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1

Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment  

E-Print Network (OSTI)

Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment V. S resistive magnetohydrodynamic MHD simulation are compared to experimental data from the Swarthmore Spheromak is shown to reproduce global equilibrium magnetic field profiles of the spheromaks as well as much

Brown, Michael R.

2

Numerical and experimental validation of transient modelling for Scramjet active cooling with supercritical  

E-Print Network (OSTI)

Numerical and experimental validation of transient modelling for Scramjet active cooling of the engine. In order to simulate the behaviour of a complete actively cooled scramjet, a one for supercritical fuel under pyrolysis. This model is called RESPIRE (French acronym for Scramjet Cooling

Paris-Sud XI, Université de

3

An active wave generating–absorbing boundary condition for VOF type numerical model  

Science Journals Connector (OSTI)

The objective of the present work is to discuss the implementation of an active wave generating–absorbing boundary condition for a numerical model based on the Volume Of Fluid (VOF) method for tracking free surfaces. First an overview of the development of VOF type models with special emphasis in the field of coastal engineering is given. A new type of numerical boundary condition for combined wave generation and absorption in the numerical model \\{VOFbreak2\\} is presented. The numerical boundary condition is based on an active wave absorption system that was first developed in the context of physical wave flume experiments, using a wave paddle. The method applies to regular and irregular waves. Velocities are measured at one location inside the computational domain. The reflected wave train is separated from the incident wave field in front of a structure by means of digital filtering and subsequent superposition of the measured velocity signals. The incident wave signal is corrected, so that the reflected wave is effectively absorbed at the boundary. The digital filters are derived theoretically and their practical design is discussed. The practical use of this numerical boundary condition is compared to the use of the absorption system in a physical wave flume. The effectiveness of the active wave generating–absorbing boundary condition finally is proved using analytical tests and numerical simulations with VOFbreak2.

Peter Troch; Julien De Rouck

1999-01-01T23:59:59.000Z

4

Numerical Modeling | Open Energy Information  

Open Energy Info (EERE)

Numerical Modeling Numerical Modeling Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Numerical Modeling Details Activities (8) Areas (2) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Data and Modeling Techniques Exploration Sub Group: Modeling Techniques Parent Exploration Technique: Modeling Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Stress fields and magnitudes Hydrological: Visualization and prediction of the flow patterns and characteristics of geothermal fluids Thermal: Thermal conduction and convection patterns in the subsurface Dictionary.png Numerical Modeling: A computer model that is designed to simulate and reproduce the mechanisms of a particular system. Other definitions:Wikipedia Reegle

5

Numerical Modeling of HCCI Combustion  

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

Numerical Modeling of HCCI Combustion Salvador M. Aceves, Daniel L. Flowers, J. Ray Smith, Joel Martinez-Frias, Francisco Espinosa-Loza, Tim Ross, Bruce Buchholz, Nick...

6

MODELING STATISTICAL PROPERTIES OF SOLAR ACTIVE REGIONS THROUGH DIRECT NUMERICAL SIMULATIONS OF 3D-MHD TURBULENCE  

SciTech Connect

Statistical properties of the Sun's photospheric turbulent magnetic field, especially those of the active regions (ARs), have been studied using the line-of-sight data from magnetograms taken by the Solar and Heliospheric Observatory and several other instruments. This includes structure functions and their exponents, flatness curves, and correlation functions. In these works, the dependence of structure function exponents ({zeta}{sub p}) of the order of the structure functions (p) was modeled using a non-intermittent K41 model. It is now well known that the ARs are highly turbulent and are associated with strong intermittent events. In this paper, we compare some of the observations from Abramenko et al. with the log-Poisson model used for modeling intermittent MHD turbulent flows. Next, we analyze the structure function data obtained from the direct numerical simulations (DNS) of homogeneous, incompressible 3D-MHD turbulence in three cases: sustained by forcing, freely decaying, and a flow initially driven and later allowed to decay (case 3). The respective DNS replicate the properties seen in the plots of {zeta}{sub p} against p of ARs. We also reproduce the trends and changes observed in intermittency in flatness and correlation functions of ARs. It is suggested from this analysis that an AR in the onset phase of a flare can be treated as a forced 3D-MHD turbulent system in its simplest form and that the flaring stage is representative of decaying 3D-MHD turbulence. It is also inferred that significant changes in intermittency from the initial onset phase of a flare to its final peak flaring phase are related to the time taken by the system to reach the initial onset phase.

Malapaka, Shiva Kumar; Mueller, Wolf-Christian [Max-Planck Institute for Plasma Physics, Boltzmannstrasse 2, D-85748 Garching bei Muenchen (Germany)

2013-09-01T23:59:59.000Z

7

Numerical Modelling of Interaction between  

E-Print Network (OSTI)

plasma in arc furnace used in toxic waste destruction Plasma etching semiconductor High intensity arc lamp Electrode temperature after 1ms of arcing with power density of 3x109 W.m-2 Electrode temperatureNumerical Modelling of Interaction between the Electric Arc and Electrodes Principal researcher: W

Sóbester, András

8

Numerical Modeling At Dixie Valley Geothermal Area (Iovenitti...  

Open Energy Info (EERE)

Iovenitti, Et Al., 2013) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Dixie Valley Geothermal Area (Iovenitti, Et Al.,...

9

Numerical Modeling At Coso Geothermal Area (1995) | Open Energy Information  

Open Energy Info (EERE)

Numerical Modeling At Coso Geothermal Area (1995) Numerical Modeling At Coso Geothermal Area (1995) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Coso Geothermal Area (1995) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 1995 Usefulness useful DOE-funding Unknown Exploration Basis Locate an active fault zone by analyzing seismic guided waves from microearthquake data Notes An active fault zone was located in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling

10

Numerical  

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

of the mean flow, in which turbulence generated currents are investigated in subcritical flows. II. NUMERICAL MODEL The numerical model used in this paper solves the MHD...

11

Numerical Modeling At Raft River Geothermal Area (1983) | Open Energy  

Open Energy Info (EERE)

Raft River Geothermal Area (1983) Raft River Geothermal Area (1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Raft River Geothermal Area (1983) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Numerical Modeling Activity Date 1983 Usefulness not indicated DOE-funding Unknown Notes The numerical modeling of the resistivity data is marginal for changes as small as those observed but the results suggest that changes of a few percent could be expected from a fracture zone extending from depth to within 100 m of the surface. References Sill, W. R. (1 September 1983) Resistivity measurements before and after injection Test 5 at Raft River KGRA, Idaho. Final report Retrieved from "http://en.openei.org/w/index.php?title=Numerical_Modeling_At_Raft_River_Geothermal_Area_(1983)&oldid=47387

12

Numerical Modeling Of Basin And Range Geothermal Systems | Open Energy  

Open Energy Info (EERE)

Numerical Modeling Of Basin And Range Geothermal Systems Numerical Modeling Of Basin And Range Geothermal Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Numerical Modeling Of Basin And Range Geothermal Systems Details Activities (3) Areas (3) Regions (0) Abstract: Basic qualitative relationships for extensional geothermal systems that include structure, heat input, and permeability distribution have been established using numerical models. Extensional geothermal systems, as described in this paper, rely on deep circulation of groundwater rather than on cooling igneous bodies for heat, and rely on extensional fracture systems to provide permeable upflow paths. A series of steady-state, two-dimensional simulation models is used to evaluate the effect of permeability and structural variations on an idealized, generic

13

Numerical study on active wave devouring propulsion  

Science Journals Connector (OSTI)

The possibility of extracting energy from gravity waves for marine propulsion was numerically studied by a two-dimensional...

Liyanarachchi Waruna Arampath De Silva…

2012-09-01T23:59:59.000Z

14

Numerical Modeling At Coso Geothermal Area (2000) | Open Energy Information  

Open Energy Info (EERE)

Numerical Modeling At Coso Geothermal Area (2000) Numerical Modeling At Coso Geothermal Area (2000) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 2000 Usefulness not indicated DOE-funding Unknown Exploration Basis Determine areas with fault patterns for geothermal development using Poisson's ratio and porosity Notes High-resolution, three-dimensional, compressional and shear wave velocity models, derived from microearthquake travel times, are used to map the distribution of Poisson's ratio and porosity at Coso Geothermal Area. Spatial resolution of the three-dimensional Poisson's ratio and porosity distributions is estimated to be 0.5 km horizontally and 0.8 km vertically. Model uncertainties, + or -1% in the interior and + or -2.3% around the

15

Numerical Modeling At Coso Geothermal Area (2010) | Open Energy Information  

Open Energy Info (EERE)

10) 10) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Coso Geothermal Area (2010) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 2010 Usefulness useful DOE-funding Unknown Exploration Basis To determine conditions when fractures nucleate Notes A numerical model was developed using Poly3D to simulate the distribution and magnitude of stress concentration in the vicinity of the borehole floor, and determine the conditions under which petal-centerline fractures nucleate. As a whole, the simulations have demonstrated that a borehole under the stress boundary conditions present at the Coso 58A-10 borehole is able to amplify the stress concentration to produce tension below the

16

Definition: Numerical Modeling | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Numerical Modeling Jump to: navigation, search Dictionary.png Numerical Modeling A computer model that is designed to simulate and reproduce the mechanisms of a particular system.[1] View on Wikipedia Wikipedia Definition A computer simulation, a computer model, or a computational model is a computer program, run on a single computer, or a network of computers, that attempts to simulate an abstract model of a particular system. Computer simulations have become a useful part of mathematical modeling of many natural systems in physics, astrophysics, chemistry and biology, human systems in economics, psychology, social science, and engineering. Simulation of a system is represented as the running of the system's model.

17

Comparing Aerodynamic Models for Numerical Simulation of  

E-Print Network (OSTI)

Comparing Aerodynamic Models for Numerical Simulation of Dynamics and Control of Aircraft and simulation of aircraft, yet other aerodynamics models exist that can provide more accurate results for certain simulations without a large increase in computational time. In this paper, sev- eral aerodynamics

Peraire, Jaime

18

Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive  

E-Print Network (OSTI)

Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive Wavelet 2008 #12;This thesis entitled: Numerical Modeling of Acoustic Timescale Detonation Initiation Using. (Ph.D.) Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive Wavelet

Vasilyev, Oleg V.

19

Numerical Modeling At Coso Geothermal Area (2006) | Open Energy Information  

Open Energy Info (EERE)

2006) 2006) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 2006 Usefulness useful DOE-funding Unknown Exploration Basis Determine areas of high permeability using isotope transport and exchange analysis Notes Finite element models of single-phase, variable-density fluid flow, conductive- convective heat transfer, fluid-rock isotope exchange, and groundwater residence times were developed. Using detailed seismic reflection data and geologic mapping, a regional cross-sectional model was constructed that extends laterally from the Sierra Nevada to Wildhorse Mesa, west of the Argus Range. The findings suggest that active faults and seismogenic zones in and around the Coso geothermal area have much higher

20

High performance computing and numerical modelling  

E-Print Network (OSTI)

Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...

,

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical Models of Extragalactic Radio Sources  

Science Journals Connector (OSTI)

...unpublished data. THOMPSON, A...unpublished data. Numerical models...observatories provided an infrastructure that resulted in high-quality data for both the expert...on an Eulerian grid in time and space...magnetic field is a hybrid of the constrained...

JACK O. BURNS; MICHAEL L. NORMAN; DAVID A. CLARKE

1991-08-02T23:59:59.000Z

22

Analytical-Numerical Modeling Of Komatiite Lava Emplacement And Thermal  

Open Energy Info (EERE)

Analytical-Numerical Modeling Of Komatiite Lava Emplacement And Thermal Analytical-Numerical Modeling Of Komatiite Lava Emplacement And Thermal Erosion At Perseverance, Western Australia Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Analytical-Numerical Modeling Of Komatiite Lava Emplacement And Thermal Erosion At Perseverance, Western Australia Details Activities (0) Areas (0) Regions (0) Abstract: We have applied a thermal-fluid dynamic-geochemical model to investigate the emplacement and erosional potential of Archean komatiite flows at Perseverance, Western Australia. Perseverance has been proposed as a site of large-scale thermal erosion by large-volume komatiite eruption(s), resulting in a 100-150-m-deep lava channel containing one of the world's largest komatiite-hosted Fe-Ni-Cu-(PGE) sulfide deposits. Using

23

Numerical Modeling At Coso Geothermal Area (2007) | Open Energy Information  

Open Energy Info (EERE)

Coso Geothermal Area (2007) Coso Geothermal Area (2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Coso Geothermal Area (2007) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 2007 Usefulness not indicated DOE-funding Unknown Exploration Basis To determine the importance of fracture networks for fluid migration in tectonically active regions such as the Coso Range. Notes A finite element analysis is used to establish the 3D state of stress within the tectonic setting of the Coso Range. The mean and differential stress distributions are used to infer fluid flow vectors and second order fracture likelihood and orientation. The results show that the Coso Range

24

Numerical Modeling At Coso Geothermal Area (1997) | Open Energy Information  

Open Energy Info (EERE)

7) 7) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 1997 Usefulness useful DOE-funding Unknown Exploration Basis Develop tool to identify low velocity zones by modeling fault-zone guided waves of microearthquakes Notes A numerical method has been employed to simulate the guided-wave propagation from microearthquakes through the fault zone. By comparing observed and synthetic waveforms the fault-zone width and its P-wave and S-wave velocity structure have been estimated. It is suggested that the identification and modeling of guided waves is an effective tool to locate fracture-induced, low-velocity fault-zone structures in geothermal fields. References Lou, M.; Rial, J.A. ; Malin, P.E. (1 July 1997) Modeling

25

numerical modeling | OpenEI Community  

Open Energy Info (EERE)

07 07 Varnish cache server Home Groups Community Central Green Button Applications Developer Utility Rate FRED: FRee Energy Database More Public Groups Private Groups Features Groups Blog posts Content Stream Documents Discussions Polls Q & A Events Notices My stuff Energy blogs 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142233807 Varnish cache server numerical modeling Home Ocop's picture Submitted by Ocop(5) Member 18 April, 2013 - 13:41 MHK LCOE Reporting Guidance Draft Cost Current DOE LCOE numerical modeling Performance Tidal Wave To normalize competing claims of LCOE, DOE has developed-for its own use-a standardized cost and performance data reporting process to facilitate uniform calculation of LCOE from MHK device developers. This

26

Numerical Modeling of PCCI Combustion | Department of Energy  

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

Modeling of HCCI and PCCI Combustion Processes Numerical Modeling of HCCI Combustion Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI Engines...

27

NUMERICAL MODELING OF CATHODE CONTACT MATERIAL DENSIFICATION  

SciTech Connect

Numerical modeling was used to simulate the constrained sintering process of the cathode contact layer during assembly of solid oxide fuel cells (SOFCs). A finite element model based on the continuum theory for sintering of porous bodies was developed and used to investigate candidate low-temperature cathode contact materials. Constitutive parameters for various contact materials under investigation were estimated from dilatometry screening tests, and the influence of processing time, processing temperature, initial grain size, and applied compressive stress on the free sintering response was predicted for selected candidate materials. The densification behavior and generated stresses within a 5-cell planar SOFC stack during sintering, high temperature operation, and room temperature shutdown were predicted. Insufficient constrained densification was observed in the stack at the proposed heat treatment, but beneficial effects of reduced grain size, compressive stack preload, and reduced thermal expansion coefficient on the contact layer densification and stresses were observed.

