector (OSTI)

Due to its computational efficiency, the kinetic-based lattice Boltzmann method has recently been used to model nonequilibrium gas dynamics. With appropriate boundary conditions, lattice Boltzmann models have been able to capture both velocity slip and temperature jump at a solid surface. To enable these models to simulate flows in the transition regime, both high-order and modified lattice Boltzmann models have been proposed. In this paper, we demonstrate the advantages of the standard lattice Bhatnagar-Gross-Krook model in predicting high-order rarefaction phenomenon. In addition, we show that current high-order lattice Boltzmann models are not yet able to capture the nonlinear constitutive relation for the stress in the Knudsen layer, despite the improved predictions of the wall slip-velocity, especially for Poiseuille flow. By considering how the wall affects the gas mean free path, we present a simplified high-order lattice Boltzmann model that can predict flow in the transition regime and is also able to capture the essential characteristics of the Knudsen layer.

Gui-Hua Tang; Yong-Hao Zhang; David R. Emerson

2008-04-21T23:59:59.000Z

254

Experimental study on heat transfer characteristics of internal heat exchangers for CO2 system under cooling condition  

Science Journals Connector (OSTI)

This paper presents the heat transfer characteristics of the internal heat exchanger (IHX) for CO2 heat pump system. The influence on the IHX length, the mass flow rate, the shape of IHX, the operating condition,...

Young Chul Kwon; Dae Hoon Kim; Jae Heon Lee…

2009-03-01T23:59:59.000Z

255

Lattice Boltzmann method for rarefied channel flows with heat transfer  

Science Journals Connector (OSTI)

Abstract A thermal lattice Boltzmann method (TLBM) is presented for the analysis of fluid flow and heat transfer in two-dimensional channels with non-continuum effects. The relaxation times ( ? f , ? g ) are linked to the Knudsen number which accounts for the rarefaction that can be present at micro geometries or at low density conditions. The TLBM used here employs inlet/outlet boundary conditions to generate a forced convection problem where the calculation of equilibrium distributions at the wall surfaces are modified to incorporate the velocity slip and temperature jump conditions. Numerical simulations are obtained for thermal micro-Couette and thermal micro-Poiseuille channel flows and the effect of the Knudsen number on the velocity and temperature profile is investigated.

Seckin Gokaltun; George S. Dulikravich

2014-01-01T23:59:59.000Z

256

Ion escape from Mars as a function of solar wind conditions: A statistical study Hans Nilsson a,*, Ella Carlsson a  

E-Print Network [OSTI]

- mately the same bulk flow energy. We did not find any clear correlation between the solar EUV flux the effective obstacle to the solar wind flow, forming a mag- netic pile up region between the outer magneticIon escape from Mars as a function of solar wind conditions: A statistical study Hans Nilsson a

California at Berkeley, University of

257

Chapter 18 - Pipeline Vibration and Condition Based Maintenance  

Science Journals Connector (OSTI)

This chapter comprises two integrated parts. The first part of the chapter devotes to a detailed discussion of the mechanism leading to pipeline vibration and the effect of internal and external fluid flow on the pipeline vibration. It summarizes the formulations used for the design of optimal free span length of pipeline segments under different boundary conditions and pipeline operating conditions. Different measures used to mitigate pipeline vibration are also briefly discussed in the section. The procedures of pipeline condition based maintenance (CBM) are discussed in the second part of the chapter using vibration and other corrective maintenance (CM) parameters as asset health indicators. The typical models including P–F curve model, proportional hazard model, and proportional covariate model used to determine the optimal threshold and inspection intervals in CBM are introduced and discussed. The chapter also discusses the optimization of long-term maintenance activities using reliability based preventive maintenance decision-making approach.

Boyun Guo; Shanhong Song; Ali Ghalambor; Tian Ran Lin

2014-01-01T23:59:59.000Z

258

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

259

Subsidiary Condition in Quantum Electrodynamics  

Science Journals Connector (OSTI)

The subsidiary condition ?A?(+)?x?|n?=0, usually known as the "Gupta-Bleuler" condition, is shown to be inadequate as a criterion for defining physical states in quantum electrodynamics in the Lorentz gauge. The condition is shown not to be covariant and to fail to define state vectors that remain in the physical subspace. An alternative subsidiary condition, which is satisfactory, is discussed and is shown to require an extensively different formulation of the collision problem in quantum electrodynamics. Some possible physical consequences of the inadequacy of ?A?(+)?x?|n?=0 are proposed; these include effects in the decays of short-lived particles, and the fact that in some types of strong interactions, acting simultaneously with electromagnetic ones, S-matrix elements may occur which predict transitions from the physical space into the part of space in which the subsidiary condition is violated. The solution to the collision problem for stable charged particles that have only electromagnetic interactions is shown to be identical to that obtainable from the present theory.

Kurt Haller and Leon F. Landovitz

1968-07-25T23:59:59.000Z

260

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

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

Module bay with directed flow  

DOE Patents [OSTI]

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

Torczynski, John R. (Albuquerque, NM)

2001-02-27T23:59:59.000Z

262

Flow Batteries: A Historical Perspective  

Broader source: Energy.gov [DOE]

Presentation by Robert Savinell, Case Western Reserve University, at the Flow Cells for Energy Storage Workshop held March 7-8, 2012, in Washington, DC.

263

Flow Relationships in Reverse Osmosis  

Science Journals Connector (OSTI)

Flow Relationships in Reverse Osmosis ... Effects of Hydrolysis on Cellulose Acetate Reverse-Osmosis Transport Coefficients ... Effects of Hydrolysis on Cellulose Acetate Reverse-Osmosis Transport Coefficients ...

Ulrich Merten

1963-08-01T23:59:59.000Z

264

Financing Program Implementation Process Flow  

Broader source: Energy.gov [DOE]

The implementation process flow for financing with two models: a generic option for primary markets and a conceptual option for secondary markets.

265

Liquid and liquid–gas 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 liquid–gas 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

266

Range Condition: Key to Sustained Ranch Productivity  

E-Print Network [OSTI]

Range condition, or a rangeland's "state of health," is an ecological measurement of the current condition of a range. Range condition is evaluated by the plant species composition. This leaflet explains the importance of range condition, how range...

McGinty, Allan; White, Larry D.

2000-04-25T23:59:59.000Z

267

Air Conditioning | Department of Energy  

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

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

268

Categorical Exclusion Determinations: National Energy Technology Laboratory  

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

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

269

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

270

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

271

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

272

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

273

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

274

Two phase flow in geothermal systems. Final report, April 1, 1984-March 31, 1985  

SciTech Connect (OSTI)

Studies were performed to better understand the physical mechanisms involved in two-phase, single substance flow and their thermodynamic and fluid-dynamic implications. Flow properties were measured over a wide range of flow conditions from low-flash Mach number to high-flash Mach numbers to simulate actual two-phase flow over the full length of a geothermal well from the flash horizon to the choked wellhead. Void fraction, friction factors and entropy production were calculated. 2 refs., 12 figs. (ACR)

Maeder, P.F.; Kestin, J.

1985-04-01T23:59:59.000Z

275

Flow and heat transfer around a linear array of spheres  

SciTech Connect (OSTI)

Laminar fluid flow and forced convection heat transfer over equally space linear arrays of spheres are analyzed using the finite element package FIDAP. For the arrays, sphere spacings of 1.5, 2, and 3 diameters are examined at Reynolds numbers of 40, 80, and 120 and Prandtl numbers ranging from 0.73 to 7.3. Average Nusselt numbers and drag coefficient data for a linear array of eight spheres (as an approximation to the developing region) and a single sphere with periodic boundary conditions (as an approximation to fully developed flow) are presented and correlated.

Lloyd, B. (Marathon Oil Co., Shreveport, LA (United States)); Boehn, R. (Univ. of Nevada, Las Vegas, NV (United States). Mechanical Engineering Dept.)

1994-08-01T23:59:59.000Z

276

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

277

Concentration polarization in cross-flow reverse osmosis  

SciTech Connect (OSTI)

A dimensionless governing equation was formulated for a cross-flow RO process in which the local variation of concentration polarization was rigorously considered. It was shown in this formulation that the cross-flow RO process could be fully characterized with a single dimensionless parameter. The coupling between permeate flux and concentration polarization was properly solved and a closed-form analytical solution was obtained. This analytical solution enabled the authors to conveniently investigate concentration polarization in the RO process. The significance of local variation of concentration polarization was demonstrated, and the operations of RO under various conditions were simulated and investigated with the newly developed model.

Song, L.; Yu, S. [Hong Kong Univ. of Science and Technology, Kowloon (Hong Kong). School of Engineering] [Hong Kong Univ. of Science and Technology, Kowloon (Hong Kong). School of Engineering

1999-05-01T23:59:59.000Z

278

LFS Exhibit A General Conditions  

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

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

279

Solitons induced by boundary conditions  

SciTech Connect (OSTI)

Although soliton phenomena have attracted wide attention since 1965, there are still not enough efforts paid to mixed-boundary - initial-value problems that are important in real physical cases. The main purpose of this thesis is to study carefully the various boundary-induced soliton under different initial conditions. The author states with three sets of nonlinear equations: KdV equations and Boussinesq equations (for water); two-fluid equations for cold-ion plasma. He was interested in four types of problems involved with water solitons: excitation by different time-dependent boundary conditions under different initial conditions; head-on and over-taking collisions; reflection at a wall and the excitation by pure initial conditions. For KdV equations, only cases one and four are conducted. The results from two fully nonlinear KdV and Boussinesq equations are compared, and agree extremely well. The Boussinesq equations permit solition head-on collisions and reflections, studied the first time. The results from take-over collision agree with KdV results. For the ion-acoustic plasma, a set of Boussinesq-type equations was derived from the standard two-fluid equations for the ion-acoustic plasma. It theoretically proves the essential nature of the solitary wave solutions of the cold-ion plasma. The ion acoustic solitons are also obtained by prescribing a potential phi/sub 0/ at one grid point.

Zhou, R.L.

1987-01-01T23:59:59.000Z

280

July 30, 2004 Crop Conditions  

E-Print Network [OSTI]

, Grapes, and Wine Tissue Analysis Grapes and Small Fruits Upcoming Meetings Crop Conditions: Apple harvest harvest management, increased fruit size, maintenance of fruit firmness, reduction of preharvest fruit drop, improved fruit quality, and enhanced storage potential. Rates of application are similar

Ginzel, Matthew

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

Cytology Automation by Flow Cytometry  

Science Journals Connector (OSTI)

...measured individually at rates of several hundred/sec...sured individually at rates of several hundred/sec...individually by flow cytometry at rates of several hundred/sec...flow cytometer (Bio/ Physics Systems Cytofluono graf...instrument and are made to pass through a 250-@rn-diameter...

Myron R. Melamed; Zbigniew Darzynkiewicz; Frank Traganos; and Thomas Sharpless

1977-08-01T23:59:59.000Z

282

Earth's Crust: Heat Flow Relationships  

Science Journals Connector (OSTI)

... of heat flow through the Earth's surface at any point requires two measurements, the geothermal gradient itself and the thermal conductivity of the adjacent rocks. In the oceanic crust, ... variations in heat flow from point to point are governed essentially by variations in the geothermal gradient. In continents, however, the story is different. Correlation and regression analyses carried ...

Our Geomagnetism Correspondent

1970-07-11T23:59:59.000Z

283

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

284

Inertial particle resuspension in a turbulent, square duct flow  

Science Journals Connector (OSTI)

Particle resuspension in a turbulent square duct flow is studied using large eddy simulation combined with Lagrangian particle tracking under conditions of one-way coupling with the particle equation of motion solved with the Stokes drag lift buoyancy and gravitational force terms. Here resuspension is taken to mean the movement of particles in close proximity to the duct walls back in to the mainstream of the flow. The flow considered has a bulk Re = 250 ? k with four particle sizes ranging from 5 to 500 ? ? m examined. The results demonstrate that turbulence-driven secondary flows within the duct play an important role in the resuspension process. In the vertical direction resuspension is promoted by the drag force arising from the secondary flows which is balanced by the gravitational force with this effect increasing with decreasing particle size. In the horizontal direction particle resuspension is promoted by the particle’s inertial force with this effect increasing with increasing particle size. For resuspension in both directions the drag force dominates small particle resuspension while for large particles the lift force is also a contributing factor. In the horizontal direction the effect of the lift force varies with the direction of the secondary flow and becomes more significant when a particle is large or close to the duct wall. The influence of the lift force is also larger in the vertical than in the horizontal direction due to the effects of gravity.

J. Yao; M. Fairweather

2010-01-01T23:59:59.000Z

285

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 Landstraße 400, 01328 Dresden (Germany)

2014-06-02T23:59:59.000Z

286

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

SciTech Connect (OSTI)

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

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

1994-09-01T23:59:59.000Z

287

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

288

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

289

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

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;DescribesRangeFlows LowFlows 40 % of the time there has been no flow at this site #12;Gather daily flow rate data Load

290

Mutiscale Modeling of Segregation in Granular Flows  

SciTech Connect (OSTI)

Modeling and simulation of segregation phenomena in granular flows are investigated. Computational models at different scales ranging from particle level (microscale) to continuum level (macroscale) are employed in order to determine the important microscale physics relevant to macroscale modeling. The capability of a multi-fluid model to capture segregation caused by density difference is demonstrated by simulating grain-chaff biomass flows in a laboratory-scale air column and in a combine harvester. The multi-fluid model treats gas and solid phases as interpenetrating continua in an Eulerian frame. This model is further improved by incorporating particle rotation using kinetic theory for rapid granular flow of slightly frictional spheres. A simplified model is implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions. The accuracy of predicting segregation rate in a gas-fluidized bed is improved by the implementation. This result indicates that particle rotation is important microscopic physics to be incorporated into the hydrodynamic model. Segregation of a large particle in a dense granular bed of small particles under vertical. vibration is studied using molecular dynamics simulations. Wall friction is identified as a necessary condition for the segregation. Large-scale force networks bearing larger-than-average forces are found with the presence of wall friction. The role of force networks in assisting rising of the large particle is analyzed. Single-point force distribution and two-point spatial force correlation are computed. The results show the heterogeneity of forces and a short-range correlation. The short correlation length implies that even dense granular flows may admit local constitutive relations. A modified minimum spanning tree (MST) algorithm is developed to asymptotically recover the force statistics in the force networks. This algorithm provides a possible route to constructing a continuum model with microstructural information supplied from it. Microstructures in gas fluidized beds are also analyzed using a hybrid method, which couples the discrete element method (DEM) for particle dynamics with the averaged two-fluid (TF) equations for the gas phase. Multi-particle contacts are found in defluidized regions away from bubbles in fluidized beds. The multi-particle contacts invalidate the binary-collision assumption made in the kinetic theory of granular flows for the defluidized regions. Large ratios of contact forces to drag forces are found in the same regions, which confirms the relative importance of contact forces in determining particle dynamics in the defluidized regions.

Jin Sun

2007-08-03T23:59:59.000Z

291

LFS Exhibit A General Conditions  

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

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

292

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

293

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 exam...

Curiel, Erik

2014-01-01T23:59:59.000Z

294

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 ...

Lämmer, Stefan

2008-01-01T23:59:59.000Z

295

Boundary Conditions for Free Interfaces with the Lattice Boltzmann Method  

E-Print Network [OSTI]

In this paper we analyze the boundary treatment of the Lattice Boltzmann method for simulating 3D flows with free surfaces. The widely used free surface boundary condition of K\\"orner et al. (2005) is shown to be first order accurate. The article presents new free surface boundary schemes that are suitable for the lattice Boltzmann method and that have second order spatial accuracy. The new method takes the free boundary position and orientation with respect to the computational lattice into account. Numerical experiments confirm the theoretical findings and illustrate the the difference between the old and the new method.

Bogner, Simon; Rüde, Ulrich

2014-01-01T23:59:59.000Z

296

Wave attenuation over coastal salt marshes under storm surge conditions  

E-Print Network [OSTI]

to fracture along lines of weakness that formed when stems folded over to high bending 108 angles. Cumulatively, this breakage resulted in a loss of 31% (30 kg) of the total 98 kg of biomass 109 after two days of runs under higher energy conditions (Fig. 2c... and tidal flow or as wave/tidal energy 37 buffers7,11–13. The inclusion of such natural features into quantitative flood risk assessments, 38 however, has been hampered by a lack of (i) empirical evidence for their capacity to act as wave 39 dissipaters...

Möller, Iris; Kudella, Matthias; Rupprecht, Franziska; Spencer, Tom; Paul, Maike; van Wesenbeeck, Bregje K.; Wolters, Guido; Jensen, Kai; Bouma, Tjeerd J.; Miranda-Lange, Martin; Schimmels, Stefan

2014-09-29T23:59:59.000Z

297

CFD Modeling of a CFB Riser Using Improved Inlet Boundary Conditions  

Science Journals Connector (OSTI)

A computational fluid dynamics (CFD) model based on Eulerian?Eulerian approach coupled with granular kinetics theory was adopted to investigate the hydrodynamics and flow structures in a circulating fluidized bed (CFB) riser column. A new approach to specify the inlet boundary conditions was proposed in this study to simulate gas?solids flow in CFB risers more accurately. Simulation results were compared with the experimental data and good agreement between the numerical results and experimental data was observed under different operating conditions which indicates the effectiveness and accuracy of the CFD model with the proposed inlet boundary conditions. The results also illustrate a clear core annulus structure in the CFB riser under all operating conditions both experimentally and numerically.

B. T. Peng; C. Zhang; J. X. Zhu; X. B. Qi

2010-01-01T23:59:59.000Z

298

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

299

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

300

Proper planning improves flow drilling  

SciTech Connect (OSTI)

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

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

1994-10-01T23:59:59.000Z

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

Zonal flow as pattern formation  

SciTech Connect (OSTI)

Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows, and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the wavelength of the zonal flows is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.

Parker, Jeffrey B.; Krommes, John A. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2013-10-15T23:59:59.000Z

302

Abstracts of the symposium on unsaturated flow and transport modeling  

SciTech Connect (OSTI)

Abstract titles are: Recent developments in modeling variably saturated flow and transport; Unsaturated flow modeling as applied to field problems; Coupled heat and moisture transport in unsaturated soils; Influence of climatic parameters on movement of radionuclides in a multilayered saturated-unsaturated media; Modeling water and solute transport in soil containing roots; Simulation of consolidation in partially saturated soil materials; modeling of water and solute transport in unsaturated heterogeneous fields; Fluid dynamics and mass transfer in variably-saturated porous media; Solute transport through soils; One-dimensional analytical transport modeling; Convective transport of ideal tracers in unsaturated soils; Chemical transport in macropore-mesopore media under partially saturated conditions; Influence of the tension-saturated zone on contaminant migration in shallow water regimes; Influence of the spatial distribution of velocities in porous media on the form of solute transport; Stochastic vs deterministic models for solute movement in the field; and Stochastic analysis of flow and solute transport. (DMC)

Not Available

1982-03-01T23:59:59.000Z

303

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

Open Energy Info (EERE)

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

304

Two phase flow in capillary tubes  

E-Print Network [OSTI]

The flow of two phases, gas and liquid, has been studied in horizontal tubes of capillary diameter. The flow has been primarily studied in the regime where the gas flows as long bubbles separated from the wall of the tube ...

Suo, Mikio

1963-01-01T23:59:59.000Z

305

Experimental Study of Two-Phase Flow Oscillation in Natural Circulation  

SciTech Connect (OSTI)

The experiment was performed on the test loop HRTL-5, which simulates the geometry and system design of the 5-MW nuclear heating reactor developed by the Institute of Nuclear Energy Technology, Tsinghua University. The flow behavior for a wide range of inlet subcoolings, in which the flow experience varies from single- to two-phase, is described in a natural circulation system at different pressures (p = 0.1, 0.24, and 1.5 MPa). Several kinds of flow instability are investigated, including geysering, flashing-related flow instability, and high-frequency flow oscillation at p = 0.1 and 0.24 MPa, as well as low steam quality density wave oscillation at p = 1.5 MPa. The mechanisms of geysering, which has new features, and flashing-related flow instability, which has never been studied well enough in this field, are particularly interpreted. The experimental results show the following: First, for a low-pressure natural circulation system, the two-phase flow is unstable in most inlet subcooling conditions, and the two-phase stable flow can be reached only with very low inlet subcoolings. Second, at high inlet subcoolings, the flow instability is dominated by subcooling boiling in the heated section, and at intermediate inlet subcoolings, it is dominated by void flashing in the adiabatic long riser. Third, in the two-phase stable flow region, the conditions for boiling out of the core, namely, single-phase flow in the heated section and two-phase flow in the riser due to vapor flashing, can be realized. The experimental results are of significance for the design and accident analysis of vessel and swimming pool-type natural circulation nuclear heating reactors.