Koeppel, Brian J.; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2011-11-01T23:59:59.000Z

28

Numerical Modeling At Coso Geothermal Area (1999) | Open Energy Information  

Open Energy Info (EERE)

9) 9) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Numerical Modeling Activity Date 1999 Usefulness not indicated DOE-funding Unknown Exploration Basis To determine three-dimensional P and S waves velocity structures Notes High precision P and S wave travel times for 2104 microearthquakes with focus <6 km are used in a non-linear inversion to derive high-resolution 3-D compressional and shear velocity structures at the Coso Geothermal Area. Block size for the inversion is 0.2 km horizontally and 0.5 km vertically and inversions are investigated in the upper 5 km of the geothermal area. Spatial resolution, calculated by synthetic modeling of a cross model at critical locations, is estimated to be 0.35 km for Vp and 0.5 km for V s . In the 2 km southwest Sugarloaf region, we found low V p

29

Forecasting wave height probabilities with numerical weather prediction models  

E-Print Network (OSTI)

Forecasting wave height probabilities with numerical weather prediction models Mark S. Roulstona; Numerical weather prediction 1. Introduction Wave forecasting is now an integral part of operational weather methods for generating such forecasts from numerical model output from the European Centre for Medium

Stevenson, Paul

30

A high-resolution, cloud-assimilating numerical weather prediction model for solar irradiance forecasting  

E-Print Network (OSTI)

Multiscale Numerical Weather Prediction Model.   Progress assimilating numerical weather prediction model for solar customizable  numerical weather prediction model that is 

Mathiesen, Patrick; Collier, Craig; Kleissl, Jan

2013-01-01T23:59:59.000Z

31

Numerical Modelling of Geothermal Systems a Short Introduction | Open  

Open Energy Info (EERE)

Numerical Modelling of Geothermal Systems a Short Introduction Numerical Modelling of Geothermal Systems a Short Introduction Jump to: navigation, search OpenEI Reference LibraryAdd to library General: Numerical Modelling of Geothermal Systems a Short Introduction Authors Mauro Cacace, Björn Onno Kaiser and Yvonne Cherubini Published Helmholtz Association, The date "N/A" was not understood.The date "N/A" was not understood. DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Numerical Modelling of Geothermal Systems a Short Introduction Citation Mauro Cacace,Björn Onno Kaiser,Yvonne Cherubini. N/A. Numerical Modelling of Geothermal Systems a Short Introduction. N/A. Helmholtz Association. N/Ap. Retrieved from "http://en.openei.org/w/index.php?title=Numerical_Modelling_of_Geothermal_Systems_a_Short_Introduction&oldid=688986"

32

Data Assimilation for Idealised Mathematical Models of Numerical Weather Prediction  

E-Print Network (OSTI)

Data Assimilation for Idealised Mathematical Models of Numerical Weather Prediction Supervisors). Background: Numerical Weather Prediction (NWP) has seen significant gains in accuracy in recent years due is directed at achieving real-world impact in numerical weather prediction by addressing fundamental issues

Wirosoetisno, Djoko

33

Numerical Modeling of the Nucleation Conditions of Petal-Centerline  

Open Energy Info (EERE)

the Nucleation Conditions of Petal-Centerline the Nucleation Conditions of Petal-Centerline Fractures below a Borehole Floor, A Sensitivity Study and Application to the Coso Geothermal Field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Numerical Modeling of the Nucleation Conditions of Petal-Centerline Fractures below a Borehole Floor, A Sensitivity Study and Application to the Coso Geothermal Field Details Activities (1) Areas (1) Regions (0) Abstract: A boundary element model using Poly3D© has been developed to investigate the conditions in which the stress concentration below the floor of a borehole can cause tensile stress necessary to nucleate petal-centerline fractures. The remote stress state, borehole geometry, and traction boundary conditions on the borehole surface are taken from direct

34

Numerical models of phosphate esters in the Chattahoochee River  

E-Print Network (OSTI)

A numerical model was constructed to assess the magnitude of organophosphoric acid triester sinks in the Chattahoochee River and to identify concentration patterns downstream of point source discharges. The model was built ...

Haffey, Samuel Fraad, 1973-

2004-01-01T23:59:59.000Z

35

Electrowetting-based microfluidics: mathematical modeling and numerical simulation  

Science Journals Connector (OSTI)

The work presented in this dissertation focuses on the mathematical modeling and numerical simulation of the dynamics of a liquid droplet undergoing electrowetting, or electrowetting-on-dielectrics (EWOD). A mathematical model is formulated for the two-phase ...

Michael Franklin / Ali Nadim

2013-01-01T23:59:59.000Z

36

A Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir  

Open Energy Info (EERE)

Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir Evaluation Details Activities (0) Areas (0) Regions (0) Abstract: A two-dimensional numerical model of coupled fluid flow, heat transfer and rock mechanics in naturally fractured rock is developed. The model is applicable to assessments of hot dry rock (HDR) geothermal reservoir characterisation experiments, and to the study of hydraulic stimulations and the heat extraction potential of HDR reservoirs. Modelling assumptions are based on the characteristics of the experimental HDR reservoir in the Carnmenellis granite in Cornwall, S. W. England. In

37

24 More Years of Numerical Weather Prediction: A Model Performance Model  

E-Print Network (OSTI)

24 More Years of Numerical Weather Prediction: A Model Performance Model Gerard Cats May 26, 2008 Abstract For two formulations of currently usual numerical weather prediction models the evolution in such a model is much 1 #12;24 More Years of Numerical Weather Prediction Gerard Cats higher than in a sis

Stoffelen, Ad

38

Numerical modelling of MILD combustion for coal  

Science Journals Connector (OSTI)

Emissions of nitrogen oxides from coal combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. Moderate and Intensive Low oxygen Dilution (MILD) combustion is a promising technology for decreasing pollutant emissions and improving combustion efficiency. A combination of air preheating and fuel dilution with combustion products of low oxygen concentration are the main features of this technique. In the MILD combustion mode, preheated air and fuel are gradually mixed with large amounts of recirculated exhaust gas. The objective of the present work is to investigate the capability of present fuel NO mechanisms for pulverised coal combustion to predict the observed nitrogen oxide levels in MILD combustion mode. For this purpose, knowledge of the fate of coal nitrogen during the combustion process is vital. The interaction between turbulence and chemistry is modelled by an advanced Eddy Dissipation Concept (EDC). The NOx model is used to predict NO profiles that are compared to measurements obtained from semi-industrial scale experiments.

Ju Pyo Kim; U. Schnell; G. Scheffknecht; A.C. Benim

2007-01-01T23:59:59.000Z

39

Multidimensional numerical modeling of heat exchangers. [LMFBR  

SciTech Connect

A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

Sha, W.T.; Yang, C.I.; Kao, T.T.; Cho, S.M.

1982-01-01T23:59:59.000Z

40

Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations  

E-Print Network (OSTI)

.S.A. Abstract We numerically model the brain dy- namics during and after impulsive head translations using brain injuries appear among boxers and shaken babies despite minimal rotations of their heads. Modeling head translations also helps understand the brain dynamics during head rotations about an arbitrary

Burtscher, Martin

Note: This page contains sample records for the topic "activity numerical modeling" 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 GIS-based open source pre-processor for georesources numerical modeling  

Science Journals Connector (OSTI)

Abstract TOUGH2 is an integral finite differences numerical simulator for non-isothermal multiphase flow in fractured porous media, which can manage complex spatial discretizations. Numerical simulation accuracy is affected, among other things, by grid resolution. Increasing the grid resolution requires computational and operating costs depending on the number of nodes and variables processed. The complexity of the management of the model increases when unstructured grids and local refinement are used. In order to improve the management and optimize the activities to update the model, an open source pre-processor has been developed using the open source codes GRASS GIS, \\{SQLite\\} and AMESH. Operations such as domain discretization, rock type assignment and mesh file generation have been automatized. Graphical interfaces allow for a user-friendly utilization. Operating errors and time required by pre-processing activities to generate and update locally refined unstructured grids have been reduced. Productivity in numerical modeling has been substantially increased.

P. Berry; S. Bonduá; V. Bortolotti; C. Cormio; E.M. Vasini

2014-01-01T23:59:59.000Z

42

Mercury's thermo-chemical evolution from numerical models constrained  

E-Print Network (OSTI)

Mercury's thermo-chemical evolution from numerical models constrained by MESSENGER observations Globe de Paris, France #12;Basics facts about Mercury · Semi-major axis: 0.39 AU · 3:2 spin Earth!) · Black body temperature: 440 K #12;Exploration of Mercury Mariner10 ·First spacecraft to use

Cerveny, Vlastislav

43

Numerical Modeling of Acoustic Timescale Detonation J.D. Regele  

E-Print Network (OSTI)

Numerical Modeling of Acoustic Timescale Detonation Initiation J.D. Regele , D.R. Kassoy and O to perform one and two-dimensional simulations of acoustic timescale detonation initiation using thermal overdriven detonation wave that decays to a steady-state CJ wave. A 1-D parametric study of acoustic

Vasilyev, Oleg V.

44

Numerical Modeling of Internal Tide Generation along the Hawaiian Ridge  

Science Journals Connector (OSTI)

Internal M2 tides near Hawaii are investigated with a two-dimensional, two-layer numerical model. It is seen that along the Hawaiian Ridge barotropic tidal energy is transformed into baroclinic internal tides that propagate in both northeast and ...

S. K. Kang; M. G. G. Foreman; W. R. Crawford; J. Y. Cherniawsky

2000-05-01T23:59:59.000Z

45

Friction versus dilation revisited: Insights from theoretical and numerical models  

E-Print Network (OSTI)

Friction versus dilation revisited: Insights from theoretical and numerical models N. Makedonska,1 controlled by the frictional strength of the fault gouge, a granular layer that accumulates between the fault friction coefficient) of such granular layers is the systems resistance to dilation, a byprocess

Einat, Aharonov

46

Numerical Wave Modeling in Conditions with Strong Currents: Dissipation, Refraction, and Relative Wind  

Science Journals Connector (OSTI)

Currents effects on waves have led to many developments in numerical wave modeling over the past two decades, from numerical choices to parameterizations. The performance of numerical models in conditions with strong currents is reviewed here, and ...

Fabrice Ardhuin; Aron Roland; Franck Dumas; Anne-Claire Bennis; Alexei Sentchev; Philippe Forget; Judith Wolf; Françoise Girard; Pedro Osuna; Michel Benoit

2012-12-01T23:59:59.000Z

47

ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS  

SciTech Connect

During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.

Chiswell, S.; Buckley, R.

2009-01-15T23:59:59.000Z

48

Numerical studies of a simple Coulomb blockade model  

E-Print Network (OSTI)

simple model of the Coulomb blockade is studied. In this model, two interacting electrons tunnel in a one-dimensional structure with two barriers in series. The two-particle, time-dependent Schrodinger equation is solved numerically. It is found... tunneling by the other, and the inside electron tunnels out only after the outside electron tunnels a second time. The distribution of the charge density for the two electrons is shown in a series of three-dimensional figures as a function of time. Also...

Shao, Jianfeng

2012-06-07T23:59:59.000Z

49

Numerical heat conduction in hydrodynamical models of colliding hypersonic flows  

E-Print Network (OSTI)

Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the postshock gas of one flow behaves quasi-adiabatically while the postshock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-he...

Parkin, E R

2010-01-01T23:59:59.000Z

50

Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model  

E-Print Network (OSTI)

Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model-off dominated. We demonstrate the ability of our cohesive zone model in simulating the hydraulic fracture in all these propagation regimes. Keywords: Hydraulic fracture, Cohesive zone model, Finite element analysis, Hydro

Paris-Sud XI, Université de

51

Numerical Modeling of WECS at Ecole Centrale de Nantes  

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

LHEEA LHEEA CNRS UMR 6598 Laboratoire de recherche en Hydrodynamique Énergétique et Environnement Atmosphérique Numerical modelling of Wave Energy Converters at LHEEA Lab Ecole Centrale de Nantes (France) Alain H. CLEMENT Senior researcher Ocean Energy and Ocean Waves Group NREL MHK Workshop - Broomfield (CO) - 9-10 July 2012 LHEEA CNRS UMR 6598 Laboratoire de recherche en Hydrodynamique Énergétique et Environnement Atmosphérique NREL MHK Workshop - Broomfield (CO) - 9-10 July 2012 The Ocean Energy and Waves group @ LHEEA Lab. LHEEA Lab. : Hydrodynamics, Energetics and Atmospheric Environment Staff : 100, Director : Prof. Pierre Ferrant

52

Numerical modeling of dish-Stirling reflux solar receivers  

SciTech Connect

Using reflux solar receivers to collect solar energy for dish-Stirling electric power generation systems is currently being investigated by several organizations, including Sandia National Laboratories, Albuquerque, New Mexico. In support of this program, Sandia has developed two numerical models describing the energy transfer within and thermal performance of pool-boiler and heat-pipe receivers. Both models are applicable to axisymmetric geometries and they both consider the radiative and convective energy transfer within the receiver cavity, the conductive and convective energy transfer within the receiver cavity, the conductive and convective energy transfer from the receiver housing, and the energy transfer to the receiver working fluid. In these models, the radiative transfer within the receiver is analyzed using a two-band (solar and infrared) net-radiation formulation for enclosure radiation. Empirical convective correlations describe the convective heat transfer from the cavity to the surroundings. The primary difference between the models is the level of detail in modeling the heat conduction through the receiver walls. The more detailed model uses a two-dimensional finite control volume method, whereas the simpler model uses a one-dimensional thermal resistance approach. 20 refs., 7 figs., 2 tabs.

Hogan, R.E.

1990-01-01T23:59:59.000Z

53

Numerical Modeling of Transient Basin and Range Extensional Geothermal  

Open Energy Info (EERE)

Transient Basin and Range Extensional Geothermal Transient Basin and Range Extensional Geothermal Systems Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Numerical Modeling of Transient Basin and Range Extensional Geothermal Systems Abstract A suite of models utilizing a range of bulkrock permeabilities were developed to analyze thetransient behavior of basin and range extensionalgeothermal systems, and particularly, the evolution ofthe system temperature with time. Each modelconsists of two mountain ranges (~1 km relief fromthe valley floor) separated by a thick sequence (about4 km) of clastic sediments derived from the adjacentranges, and a relatively permeable, high angle faultthat functions as a conduit for subsurface fluids. Thisgeometry is typical of Basin and Range extensionalsystems.We

54

The Numerical Modelling Research and Development Division is responsible for research into and develop-  

E-Print Network (OSTI)

into and develop- ment of numerical weather prediction models and other meteorological applications, that are opera in the field of numerical weather prediction: atmospheric and oceanographic modelling, physical and statistical132 The Numerical Modelling Research and Development Division is responsible for research

Haak, Hein

55

Evaluating the ability of a numerical weather prediction model to forecast tracer concentrations during ETEX 2  

E-Print Network (OSTI)

Evaluating the ability of a numerical weather prediction model to forecast tracer concentrations an operational numerical weather prediction model to forecast air quality are also investigated. These potential a numerical weather prediction (NWP) model independently of the CTM. The NWP output is typically archived

Dacre, Helen

56

USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS,  

E-Print Network (OSTI)

USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS simulation by means of a Numerical Weather Prediction Model (NWP), Skiron. After that, we have made spatial solar resource map. 2.1. Meteorological simulation The numerical weather prediction model used is SKIRON

Paris-Sud XI, Université de

57

Numerical Modeling of Thermal EOR: Comprehensive Coupling of an AMR-Based Model  

E-Print Network (OSTI)

Numerical Modeling of Thermal EOR: Comprehensive Coupling of an AMR-Based Model of Thermal Fluid.renard@ifpen.fr * Corresponding author Résumé -- Modélisation numérique d'EOR thermique : couplage complet entre un modèle d of Thermal EOR: Comprehensive Coupling of an AMR-Based Model of Thermal Fluid Flow and Geomechanics

Paris-Sud XI, Université de

58

Numerical Modeling of Failure in Magnesium Alloys under Axial Compression and Bending for Crashworthiness Applications.  