Jiang, S.Y.; Wu, X.X.; Zhang, Y.J. [Tsinghua University (China)

2000-06-15T23:59:59.000Z

306

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

SepĂșlveda, Mauricio

307

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

E-Print Network [OSTI]

analysis is shown in table 3. Tab.3 Calculation results of direct return system terminal control j i 1 2 3 4 5 Yi 1 0 1 1 1 1 0 2 0.965 0 1 1 1 0.009 3 0.841 0.863 0 1 1 0.074 4 0.873 0.900 0.955 0 1 0.068 5 0.797 0.821 0.872 0.913 0 0.149 j... analysis is shown in table 3. Tab.3 Calculation results of direct return system terminal control j i 1 2 3 4 5 Yi 1 0 1 1 1 1 0 2 0.965 0 1 1 1 0.009 3 0.841 0.863 0 1 1 0.074 4 0.873 0.900 0.955 0 1 0.068 5 0.797 0.821 0.872 0.913 0 0.149 j...

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

2006-01-01T23:59:59.000Z

308

Effect of operating conditions on wax deposition in a laboratory flow loop characterized with DSC technique  

Science Journals Connector (OSTI)

Crude oil is a mixture of a diverse group of paraffins, aromatics, naphthenes, resins, asphaltenes, etc. Among these groups of hydrocarbons, heavy paraffinic hydrocarbons (waxes) can cause wax deposition on the pipeline

Wenda Wang; Qiyu Huang; Changhui Wang; Si Li…

2014-10-01T23:59:59.000Z

309

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

310

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

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

Weilin - Department of Mechanical Engineering, University of Hawai'i at Manoa Collection: Engineering 10 INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth....

311

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

312

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

313

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,...

314

The lattice Boltzmann method for complex flows.  

E-Print Network [OSTI]

??This thesis presents the extension of the lattice Boltzmann equation (LBE) to several well-known flows. First, the flow over a cylinder is studied using the… (more)

Reis, Tim

2007-01-01T23:59:59.000Z

315

COMMON SENSE REASONING ABOUT PETROLEUM FLOW  

E-Print Network [OSTI]

SENSE REASONING ABOUT . PETROLEUM FLOW Steven Rosenberg I 'Sense Reasoning about Petroleum Flow By Steven Rosenbergand reasoning in a petroleum resources domain. A basic model

Rosenberg, Steven

2014-01-01T23:59:59.000Z

316

Category:Flow Test | Open Energy Information  

Open Energy Info (EERE)

| Sign Up Search Category Edit History Facebook icon Twitter icon Category:Flow Test Jump to: navigation, search Geothermalpower.jpg Looking for the Flow Test page? For...

317

Acoustic concentration of particles in fluid flow  

SciTech Connect (OSTI)

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

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

2010-11-23T23:59:59.000Z

318

Acoustic Concentration Of Particles In Fluid Flow  

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

in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. Available for thumbnail of...

319

Coal flows | OpenEI  

Open Energy Info (EERE)

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

320

Multiscale modeling in granular flow  

E-Print Network [OSTI]

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

Rycroft, Christopher Harley

2007-01-01T23:59:59.000Z

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


321

Studies of Flows in Plasmas  

SciTech Connect (OSTI)

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

Gekelman, Walter; Morales, George; Maggs, James

2009-03-07T23:59:59.000Z

322

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

323

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

324

Flow assurance and multiphase pumping  

E-Print Network [OSTI]

. LITERATURE REVIEW???????????????????????????????????.. 5 Deepwater Oilfields???????????????????????????????????.. 7 Flow Assurance?????????????????????????????????????.. 9 Hydrate Management??????????????????????????????????. 11 Stranded Gas...???????????????????????????????????????.. 172 Management in Oil and Gas???????????????????????????????. 172 Constraints and Recent Advances????????????????????????????. 173 Optimization for Oilfield Management??????????????????????????. 174 Asset Management...

Nikhar, Hemant G.

2009-05-15T23:59:59.000Z

325

Energy flows, metabolism and translation  

Science Journals Connector (OSTI)

...L. , Pascal, R. 2011 Energy sources, self-organization...E. 1946 What's life. New York, NY: McMillan. 14 Lotka...nonequilibrium systems. New York, NY: Wiley. 17 Morowitz, H. , Smith, E. 2007 Energy flow and the organization...

2011-01-01T23:59:59.000Z

326

Measurement of VOC reactivities using a photochemical flow reactor  

SciTech Connect (OSTI)

A commercial ambient air monitoring instrument, the Airtrak 2000, has been modified for use as a photochemical flow reactor and used to measure the absolute and incremental reactivity of 18 single test VOCs and the incremental reactivity of six multicomponent VOC mixtures. A flow technique is a useful supplement to traditional static chamber experiments. The static chamber technique involves periodic sampling of an irradiated mixture in a photochemical chamber. Under these conditions, the irradiated mixture is always in transition. Using a flow system, a steady-state condition is established within the flow reactor that is representative, in this case, of the early stages of the smog forming process in the atmosphere. The measurement technique also allows changes in the background chamber reactivity to be monitored and taken into account. The incremental reactivity of 13 of the 18 test compounds measured is compared with previously reported results from a static chamber experiment, and the two data sets are generally in good agreement. The additivity of reactivity was tested by measuring the incremental reactivity of six multicomponent mixtures, the components being compounds measured individually in this study. The measured reactivity of a mixture was compared to that calculated from the sum of the measured reactivity of the mixture`s individual components. The results show that reactivity is additive for the concentration range studied.

Hurley, M.D.; Chang, T.Y.; Japar, S.M.; Wallington, T.J. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.] [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.

1998-07-01T23:59:59.000Z

327

Solid particle deposition during turbulent flow production operations  

SciTech Connect (OSTI)

The production and transportation of petroleum fluids could be severely affected by deposition of suspended particles (i.e., asphaltene, paraffin/wax, sand, and/or diamondoid) in the production wells and/or transfer pipelines. In many instances the amount of precipitation is rather large causing complete plugging of these conduits. Therefore, it is important to understand the behavior of suspended particles during flow conditions. In this paper the authors present an analysis of the diffusional effects on the rate of solid particle deposition during turbulent flow conditions (crude oil production generally falls within this regime). The turbulent boundary layer theory and the concepts of mass transfer have been utilized to calculate the particle deposition rates on the walls of the flowing conduit. The developed model accounts for the eddy and Brownian diffusivities as well as for inertial effects. The analysis presented in this paper shows that rates of solid-particle deposition (during crude oil production) on the walls of the flowing channel due solely to diffusional effects are small. It is also shown that deposition rates decrease with increasing particle size. However, when the process is momentum controlled (large particle sizes) higher deposition rates are expected.

Escobedo, J.; Mansoori, G.A. [Univ. of Illinois, Chicago, IL (United States)

1995-12-31T23:59:59.000Z

328

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

329

Nonequilibrium flows with smooth particle applied mechanics  

SciTech Connect (OSTI)

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

Kum, O.

1995-07-01T23:59:59.000Z

330

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

331

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

332

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

333

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

334

The electron distribution function in flowing afterglow argon plasma with the D.C. discharge plasma source  

Science Journals Connector (OSTI)

The measurements presented in this paper show that in our experimental conditions, in the flowing afterglow plasma generated by the D.C. plasma source the electron distribution function is not Maxwellian in the ....

J. Glosík; J. Pavlík; M. Šícha

1983-01-01T23:59:59.000Z

335

TRAVELING WAVES IN 2D REACTIVE BOUSSINESQ SYSTEMS WITH NO-SLIP BOUNDARY CONDITIONS  

E-Print Network [OSTI]

TRAVELING WAVES IN 2D REACTIVE BOUSSINESQ SYSTEMS WITH NO-SLIP BOUNDARY systems of reactive Boussinesq equations in two di* *men- sional strips that are not aligned Boussinesq systems with no-slip boundary conditions (the fluid flow vanishes at* * the boundary). Much

Constantin, Peter

336

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

337

The effect of the exit condition on the performance of intube condensers  

SciTech Connect (OSTI)

Data collected from the open literature plus some new, unpublished data will be used to show that the exit condition can change the flow regimes, introduce certain types of instabilities, and alter flooding velocities with intube condensation. The major orientations will be considered: horizontal, vertical with vapor downflow, and vertical with vapor upflow (refluxing).

Rabas, T.J.; Arman, B.

1995-07-01T23:59:59.000Z

338

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

339

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

340

Investigation of single-substance horizontal two-phase flow  

SciTech Connect (OSTI)

Despite the abundance of work in the field of two-phase flow, it seems as though a consensus has not been reached on some of the fundamental points. Although exceptions exist, adequate physical interpretation of the flow seems to be hindered either by complexity of analysis or, in the opposite extreme, the trend toward limited-range analysis and correlations. The dissertation presents the derivation of basic conservation equations for the phases. The combined equations are used to examine the phenomenon of slip and its practical limitations, the Fanno line for single-substance flow and the effect of slip on choking. Equations for critical mass flux in the presence of slip are derived. The Mach, Reynolds and Froude numbers based on conditions at flashing are introduced as the characteristic parameters, and the importance of compressibility in single-substance two-phase flow is discussed. Experimental measurements of pressure change and void fraction for flow in the highly compressible range (.5 < Ma < 1) are presented. The working fluid is Refrigerant R-114, at room temperature, in a test section of diameter 5 cm and length 8 m. The effect of the Froude and Mach numbers is examined. The experimental facility is operated intermittently with running times of approximately two minutes and is instrumented for rapid measurements using a computer data acquisition and control system. A description of the facility and procedure is provided.