E-Print Network (OSTI)

??Numerical modeling of failure was performed for magnesium alloys with circular and square cross-sections under axial compression. The failure criterion was employed using material model… (more)

Ali, Usman

2012-01-01T23:59:59.000Z

59

Integrated Numerical Modeling Process for Evaluating Automobile Climate Control Systems  

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

FCC-70 FCC-70 Integrated Numerical Modeling Process for Evaluating Automobile Climate Control Systems John Rugh National Renewable Energy Laboratory Copyright © 2002 Society of Automotive Engineers, Inc. ABSTRACT The air-conditioning (A/C) system compressor load can significantly impact the fuel economy and tailpipe emissions of conventional and hybrid electric automobiles. With the increasing emphasis on fuel economy, it is clear that the A/C compressor load needs to be reduced. In order to accomplish this goal, more efficient climate control delivery systems and reduced peak soak temperatures will be necessary to reduce the impact of vehicle A/C systems on fuel economy and tailpipe emissions. Good analytical techniques are important in identifying promising concepts. The goal at

60

A numerical model of aerosol scavenging: Part 1, Microphysics parameterization  

SciTech Connect

We have developed a three-dimensional numerical model (OCTET) to simulate the dynamics and microphysics of clouds and the transport, diffusion and precipitation scavenging of aerosol particles. In this paper we describe the cloud microphysics and scavenging parameterizations. The representation of cloud microphysics is a bulk- water parameterization which includes water vapor and five types of hydrometeors (cloud droplets, rain drops, ice crystals, snow, and graupel). A parallel parameterization represents the scavenging interactions between pollutant particles and hydrometeors including collection of particles because of condensation nucleation, Brownian and phoretic attachment, and inertial capture, resuspension because of evaporation and sublimation; and transfer interactions where particles collected by one type of hydrometeor are transferred to another type of freezing, melting, accretion, riming and autoconversion.

Molenkamp, C.R.; Bradley, M.M.

1991-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

The Dynamics of Deterministic Chaos in Numerical Weather Prediction Models  

E-Print Network (OSTI)

Atmospheric weather systems are coherent structures consisting of discrete cloud cells forming patterns of rows/streets, mesoscale clusters and spiral bands which maintain their identity for the duration of their appreciable life times in the turbulent shear flow of the planetary Atmospheric Boundary Layer. The existence of coherent structures (seemingly systematic motion) in turbulent flows has been well established during the last 20 years of research in turbulence. Numerical weather prediction models based on the inherently non-linear Navier-Stokes equations do not give realistic forecasts because of the following inherent limitations: (1) the non-linear governing equations for atmospheric flows do not have exact analytic solutions and being sensitive to initial conditions give chaotic solutions characteristic of deterministic chaos (2) the governing equations do not incorporate the dynamical interactions and co-existence of the complete spectrum of turbulent fluctuations which form an integral part of the large coherent weather systems (3) limitations of available computer capacity necessitates severe truncation of the governing equations, thereby generating errors of approximations (4) the computer precision related roundoff errors magnify the earlier mentioned uncertainties exponentially with time and the model predictions become unrealistic. The accurate modelling of weather phenomena therefore requires alternative concepts and computational techniques. In this paper a universal theory of deterministic chaos applicable to the formation of coherent weather structures in the ABL is presented.

A. Mary Selvam

2003-10-07T23:59:59.000Z

62

Sustainable heat extraction from abandoned mine tunnels: A numerical model  

Science Journals Connector (OSTI)

Abandoned mines are often associated with enduring liabilities which involve significant costs for decades after the decommissioning of the mine. Using a decommissioned mine as a geothermal resource can offset the environmental costs by supplying green heat to the communities living in and around the mine area. In this paper a numerical assessment of geothermal heat extraction from underground mine workings using an open loop geothermal system is carried out. In this study our focus is on fully flooded mines where the heat flow from the rock mass to the mine cavities is dominantly controlled by conduction in the rock mass. The sustainable heat flux into the mine workings is assessed using a transient two-dimensional axisymmetric heat transfer model. Finite volume method is applied to solve the model and simulate the transient temperature fields in the rock mass and within the water (flowing through cavities). The model is capable of controlling the rate of heat extraction through continuous adjustment of the rate of water flow through the mine. Sustainable rate of heat extraction is calculated for seasonally varied heat loads and for different project life cycles. It is shown that with proper resource management each kilometre of a typical deep underground mine tunnel can produce about 150?kW of usable heat in a sustainable manner. The model is validated by comparing its results with other published models and realistic data available from Springhill mine Nova Scotia Canada. It is found that the sustainable heat extraction is controlled dominantly by virgin rock temperature thermal conductivity of the rock mass and seasonal heat load variations.

S. A. Ghoreishi Madiseh; Mory M. Ghomshei; F. P. Hassani; F. Abbasy

2012-01-01T23:59:59.000Z

63

NUMERICAL MODELING OF SPACE PLASMA FLOWS / ASTRONUM-2007 ASP Conference Series, Vol. 385, c 2008  

E-Print Network (OSTI)

model The ENLIL (Sumerian god of wind) code is a numerical model for simulations of background solar- energetic-particles (SEP) models (Luhmann et al. 2004). 3. Coupling with empirical coronal models Accurate

California at Berkeley, University of

64

Numerical models of black body dominated GRBs: II. Emission properties  

E-Print Network (OSTI)

We extend an existing theoretical model to explain the class of Black-Body Dominated (BBD) gamma-ray bursts (GRBs), long lasting events characterized by the presence of a significant thermal component trailing the GRB prompt emission, and also by an absence of a traditional afterglow. GRB 101225A, the Christmas Burst, is a prototype of such class. It has been suggested that BBD-GRBs could be observed after a merger in a binary system consisting of a neutron star and a Helium core of a main sequence star. Using detailed relativistic hydrodynamic numerical simulations we model the propagation of ultrarelativistic jets through the environments created by such mergers. In this paper we focus on explaining the emission properties of the jet evolution computing the whole radiative signature (both thermal and non-thermal) of the jet dynamical evolution. A comprehensive parameter study of the jet/environment interaction has been performed and synthetic spectra and light curves are compared with the observational data...

Cuesta-Martínez, Carlos F; Mimica, Petar; Thöne, Christina C; de Ugarte-Postigo, Antonio

2014-01-01T23:59:59.000Z

65

NUMERICAL MODELING OF DEFORMATION AND FRACTURE OF WOOD INCLUDING HETEROGENEITY AND ANISOTROPY  

E-Print Network (OSTI)

NUMERICAL MODELING OF DEFORMATION AND FRACTURE OF WOOD INCLUDING HETEROGENEITY AND ANISOTROPY John A. Nairn Wood Science & Engineering, Oregon State University, USA Abstract The challenge in numerical modeling of wood is to have the model closely match the structure of a real specimen. The model

Nairn, John A.

66

Representing Cloud Processing of Aerosol in Numerical Models  

SciTech Connect

The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.

Mechem, D.B.; Kogan, Y.L.

2005-03-18T23:59:59.000Z

67

An Evaluation of Tropical Cyclone Genesis Forecasts from Global Numerical Models  

Science Journals Connector (OSTI)

Tropical cyclone (TC) forecasts rely heavily on output from global numerical models. While considerable research has investigated the skill of various models with respect to track and intensity, few studies have considered how well global models ...

Daniel J. Halperin; Henry E. Fuelberg; Robert E. Hart; Joshua H. Cossuth; Philip Sura; Richard J. Pasch

2013-12-01T23:59:59.000Z

68

Numerical modeling of mountain building: Interplay between erosion law and crustal rheology  

E-Print Network (OSTI)

Numerical modeling of mountain building: Interplay between erosion law and crustal rheology V. Cattin, and J. Lave´ (2004), Numerical modeling of mountain building: Interplay between erosion law by a 2D finite element model that incorporates the rheological layering of the crust and the main

Demouchy, Sylvie

69

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation  

E-Print Network (OSTI)

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation Cyril a hybrid ARMA/ANN model and data issued from a numerical weather prediction model (ALADIN). We particularly@gmail.com #12;Abstract. We propose in this paper an original technique to predict global radiation using

Paris-Sud XI, Université de

70

An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling  

E-Print Network (OSTI)

An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark Williamson Working Paper 83 #12;An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark for long time period simulations and large ensemble studies in Earth system models of intermediate

Williamson, Mark

71

Numerical Methods for Multiphysics, Multiphase, and Multicomponent Models for Fuel Cells.  

E-Print Network (OSTI)

??In this dissertation, we design and analyze efficient numerical methods for obtaining accurate solutions to model problems arising in fuel cells. A basic fuel cell… (more)

Xue, Guangri

2008-01-01T23:59:59.000Z

72

A numerical procedure to model and monitor CO2 sequestration in ...  

E-Print Network (OSTI)

Sep 7, 2012 ... analyze storage integrity, providing early warning should any leakage occurs. A numerical procedure to model and monitor CO2 sequestration ...

santos

73

Numerical tools for musical instruments acoustics: analysing nonlinear physical models using continuation  

E-Print Network (OSTI)

self-sustained oscillations. Several physical models (clarinet and saxophone) are formulated the dynamical properties of self-sustained musical instruments using tra- ditional numerical techniques

Boyer, Edmond

74

A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano,  

Open Energy Info (EERE)

For The Dynamics Of Pyroclastic Flows At Galeras Volcano, For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a two-dimensional model for dilute pyroclastic flow dynamics that uses the compressible Navier-Stokes equation coupled with the Diffusion-Convection equation to take into account sedimentation. The model is applied to one of the slopes of Galeras Volcano to show: (1) the temperature evolution with the time; (2) dynamic pressure change; and (3) particle concentration along the computer domain from the eruption to the impact with a topographic barrier located more than 16 km

75

Numerical model of planar heterojunction organic solar cells  

Science Journals Connector (OSTI)

We present a numerical study of the effects of the energy barrier between the lowest unoccupied molecular orbital of the acceptor layer and the cathode, the thicknesses of the donor layer and acceptor layer on th...

ChaoZhu Ma; YingQuan Peng; RunSheng Wang; RongHua Li…

2011-07-01T23:59:59.000Z

76

Manual sorting of numerals in an inflective language for language modelling  

Science Journals Connector (OSTI)

In speech recognition systems language models are used to estimate the probabilities of word sequences. In this paper special emphasis is given to numerals---words that express numbers. One reason for this is the fact that in a practical application ... Keywords: Language models, Manual sorting, Numerals, Speech recognition

Gregor Donaj; Zdravko Ka?i?

2014-09-01T23:59:59.000Z

77

Numerical Early Warning Model Research of Landfill Gas Permeation and Diffusion Considering Flow-Temperature Coupling  

Science Journals Connector (OSTI)

Based on seepage mechanics in porous medium gas and heat transfer theory, numerical early warning model is established, which is on quantitative description of migration and release of landfill gas and penetration and diffusion of energy, and dynamic ... Keywords: component, landfill gas, flow-temperature coupling, gas pressure and temperature distribution, numerical early warning model

Xue Qiang; Feng Xia-ting; Ma Shi-jin; Zhou Xiao-jun

2009-10-01T23:59:59.000Z

78

Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design  

E-Print Network (OSTI)

1973; Oran and Boris 1987; Murray 1989; Gershenfeld 1999). Weather and climate prediction models, which to the initial conditions, which is a major source of uncertainty in Numerical Weather Prediction (NWP; eTime Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error

Judd, Kevin

79

Modelling and Control of Activated Sludge Processes  

E-Print Network (OSTI)

Modelling and Control of Activated Sludge Processes Michela Mulas Dottorato di Ricerca of Activated Sludge Processes Michela Mulas Supervisors: Prof. Roberto Baratti Ing. Stefania Tronci Dottorato . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 ASP Models and Simulations 7 2.1 The Activated Sludge Process

Skogestad, Sigurd

80

Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Boussinesq model  

E-Print Network (OSTI)

Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Boussinesq model Philip for the December 26, 2004 Indian Ocean tsunami. Calculations are based on Boussinesq model FUNWAVE and are carried

Kirby, James T.

Note: This page contains sample records for the topic "activity numerical modeling" 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

A Parameterization of Heterogeneous Land Surfaces for Atmospheric Numerical Models and Its Impact on Regional Meteorology  

Science Journals Connector (OSTI)

Natural land surfaces are usually heterogeneous over the resolvable scales considered in atmospheric numerical models. Therefore, model surface parameterizations that assume surface homogeneity may fail to represent the surface forcing ...

R. Avissar; R. A. Pielke

1989-10-01T23:59:59.000Z

82

NUMERICAL ANALYSIS OF A STEEPEST-DESCENT PDE MODEL FOR SURFACE RELAXATION BELOW THE ROUGHENING  

E-Print Network (OSTI)

NUMERICAL ANALYSIS OF A STEEPEST-DESCENT PDE MODEL FOR SURFACE RELAXATION BELOW THE ROUGHENING addresses a widely-used PDE model for the relaxation of a crystalline surface below the roughening

83

Assessment of Wind Power Potential for Two Contrasting Coastlines of South Africa Using a Numerical Model  

Science Journals Connector (OSTI)

A two-dimensional numerical model is used to predict near surface wind velocities, and consequently wind power, for five distinct synoptic regimes for contrasting east and west coasts of South Africa. The model results suggest that no one ...

R. D. Diab; M. Garstang

1984-12-01T23:59:59.000Z

84

Non-smooth Dynamics Using Differential-algebraic Equations Perspective: Modeling and Numerical Solutions  

E-Print Network (OSTI)

mathematical tools. On the other hand, the approach based on differential-algebraic equations gives more insight into the constitutive assumptions of a chosen model and easier to obtain numerical solutions. Bingham-type models in which the force cannot...

Gotika, Priyanka

2012-02-14T23:59:59.000Z

85

A 3D numerical model for Kepler's supernova remnant  

Science Journals Connector (OSTI)

......28, 1428 Buenos Aires, Argentina 3 Facultad de Ciencias Exactas...Universidad de Buenos Aires, Argentina We present new 3D numerical...density of 103 and an explosion energy of 7-1050-erg. The obtained...the gas pressure. The total energy density E is given by where......

J. C. Toledo-Roy; A. Esquivel; P. F. Velázquez; E. M. Reynoso

2014-01-01T23:59:59.000Z

86

A 3D numerical model for Kepler's supernova remnant  

Science Journals Connector (OSTI)

......synthetic X-ray maps from the numerical...considering an AGB mass-loss rate...Mo-yr1, a wind terminal velocity of 10-km-s1...of the AGB wind mass-loss rate, terminal velocity and ISM density...out of the wind bubble considerably...X-ray emission maps, taking into......

J. C. Toledo-Roy; A. Esquivel; P. F. Velázquez; E. M. Reynoso

2014-01-01T23:59:59.000Z

87

Numerical implementation of shape memory alloy (SMA) constitutive response and structural analysis of active composites  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . B. 3. Stresses B. 4. Incremental Constitutive Relationship . B. 5. Principle of Virtual Work B. 6. Finite Element Formulation of Equilibrium Equations . . . . B. 7. Final Equations . 116 116 117 117 118 120 122 VITA 126 LIST OF TABLES... of Active Composites. (December 1995) Muhammad Abu Bakar Siddiq Qidwai, B. S. , Middle East Technical University Chair of Advisory Committee: Dr. Dimittis C. Lagoudas Numerical implementation of the thermomechanical constitutive response of shape memory...

Qidwai, Muhammad Abu Bakar Siddiq

2012-06-07T23:59:59.000Z

88

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD-RADIATION INTERACTIONS OVER THE SOUTHERN GREAT PLAINS  

E-Print Network (OSTI)

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD- RADIATION INTERACTIONS OVER.bnl.gov ABSTRACT Numerical weather prediction (NWP) is the basis for present-day weather forecasts, and NWP- and satellite- based observations over the Southern Great Plains to evaluate how well cloud

Johnson, Peter D.

89

An Updated Numerical Model Of The Larderello-Travale Geothermal System,  

Open Energy Info (EERE)

Of The Larderello-Travale Geothermal System, Of The Larderello-Travale Geothermal System, Italy Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Updated Numerical Model Of The Larderello-Travale Geothermal System, Italy Details Activities (0) Areas (0) Regions (0) Abstract: Larderello-Travale is one of the few geothermal systems in the world that is characterized by a reservoir pressure much lower than hydrostatic. This is a consequence of its natural evolution from an initial liquid-dominated to the current steam-dominated system. Beneath a nearly impermeable cover, the geothermal reservoir consists of carbonate-anhydrite formations and, at greater depth, by metamorphic rocks. The shallow reservoir has temperatures in the range of 220-250°C, and pressures of about 20 bar at a depth of 1000 m, while the deep metamorphic reservoir has

90

Experimental and numerical modeling of convective proppant transport  

SciTech Connect

Slurry-transport and -settling experiments were conducted to improve current descriptions of proppant transport, and the results were used to formulate a new slurry-transport model incorporated into a fully 3D fracture simulator. The model was tested and verified vs. experimental observations of slurry transport in a 4 x 16-ft slot model. Results of the study indicate that proppant-slurry transport can be modeled accurately by accounting for the effects of single-particle settling, density-driven flow, particle-velocity profiles, and slurry rheology.

Barree, R.D. [Marathon Oil Co., Littleton, CO (United States); Conway, M.W. [Stim-Lab Inc., Duncan, OK (United States)

1995-03-01T23:59:59.000Z

91

A Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal...  

Open Energy Info (EERE)

to the most hydraulically conductive fractures in two orthogonal and vertical fracture sets. The mathematical model representing the hydro-mechanical interactions that are...

92

Numerical Modeling At Dixie Valley Geothermal Area (Benoit, 1999...  

Open Energy Info (EERE)

be interpreted. A large geothermal flow test was performed where there was 6 geothermal wells flowing at once and 8 idle wells being monitored. The conceptual model developed...

93

Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment  

Science Journals Connector (OSTI)

Results from a three-dimensional axisymmetric resistive magnetohydrodynamic(MHD) simulation are compared to experimental data from the Swarthmore SpheromakExperiment (SSX) [M. R. Brown Phys. Plasmas 6 1717 (1999)]. The MHD simulation is run under conditions and with dimensionless parameters similar to the experiment (Lundquist number S=1000 plasma beta ?=0.1). The simulation is shown to reproduce global equilibrium magnetic field profiles of the spheromaks as well as much of the detailed reconnectiondynamics measured when two spheromaks are merged. It is concluded that SSX merger dynamics may be characterized as MHDreconnection with the likelihood that extensions are needed to account for kinetic effects in the associated current sheet. High spatial and temporal resolution MHD simulation data will be used as input for a particle orbit and energization code.

V. S. Lukin; G. Qin; W. H. Matthaeus; M. R. Brown

2001-01-01T23:59:59.000Z

94

Numerical modelling of plasticity induced by transcranial magnetic stimulation  

Science Journals Connector (OSTI)

We use neural field theory and spike-timing dependent plasticity to make a simple but biophysically reasonable model of long-term plasticity changes in the cortex due to transcranial magnetic stimulation (TMS). We show how common TMS protocols can be ... Keywords: Modelling, Neural field theory, Plasticity, Theta burst stimulation, Transcranial magnetic stimulation

M. T. Wilson; D. P. Goodwin; P. W. Brownjohn; J. Shemmell; J. N. Reynolds

2014-06-01T23:59:59.000Z

95

Numerical modelling and analysis of a room temperature magnetic  

E-Print Network (OSTI)

are separated by channels of a heat transfer fluid. The time-dependent model solves the momentum and continuity equations of the flow of the heat transfer fluid and the coupled energy equations of the heat transfer and it was concluded that the model has energy conservation and that the solution is independent of the chosen grid

96

Polya Dobreva, Monio Kartalev NUMERICAL MODELING OF THE MAGNETOSPHERE  

E-Print Network (OSTI)

main objective is a description of the magnetosphere. Regions, formed in solar wind flow around magnetic field model Problem formulation Dirichlet #12;Input parameters solar wind parameters ­ Dp, By, Bz(IMF) Dst index dipole inclination (tilt angle) The parameters are needed by Tsyganenko model

Mustakerov, Ivan

97

A LARGE SCALE CONTINUUM-DISCRETE NUMERICAL MODELLING: APPLICATION TO OVERBURDEN DAMAGE OF A SALT CAVERN  

E-Print Network (OSTI)

CAVERN SOULEY Mountaka1 , MERCERAT Diego2 , DRIAD-LEBEAU Lynda1 , BERNARD Pascal2 1 INERIS, Ecole des collapse). KEYWORDS: cavern, numerical modelling, continuum-discrete, overburden, damage. RÃ?SUMÃ?: Dans l

Boyer, Edmond

98

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling  

E-Print Network (OSTI)

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling telluride TEMs. Key words: Thermoelectric generators, waste heat recovery, automotive exhaust, skutterudites bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from

Xu, Xianfan

99

Applying methods of numerical modeling to optimize a plasma burner of atmospheric pressure  

Science Journals Connector (OSTI)

The shape of a plasma burner is optimized by the methods of numerical modeling. Vortex-free flow is created in the burner merely at the expense of selecting the external tube profile rather than by introductio...

S. M. Perminov; V. N. Perminova…

1993-09-01T23:59:59.000Z

100

Simulating Flood Propagation in Urban Areas using a Two-Dimensional Numerical Model.  

E-Print Network (OSTI)

??A two-dimensional numerical model (RiverFLO-2D) has been enhanced to simulate flooding of urban areas by developing an innovative wet and dry surface algorithm, accounting for… (more)

Gonzalez-Ramirez, Noemi

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow  

E-Print Network (OSTI)

and poroelastic deformation using a range of realistic physical parameters and processes. Hydrothermal fluidNumerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal. Although hydrothermal fluids have been discussed as a possible deformation agent, very few quantitative

102

Numerical Modeling of the Propagation Environment in the Atmospheric Boundary Layer over the Persian Gulf  

Science Journals Connector (OSTI)

Strong vertical gradients at the top of the atmospheric boundary layer affect the propagation of electromagnetic waves and can produce radar ducts. A three-dimensional, time-dependent, nonhydrostatic numerical model was used to simulate the ...

B. W. Atkinson; J-G. Li; R. S. Plant

2001-03-01T23:59:59.000Z

103

Numerical modeling of Persian Gulf salinity variations due to tidal effects  

Science Journals Connector (OSTI)

Numerical modeling of salinity changes in marine environment of Persian Gulf is investigated in this paper. Computer simulation ... in arbitrary and complex geometries, such as Persian Gulf domain. The results of...

S. R. Sabbagh Yazdi

2004-03-01T23:59:59.000Z

104

Numerically Solvable Model for Resonant Collisions of Electronswith Diatomic Molecules  

SciTech Connect

We describe a simple model for electron-molecule collisions that has one nuclear and one electronic degree of freedom and that can be solved to arbitrarily high precision, without making the Born-Oppenheimer approximation, by employing a combination of the exterior complex scaling method and a finite-element implementation of the discrete variable representation. We compare exact cross sections for vibrational excitation and dissociative attachment with results obtained using the local complex potential approximation as commonly applied in the ''boomerang'' model, and suggest how this two-dimensional model can be used to test the underpinnings of contemporary nonlocal approximations to resonant collisions.

Houfek, Karel; Rescigno, T.N.; McCurdy, C.W.

2006-01-27T23:59:59.000Z

105

Pyrolysis in Porous Media: Numerical model and parametric study.  

E-Print Network (OSTI)

Transpiration cooling of structures by means of hydrocarbon fuel is a way to sustain the large heat load heat load due to combustion [1-4]. Active transpiration cooling enables the internal cooling encountered in combustion chambers. An European collaboration has been set up to investigate the fluid flow

Paris-Sud XI, Université de

106

Evaluation of Tropical Cyclone Center Identification Methods in Numerical Models  

Science Journals Connector (OSTI)

Identifying the center of a tropical cyclone in a high-resolution model simulation has a number of operational and research applications, including constructing a track, calculating azimuthal means and perturbations, and diagnosing vortex tilt. ...

Leon T. Nguyen; John Molinari; Diana Thomas

2014-11-01T23:59:59.000Z

107

A Numerical Model for the Equilibrium Shape of Electrified Raindrops  

Science Journals Connector (OSTI)

The model Beard Chuang, using the differential form of Laplace's formula, has been extended to raindrop shapes under the influence of vertical electric fields and drop charges. A finite volume method was used with a boundary-fitted coordinate ...

Catherine C. Chuang; Kenneth V. Beard

1990-06-01T23:59:59.000Z

108

Numerical modeling of hydrofracturing in a multilayer coal seam  

SciTech Connect

The mathematical model of the process for hydrodynamic fracturing in a multilayer coal seam is proposed. The model is based on the equation of continuity and Darcy's law. The filtration-temperature analogy allows solving the obtained non-linear, non-stationary problem in an axisymmetric statement for the pressure function as the heat-conductivity problem, by the finite-element method. The calculation results yield estimation of the radius of degassing borehole influence zone.

Nasedkina, A.A.; Trufanov, V.N. [Rostov State University, Rostov Na Donu (Russian Federation)

2006-01-15T23:59:59.000Z

109

A robotic crawler exploiting directional frictional interactions: experiments, numerics, and derivation of a reduced model  

E-Print Network (OSTI)

We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. 'breathing-like' deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.

Giovanni Noselli; Antonio DeSimone

2014-08-26T23:59:59.000Z

110

The effect of simplifying the building description on the numerical modeling of its thermal performance  

SciTech Connect

A thermal building simulation program is a numerical model that calculates the response of the building envelopes to weather and human activity, simulates dynamic heating and cooling loads, and heating and cooling distribution systems, and models building equipment operation. The scope of the research is to supply the users of such programs with information about the dangers and benefits of simplifying the input to their models. The Introduction describes the advantages of modeling the heat transfer mechanisms in a building. The programs that perform this type of modeling have, however, limitations. The user is therefore often put in the situation of simplifying the floor plans of the building under study, but not being able to check the effects that this approximation introduces in the results of the simulation. Chapter 1 is a description of methods. It also introduces the floor plans for the office building under study and the ``reasonable`` floor plans simplifications. Chapter 2 presents DOE-2, the thermal building simulation program used in the sensitivity study. The evaluation of the accuracy of the DOE-2 program itself is also presented. Chapter 3 contains the sensitivity study. The complicated nature of the process of interpreting the temperature profile inside a space leads to the necessity of defining different building modes. The study compares the results from the model of the detailed building description with the results from the models of the same building having simplified floor plans. The conclusion is reached that a study of the effects of simplifying the floor plans of a building is important mainly for defining the cases in which this approximation is acceptable. Different results are obtained for different air conditioning/load regimes of the building. 9 refs., 24 figs.

Stetiu, C.

1993-07-01T23:59:59.000Z

111

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system  

E-Print Network (OSTI)

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system S [1, 2] widely validated in various rotor-stator cavities with throughflow [3­5] and heat transfer [6: RANS modeling, Reynolds Stress Model, Taylor-Couette-Poiseuille flow, turbulence, heat transfer. hal

Paris-Sud XI, Université de

112

A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller  

E-Print Network (OSTI)

A Numerical Model for the Dynamic Simulation of a Recirculation Single- Effect Absorption Chiller A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller. Keywords: absorption; chiller; modelling; transient; water-lithium bromide; falling film hal-00713904

Paris-Sud XI, Université de

113

Foundation heat exchangers for residential ground source heat pump systems Numerical modeling and experimental validation  

SciTech Connect

A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University

2011-01-01T23:59:59.000Z

114

A numerical model of hydrothermal cooling and crustal accretion at a fast spreading mid-ocean ridge  

E-Print Network (OSTI)

: 7360 words, 11 figures. Keywords: Mid-ocean ridge processes; hydrothermal cooling; numerical modelA numerical model of hydrothermal cooling and crustal accretion at a fast spreading mid-ocean ridge present a steady state numerical representation of the sill model that explicitly includes hydrothermal

Toomey, Doug

115

Introduction Application of numerical models of ground water flow  

E-Print Network (OSTI)

(Portniaguine and Solomon 1998), and ground water temperature (Doussan et al. 1994). Compared to calibration depended on calibration methodology; models calibrated with multiple targets simulated q more accurately of Calibration Methodology on Ground Water Flow Predictions by James E. Saiers1, David P. Genereux2, and Carl H

Saiers, James

116

Numerical modeling of an all vanadium redox flow battery.  

SciTech Connect

We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.

Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.

2014-01-01T23:59:59.000Z

117

Mathematical and Numerical Techniques in Energy and Environmental Modeling  

E-Print Network (OSTI)

and transport of ground- water contaminants and to design in situ remediation strategies. Three basic problem and optimize remediation of groundwater contaminants. Toward that end, one must be able to pre- dict the performance of the reservoir under various remediation schemes. To do this, a model of the reservoir and its

Ewing, Richard E.

118

Joint physical and numerical modeling of water distribution networks.  

SciTech Connect

This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.

Zimmerman, Adam; O'Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei

2009-01-01T23:59:59.000Z

119

Numerically Efficient Water Quality Modeling and Security Applications  

E-Print Network (OSTI)

to consider e ective tools and mitigation strategies to improve water network security. This work presents two components that have been integrated into EPA?s Water Security Toolkit, an open-source software package that includes a set of tools to help water... several advantages and potential uses that are aligned with current emerging water security applications. This computational framework is able to e ciently generate an explicit mathematical model that can be easily embedded into larger mathematical...

Mann, Angelica

2013-02-04T23:59:59.000Z

120

Two- and three-dimensional numerical models of internal tide generation at a continental slope  

Science Journals Connector (OSTI)

Some numerical models of internal tide generation at a continental slope are two-dimensional where the along-slope variation is neglected. The energy flux carried by internal tides computed using such two-dimensional models is often underestimated, compared with three-dimensional simulations of the same region, by a factor of 10 or more. The reason for this difference is investigated using both numerical and analytical models. It is shown that in numerical models, it is not the lack of the along-shelf forcing but the use of sponge or radiating conditions at the cross-shelf boundaries that leads to the severe underestimate of the offshore flux. To obtain realistic estimates of energy flux a three-dimensional model with an along-shelf scale of at least 5 internal tide wave lengths at the depth of maximum forcing is necessary.