Dickinson, D.A.; Maeder, P.F.

1984-03-01T23:59:59.000Z

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.


341

Proc. IEEE PowerTech, Bucharest, June 2009. 1 Abstract-Power flow studies are typically used to determine  

E-Print Network [OSTI]

to determine the steady state or operating conditions of power systems for specified sets of load, and hence reliable solution algorithms that incorporate the effect of data uncertainty into the power flow that incorporate the effect of data uncertainties into the power flow This work was partially supported by NSERC

Cañizares, Claudio A.

342

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

343

On free convection heat transfer with well defined boundary conditions  

SciTech Connect (OSTI)

The scaling of free convection heat transfer is investigated. The non-dimensional groups for Boussinesq and fully compressible variable property free convection, driven by isothermal surfaces, are derived using a previously published novel method of dimensional analysis. Both flows are described by a different set of groups. The applicability of each flow description is experimentally investigated for the case of the isothermal horizontal cylinder in an air-filled isothermal enclosure. The approach taken to the boundary conditions differs from that of previous investigations. Here, it is argued that the best definition of the boundary conditions is achieved for heat exchange between the cylinder and the enclosure rather than the cylinder and an arbitrarily chosen fluid region. The enclosure temperature is shown both analytically and experimentally to affect the Nusselt number. The previously published view that the Boussinesq approximation has only a limited range of application is confirmed, and the groups derived for variable property compressible free convection are demonstrated to be correct experimentally. A new correlation for horizontal cylinder Nusselt number prediction is presented.

Davies, M.R.D.; Newport, D.T.; Dalton, T.M.

1999-07-01T23:59:59.000Z

344

Property:Optimum Marine/Riverline Conditions | Open Energy Information  

Open Energy Info (EERE)

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

345

Study of ash deposition during coal combustion under oxyfuel conditions  

Science Journals Connector (OSTI)

This paper presents a comparative study on ash deposition of two selected coals, Russian coal and lignite, under oxyfuel (O2/CO2) and air combustion conditions. The comparison is based on experimental results and subsequent evaluation of the data and observed trends. Deposited as well as remaining filter ash (fine ash) samples were subjected to XRD and ICP analyses in order to study the chemical composition and mineral transformations undergone in the ash under the combustion conditions. The experimental results show higher deposition propensities under oxyfuel conditions; the possible reasons for this are investigated by analyzing the parameters affecting the ash deposition phenomena. Particle size seems to be larger for the Russian coal oxy-fired ash, leading to increased impaction on the deposition surfaces. The chemical and mineralogical compositions do not seem to differ significantly between air and oxyfuel conditions. The differences in the physical properties of the flue gas between air combustion and oxyfuel combustion, e.g. density, viscosity, molar heat capacity, lead to changes in the flow field (velocities, particle trajectory and temperature) that together with the ash particle size shift seem to play a role in the observed ash deposition phenomena.

L. Fryda; C. Sobrino; M. Glazer; C. Bertrand; M. Cieplik

2012-01-01T23:59:59.000Z

346

Conditions on Electric Power Generation  

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

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

347

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

348

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

349

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

350

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

351

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

352

Microbial Adhesion in Flow Displacement Systems  

Science Journals Connector (OSTI)

...surface in flow displacement systems...in a flow displacement system contributes...substratum surface, is the...is the contact angle between...established parabolic flow between parallel plates. FIG. 9...more than half the length...and right: After addition...rectangular flow displacement systems Configuration...liquid surface tension...degrees) , contact angle between...wall shear stress (N m2...

Henk J. Busscher; Henny C. van der Mei

2006-01-01T23:59:59.000Z

353

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

354

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

355

Flow distribution in a solar collector panel with horizontally inclined absorber strips  

Science Journals Connector (OSTI)

The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontally inclined strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics (CFD) calculations. Further, experimental investigations of a 12.5 m2 solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured temperatures are compared to the temperatures determined by the CFD model and there is a good similarity between the measured and calculated results. Calculations with the CFD model elucidate the flow and temperature distribution in the collector. The influences of different operating conditions such as flow rate, properties of solar collector fluid, solar collector fluid inlet temperature and collector tilt angle are shown. The flow distribution through the absorber fins is uniform if high flow rates are used. By decreased flow rate and decreased content of glycol in the glycol/water mixture used as solar collector fluid, and by increased collector tilt and inlet temperature, the flow distribution gets worse resulting in an increased risk of boiling in the upper part of the collector panel.

Jianhua Fan; Louise Jivan Shah; Simon Furbo

2007-01-01T23:59:59.000Z

356

Summary of and observations about WIPP (Waste Isolation Pilot Plant) Facility horizon flow measurements through 1986  

SciTech Connect (OSTI)

Numerous gas flow measurements have been made at the Waste Isolation Pilot Plant (WIPP) Facility horizon from 1984 through 1986. Almost all tests have been constant-pressure or pressure-decay tests from single boreholes drilled in the underground excavations. Results indicate that beyond about 2 m from an excavation, both halite and interbeds (anhydrite and clay layers) allowed very low gas flows, and calculated permeabilities are below 1 microdarcy. In regions within 2 m of an excavation very high flow rates were measured in the interbeds immediately above and below an excavation when the test hole was drilled from near the center of the excavation. Further, measured flow rates increase with the width of the excavation. The halite also permits substantially greater gas flow within about 1 m of the excavations. Limited tracer measurements reveal that flow paths in both the halite and interbeds in the near field region are significantly larger than those in the presumed undisturbed condition. The gas flow measurements are consistent with the development of a (perhaps partially-saturated) dilatant zone (increased porosity) around the excavations. Considerable uncertainty is associated with permeabilities calculated from these flow measurements, due to unknowns of rock saturation, entry pressure effects, flow homogeneity, etc.

Stormont, J.C.; Peterson, E.W.; Lagus, P.L.

1987-05-01T23:59:59.000Z

357

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

358

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

359

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

360

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

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

Renormalization Group and the Ricci flow  

E-Print Network [OSTI]

We discuss from a geometric point of view the connection between the renormalization group flow for non--linear sigma models and the Ricci flow. This offers new perspectives in providing a geometrical landscape for 2D quantum field theories. In particular we argue that the structure of Ricci flow singularities suggests a natural way for extending, beyond the weak coupling regime, the embedding of the Ricci flow into the renormalization group flow.

Mauro Carfora

2010-01-20T23:59:59.000Z

362

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

363

11 - Knowledge Flow in Universities  

Science Journals Connector (OSTI)

In this chapter, a typical American university is chosen as a model for the quantitative analysis for the flow of knowledge in a reasonably well-defined academic setting. Knowledge flow assumes quantifiable patterns and much like the flow and retention of rain water over a given terrain of land; the quality (of teaching) and quantity (number of credit hours) of knowledge retained by students is estimated on a qualitative and quantitative basis. The model presented in this chapter is entirely generic. It can be applied in any center of learning and during any period of training, residency in limited time frame, or even to the evolution of species as they gain survival skills, and build their knowledge potential to survive, another generation, calamity, meteor fall, a catastrophic disaster, or a global nuclear fall-out. Though the probability of outcome is not accurately known, it is still bounded by confidence limits.

Syed V. Ahamed

2014-01-01T23:59:59.000Z

364

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

365

Flow optimization in diving helmets  

SciTech Connect (OSTI)

Improved carbon dioxide transport from the annular space between the head and helmet is necessary to reduce fresh gas flow and associated noise. This paper gives an overview of new techniques for investigating this transport, and for optimizing helmet flow to remove CO{sub 2}. An analytical model predicts inhaled carbon dioxide fraction in terms of helmet and respiration characteristics. Fundamental behavior over a wide range of helmet parameters is computed. An experimental model uses Reynolds scaling with water and dye to simulate fresh gas and carbon dioxide respectively. The water/dye model supports measurement of inhaled dye concentration, and flow visualization. Detailed behavior is investigated for one helmet with air/CO{sub 2} and water/dye experiments. Results support validity of the analytic and water models, provide new insight to CO{sub 2} transport mechanisms, and suggest directions for optimizing helmet design.

Camperman, J.M. [Naval Surface Warfare Center, Panama City, FL (United States). Coastal Systems Station; Tennant, J.S. [Florida Atlantic Univ., Boca Raton, FL (United States). Ocean Engineering Dept.

1996-09-01T23:59:59.000Z

366

The low temperature differential Stirling engine with working fluid operated on critical condition  

SciTech Connect (OSTI)

The research and development of low temperature differential Stirling engine has a great potential market since a lot of thermal energy at low temperature can supply it and the cost of this kind of engine is lower than general Stirling engine. The characteristics of low compression ratio and low differential temperature Stirling engine may be satisfied with working fluid compressed on critical conditions. By combining two phase heat transfer with forced convective flow in compression space and through the regenerator in the engine, a new heat transfer coefficient emerges capable of absorbing and releasing high heat fluxes without the corresponding low temperature increase. The current analysis focuses on the study of Stirling engines with working fluid compressed on critical conditions, thus at two-phase heat transfer in compression space and regenerator of the engine under forced convective flow conditions.

Naso, V.; Dong, W.; Lucentini, M.; Capata, R.

1998-07-01T23:59:59.000Z

367

FE Categorical Exclusions | Department of Energy  

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

082: Categorical Exclusion Determination 082: Categorical Exclusion Determination Gas Well Pressure Drop Prediction Under Foam Flow Conditions CX(s) Applied: A9, A11, B3.6 Date: 09/30/2010 Location(s): Tulsa, Oklahoma Office(s): Fossil Energy, National Energy Technology Laboratory September 30, 2010 CX-004071: Categorical Exclusion Determination Utah Coal and Biomass Fueled Pilot Plant CX(s) Applied: A9, B3.1 Date: 09/30/2010 Location(s): Kanab, Utah Office(s): Fossil Energy, National Energy Technology Laboratory September 29, 2010 CX-004161: Categorical Exclusion Determination Reduction of Heavy Oil Viscosity Using Solid Sorbents CX(s) Applied: B3.6 Date: 09/29/2010 Location(s): Laramie, Wyoming Office(s): Fossil Energy, National Energy Technology Laboratory September 29, 2010 CX-004162: Categorical Exclusion Determination

368

The effect of temperature gradient on the transport phenomenon in roots of maize plants grown under salinity conditions. conductivity and filtration properties  

Science Journals Connector (OSTI)

An analysis of flows through primary root and first node root tissues of plants grown under conditions of salinity and nutrient deficiency induced by temperature gradients was carried out using. a mathematical mo...