K. Katsumata

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Global temperatures using satellite and numerical model assimilated data  

SciTech Connect

The Microwave Sounding Unit (MSU) aboard the National Oceanic and Atmospheric Administration (NOAA) series of polar orbiting satellites (TIROS-N to NOAA-11) have provided stable, precise measurements of vertically integrated, atmospheric temperature since December 1978. In this study, comparisons are made between the MSU channel measurements and those derived from the Global Data Assimilation System (GDAS) at the National Meteorological Center (NMC) over the period 1979 to 1990. Land areas rich in Radiosonde Observations (RAOBS) showed similar magnitudes of spatial variability between the NMC GDAS and the MSU temperatures. Excessive spatial variability can be noted in the GDAS over land areas where conventional data is poor. Over the ocean, however, the assimilation of satellite data into the model improves the spatial variability detected by the GDAS.

Basist, A.; Ropelewski, C.; Grody, N. (NOAA/NWS/NMC, Washington, DC (United States) NOAA/NESDIS, Washington, DC (United States))

1994-01-01T23:59:59.000Z

122

An XFEM Model for Carbon Sequestration Journal: International Journal for Numerical Methods in Engineering  

E-Print Network (OSTI)

PeerReview Only An XFEM Model for Carbon Sequestration Journal: International Journal for Numerical method, Carbon Sequestration, Multiphase flow, XFEM, Multifield systems, Petrov-Galerkin httpScience (www.interscience.wiley.com). DOI: 10.1002/nme An XFEM Model for Carbon Sequestration Chris Ladubec

Gracie, Robert

123

NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE  

E-Print Network (OSTI)

NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A. Consequently specific baseline parameters for CIGS and CdTe are proposed. The modeling results important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION

Sites, James R.

124

Improving the Performance of Mass-Consistent Numerical Models Using Optimization Techniques  

Science Journals Connector (OSTI)

This paper describes a technique of using a mass-consistent model to derive wind speeds over a microscale region (about 4 km2) of complex terrain. A serious limitation of these numerical models is that the calculated wind field is highly ...

J. C. Barnard; H. L. Wegley; T. R. Hiester

1987-06-01T23:59:59.000Z

125

Laboratory experiments and numerical modeling of wave attenuation through artificial vegetation  

E-Print Network (OSTI)

? 5.1. Introduction to COULWAVE Boussinesq Model ................................................. 51? 5.2. Numerical Modeling of Vegetation Friction Factor .............................................. 53? CHAPTER VI - CONCLUSIONS... Additionally, vegetation directly increases the durability of shorelines through the root systems and enhances the storage of sand in dunes (Dean, 1978). Until recently the importance and function of wetlands was not well understood, and the amount...

Augustin, Lauren Nicole

2009-05-15T23:59:59.000Z

126

EXPLICIT SIMULATION OF ICE PARTICLE HABITS IN A NUMERICAL WEATHER PREDICTION MODEL  

E-Print Network (OSTI)

EXPLICIT SIMULATION OF ICE PARTICLE HABITS IN A NUMERICAL WEATHER PREDICTION MODEL by Tempei This study develops a scheme for explicit simulation of ice particle habits in Cloud Resolving Models (CRMs is called Spectral Ice Habit Prediction System (SHIPS), which represents a continuous-property approach

Wisconsin at Madison, University of

127

Two-Dimensional Numerical Modeling of Radio-Frequency Ion Engine Discharge  

E-Print Network (OSTI)

Two-Dimensional Numerical Modeling of Radio-Frequency Ion Engine Discharge Michael Meng-Tsuan Tsay-Frequency Ion Engine Discharge Michael Meng-Tsuan Tsay, Manuel Martinez-Sanchez August 2010 SSL # 14 Modeling of Radio-Frequency Ion Engine Discharge by Michael Meng-Tsuan Tsay Submitted to the Department

128

From concentric eyewall to annular hurricane: A numerical study with the cloud-resolved WRF model  

E-Print Network (OSTI)

(secondary eyewall) in coincidence with a local tangential wind max- imum around the pre-existing eyewallFrom concentric eyewall to annular hurricane: A numerical study with the cloud-resolved WRF model Research and Forecasting (WRF) model, the transformation from a non- AH to an AH through a concentric

Wang, Bin

129

Estimation of the mean depth of boreal lakes for use in numerical weather prediction and climate modelling  

E-Print Network (OSTI)

in the numerical weather prediction (NWP) and climate models through parameterisation. For parameterisation, data. The effect of lakes should be parameterised in numerical weather prediction (NWP) and climate modellingEstimation of the mean depth of boreal lakes for use in numerical weather prediction and climate

Paris-Sud XI, Université de

130

Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Higher-order Boussinesq Model  

E-Print Network (OSTI)

Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Higher-order Boussinesq of the tsunami, with a higher-order Boussinesq model. We find reasonable agreement of numerical results

Grilli, Stéphan T.

131

Parameter-oriented Visualization of a Modelica Model with a Numerical Data Integration Feature  

Science Journals Connector (OSTI)

Abstract In model-based development, designers develop models of complex engineered systems from combinations of building blocks, and then simulate the system behavior. The design process is assisted by multi-domain system modeling and simulation tools. These tools should be able to allow users to understand and validate the simulated behavior in terms of parameters and their dependencies with effective use of quantitative information, such as simulation results, experiments, and catalog data, in the system model. This paper proposes a tool that displays the parameters and their dependencies in system models written in Modelica, and integrates these models with numerical data. The latter feature is useful for evaluating quantitative performance.

Hitoshi Komoto; Shinsuke Kondoh; Keijiro Masui; Akira Tezuka

2014-01-01T23:59:59.000Z

132

Parareal in time 3D numerical solver for the LWR Benchmark neutron diffusion transient model  

E-Print Network (OSTI)

We present a parareal in time algorithm for the simulation of neutron diffusion transient model. The method is made efficient by means of a coarse solver defined with large time steps and steady control rods model. Using finite element for the space discretization, our implementation provides a good scalability of the algorithm. Numerical results show the efficiency of the parareal method on large light water reactor transient model corresponding to the Langenbuch-Maurer-Werner (LMW) benchmark [1].

Baudron, Anne-Marie A -M; Maday, Yvon; Riahi, Mohamed Kamel; Salomon, Julien

2014-01-01T23:59:59.000Z

133

Characterization of Texas lignite and numerical modeling of its in-situ gasification  

E-Print Network (OSTI)

CHARACTERIZATION OF TEXAS LIGNITE AND NUMERICAL MODELING OF ITS IN-SITU GASIFICATION A Thesis by YIH-JY WANG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1983 Major Subject: Geophysics CHARACTERIZATION OF TEXAS LIGNITE AND NUMERICAL MODELING OF ITS IN-SITU GASIFICATION A Thesis by YIH-JY WANG Approved as to style and content by: James E. Russell (Chairman of Committee) M. Caputo...

Wang, Yih-Jy

2012-06-07T23:59:59.000Z

134

A general numerical solution of dispersion relations for the nuclear optical model  

E-Print Network (OSTI)

A general numerical solution of the dispersion integral relation between the real and the imaginary parts of the nuclear optical potential is presented. Fast convergence is achieved by means of the Gauss-Legendre integration method, which offers accuracy, easiness of implementation and generality for dispersive optical model calculations. The use of this numerical integration method in the optical-model parameter search codes allows for a fast and accurate dispersive analysis. PACS number(s): 11.55.Fv, 24.10.Ht, 02.60.Jh

Roberto Capote; Alberto Molina; Jose Manuel Quesada

2001-05-09T23:59:59.000Z

135

Proceedings of the Numerical Modeling for Underground Nuclear Test Monitoring Symposium  

SciTech Connect

The purpose of the meeting was to discuss the state-of-the-art in numerical simulations of nuclear explosion phenomenology with applications to test ban monitoring. We focused on the uniqueness of model fits to data, the measurement and characterization of material response models, advanced modeling techniques, and applications of modeling to monitoring problems. The second goal of the symposium was to establish a dialogue between seismologists and explosion-source code calculators. The meeting was divided into five main sessions: explosion source phenomenology, material response modeling, numerical simulations, the seismic source, and phenomenology from near source to far field. We feel the symposium reached many of its goals. Individual papers submitted at the conference are indexed separately on the data base.

Taylor, S.R.; Kamm, J.R. [eds.

1993-11-01T23:59:59.000Z

136

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network (OSTI)

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

Boyer, Edmond

137

Numerical Modeling and Experimental Study of Combustion and Soot Formation in a Direct Injection Diesel Engine  

Science Journals Connector (OSTI)

Numerical Modeling and Experimental Study of Combustion and Soot Formation in a Direct Injection Diesel Engine ... The major problems associated with diesel engines are the high levels of nitrogen oxides (NOX) and particulate emissions. ... (11)?Flagan, R. C.; Seinfeld, J. H. Fundamentals of Air Pollution Engineering; Prentice Hall Inc.:? New York, 1988. ...

T. L. Chan; X. B. Cheng

2007-04-10T23:59:59.000Z

138

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics  

E-Print Network (OSTI)

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics problems, particularly for high-speed Surface Effect Ships (SES) such as the recently proposed Harley FastShip and/or a surface-piercing body (ship), within the framework of potential flow theory. The three

Grilli, Stéphan T.

139

An improved numerical scheme for a coupled system to model soil erosion and polydispersed sediments transport  

E-Print Network (OSTI)

An improved numerical scheme for a coupled system to model soil erosion and polydispersed sediments, the positivity of both water depth and sediment concentrations. Recently, a well-balanced MUSCL-Hancock scheme step is required to ensure the positivity of sediment concentrations. The main result of this paper

Boyer, Edmond

140

LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY CONVERTERS  

E-Print Network (OSTI)

1 LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY of wave energy converters (WECs) on water waves through the analysis of extensive laboratory experiments absorption is a reasonable predictor of the effect of WECs on the far field. Keywords: wave- energy; spectral

Haller, Merrick

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical modeling of extreme rogue waves generated by directional energy focusing  

E-Print Network (OSTI)

Numerical modeling of extreme rogue waves generated by directional energy focusing Christophe angle of directional energy focusing. We find that an over- turning rogue wave can have different are characterized by their brief occurrence in space and time, resulting from a local focusing of wave energy

Grilli, Stéphan T.

142

Mathematical formulation and numerical modeling of wax deposition in pipelines from enthalpyporosity approach  

E-Print Network (OSTI)

Mathematical formulation and numerical modeling of wax deposition in pipelines from enthalpy and in the North Sea, the deposition of wax crystals in oil and gas pipelines becomes a major concern operational complexities. To pre- vent blockage of pipelines, wax deposits should be removed periodically

Firoozabadi, Abbas

143

NUMERICAL MODELING OF 3D ORGANIC SOLAR CELLS Presented to the  

E-Print Network (OSTI)

NUMERICAL MODELING OF 3D ORGANIC SOLAR CELLS _______________ A Thesis Presented to the Faculty Solar Cells by Anurag Kaushik Master of Science in Electrical Engineering San Diego State University and nanofabrication technologies offer a unique opportunity for meshing it with organic PV cell technology

Kassegne, Samuel Kinde

144

Modification of the Physics and Numerics in a Third-Generation Ocean Wave Model  

Science Journals Connector (OSTI)

The ocean wave model WAM was recently upgraded to improve the coupling between the sea state and the air flow and, in particular, enhance the growth of young wind sea over that of old wind sea. Prior to this change, numerous validations of the ...

Leslie C. Bender

1996-06-01T23:59:59.000Z

145

January 2, 2008 Numerical modeling of the effect of carbon dioxide  

E-Print Network (OSTI)

January 2, 2008 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la déformation des calcaires par dissolution sous contrainte: résultats;Abstract When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its

Boyer, Edmond

146

MODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI-DATION OF CERAMIC COMPOSITES  

E-Print Network (OSTI)

. INTRODUCTION Oxidation shortens the life of ceramic matrix composites by, e.g., chang- ing the elasticMODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI- DATION OF CERAMIC COMPOSITES S. Adjerid, M. Ai reaction 1-3 . Composite materials are protected by coatings; however, cracks that form as a result

Adjerid, Slimane

147

Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water  

E-Print Network (OSTI)

for femtosecond laser excitation and time-resolved X-ray probing of gold nanoparticles demonstrates that the vaporNumerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water Alexey, University of Virginia, USA Available online 3 February 2007 Abstract Short pulse laser interaction

Zhigilei, Leonid V.

148

Numerical modeling and experimental validation of uniform microchamber filling in centrifugal microfluidics  

E-Print Network (OSTI)

microfluidics Jonathan Siegrist,*a Mary Amasia,a Navdeep Singh,b Debjyoti Banerjeeb and Marc Madoua Received 1st analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro on centrifugal microfluidic platforms, numerical modeling using the Volume of Fluids method is performed

Banerjee, Debjyoti

149

COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS  

E-Print Network (OSTI)

COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS I. DIMOV , K. GEORGIEVy, TZ. OSTROMSKY , R. J. VAN DER PASz, AND Z. ZLATEVx Abstract. The air pollution, and especially the reduction of the air pollution to some acceptable levels, is an important environmental problem, which

Dimov, Ivan

150

Mathematical, physical and numerical principles essential for models of turbulent mixing  

SciTech Connect

We propose mathematical, physical and numerical principles which are important for the modeling of turbulent mixing, especially the classical and well studied Rayleigh-Taylor and Richtmyer-Meshkov instabilities which involve acceleration driven mixing of a fluid discontinuity layer, by a steady accerleration or an impulsive force.

Sharp, David Howland [Los Alamos National Laboratory; Lim, Hyunkyung [STONY BROOK UNIV; Yu, Yan [STONY BROOK UNIV; Glimm, James G [STONY BROOK UNIV

2009-01-01T23:59:59.000Z

151

NUMERICAL VERIFICATION OF THE RELAP-7 CORE CHANNEL SINGLE-PHASE MODEL  

SciTech Connect

The RELAP-7 code is the next generation of nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). All the physics in RELAP-7 are fully coupled and the errors resulted from the traditional operator-splitting approach are eliminated. By using 2nd order methods in both time and space and eliminating operator-splitting errors, the numerical error of RELAP-7 can be minimized. Numerical verification is the process to verify the orders of numerical methods. It is an important part of modern verification and validation process. The core channel component in RELAP-7 is designed to simulate coolant flow as well as the conjugated heat transfer between coolant flow and the fuel rod. A special treatment at fuel centerline to avoid numerical singularity for the cylindrical heat conduction in the continuous finite element mesh is discussed. One steady state test case and one fast power up transient test case are utilized for the verification of the core channel model with single-phase flow. Analytical solution for the fuel pin temperature and figures of merit such as peak clad temperature and peak fuel temperature are used to define numerical errors. These cases prove that the mass and energy are well conserved and 2nd order convergence rates for both time and space are achieved in the core channel model.

Haihua Zhao; Ling Zou; Hongbin Zhang; Richard Martineau

2014-06-01T23:59:59.000Z

152

Modelling and Numerical Simulation of Gas Migration in a Nuclear Waste Repository  

E-Print Network (OSTI)

We present a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological radioactive waste repository. This model includes capillary effects and the gas diffusivity. The choice of the main variables in this model, Total or Dissolved Hydrogen Mass Concentration and Liquid Pressure, leads to a unique and consistent formulation of the gas phase appearance and disappearance. After introducing this model, we show computational evidences of its adequacy to simulate gas phase appearance and disappearance in different situations typical of underground radioactive waste repository.

Bourgeat, Alain; Smai, Farid

2010-01-01T23:59:59.000Z

153

Numerical estimation model of energy conversion for small hybrid solar–wind system  

Science Journals Connector (OSTI)

This article presents a numerical model which can estimate the energy conversions of separate and hybrid solar–wind systems under variable weather. The model integrates the equations associated with the characteristics of photovoltaic generation, wind energy conversion, energy balance, and battery bank, and uses the local database for radiation, wind speed, and ambient temperature. Once the equation associated with the characteristics of load is given, the numerical model can estimate the monthly and yearly powers output of the separate and hybrid solar–wind systems provided with different configurations. As a fundamental research, the presentations of daily profiles of solar radiation, wind energy, and ambient temperature are explained in detail, and the combination of the characteristics of wind energy conversion and battery bank is determined. The condition of hybrid action is shown, and the solutions are certain to be found. The operation strategies of separate and hybrid systems are also presented.

Shun Ching Lee

2012-01-01T23:59:59.000Z

154

Modeling and simulation of the industrial numerical distance relay aimed at knowledge discovery in resident event reporting  

Science Journals Connector (OSTI)

In the motivation of tapping the strong potential of computational intelligence in discovering knowledge of protective relay operations using data mining, modeling and simulation of an actual industrial numerical distance relay and its recording facility ... Keywords: Distance protection, Knowledge Discovery in Databases, Rough Set Theory, association rule, computational intelligence, data mining, numerical protective relay, relay modeling

Mohammad Lutfi Othman, Ishak Aris, Noor Izzri Abdul Wahab

2014-06-01T23:59:59.000Z

155

A Shallow Water model for the numerical simulation of overland flow on surfaces with ridges and furrows  

E-Print Network (OSTI)

A Shallow Water model for the numerical simulation of overland flow on surfaces with ridges Abstract We introduce a new Shallow Water model for the numerical simulation of overland flow with furrow conservation (decreases soil thickness by erosion and causes nutrient loss), infrastruc- tures (flooding

d'Orléans, Université

156

Mathematical modelling approach for determining optimal machining parameters in turning with computer numerical control (CNC) machines  

Science Journals Connector (OSTI)

Due to advancement in the manufacturing technology the application of computer numerical control (CNC) machines have increased manifolds. The determination of machining parameters for optimal results in machining is a part of computer aided process planning. In computer numerical control (CNC) machining, determining optimum or appropriate cutting parameters can minimise machining errors such as tool breakage, tool deflection and tool wear, thus yielding a high productivity or minimum cost. Different mathematical models have been proposed by various researchers in the past for the determination of optimal machining parameters. The present paper attempt's to review the literature regarding 'machining parameter optimisation' for turning operation in CNC machines. Diverse contributing and important factors in mathematical modelling like, the economic criteria's, single and multi-pass turning, optimisation techniques and practical constraints deployed have been considered. A detailed discussion is presented regarding the topic and in the end conclusions are drawn.

Bhaskar Naithani; Santram Chauhan

2012-01-01T23:59:59.000Z

157

Energy barriers of the Ising model on percolation clusters : a numerical study  

E-Print Network (OSTI)

L- 667 Energy barriers of the Ising model on percolation clusters : a numerical study R. Rammal fini de spins d'Ising ferromagnétiques. Cette méthode est illustrée dans le cas des amas de percolation puissance bien connue dans les réseaux euclidiens. Certaines conséquences de ces résultats pour le modèle d'Ising

Paris-Sud XI, Université de

158

Numerical-Model Investigation of the Hydrothermal Regime of a Straight-Through Shallow Cooling Pond  

SciTech Connect

A mathematic model based on solution of hydrodynamics and heat-transfer equations by the finite-element method is constructed to predict the hydrothermal regime of a straight-through shallow cooling pond, which provides cooling circulating water to a repository of spent nuclear fuel. Numerical experiments made it possible to evaluate the influence exerted by wind conditions and flow rate of water in the river on the temperature of the circulating water.

Sokolov, A. S. [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)] [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)

2013-11-15T23:59:59.000Z

159

Numerical modeling of dust particle configurations in a cylindrical radio-frequency plasma reactor  

Science Journals Connector (OSTI)

In the present work, first, plasma phase variables in a cylindrical radio-frequency (rf) plasma reactor are numerically solved using the local field approximation model. Then, equilibrium configurations of a few interacting (sub-)micron-sized dust particles are obtained by integrating the particles equations for their motion and charge, accounting for the various forces acting on each particle in a three-dimensional Lagrangian framework. Direct comparison of the results with experiment demonstrates excellent qualitative agreement. Based on the ion focus phenomenon, a physical model is formulated and proven successful in simulating the vertically aligned structures.

M. Davoudabadi and F. Mashayek

2007-11-30T23:59:59.000Z

160

The numerical calculation of single-diode solar-cell modelling parameters  

Science Journals Connector (OSTI)

Abstract The accurate simulation of a photovoltaic solar cell requires the precise determination of modelling parameters specific to the device under study. For the case of the single diode model, five parameters must be determined; Iph, I0, Rs, Rsh, and n. Generally speaking these values may be calculated either by analytical or numerical methods. Although analytical approaches are simple and fast to carry out, the assumptions and simplifications they introduce in order to deal with the non-linear characteristics of a solar cell may result in modelling inaccuracies. In this study a new approach is presented to calculate all five parameter values numerically minimising assumptions and simplifications. The method proposed is based on solving the single diode current–voltage equation expressed using the Lambert W-function at five experimentally obtained points along the current–voltage curve. To solve the system of non-linear equations, the multi-dimensional variant of the Newton–Raphson method is applied. All necessary first order partial differential equations are provided in closed form. Experimental validation of the proposed method revealed an improvement in modelling accuracy over one commonly used analytical approach. Furthermore, using TRNSYS software to simulate the annual energy output we show that modelling photovoltaic systems with small variations in solar cell parameters can result in non-trivial variations in annual energy output highlighting the importance of their calculation.

F. Ghani; G. Rosengarten; M. Duke; J.K. Carson

2014-01-01T23:59:59.000Z

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161

On the formulation, parameter identification and numerical integration of the EMMI model :plasticity and isotropic damage.  

SciTech Connect

In this report we present the formulation of the physically-based Evolving Microstructural Model of Inelasticity (EMMI) . The specific version of the model treated here describes the plasticity and isotropic damage of metals as being currently applied to model the ductile failure process in structural components of the W80 program . The formulation of the EMMI constitutive equations is framed in the context of the large deformation kinematics of solids and the thermodynamics of internal state variables . This formulation is focused first on developing the plasticity equations in both the relaxed (unloaded) and current configurations. The equations in the current configuration, expressed in non-dimensional form, are used to devise the identification procedure for the plasticity parameters. The model is then extended to include a porosity-based isotropic damage state variable to describe the progressive deterioration of the strength and mechanical properties of metals induced by deformation . The numerical treatment of these coupled plasticity-damage constitutive equations is explained in detail. A number of examples are solved to validate the numerical implementation of the model.

Bammann, Douglas J.; Johnson, G. C. (University of California, Berkeley, CA); Marin, Esteban B.; Regueiro, Richard A. (University of Colorado, Boulder, CO)

2006-01-01T23:59:59.000Z

162

Hydraulic model and steam flow numerical simulation of the Cerro Prieto geothermal field, Mexico, pipeline network  

Science Journals Connector (OSTI)

Abstract The development of a hydraulic model and numerical simulation results of the Cerro Prieto geothermal field (CPGF) steam pipeline network are presented. Cerro Prieto is the largest water-dominant geothermal field in the world and its transportation network has 162 producing wells, connected through a network of pipelines that feeds 13 power-generating plants with an installed capacity of 720 MWe. The network is about 125 km long and has parallel high- and low-pressure networks. Prior to this study, it was suspected that steam flow stagnated or reversed from its planned direction in some segments of the network. Yet, the network complexity and extension complicated the analysis of steam transport for adequate delivery to the power plants. Thus, a hydraulic model of the steam transportation system was developed and implemented numerically using an existing simulator, which allowed the overall analysis of the network in order to quantify the pressure and energy losses as well as the steam flow direction in every part of the network. Numerical results of the high-pressure network were obtained which show that the mean relative differences between measured and simulated pressures and flowrates are less than 10%, which is considered satisfactory. Analysis of results led to the detection of areas of opportunity and to the recommendation of changes for improving steam transport. A main contribution of the present work is having simulated satisfactorily the longest (to our knowledge), and probably the most complex, steam pipeline network in the world.

A. García-Gutiérrez; A.F. Hernández; J.I. Martínez; M. Ceceñas; R. Ovando; I. Canchola

2015-01-01T23:59:59.000Z

163

Numerical modelling of sandstone uniaxial compression test using a mix-mode cohesive fracture model  

E-Print Network (OSTI)

A mix-mode cohesive fracture model considering tension, compression and shear material behaviour is presented, which has wide applications to geotechnical problems. The model considers both elastic and inelastic displacements. Inelastic displacement comprises fracture and plastic displacements. The norm of inelastic displacement is used to control the fracture behaviour. Meantime, a failure function describing the fracture strength is proposed. Using the internal programming FISH, the cohesive fracture model is programmed into a hybrid distinct element algorithm as encoded in Universal Distinct Element Code (UDEC). The model is verified through uniaxial tension and direct shear tests. The developed model is then applied to model the behaviour of a uniaxial compression test on Gosford sandstone. The modelling results indicate that the proposed cohesive fracture model is capable of simulating combined failure behaviour applicable to rock.

Gui, Yilin; Kodikara, Jayantha

2015-01-01T23:59:59.000Z

164

The NINJA-2 project: Detecting and characterizing gravitational waveforms modelled using numerical binary black hole simulations  

E-Print Network (OSTI)

The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered with false alarm rates smaller than 1 in a thousand years. Parameter estimation algorithms were run on each of these waveforms to explore the ability to constrain the masses, component angular momenta and sky position of these waveforms. We also perform a large-scale monte-carlo study to assess the ability to recover each of the 60 hybrid waveforms with early Advanced LIGO and Advanced Virgo sensitivity curves. Our results predict that early Advanced LIGO and Advanced Virgo will have a volume-weighted average sensitive distance of 300Mpc (1Gpc) for $10M_{\\odot}+10M_{\\odot}$ ($50M_{\\odot}+50M_{\\odot}$) binary black hole coalescences. We demonstrate that neglecting the component angular momenta in the waveform models used in matched-filtering will result in a reduction in sensitivity for systems with large component angular momenta. [Abstract abridged for ArXiv, full version in PDF

The LIGO Scientific Collaboration; the Virgo Collaboration; the NINJA-2 Collaboration; :; J. Aasi; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; K. Ackley; C. Adams; T. Adams; P. Addesso; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; A. Ain; P. Ajith; A. Alemic; B. Allen; A. Allocca; D. Amariutei; M. Andersen; R. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; M. Barbet; B. C. Barish; D. Barker; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. C. Batch; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. Bejger; M. G. Beker; C. Belczynski; A. S. Bell; C. Bell; G. Bergmann; D. Bersanetti; A. Bertolini; J. Betzwieser; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Biscans; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; S. Bloemen; M. Blom; O. Bock; T. P. Bodiya; M. Boer; G. Bogaert; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; Sukanta Bose; L. Bosi; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brückner; S. Buchman; T. Bulik; H. J. Bulten; A. Buonanno; R. Burman; D. Buskulic; C. Buy; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; C. Celerier; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. J. Chamberlin; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; C. Collette; M. Colombini; L. Cominsky; M. Constancio Jr.; A. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corpuz; A. Corsi; C. A. Costa; M. W. Coughlin; S. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; R. Coyne; K. Craig; J. D. E. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; G. Debreczeni; J. Degallaix; S. Deléglise; W. Del Pozzo; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. De Rosa; R. T. DeRosa; R. DeSalvo; S. Dhurandhar; M. Díaz; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; A. Donath; F. Donovan; K. L. Dooley; S. Doravari; S. Dossa; R. Douglas; T. P. Downes; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; S. Dwyer; T. Eberle; T. Edo; M. Edwards; A. Effler; H. Eggenstein; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endr?czi; R. Essick; T. Etzel; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. M. Farr; M. Favata; H. Fehrmann; M. M. Fejer; D. Feldbaum; F. Feroz; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; S. Gaonkar; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; S. Ghosh; J. A. Giaime; K. D. Giardina; A. Giazotto; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Gräf; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. Gushwa; E. K. Gustafson; R. Gustafson; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. Hart; M. T. Hartman; C. -J. Haster; K. Haughian; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; S. Hooper; P. Hopkins; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; P. Jaranowski; Y. Ji; F. Jiménez-Forteza; W. W. Johnson; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; J. Karlen; M. Kasprzack; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; F. Kawazoe; F. Kéfélian; G. M. Keiser; D. Keitel; D. B. Kelley; W. Kells; A. Khalaidovski

2014-01-05T23:59:59.000Z

165

The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and inundation  

E-Print Network (OSTI)

A novel tool for tsunami wave modelling is presented. This tool has the potential of being used for operational purposes: indeed, the numerical VOLNA code is able to handle the complete life-cycle of a tsunami (generation, propagation and run-up along the coast). The algorithm works on unstructured triangular meshes and, thus, can be run in arbitrary complex domains. It is often the case since natural coasts tend to be of fractal shape [Sapoval et al, 2004]. This paper contains the detailed description of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet/dry transition. This point is crucial for accurate run-up computation. Most existing tsunami codes use semi-empirical techniques at this stage, which are not always sufficient. The main reason is that people evacuation is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we present several realistic test cases that partially validate our algorithm. Comparisons wit...

Dutykh, Denys; Dias, Frédéric

2010-01-01T23:59:59.000Z

166

Assimilation of Satellite Cloud and Precipitation Observations in Numerical Weather Prediction Models: Introduction to the JAS Special Collection  

Science Journals Connector (OSTI)

To date, the assimilation of satellite measurements in numerical weather prediction (NWP) models has focused on the clear atmosphere. But satellite observations in the visible, infrared, and microwave provide a great deal of information on clouds ...

Ronald M. Errico; George Ohring; Fuzhong Weng; Peter Bauer; Brad Ferrier; Jean-François Mahfouf; Joe Turk

2007-11-01T23:59:59.000Z

167

A viscous vortex single-mode bubble evolution model of Rayleigh-Taylor instability and its numerical study  

Science Journals Connector (OSTI)

This paper has developed a viscous single-mode bubble evolution model of Rayleigh-Taylor instabilities (RTIs), which is an extension of the single-mode potential models of Jacobs and Rikanati. The viscous vortex model explained the viscous effects of its early stage of RTI development for low Atwood number flow. Furthermore, direct numerical simulations of RTI are studied with Navier-Stokes equations and a transport-diffusive equation. Agreement between the theoretical model and the numerical results shows that simulations of these instabilities is feasible using the mathematical miscible fluid model simulating RTI.