J. Michalov

1989-07-01T23:59:59.000Z

369

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

370

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

371

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

372

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

373

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

Open Energy Info (EERE)

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

374

Visualization of the recovery-bioler flow fields predicted by computational fluid dynamics  

SciTech Connect (OSTI)

Flow patterns in the kraft recovery furnace can be simulated using models based on computational fluid dynamics (CFD). The use of CFD is becoming increasingly common as computer workstations become more powerful and CFD software is improved. In this article, the authors present simulated results for flow fields in the lower furnace. Because the flows in the lower furnace are dominated by the air system, the authors chose to simulate flow fields under isothermal conditions. The predicted flow fields were used to supplement results obtained from physical modeling. When a physical model is used for testing, each air-system configuration is typically evaluated based on air and gas velocities and the mixing distribution as measured at a limited number of test planes. Such measurements are commonly used to quantitatively assess air-system configurations for modeling studies or to validate CFD models.

Chapman, P.J.; Janik, S.G. (Kreisinger Development Lab. ABB Combustion Engineering Systems, Windsor, CT (United States)); Jones, A.K. (ABB Canada, Ottawa, ON (Canada))

1992-03-01T23:59:59.000Z

375

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

Open Energy Info (EERE)

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

376

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

377

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

378

Numerical simulation of buoyant turbulent flow. Final report  

SciTech Connect (OSTI)

Two models have been developed for predicting low Reynolds number turbulent flows in the free and mixed convection regimes. One, the KEM model, is based on the notion of eddy diffusivities for momentum and heat. The other, the ASM model, is based on algebraic relations derived for the anisotropic turbulent fluxes by suitable truncation of the parent transport equations. Both formulations apply to variable property flows with high overheat ratios. A comparison between measurements and predictions for the case of the vertical plate shows that both models yield fairly accurate results for the mean flow and heat transfer. As a result, only the simpler of the two models, the KEM, was used to predict the cavity flows. Predictions for the case of the vertical flat plate show excellent agreement with measurements of mean velocity, temperature and Nusselt number. Nearwall results predicted by both models reveal the existence of a 1/3 power-law dependence. Regions of negative buoyant and shear production of turbulence kinetic energy are clearly revealed by the calculations. Calculations of the cavity configuration were performed for the free and mixed flow conditions. Fairly good agreement is obtained between measurements and predictions of the velocity and temperature fields. Many of the complex characteristics of heated cavity flows, revealed experimentally, are resolved numerically. Although differing in absolute value, calculations of the cavity Nusselt number show trends which are in accord with the measurements. Thus, in the free convection regime it is shown that when the cavity is tilted forwards stable stratification of fluid dampens the turbulence fluctuations which works to reduce heat transfer.

Humphrey, J.A.C.; Sherman, F.S.; To, W.M.

1985-08-01T23:59:59.000Z

379

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

380

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

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

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

382

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

383

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 suĂ?cient coverage under some speci#12;c well-de#12;ned test coverage criterion

Gupta, Rajiv

384

Hydroplaning of subaqueous debris flows  

Science Journals Connector (OSTI)

...contiguous deposit of a subaqueous flow may be fringed by discrete parcels of debris that appear to have separated from the toe of the...can be introduced at the start of the channel either from a conveyor belt or from a head tank. With the head-tank configuration...

385

Thermodynamics of urban population flows  

Science Journals Connector (OSTI)

Orderliness, reflected via mathematical laws, is encountered in different frameworks involving social groups. Here we show that a thermodynamics can be constructed that macroscopically describes urban population flows. Microscopic dynamic equations and simulations with random walkers underlie the macroscopic approach. Our results might be regarded, via suitable analogies, as a step towards building an explicit social thermodynamics.

A. Hernando and A. Plastino

2012-12-05T23:59:59.000Z

386

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

387

Sedimentation Field Flow Fractionation: Applications  

Science Journals Connector (OSTI)

...FIELD-FLOW FRACTIONATION OF ALKALI-LIBERATED NUCLEAR POLYHEDROSIS-VIRUS FROM GYPSY-MOTH...FRACTIONATION TO RADIOACTIVE-WASTE DISPOSAL, NUCLEAR TECHNOLOGY 51 : 147 ( 1980 ). SOBER...perThe SFFF separation in Fig. 9a was ic dispersant moarbitrarily concluded shortly after...

J. J. Kirkland; W. W. Yau

1982-10-08T23:59:59.000Z

388

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

E-Print Network [OSTI]

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

Nolan, Sean Patrick Rock

2005-01-01T23:59:59.000Z

389

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...

390

Conditional Similarity Solutions of the Boussinesq Equation  

Science Journals Connector (OSTI)

The direct method proposed by Clarkson and Kruskal is modified to obtain some conditional similarity solutions of a nonlinear physics model. Taking the -dimensional Boussinesq equation as a simple example, six types of conditional similarity reductions are obtained.

Tang Xiao-Yan; Lin Ji; Lou Sen-Yue

2001-01-01T23:59:59.000Z

391

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

392

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS  

E-Print Network [OSTI]

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS KARLHEINZ GRïżœOCHENIG, GITTA KUTYNIOK's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics

Seip, Kristian

393

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS  

E-Print Network [OSTI]

LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS KARLHEINZ GRšOCHENIG, GITTA KUTYNIOK's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics

Kutyniok, Gitta

394

Credit Conditions and Stock Return Predictability  

E-Print Network [OSTI]

This dissertation examines stock return predictability with aggregate credit conditions. The aggregate credit conditions are empirically measured by credit standards (Standards) derived from the Federal Reserve Board's Senior Loan Officer Opinion...

Park, Heungju

2012-10-19T23:59:59.000Z

395

Space Conditioning Standing Technical Committee Strategic Plan  

Broader source: Energy.gov [DOE]

This strategic plan document outlines the gaps, barriers, and opportunities identified by the Building America Space Conditioning Standing Technical Committee.

396

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...

397

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

398

Studies on flow resistance of regenerator in Stirling engine  

SciTech Connect (OSTI)

Studies on flow resistance of regenerator in Stirling engine are to be reported. The purpose of this study is to measure the flow resistance of regenerator in oscillating flow condition, compare with the results of previous studies and examine whether the friction factor changes between accelerating period and decelerating period of the oscillation cycle. New experimental apparatus for measurement of flow resistance of regenerator element was designed and built. Using semiconductor pressure transducer, instantaneous pressure drops during many oscillation cycle were measured. As regenerator elements, layer of usual mesh and packed mesh were used. It was clear that friction factor of usual mesh, obtained from maximum values of pressure drops in oscillation cycle, lay between two previous studies, while friction factor of packed mesh became higher than the previous studies. Also it became obvious that friction factor did not change between accelerating period and decelerating period of oscillation cycle under revolution speed of 100 rpm, while over 200 rpm, friction factor in decelerating period became higher than in accelerating period at same lower Reynolds number.

Sakano, Akira; Isshiki, Seita; Ushiyama, Izumi [Ashikaga Inst. of Technology, Ashikaga, Tochigi (Japan). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

399

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

400

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.


401

Flow frictional characteristics of microencapsulated phase change material suspensions flowing through rectangular minichannels  

Science Journals Connector (OSTI)

An experimental investigation was conducted on the laminar flow frictional characteristics of suspensions with microencapsulated phase change material (MEPCM) in water flowing through rectangular...

Yu Rao; Frank Dammel; Peter Stephan…

2006-08-01T23:59:59.000Z

402

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 Laboratory’s (INL) matched index of refraction (MIR) test facility and data were taken. The data were then studied and compared to CFD calculations to help determine their suitability for validation data. One of the main findings was that the inlet data, which were measured and controlled by calibrated mass flow rotameters and were also measured using detailed stereo particle image velocimetry (PIV) showed considerable discrepancies in mass flow rate between the two methods. The other finding was that a randomly unstable recirculation zone occurs in the flow. This instability has a very significant effect on the flow field in the vicinity of the inlet jets. Because its time scale is long and because it is apparently a random instability, it was deemed undesirable for a validation data set. It was predicted using CFD that by eliminating the first of the four jets, the recirculation zone could be stabilized. The present paper reports detailed results for the three-jet case with comparisons to the four-jet data inasmuch as three-jet data are still unavailable. Hence, the present simulations are true or blind predictions.

Richard W. Johnson; Hugh M. McIlroy

2010-08-01T23:59:59.000Z

403

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

404

Numerical Analysis of Heat Transfer and Fluid Characteristics of Flowing Liquid Nitrogen in HTS Cable  

Science Journals Connector (OSTI)

Abstract High-temperature superconducting (HTS) cable has heat intrusion from the termination including joule heat generation at the terminal joint and from the room temperature cable through the Cu current lead. According to the length of the HTS cable, this heat loss may become a considerable amount which cannot be ignored in the HTS cable system. In this study, referring to a high-voltage cable (HV cable) which was developed in M-PACC project, the effect of heat transfer at the interface between the terminal joint and LN2 in the terminal vessel (ho) on the temperature of the HTS cable were calculated and evaluated. The condition of flow in the terminal vessel was assumed to be natural convection, forced flow or static condition for evaluating this effect with various heat transfer condition. As a result, in the case of the natural convection, most of heats flow into the LN2 in the terminal vessel where the volumetric flow of the LN2 is large since ho becomes high. Accordingly, the temperature rise of the LN2 in the inner pipe of Cu former and the terminal vessel can be restricted. However, in the cases of the forced flow and the static condition, most of heats flow into the LN2 in the inner pipe where the volumetric flow of the LN2 is small since ho becomes small. Accordingly, the temperature rise of the LN2 in the inner pipe becomes high. This temperature rise of the LN2 in the inner pipe makes the temperature of the HTS conductor large resulting in remarkable increase of AC losses. Consequently, on the HV cable design, for restriction of the AC loss increase, it is expected that designing the HTS cable termination such as extending outer surface of the terminal joint for increasing of the heat inflow from the terminal joint to the LN2 in the vessel is effective.

O. Maruyama; T. Ohkuma; T. Izumi; Y. Shiohara

2014-01-01T23:59:59.000Z

405

A 1-D gas dynamics code for subsonic and supersonic flows applied to predict EGR levels in a heavy-duty diesel engine  

Science Journals Connector (OSTI)

The development of a 1-D gas dynamics code for unsteady flow in internal combustion (IC) engines as well as its validation and application for predicting residual gas fraction are introduced in this paper. Some new approaches are presented for modelling flows in diverging ducts and for treating boundary conditions. These include the use of flow resistance correlation to describe separated flows and flows in bends. Excellent agreement with analytical solutions and test results has been obtained when the code was validated with fundamental gas dynamic problems, including converging-diverging nozzle flows with and without shocks; Fanno and Rayleigh flows; the Riemann shock tube problem; and engine rig experiments for modelling flow with different property gases. The code has been applied satisfactorily to predict the gas exchange process of a spark ignition (SI) engine following exhaust blow-down and exhaust gas recirculation (EGR) levels in a heavy-duty diesel engine.

Yuhua Zhu; R.D. Reitz

1999-01-01T23:59:59.000Z

406

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

407

Distinguishing features of flow in heterogeneous porous media: 4, Is a more general dynamic description required  

SciTech Connect (OSTI)

Groundwater theory that applies to only homogeneous systems is often too restricted to adequately solve actual groundwater pollution problems. For adequate solutions, the more general theory for heterogeneous porous systems is needed. However, the present dynamic and kinematic descriptions in heterogeneous materials have evolved largely from the restricted and less general homogeneous theory. These descriptions are inadequate because they fail to account for all the energy dissipation in the system. The basic distinguishing dynamic feature of heterogeneous flow theory from the less general homogeneous-based theory is the macroscopic rotational flow component. Specifically, existence of rotational flow components and their independence from the translational flow components are the necessary and sufficient conditions that completely differentiate between the complex lamellar heterogeneous flow theory and the simpler lamellar flow of homogeneous theory. This paper proposes a more general dynamic form of the flow equation to include the added rotational dissipation that is missing from the present Darcian description of flow in heterogeneous media. 31 refs.

Nelson, R.W.

1990-11-01T23:59:59.000Z

408

Flow near the critical point: Examination of some pressure-enthalpy paths  

SciTech Connect (OSTI)

Quantitative flow modeling of fluids at elevated temperatures and pressures has generally been limited to consideration of either single-phase flow or two-phase flow at conditions below the critical point of water. In this paper, we introduce a version of the GEOTHER model that can simulate both multiphase flow and flow above the critical point, and demonstrate its capabilities by simulating flow in the vicinity of the critical point. GEOTHER2 is a multiphase, finite-difference model that simulates three-dimensional flow of pure water and heat at temperatures ranging from 0{degree} to 1,200{degree}C and pressures ranging from 0.5 to 10,000 bars. The governing equations are expressions of mass and energy conservation that are posed in terms of pressure and enthalpy. A series of one-dimensional experiments indicates that permeability is a pivotal factor in determining pressure-enthalpy/temperature trajectories near the critical point. At low permeabilities (<10{sup -18} m{sup 2}), heat transport by conduction dominates, and the trajectoq defines a constant thermal gradient. At higher permeabilities (>10{sup -16} m{sup 2}), advective heat transport dominates, and the pressure-enthalpy trajectory maintains a constant "flowing enthalpy".

Hayba, Daniel O.; Ingebritsen, Steven E.

1994-01-20T23:59:59.000Z

409

Why Do Continuum Gas-Solids Flow Models Predict Core-Annulus Flow?  

SciTech Connect (OSTI)

Core-annulus flow is an experimentally well established, industrially significant flow pattern of circulating fluidized beds. Several studies reported in the literature have shown that continuum gas-solids flow models are able to predict that flow pattern. But the crucial features of the model that give rise to the core-annulus flow structure have not been identified. To determine those features, we conduct transient simulations and analyze the results. Furthermore we time-average the results and investigate the formulation of time-averaged equations. We use transient, highly resolved, 1-D, grid-independent numerical solutions of a continuum model in this study. We show that the results could be even qualitatively incorrect (high solids concentration at the center of the channel) unless grid-independence is established. This explains why in certain coarse grid computations reported in the literature it was necessary to remove a dissipation term or to increase the particle size. Our simulations verify that the core-annulus structure arises in a time-averaged sense from unsteady gas-solids flow, as observed in experiments. We show that the key term that makes the flow unsteady is the dissipation term in the granular energy equation. Without that term the simulation yields a steady-state solution. The intuition based on steady-state solutions may not be valid. Unlike steady-state solutions, the transient solutions are not unduly sensitive to the restitution coefficient. The effect of restitution coefficient in transient simulations is remarkably different: a smaller restitution coefficient gives a higher average granular temperature. Both the micro-scale (clusters resolved) and meso-scale (clusters time-averaged) phenomena are important, unlike turbulent single-phase flows where the meso-scale (turbulent) stresses dominate. The prediction of core-annulus flow is strongly affected by the parameters used in the (micro-scale) wall boundary conditions; it is essential that the parameters are such that no granular energy is produced at the wall. The normal stress based on kinetic theory (Ps, micro) is an order of magnitude larger than normal stress arising from fluctuations (Ps, meso). Therefore, the granular temperature and solids fraction are approximately inversely correlated, just as shown by a steady-state analysis. However, the gradient of Ps, micro is of the same order of magnitude as the gradient of Ps, meso; those gradients adjust to ensure that the time averaged total Ps gradient in the radial direction is zero. The meso-scale shear stress is larger than the micro-scale shear stress. The meso-scale granular energy production term dominates the corresponding micro-scale term and must be included in time-averaged equations. That term is responsible for the maximum at the center in the granular temperature profile. The micro-scale granular energy production term is identically zero at the center because it is proportional to the gradient of solids velocity, which is zero at the center. The instantaneous gradient of solids velocity at the center, however, is not zero because of the down flow of clusters near the walls; it takes positive and negative values making the time-averaged velocity gradient exactly zero at the center. Therefore, the time-averaged square of the velocity gradient is non-zero at the center, which results in a production term in the time-averaged equations that is non-zero at the center. We find that the predictions are insensitive to the currently available k-ć type turbulence models. The traditional k-ć type models, based on the experience with single phase flow calculations, may not be adequate because meso-scale terms do not necessarily dominate the micro-scale terms. And certain parameters could behave counter to our intuition based on single phase flows: we compute and confirm with physical arguments that the gas-phase turbulent (meso-scale) viscosity could become negative.

Benyahia, S.; Syamlal, M.; O'Brien, T.J.

2006-11-01T23:59:59.000Z

410

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

411

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

Open Energy Info (EERE)

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

412

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

413

Subsurface Flow and Contaminant Transport Documentation and User's Guide  

SciTech Connect (OSTI)

This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogeneous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally, 1-D and 2-D (in Cartesian coordinates) problems are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates.

Aleman, S.E.

1999-07-28T23:59:59.000Z

414

Combustion Stability in Complex Engineering Flows | Argonne Leadership  

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

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

415

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

416

Flow in Computer Hacking: A Model  

Science Journals Connector (OSTI)

In this study hackers’ motivation is investigated, using the flow paradigm. It was hypothesized that flow increases with the increase of hackers’ competence in the IT use. An on-line research was administered wit...

Alexander E. Voiskounsky; Olga V. Smyslova

2003-01-01T23:59:59.000Z

417

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

418

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

419

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

420

Definition: Flow Test | Open Energy Information  

Open Energy Info (EERE)

Flow Test Flow tests are typically conducted shortly after a well has been drilled to test its productivity. The well is opened and fluids are released, the volume of fluids...

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

Floating Robots Track Water Flow With Smartphones  

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

Floating Robots Track Water Flow, Stream Data via Smartphones Floating Robots Track Water Flow, Stream Data via Smartphones May 9, 2012 | Tags: Carver Jon Bashor, Jbashor@lbl.gov,...

422

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

423

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

424

Turbine Vanes and Endwalls with Realistic Surface Conditions  

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

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

425

Magnetosheath conditions and magnetopause structure for high magnetic shear  

Science Journals Connector (OSTI)

The supersonic solar wind - Earth's magnetosphere coupling plays the main role in the solar wind energy, momentum and mass input into the magnetosphere. A new dynamic model of the magnetic field in the coupled solar wind — magnetosphere system taking into account bow shock formation is considered. The solution for plasma flow and magnetic field upstream and downstream the bow shock was obtained in kinematic approximation. The magnetic field near the magnetopause was compared with those obtained in terms of subsonic solar wind - magnetosphere interaction. For typical magnetosheath conditions, the former is about twice the latter. The magnetic field near the magnetopause is formed due to mutual diffusion of the magnetospheric and interplanetary magnetic fields. The proposed model allows to determine reconnection efficiency by IMF and solar wind parameters: velocity, density, conductivity. The calculated magnetic field in the magnetosheath is compared with those measured by AMPTEARM satellite for high magnetopause magnetic shear.

V.V. Kalegaev

2000-01-01T23:59:59.000Z

426

Elliptic flow of heavy flavors  

E-Print Network [OSTI]

The propagation of charm and bottom quarks through a ellipsoidal domain of quark gluon plasma has been studied within the ambit of non-equilibrium statistical mechanics. Energy dissipation of heavy quarks by both radiative and collisional processes are taken in to account. The experimental data on the elliptic flow of the non-photonic electrons resulting from the semi-leptonic decays of hadrons containing heavy flavours has been reproduced with the same formalism that has been used earlier to reproduce the nuclear suppression factors. The elliptic flow of the non-photonic electron from heavy meson decays produced in nuclear collisions at LHC and low energy RHIC run have also been predicted.