Xu Zhang; Jinhong Liu

2013-01-01T23:59:59.000Z

168

Numeric-modeling sensitivity analysis of the performance of wind turbine arrays  

SciTech Connect

An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

1982-06-01T23:59:59.000Z

169

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation  

E-Print Network (OSTI)

We propose in this paper an original technique to predict global radiation using a hybrid ARMA/ANN model and data issued from a numerical weather prediction model (ALADIN). We particularly look at the Multi-Layer Perceptron. After optimizing our architecture with ALADIN and endogenous data previously made stationary and using an innovative pre-input layer selection method, we combined it to an ARMA model from a rule based on the analysis of hourly data series. This model has been used to forecast the hourly global radiation for five places in Mediterranean area. Our technique outperforms classical models for all the places. The nRMSE for our hybrid model ANN/ARMA is 14.9% compared to 26.2% for the na\\"ive persistence predictor. Note that in the stand alone ANN case the nRMSE is 18.4%. Finally, in order to discuss the reliability of the forecaster outputs, a complementary study concerning the confidence interval of each prediction is proposed

Voyant, Cyril; Paoli, Christophe; Nivet, Marie Laure

2012-01-01T23:59:59.000Z

170

Numerical modelling of solid fuel combustion processes using advanced CFD-based simulation tools  

Science Journals Connector (OSTI)

Computational modelling of combustion processes has been the subject of coninuous research at the Institute of Process Engineering and Power Plant Technology (IVD) over the last two decades. To this end, finite-volume-based computer codes have been developed. In the present paper, some fundamental ideas and approaches of the applied mathematical models and the numerical methods are described, followed by some examples of typical applications of the procedures with special emphasis on the validation of simulation results. These examples show that the application of combustion simulation codes has been extended to comprise a wide range of several different areas ranging from huge bituminous coal-fired utility boilers for electricity production to decentralised small-scale furnaces and tile stove heating inserts for domestic heating.

Uwe Schnell

2001-01-01T23:59:59.000Z

171

Comment on "Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design" Teixeira et al. (2007)  

E-Print Network (OSTI)

Comment on "Time Step Sensitivity of Nonlinear Atmospheric Models: Numerical Convergence, Truncation Error Growth, and Ensemble Design" Teixeira et al.

Lun-Shin Yao; Dan Hughes

2007-04-26T23:59:59.000Z

172

Modeling active electrolocation in weakly electric fish  

E-Print Network (OSTI)

In this paper, we provide a mathematical model for the electrolocation in weakly electric fishes. We first investigate the forward complex conductivity problem and derive the approximate boundary conditions on the skin of the fish. Then we provide a dipole approximation for small targets away from the fish. Based on this approximation, we obtain a non-iterative location search algorithm using multi-frequency measurements. We present numerical experiments to illustrate the performance and the stability of the proposed multi-frequency location search algorithm. Finally, in the case of disk- and ellipse-shaped targets, we provide a method to reconstruct separately the conductivity, the permittivity, and the size of the targets from multi-frequency measurements.

Habib Ammari; Thomas Boulier; Josselin Garnier

2012-03-05T23:59:59.000Z

173

Electrochimica Acta 51 (2006) 31393150 Direct numerical simulation (DNS) modeling of PEFC electrodes  

E-Print Network (OSTI)

Elsevier Ltd. All rights reserved. Keywords: Polymer electrolyte fuel cell; Cathode catalyst layer; Pore. The fuel (i.e. hydrogen) and oxidant (i.e. oxygen) react electrochemically in the active catalyst layers) model is developed to achieve pore-level description of polymer electrolyte fuel cell (PEFC) electrodes

174

Combined Modeling of Acceleration, Transport, and Hydrodynamic Response in Solar Flares. I. The Numerical Model  

Science Journals Connector (OSTI)

Acceleration and transport of high-energy particles and fluid dynamics of atmospheric plasma are interrelated aspects of solar flares, but for convenience and simplicity they were artificially separated in the past. We present here self-consistently combined Fokker-Planck modeling of particles and hydrodynamic simulation of flare plasma. Energetic electrons are modeled with the Stanford unified code of acceleration, transport, and radiation, while plasma is modeled with the Naval Research Laboratory flux tube code. We calculated the collisional heating rate directly from the particle transport code, which is more accurate than those in previous studies based on approximate analytical solutions. We repeated the simulation of Mariska et al. with an injection of power law, downward-beamed electrons using the new heating rate. For this case, a ~10% difference was found from their old result. We also used a more realistic spectrum of injected electrons provided by the stochastic acceleration model, which has a smooth transition from a quasi-thermal background at low energies to a nonthermal tail at high energies. The inclusion of low-energy electrons results in relatively more heating in the corona (versus chromosphere) and thus a larger downward heat conduction flux. The interplay of electron heating, conduction, and radiative loss leads to stronger chromospheric evaporation than obtained in previous studies, which had a deficit in low-energy electrons due to an arbitrarily assumed low-energy cutoff. The energy and spatial distributions of energetic electrons and bremsstrahlung photons bear signatures of the changing density distribution caused by chromospheric evaporation. In particular, the density jump at the evaporation front gives rise to enhanced emission, which, in principle, can be imaged by X-ray telescopes. This model can be applied to investigate a variety of high-energy processes in solar, space, and astrophysical plasmas.

Wei Liu; Vahé Petrosian; John T. Mariska

2009-01-01T23:59:59.000Z

175

COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC RESPONSE IN SOLAR FLARES. I. THE NUMERICAL MODEL  

SciTech Connect

Acceleration and transport of high-energy particles and fluid dynamics of atmospheric plasma are interrelated aspects of solar flares, but for convenience and simplicity they were artificially separated in the past. We present here self-consistently combined Fokker-Planck modeling of particles and hydrodynamic simulation of flare plasma. Energetic electrons are modeled with the Stanford unified code of acceleration, transport, and radiation, while plasma is modeled with the Naval Research Laboratory flux tube code. We calculated the collisional heating rate directly from the particle transport code, which is more accurate than those in previous studies based on approximate analytical solutions. We repeated the simulation of Mariska et al. with an injection of power law, downward-beamed electrons using the new heating rate. For this case, a {approx}10% difference was found from their old result. We also used a more realistic spectrum of injected electrons provided by the stochastic acceleration model, which has a smooth transition from a quasi-thermal background at low energies to a nonthermal tail at high energies. The inclusion of low-energy electrons results in relatively more heating in the corona (versus chromosphere) and thus a larger downward heat conduction flux. The interplay of electron heating, conduction, and radiative loss leads to stronger chromospheric evaporation than obtained in previous studies, which had a deficit in low-energy electrons due to an arbitrarily assumed low-energy cutoff. The energy and spatial distributions of energetic electrons and bremsstrahlung photons bear signatures of the changing density distribution caused by chromospheric evaporation. In particular, the density jump at the evaporation front gives rise to enhanced emission, which, in principle, can be imaged by X-ray telescopes. This model can be applied to investigate a variety of high-energy processes in solar, space, and astrophysical plasmas.

Liu Wei [Stanford-Lockheed Institute for Space Research, 466 Via Ortega, Cypress Hall, Stanford, CA 94305-4085 (United States); Petrosian, Vahe [Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States); Mariska, John T. [Naval Research Laboratory, Code 7673, Washington, DC 20375-5000 (United States)

2009-09-10T23:59:59.000Z

176

Using numerical models of bow shocks to investigate the circumstellar medium of massive stars  

E-Print Network (OSTI)

Many massive stars travel through the interstellar medium at supersonic speeds. As a result they form bow shocks at the interface between the stellar wind. We use numerical hydrodynamics to reproduce such bow shocks numerically, creating models that can be compared to observations. In this paper we discuss the influence of two physical phenomena, interstellar magnetic fields and the presence of interstellar dust grains on the observable shape of the bow shocks of massive stars. We find that the interstellar magnetic field, though too weak to restrict the general shape of the bow shock, reduces the size of the instabilities that would otherwise be observed in the bow shock of a red supergiant. The interstellar dust grains, due to their inertia can penetrate deep into the bow shock structure of a main sequence O-supergiant, crossing over from the ISM into the stellar wind. Therefore, the dust distribution may not always reflect the morphology of the gas. This is an important consideration for infrared observati...

van Marle, Allard Jan; Cox, Nick; Meliani, Zakaria

2014-01-01T23:59:59.000Z

177

Numerical simulation of swirling flow in complex hydroturbine draft tube using unsteady statistical turbulence models  

SciTech Connect

A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90 degree elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.

Paik, Joongcheol [University of Minnesota; Sotiropoulos, Fotis [University of Minnesota; Sale, Michael J [ORNL

2005-06-01T23:59:59.000Z

178

Numerical determination of OPE coefficients in the 3D Ising model from off-critical correlators  

E-Print Network (OSTI)

We propose a general method for the numerical evaluation of OPE coefficients in three dimensional Conformal Field Theories based on the study of the conformal perturbation of two point functions in the vicinity of the critical point. We test our proposal in the three dimensional Ising Model, looking at the magnetic perturbation of the $$, $$ and $$ correlators from which we extract the values of $C^{\\sigma}_{\\sigma\\epsilon}=1.07(3)$ and $C^{\\epsilon}_{\\epsilon\\epsilon}=1.45(30)$. Our estimate for $C^{\\sigma}_{\\sigma\\epsilon}$ agrees with those recently obtained using conformal bootstrap methods, while $C^{\\epsilon}_{\\epsilon\\epsilon}$, as far as we know, is new and could be used to further constrain conformal bootstrap analyses of the 3d Ising universality class.

Caselle, M; Magnoli, N

2015-01-01T23:59:59.000Z

179

Equation of State and Constitutive Models for Numerical Simulations of Dust Impacts on the Solar Probe  

E-Print Network (OSTI)

This report presents new EOS and strength models for use in numerical hydrocode simulations of dust impacts on the NASA solar probe space vehicle. This spacecraft will be subjected to impact at velocities up to 300 km/s, producing pressures as high as 100 TPa and temperatures as high as 200 eV. Hence the material models must treat a variety of physical and chemical phenomena, including solid-solid transitions, melting and vaporization, chemical reactions, electronic excitation and ionization. The EOSPro code is used to develop tabular EOS that include these effects. The report discusses the theoretical methods used to create the new EOS tables and constitutive models for six materials--Al2O3, two porous carbon materials, fused SiO2, a silicone elastomer, and germanium--which will be used in the thermal protection shield (TPS) and solar cells, the components most vulnerable to dust impacts. It also presents the results of hydrocode simulations of dust impacts on the TPS and on glass targets. It discusses the i...

Kerley, Gerald I

2013-01-01T23:59:59.000Z

180

Temperature Modeling in Activated Sludge Systems: A Case Study  

E-Print Network (OSTI)

Temperature Modeling in Activated Sludge Systems: A Case Study Jacek Makinia, Scott A. Wells, Piotr Zima ABSTRACT: A model of temperature dynamics was developed as part of a general model of activated-sludge biochemical-energy inputs and other activated-sludge, heat-balance terms. All the models were tested under

Wells, Scott A.

Note: This page contains sample records for the topic "activity numerical modeling" 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

Improving the assessment of wave energy resources by means of coupled wave-ocean numerical modeling  

Science Journals Connector (OSTI)

Abstract Sea waves energy represents a renewable and sustainable energy resource, that nevertheless needs to be further investigated to make it more cost-effective and economically appealing. A key step in the process of Wave Energy Converters (WEC) deployment is the energy resource assessment at a sea site either measured or obtained through numerical model analysis. In these kind of studies, some approximations are often introduced, especially in the early stages of the process, viz. waves are assumed propagating in deep waters without underneath ocean currents. These aspects are discussed and evaluated in the Adriatic Sea and its northern part (Gulf of Venice) using locally observed and modeled wave data. In particular, to account for a “state of the art” treatment of the Wave–Current Interaction (WCI) we have implemented the Simulating \\{WAves\\} Nearshore (SWAN) model and the Regional Ocean Modeling System (ROMS), fully coupled within the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) system. COAWST has been applied to a computational grid covering the whole Adriatic Sea and off-line nested to a high-resolution grid in the Gulf of Venice. A 15-year long wave data set collected at the oceanographic tower “Acqua Alta”, located approximately 15 km off the Venice coast, has also been analyzed with the dual purpose of providing a reference to the model estimates and to locally assess the wave energy resource. By using COAWST, we have quantified for the first time to our best knowledge the importance of the WCI effect on wave power estimation. This can vary up to 30% neglecting the current effect. Results also suggest the Gulf of Venice as a suitable testing site for WECs, since it is characterized by periods of calm (optimal for safe installation and maintenance) alternating with severe storms, whose wave energy potentials are comparable to those ordinarily encountered in the energy production sites.

Francesco Barbariol; Alvise Benetazzo; Sandro Carniel; Mauro Sclavo

2013-01-01T23:59:59.000Z

182

Experimental results and numerical modeling of a high-performance large-scale cryopump. I. Test particle Monte Carlo simulation  

Science Journals Connector (OSTI)

For the torus of the nuclear fusion project ITER (originally the International Thermonuclear Experimental Reactor but also Latin: the way) eight high-performance large-scale customized cryopumps must be designed and manufactured to accommodate the very high pumping speeds and throughputs of the fusion exhaust gas needed to maintain the plasma under stable vacuum conditions and comply with other criteria which cannot be met by standard commercial vacuum pumps. Under an earlier research and development program a model pump of reduced scale based on active cryosorption on charcoal-coated panels at 4.5 K was manufactured and tested systematically. The present article focuses on the simulation of the true three-dimensional complex geometry of the model pump by the newly developed PROVAC3D Monte Carlo code. It is shown for gas throughputs of up to 1000 sccm (?1.69 Pa m3/s at T?=?0° C) in the free molecular regime that the numerical simulation results are in good agreement with the pumping speeds measured. Meanwhile the capture coefficient associated with the virtual region around the cryogenic panels and shields which holds for higher throughputs is calculated using this generic approach. This means that the test particle Monte Carlo simulations in free molecular flow can be used not only for the optimization of the pumping system but also for the supply of the input parameters necessary for the future direct simulation Monte Carlo in the full flow regime.

Xueli Luo; Christian Day; Horst Haas; Stylianos Varoutis

2011-01-01T23:59:59.000Z

183

Experimental results and numerical modeling of a high-performance large-scale cryopump. I. Test particle Monte Carlo simulation  

SciTech Connect

For the torus of the nuclear fusion project ITER (originally the International Thermonuclear Experimental Reactor, but also Latin: the way), eight high-performance large-scale customized cryopumps must be designed and manufactured to accommodate the very high pumping speeds and throughputs of the fusion exhaust gas needed to maintain the plasma under stable vacuum conditions and comply with other criteria which cannot be met by standard commercial vacuum pumps. Under an earlier research and development program, a model pump of reduced scale based on active cryosorption on charcoal-coated panels at 4.5 K was manufactured and tested systematically. The present article focuses on the simulation of the true three-dimensional complex geometry of the model pump by the newly developed ProVac3D Monte Carlo code. It is shown for gas throughputs of up to 1000 sccm ({approx}1.69 Pa m{sup 3}/s at T = 0 deg. C) in the free molecular regime that the numerical simulation results are in good agreement with the pumping speeds measured. Meanwhile, the capture coefficient associated with the virtual region around the cryogenic panels and shields which holds for higher throughputs is calculated using this generic approach. This means that the test particle Monte Carlo simulations in free molecular flow can be used not only for the optimization of the pumping system but also for the supply of the input parameters necessary for the future direct simulation Monte Carlo in the full flow regime.