Das, Santosh K

2010-01-01T23:59:59.000Z

427

Elliptic flow of heavy flavors  

E-Print Network [OSTI]

The propagation of charm and bottom quarks through an ellipsoidal domain of quark gluon plasma has been studied within the ambit of non-equilibrium statistical mechanics. Energy dissipation of heavy quarks by both radiative and collisional processes are taken in to account. The experimental data on the elliptic flow of the non-photonic electrons resulting from the semi-leptonic decays of hadrons containing heavy flavours has been reproduced with the same formalism that has been used earlier to reproduce the nuclear suppression factors. The elliptic flow of the non-photonic electron from heavy meson decays produced in nuclear collisions at LHC and low energy RHIC run have also been predicted.

Santosh K Das; Jan-e Alam

2010-08-16T23:59:59.000Z

428

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

429

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

430

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

431

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

432

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

433

Anisotropic Flow from RHIC to the LHC  

E-Print Network [OSTI]

Anisotropic flow is recognized as one of the main observables providing information on the early stage of a heavy-ion collision. At RHIC the large observed anisotropic flow and its successful description by ideal hydrodynamics is considered evidence for an early onset of thermalization and almost ideal fluid properties of the produced strongly coupled Quark Gluon Plasma. This write-up discusses some key RHIC anisotropic flow measurements and for anisotropic flow at the LHC some predictions.

Raimond Snellings

2006-10-05T23:59:59.000Z

434

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

2014-05-08T23:59:59.000Z

435

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

436

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

437

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

438

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data there has been no flow at this site #12;Gather daily flow rate data Load data into a spreasheet Sort largest, etc) Calculate percentage of days flow was exceeded: How do you estimate load with given data

439

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

440

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

Note: This page contains sample records for the topic "flow conditions cxs" from the National Library of EnergyBeta (NLEBeta).
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441

Geothermal Heat Flow and Existing Geothermal Plants | Department...  

Energy Savers [EERE]

Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Plants With plants in development. Click...

442

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

443

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-François; Imbeaux, Frédéric [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar—382428 (India)

2014-07-15T23:59:59.000Z

444

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

445

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

446

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

447

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

448

Model of bubble velocity vector measurement in upward and downward bubbly two-phase flows using a four-sensor optical probe  

Science Journals Connector (OSTI)

Abstract The knowledge of bubble behaviors is of considerable significance for a proper understanding and modeling of two-phase flows. To obtain the information on the bubble motion, a novel model was developed, by which the bubble velocity vector can be directly calculated from six time intervals measured with a four-sensor probe. The measurements of local bubble velocity vector and void fraction were performed in both upward and downward bubbly flows by using a four-sensor optical probe. The area-averaged void fraction and bubble velocity obtained from the probe agree well with those measured by other cross-calibration methods, and the measurement errors are within 15% under various flow conditions. Experimental results of the bubble velocity vector reveal that the bubble lateral migration may be suppressed in upward flows, but be strengthened in downward flows as the liquid flow rate increases. Also, with an increase in gas flow rate, the bubble velocity distribution varies into the power–law profile in upward flows, but into an off-center peak profile in downward flows. In addition, the void fraction shows a core peak distribution at low void fraction for downward flows, but a wall peak distribution for upward flows. However, when the void fraction is relatively high, it displays an off-center peak distribution for downward flows but a core peak distribution for upward flows.

Daogui Tian; Changqi Yan; Licheng Sun

2015-01-01T23:59:59.000Z

449

Central Air Conditioning | Department of Energy  

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

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

450

Energy conditions in f(R)-gravity  

E-Print Network [OSTI]

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

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

2007-09-06T23:59:59.000Z

451

Methods of Conditioning Direct Methanol Fuel Cells  

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

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

452

Definition: Equipment Condition Monitor | Open Energy Information  

Open Energy Info (EERE)

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

453

Convective exergy losses of developing slip flow in microchannels  

Science Journals Connector (OSTI)

A numerical formulation of convective exergy losses in microchannels is developed. Using a new convection model (called Non-Inverted Skew Upwind Scheme (NISUS)), the predicted velocity field is post-processed to determine frictional irreversibilities within the microchannel. Boundary conditions are established from a first-order slip velocity, based on streamwise temperature gradients and transverse velocity gradients at the wall. Parametric studies are conducted for varying flow rates, channel aspect ratios, slip coefficients and pressure ratios across the microchannel. The predicted exergy destruction results provide useful new data, from which design modifications can be made to reduce power input when transporting fluid through a microchannel.

E.O.B. Ogedengbe; G.F. Naterer; M.A. Rosen

2007-01-01T23:59:59.000Z

454

Near-surface meteorological conditions associated with active resuspension of dust by wind erosion  

SciTech Connect (OSTI)

The meteorological conditions associated with extreme winds in the lee of the Colorado Rocky Mountains were studied from the viewpoint of dust resuspension and dispersion. Wind, dispersion, temperature, and dew point conditions occurring near the surface were discussed in detail for a selected event. Near-surface wind speeds were compared to observations made at a standard sampling height. These field data were developed to aid in validation and interpretation of wind tunnel observations and application of dispersion models to wind erosion resuspension. Three conclusions can immediately be drawn from this investigation. First, wind storms in nature are quite gusty, with gusts exceeding the mean speed by 50 percent or more. However, wind direction variations are small by comparison. Thus, wind tunnel studies should be able to simulate the large along-flow turbulence, while keeping cross-flow turbulence to a moderate level. This also has an application to the puff modeling of high winds. Puff models normally assume that the along-flow dispersion coefficient is equal to the cross-flow value. This study suggests that the along-flow coefficient should be much larger than its cross-flow counterpart. Another conclusion involves the usual assumption of Pasquill-Gifford stability class D. In the event studied here, the atmosphere was well mixed with near-neutral thermal stability, yet the horizontal dispersion stability class varied from G to A. Thus, an assumption of Class D horizontal dispersion during high winds would not have been valid during this case. A final conclusion involves the widely applied assumption of a logarithmic wind speed profile during high wind events. This study has indicated that such an assumption is appropriate.

Hodgin, C.R.

1982-01-01T23:59:59.000Z

455

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

456

Self-regulating flow control device  

SciTech Connect (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

457

Time and Materials Exhibit A General Conditions  

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

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

458

TIC et conditions de travail. Les enseignements  

E-Print Network [OSTI]

TIC et conditions de travail. Les enseignements de l'enquĂȘte COI Juin 2012 Nathalie Greenan, Sylvie TIC et conditions de travail Les enseignements de l'enquĂȘte COI NATHALIE GREENAN Centre d'Ă©tudes de l-2-11-128685-6 www.cee-recherche.fr #12;TIC et conditions de travail. Les enseignements de l'enquĂȘte COI RĂ?SUMĂ? Le

Paris-Sud XI, Université de

459

Load following capability of CANDLE reactor by adjusting coolant operation condition  

SciTech Connect (OSTI)

The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and {sup 208}Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

Sekimoto, Hiroshi; Nakayama, Sinsuke [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-17, Ookayama, Meguro-ku 152-8550 (Japan)

2012-06-06T23:59:59.000Z

460

Effect of reactor conditions on MSIV (main steam isolation valves)-ATWS power level  

SciTech Connect (OSTI)

In a boiling water reactor (BWR) when there is closure of the main steam isolation valves (MSIVs), the energy generated in the core will be transferred to the pressure suppression pool (PSP) via steam flows out of the relief valves. The pool has limited capacity as a heat sink and hence, if there is no reactor trip (an ATWS event), there is the possibility that the pool temperature may rise beyond acceptable limits. The present study was undertaken to determine how the initial reactor conditions affect the power during an MSIV-ATWS event. The time of interest is during the 20-30 minute period when it is assumed that the reactor is in a quasi-equilibrium condition with the water level and pressure fixed, natural circulation conditions and no control rod movement or significant boron in the core. The initial conditions of interest are the time during the cycle and the operating state. 4 refs., 2 tabs.

Diamond, D.J.

1987-01-01T23:59:59.000Z

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.


461

President Obama Announces $400 Million Conditional Commitment...  

Office of Environmental Management (EM)

840 megawatts (MW) of new solar power annually. The project is expected to reach full capacity by 2013. Including the conditional commitment announced today, the Department has...

462

Wave Energy Converter Extreme Conditions Modeling Workshop |...  

Open Energy Info (EERE)

adopted extreme conditions design, modeling, and analysis techniques developed for offshore oil & gas and naval architecture applications. While leveraging these existing design...

463

Condition Monitoring of Offshore Wind Turbines.  

E-Print Network [OSTI]

?? The growing interest around offshore wind power, providing at the same time better wind conditions and fewer visual or environmental impacts, has lead many… (more)

Wisznia, Roman

2013-01-01T23:59:59.000Z

464

Aluminoborosilicate Waste Glass Dissolution under Alkaline Conditions...  

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

Aluminoborosilicate Waste Glass Dissolution under Alkaline Conditions at 40°C: Implications for a Chemical Affinity-Based Aluminoborosilicate Waste Glass Dissolution under...

465

Nitrate and colloid transport through coarse Hanford sediments under steady state, variably saturated flow  

E-Print Network [OSTI]

Nitrate and colloid transport through coarse Hanford sediments under steady state, variably] At the U.S. Department of Energy's Hanford Reservation, colloid-facilitated transport is a potential of colloids through Hanford sediments under steady state, unsaturated flow conditions. We isolated colloids

Flury, Markus

466

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.

467

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

468

Matrix-Free Second-Order 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 three-dimensional simulation of the flow field around an aircraft requires accurate and efficient numerical methods in order to resolve all of high-capacity aircraft in transonic conditions, such as deformation of airplane wings and wake vortices

469

CFD Simulation and Experimental Testing of Multiphase Flow Inside the MVP Electrical Submersible Pump  

E-Print Network [OSTI]

to test the pump at different operating conditions. The pump is modeled and tested at two speeds; 3300 and 3600 rpm, using air-water mixtures with GVFs of 0, 5, 10, 25, 32 and 35%. The flow loop is controlled to produce different suction pressures up...

Rasmy Marsis, Emanuel 1983-

2012-08-16T23:59:59.000Z

470

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

471

IMECE2009-13258 SIMULATION OF OPEN CHANNEL TURBULENT FLOW OVER BRIDGE  

E-Print Network [OSTI]

surface above channel bed * h - Inundation ratio k m2 /s2 Turbulence kinetic energy bridgeL m LengthIMECE2009-13258 SIMULATION OF OPEN CHANNEL TURBULENT FLOW OVER BRIDGE DECKS AND FORMATION OF SCOUR HOLE BENEATH THE BRIDGE UNDER FLOODING CONDITIONS Bishwadipa Adhikary, Pradip Majumdar, and Milivoje

Kostic, Milivoje M.

472

Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing  

Broader source: Energy.gov [DOE]

Project objective: A New Geothermal Well Imaging Tool. 1.To develop a robust and easily deployable DTPS for monitoring in geothermal wells; and 2. Develop the associated analysis methodology for flow imaging; and?when possible by wellbore conditions?to determine in situthermal conductivity and basal heat flux.

473

Volume 106A, number 4 PHYSICS LETTERS 3 December 1984 MULTIPRESSURE REGULARIZATION FOR MULTIPHASE FLOW  

E-Print Network [OSTI]

.g., viscous dissipation [2], numerical f~tltering [3], surface tension [4], bubble inertia [5 of multiple pressures. This formalism is used to find Lyapunov stability conditions for the regularized system to the presence of the single pressure and, thus, the Lyapunov stability of stationary flows is prevented [8

Holm, Darryl D.

474

Design of a free-running, 1/30th Froude scaled model destroyer for in-situ hydrodynamic flow visualization  

E-Print Network [OSTI]

Hydrodynamic flow visualization techniques of scaled hull forms and propellers are typically limited to isolating certain operating conditions in a tow tank, circulation tunnel, or large maneuvering basin. Although cost ...

Cope, David M. (David Michael)

2012-01-01T23:59:59.000Z

475

Stability of quasi-Keplerian Shear Flow in a Laboratory Experiment  

SciTech Connect (OSTI)

Subcritical transition to turbulence has been proposed as a source of turbulent viscosity required for the associated angular momentum transport for fast accretion in Keplerian disks. Previously cited laboratory experiments in supporting this hypothesis were performed either in a di erent type of flow than Keplerian or without quantitative measurements of angular momentum transport and mean flow profile, and all of them appear to su er from Ekman e ects, secondary flows induced by nonoptimal axial boundary conditions. Such Ekman e ects are expected to be absent from astronomical disks, which probably have stress-free vertical boundaries unless strongly magnetized. Aims. To quantify angular momentum transport due to subcritical hydrodynamic turbulence, if exists, in a quasi-Keplerian flow with minimized Ekman e ects. Methods.We perform a local measurement of the azimuthal-radial component of the Reynolds stress tensor in a novel laboratory apparatus where Ekman e ects are minimized by flexible control of axial boundary conditions. Results.We find significant Ekman e ects on angular momentum transport due to nonoptimal axial boundary conditions in quasi-Keplerian flows. With the optimal control of Ekman e ects, no statistically meaningful angular momentum transport is detected in such flows at Reynolds number up to two millions. Conclusions. Either a subcritical transition does not occur, or, if a subcritical transition does occur, the associated radial transport of angular momentum in optimized quasi-Keplerian laboratory flows is too small to directly support the hypothesis that subcritical hydrodynamic turbulence is responsible for accretion in astrophysical disks. Possible limitations in applying laboratory results to astrophysical disks due to experimental geometry are discussed.

Ethan Schartman, Hantao Ji, Michael J. Burin and Jeremy Goodman

2012-06-19T23:59:59.000Z

476

Flow Test At Raft River Geothermal Area (2004) | Open Energy Information  

Open Energy Info (EERE)

Flow Test At Raft River Geothermal Area (2004) Flow Test At Raft River Geothermal Area (2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Flow Test At Raft River Geothermal Area (2004) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Flow Test Activity Date 2004 Usefulness useful DOE-funding GRED II Notes Geothermal Resource Exploration and Definition Projects Raft River (GRED II): Re-assessment and testing of previously abandoned production wells. The objective of the U.S. Geothermal effort is to re-access the available wellbores, assess their condition, perform extensive testing of the reservoir to determine its productive capacity, and perform a resource utilization assessment. At the time of this paper, all five wells had been

477

Influence of variable property effects on natural convection flows in asymmetrically-heated vertical channels  

SciTech Connect (OSTI)

The influence of variable property effects on the laminar air flow induced by natural convection in a vertical, asymmetrically-heated channel is investigated. A full-elliptic model that accounts for variations of viscosity and thermal conductivity with temperature and determines the density from the state equation, has been solved numerically for cases for which variable property effects are important, particularly for conditions for which flow reversals may appear. The corresponding numerical results are compared with those obtained from an alternative model in which all thermophysical properties are assumed to be constant and the Boussinesq approximation is used. It has been found that variable property effects have a strong influence, not reported in previous works, on the recirculation patterns, and may produce, for certain ranges of parameters that roughly coincide with those for which flow reversals exist, an increase in the mass flow rate induced in the channel.

Zamora, B. [Univ. de Murcia (Spain)] [Univ. de Murcia (Spain); Hernandez, J. [Ciudad Universitaria, Madrid (Spain)] [Ciudad Universitaria, Madrid (Spain)

1997-12-01T23:59:59.000Z

478

Flow-field dynamics during droplet formation by dripping in hydrodynamic-focusing microfluidics  

Science Journals Connector (OSTI)

Using microscopic particle image velocimetry, we examine the flow field around an oil droplet as it is formed by hydrodynamic focusing in an aqueous solution using a pressure-driven cross-channel microfluidic device. By detecting the temporal dependence of the instantaneous flow fields of the continuous phase in the dripping regime, we show that shear is not the primary mechanism that initiates droplet formation in our low flow rate and moderate capillary number experimental conditions. Instead, the advancing finger of oil partially and temporarily plugs the outlet channel, creating a pressure difference that builds up and is released when water from the side channels pushes the tip of the finger into the outlet channel, thereby facilitating the birth of the droplet by interfacial pinch-off that is primarily initiated by an extensional flow.

D. Funfschilling; H. Debas; H.-Z. Li; T. G. Mason

2009-07-06T23:59:59.000Z

479

Energy focusing in bubbly flows  

Science Journals Connector (OSTI)

Sonoluminescence cavitation damage at surfaces and cavitation in accelerating flows are realizations of spectacular levels of energy focusing in nature. In a resonant sound field a single trapped bubble of gas can focus the ambient sound energy by 12 orders of magnitude to generate a clocklike string of picosecond flashes of ultraviolet light. [Barber et al. ‘‘Defining the unknowns of sonoluminescence ’’ Phys. Rep. 281 65 (1977)]. In more complicated geometries a high level of sound leads to the formation of hemispherical bubbles attached to an exposed surface. These bubbles also emit light and in addition damage the surface. Measurements show that the pulsation of these bubbles maintains the hemispherical symmetry [Weninger et al. ‘‘Sonoluminescence from an isolated bubble on a solid surface ’’ Phys. Rev. E 56 6745 (1997)] thus raising the question as to whether cavitation damage is due to (micro)jets or imploding (hemispherical) shock waves. Finally flow through a Venturi tube generates a stream of bubbles which also emit subnanosecond flashes of light [F. B. Peterson and T. P. Anderson Phys. Fluids 10 874 (1967)]. Luminescence from an isolated trapped bubble in water seems to work well with any noble gas whereas luminescence from cavitating flows and surface bubbles is quite dependent on xenon [argon bubbles appear to give no light at all]. The width of the SL flash [Gompf et al. Phys. Rev. Lett. 79 1405 (1997) Hiller et al. Phys. Rev. Lett. 80 1090 (1998)] has been found to be independent of wavelength suggesting that light is emitted from a new high energy phase of matter?probably a cold dense nano?plasma. The key unknowns of SL are the size and temperature of the hot spot from which the light is emitted. Experiments aimed at measuring these quantities will be discussed. [Research supported by the NSF.] a)Present address: CMS Los Alamos National Laboratories Los Alamos NM. b)Present address: Lucent Technologies Murray Hill NJ.

Seth Putterman; Keith Weninger; Robert A. Hiller; Bradley P. Barber

1998-01-01T23:59:59.000Z

480

Enthalpy Diffusion in Multicomponent Flows  

SciTech Connect (OSTI)

The conclusions of this paper are: (1) Enthalpy diffusion preserves the second law. (2) Euler solvers will not produce correct temperatures in mixing regions. (3) Navier-Stokes solvers will only produce correct temperatures if q{sub d} is included. (4) Errors from neglecting enthalpy diffusion are most severe when differences in molecular weights are large. (5) In addition to temperature, enthalpy diffusion affects density, dilatation and other fields in subtle ways. (6) Reacting flow simulations that neglect the term are a dubious proposition. (7) Turbulence models for RANS and LES closures should preserve consistency between energy and species diffusion.

Cook, A W

2009-01-20T23:59:59.000Z

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.


481

Characterization of groundwater flow and transport in the General Separations Areas, Savannah River Plant: Flow model refinement and particle-tracking analysis report  

SciTech Connect (OSTI)

The Department of Energy (DOE) is preparing the necessary NEPA documentation for an Environmental Impact Statement (EIS) to address the waste disposal activities for groundwater protection at the Savannah River Plant (SRP). For purposes of this EIA, the areas within the plant have been separated into 26 functional groups based primarily on hydrogeologic setting and types of disposed waste materials. The overall objective is to provide an appropriate quantitative assessment of the environmental impacts from past and future operations within each functional group. The analysis from each functional group will be integrated to assess the impacts of plant-wide operations. A flexible approach to quantifying the impacts using several methods of quantitative analysis is being employed. Numerical flow and transport modeling is one method being applied to several functional groups. The scope of work can be divided into four broad categories: (1) Data Review and Conceptual Model Development, (2) Groundwater Flow Model Construction and Refinement, (3) Solute Transport Model Construction, and (4) Remedial Alternative Simulations. The major topics covered in this report are: (1) summary of the hydrogeologic conditions of the area, (2) observed flow velocities at the study site, (3) a summary of results from the preliminary flow modeling effort, (4) flow model refinement and results, and (5) particle tracking analyses based on the refined flow model.

Duffield, G.M.; Buss, D.R.; Root, R.W. Jr.; Hughes, S.S.; Mercer, J.W. [GeoTrans, Inc., Sterling, VA (United States)

1986-03-01T23:59:59.000Z