Luo Xueli; Day, Christian; Haas, Horst; Varoutis, Stylianos [Karlsruhe Institute of Technology, Institute for Technical Physics, 76021 Karlsruhe (Germany)

2011-07-15T23:59:59.000Z

184

Numerical calculation of AC substation grounding systems buried in a vertical multilayered earth model by higher-order basis function  

Science Journals Connector (OSTI)

To study the accuracy of numerical simulations for an AC substation grounding problem embedded in a vertical multilayered earth model, this paper proposes a novel algorithm combining the rapidly convergent one-dimensional Galerkin's BEM with higher-order ... Keywords: Green's function, high-order basic function, vertical multilayered earth model

Zhong-Xin Li; Jian-Bin Fan; Yu Yin

2012-05-01T23:59:59.000Z

185

Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model  

E-Print Network (OSTI)

Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model in the coplanar orbit transfer problem M. Cerf1, T. Haberkorn, SADCO 2011, March 2nd M. Cerf, T. Haberkorn, E. Tr´elat Continuation from a flat to a round Earth model

Boyer, Edmond

186

Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 episodic events in southern Lake  

E-Print Network (OSTI)

Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 2006; published 17 February 2007. [1] A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied

187

Size-velocity correlations in high order moment methods for polydisperse evaporating sprays: modelling and numerical issues  

E-Print Network (OSTI)

, such as internal combustion engine ([1, 2] and references therein), gas turbine [3] or rocket booster [4]. Those developed the Eulerian Multi-Size Moment model (EMSM) which tackles the modelling and the numerical aspects of the disperse phase. The full strategy is evaluated in 1D and 2D cases and shows the ability of the CSVM and its

Paris-Sud XI, Université de

188

Coastal numerical modelling of tides: Sensitivity to domain size and remotely generated internal tide  

Science Journals Connector (OSTI)

The propagation of remotely generated superinertial internal tides constitutes a difficulty for the modelling of regional ocean tidal variability which we illustrate in several ways. First, the M2 tidal solution inside a control region located along the Southern California Bight coastline is monitored while the extent of the numerical domain is increased (up to 512 × 512  km). While the amplitude and phase of sea level averaged over the region is quasi-insensitive to domain size, a steady increase of kinetic energy, predominantly baroclinic, is observed with increasing domain size. The increasing flux of energy into the control region suggests that this trend is explained by the growing contribution from remote generation sites of internal tide which can propagate up to the control region. Increasing viscosities confirms this interpretation by lowering baroclinic energy levels and limiting their rate of increase with domain size. Doubling the grid spacing allows consideration of numerical domains 2 times larger. While the coarse grid has lower energy levels than the finer grid, the rate of energy increase with domain size appears to be slowing for the largest domain of the coarse grid simulations. Forcing the smallest domain with depth-varying tidal boundary conditions from the simulation in the largest domain produces energy levels inside the control region comparable to those in the control region for the largest domain, thereby confirming the feasibility of a nested approach. In contrast, simulations forced with a subinertial tidal constituent (K1) show that when the propagation of internal tide is limited, the control region kinetic energy is mostly barotropic and the magnitudes of variations of the kinetic energy with domain size are reduced.

Aurelien L. Ponte; Bruce D. Cornuelle

2013-01-01T23:59:59.000Z

189

Numerical modeling of air?to?sea transmission of light aircraft noise  

Science Journals Connector (OSTI)

Recent experiments at SIO have shown that the acoustic signature of a light aircraft can be detected by sensors in the water column as well as buried in the underlying sediment and a method for extracting the sound speed and attenuation from this Doppler shifted signal has been proposed. To test the accuracy of this geoacoustic inversion technique a numerical model of the air?water?sediment acoustic propagation including the effects of a high?speed airborne source has been developed based on the spectral method. Simulated acoustic data have been generated representing an aircraft flying over a microphone in the atmosphere a vertical line array in the ocean and a hydrophone buried 1?m deep in the sediment. The results of the geoacoustic inversion for sound speed and attenuation are compared to the known input parameter values of the model giving a sense of the relative errors that may be expected when applying the technique to experimental data. [Work supported by ONR.

2003-01-01T23:59:59.000Z

190

Numerical Modeling of Geomechanical Processes Related to CO{sub 2} Injection within Generic Reservoirs  

SciTech Connect

In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ?P{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ?P{sub c} magnitudes, especially for the compressional stress regime.

Eckert, Andreas

2013-05-31T23:59:59.000Z

191

Modelling and simulation of faults in synchronous generators for robust numerical protection  

Science Journals Connector (OSTI)

When an internal fault occurs in a synchronous generator, the symmetry between the parallel paths of the winding is broken and different currents flow in them, due to unsymmetrical magnetic linkage between the stator windings. The aim of this paper is to present a simulation model to investigate the effect of internal fault on the parallel path currents of a large synchronous generator using direct phase quantities. This model is based on a modified winding function approach where the machine inductances are calculated directly from the machine winding distribution using machine electrical parameters instead of the geometrical ones. The simulation results for different cases of internal faults in salient-pole and non-salient-pole synchronous machines have been obtained. Salient-pole synchronous generator has wave winding distribution while the non-salient-pole generator has lap winding arrangement. Due to different stator winding arrangements, the two machines have been simulated individually. By using the simulated fault data, a suitable numerical protection scheme for synchronous generators can be developed.

Amrita Sinha; D.N. Vishwakarma; R.K. Srivastava

2012-01-01T23:59:59.000Z

192

Three-dimensional numerical modeling of thermohaline and wind-driven circulations in the Persian Gulf  

Science Journals Connector (OSTI)

The Persian Gulf circulation is investigated with respect to the relevant forcing mechanism including wind stress and thermohaline surface fluxes by using a three-dimensional numerical hydrodynamic model. The model results show a correlation between the strength of the bottom layer outflow of the Persian Gulf and that of the Indian Ocean Surface Water (IOSW) inflow into the Gulf. The inflow of IOSW into the Gulf attain maximum values in May–June in conjunction with peak bottom outflow through the Hormuz Strait. The results of sensitivity experiment indicate that circulation is dominated by thermohaline flows at almost all parts of the Gulf. The heat fluxes play an essential role on the general circulation of the Persian Gulf. In spring and summer, the wind stress generates southeast-flowing surface currents of magnitude about 5 cm/s along the Saudi Arabia and Iranian coasts on the northern Gulf. In winter and autumn, due to weak static stability, the wind produces mesoscale eddies in most parts of the Gulf. In winter and spring the wind stress acts to reinforce the thermohaline circulation of deep outflow. Conversely, in summer and autumn the wind forcing acts in opposition to the thermohaline forcing and causes a bottom inflow from Oman Sea into the Gulf.

F. Hosseinibalam; S. Hassanzadeh; A. Rezaei-Latifi

2011-01-01T23:59:59.000Z

193

Theory and modeling of active brazing.  

SciTech Connect

Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.

van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.

2013-09-01T23:59:59.000Z

194

IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS  

E-Print Network (OSTI)

1 IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS Jacek Makinia*, Scott A in a full-scale activated sludge reactor. The Activated Sludge Model No. 1 was used to describe for dissolved oxygen. KEYWORDS Activated sludge; dispersion; dissolved oxygen dynamics; mass transfer

Wells, Scott A.

195

Numerical modeling of two-phase behavior in the PEFC gas diffusion layer  

SciTech Connect

A critical performance limitation in the polymer electrolye fuel cell (PEFC) is attributed to the mass transport loss originating from suboptimal liquid water transport and flooding phenomena. Liquid water can block the porous pathways in the fibrous gas diffusion layer (GDL) and the catalyst layer (CL), thus hindering oxygen transport from the flow field to the electrochemically actives sites in the catalyst layer. In this paper, the study of the two phase behavior and the durability implications due to the wetting characteristics in the carbon paper GDL are presented using a pore-scale modeling framework.

Mukherjee, Partha Pa223876 [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rod L [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

196

Numerical Modeling of the Stability of Face-Centered Cubic Metals with High Vacancy Concentration  

SciTech Connect

The objective of this research is to assess the possibility of forming an atomically porous structure in a low-density metal, e.g., Al with vacancies up to 0.20/lattice site; and to examine the effects of hydrogen and vacancy concentration on the stability of an atomically porous structure that has been experimentally produced in nickel. The approach involves numerical modeling using the Embedded-Atom Method (EAM). High vacancy concentrations cause the Al lattice to disorder at 300K. In contrast, Ni retains the face-centered-cubic structure at 300K for vacancy concentrations up to 0.15 Vac/lattice site. Unexpectedly, the lattice with 0.15 Vac/lattice site is more stable than the lattice with 0.10 or 0.20 Vac/lattice site. The Ni systems with 0.10 and 0.15 Vac/lattice site exhibit domains consisting of uniform lattice rotations. The Ni lattice with 0.15 Vac/lattice site is more stable with an initial distribution of random vacancies compared to ordered vacancies. The equilibrium lattice structures of Ni a d Al containing vacancies and H are less ordered to structures with vacancies only at 300K.

Brian P. Somerday; M. I. Baskes

1998-12-01T23:59:59.000Z

197

Numerical modeling of deep groundwater flow and heat transport in the Williston Basin  

SciTech Connect

A numerical modeling approach has been used to evaluate quantitatively the effects of fluid flow on contemporary heat flow in an intracratonic basin. The authors have selected the Williston basin for this hydrodynamic study because of the opportunity it presents to assess the relation of deep groundwater flow to basin geothermics and the associated features of diagenesis and petroleum accumulation. The finite element method is used to solve the coupled equations of fluid flow and heat transport in two-dimensional sections of the basin. Both the fluid- and heat-flow regime are assumed to be at steady state, and the fluid flow is driven primarily by the water-table relief which is taken to be a subdued replica of land-surface topography. Buoyancy forces may also affect flow through fluid density gradients created by temperature and salinity effects. Three southwest-northwest oriented sections across the basin were modeled using available and estimated parameter data. The predicted flow patterns are most strongly affected by the topography, but the Devonian salt unit and Cretaceous shale unit exert some control. Cross-formational flow is especially important near the downdip, solution edge of the salt beds. Flow rates rarely exceed 0.5 m/year in the deep-central part of the basin, yet there does exist a marked effect on heat flow, albeit subdued by the blanket effect of the low-permeability Cretaceous shales. The regional effect of the topography-driven flow system is reflected in present-day salinity patterns and heat-flow data.

Garven, G.; Vigrass, L.

1985-01-01T23:59:59.000Z

198

Wind assessment in complex terrain with the numeric model Aiolos implementation of the influence of roughness changes and stability  

E-Print Network (OSTI)

Wind assessment in complex terrain with the numeric model Aiolos ­ implementation of the influence of roughness changes and stability Ulrich Focken, Detlef Heinemann, Hans-Peter Waldl Department of Energy (EWA) gives good results for the wind potential estimation in flat areas. But besides many

Heinemann, Detlev

199

Numerical modelling of erosion processes in the Himalayas of Nepal: effects of spatial variations of rock strength and precipitation  

E-Print Network (OSTI)

Numerical modelling of erosion processes in the Himalayas of Nepal: effects of spatial variations of the morphology of mountain belts. Here we investigate the modalities of defor- mation in Central Nepal on a c that the pattern of uplift in Nepal is mainly dependent on both erodability and fault geometry, rather than

Demouchy, Sylvie

200

A depth-averaged debris-flow model that includes the effects of evolving dilatancy. II. Numerical predictions and experimental tests  

Science Journals Connector (OSTI)

...Numerical predictions and experimental tests David L. George Richard M. Iverson e-mail...software package we call D-Claw. As tests of D-Claw, we compare model output with...our numerical solution technique, and tests of numerical predictions against experimental...

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

EnKF Assimilation of High-Resolution, Mobile Doppler Radar Data of the 4 May 2007 Greensburg, Kansas, Supercell into a Numerical Cloud Model  

E-Print Network (OSTI)

Kalman filter (EnKF) technique into a non- hydrostatic, compressible numerical weather prediction model weather prediction (NWP) models to improve under- standing of convective storm dynamics is now a fairly, Kansas, Supercell into a Numerical Cloud Model ROBIN L. TANAMACHI,*,1,# LOUIS J. WICKER,@ DAVID C. DOWELL

Xue, Ming

202

Proceedings of the Workshop on Numerical Modeling of Thermohydrological Flow in Fractured Rock Masses, Feb. 19-20, 1980, Berkeley, CA  

E-Print Network (OSTI)

Mathematical modeling of thermal energy storage in aquifers:presented at the Thermal Energy storage in aquifers1979; Aquifer thermal energy storage—a numerical simulation

Witherspoon, P.A.

2010-01-01T23:59:59.000Z

203

Numerical Experiments on Soft X-ray Emission Optimization of Nitrogen Plasma in 3 kJ Plasma Focus SY-1 Using Modified Lee Model  

Science Journals Connector (OSTI)

The X-ray emission properties of nitrogen plasmas are numerically investigated using corona plasma equilibrium model. The X-ray emission intensities... ? , Ly ?

M. Akel; Sh. Al-Hawat; S. Lee

2009-12-01T23:59:59.000Z

204

A Numerical Model Without Truncation Error for a Steady-State Analysis of a Once-Through Steam Generator  

SciTech Connect

To overcome the drawbacks of conventional schemes for a numerical analysis of a steam generator (SG), an efficient numerical model has been developed to analyze the steady state of a once-through-type SG where the feedwater is heated to superheated steam. In the developed model, the temperature and enthalpy are defined at the boundary of a calculation cell, and the exact solutions for the temperature distribution in a calculation cell are utilized. This feature of the developed model frees calculation from the undesirable effects of numerical diffusion, and only a small number of nodes are required. Also, the developed model removes the ambiguity from the parameter values at the inlet and exit of a calculation.The BoSupSG-SS computer code was developed by using the analysis model, and it performed well with only three calculation nodes to analyze a superheated SG. The developed model can be effectively used for the cases where a fast one-dimensional calculation is required such as an SG or system design analysis.

Sim, Yoon Sub; Kim, Eui Kwang; Eoh, Jae Hyuk [Korea Atomic Energy Research Institute (Korea, Republic of)

2005-06-15T23:59:59.000Z

205

Numerical Modeling of the Distributed Electrochemistry and Performance of Solid Oxide Fuel Cells  

SciTech Connect

A cell-level distributed electrochemistry (DEC) modeling tool has been developed to enable prediction of solid oxide fuel cell performance by considering the coupled and spatially varying multi-physics that occur within the tri-layer. The approach calculates the distributed electrochemistry within the electrodes, which includes the charge transfer and electric potential fields, ion transport throughout the tri-layer, and gas distributions within the composite and porous electrodes. The thickness of the electrochemically active regions within the electrodes is calculated along with the distributions of charge transfer. The DEC modeling tool can examine the overall SOFC performance based on electrode microstructural parameters, such as particle size, pore size, porosity factor, electrolyte and electrode phase volume fractions, and triple-phase-boundary length. Recent developments in electrode fabrication methods have lead to increased interest in using graded and nano-structured electrodes to improve the electrochemical performance of SOFCs. This paper demonstrates how the DEC modeling tool can be used to help design novel electrode microstructures by optimizing a graded anode for high electrochemical performance.

Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

2011-12-01T23:59:59.000Z

206

Numerical modeling of combustion processes and pollutant formations in direct-injection diesel engines  

Science Journals Connector (OSTI)

The Representative Interactive Flamelet (RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the direct injection...X formation including thermal NO path, pro...

Seong-Ku Kim; Joon Kyu Lee; Yong-Mo Kim; Jae-Hyun Ahn

2002-07-01T23:59:59.000Z

207

Using GIS and numerical modeling to assess subsidence over abandoned mines  

SciTech Connect

The US Bureau of Mines (USBM) has been developing techniques to assess surface subsidence over abandoned coal mines. One technique has involved estimation of stress acting on every pillar of an abandoned mine then comparing it to pillar strength and floor bearing capacity. This required computations for several thousand pillars for one mine. Mine maps are digitized and saved as a computer drawing file. Then the tributary area loading each pillar was determined graphically and outlined. Geographic Information System (GIS) software was used to compute the ratio of pillar area to tributary area for each pillar and then divide the average overburden stress by this ratio to compute an estimated pillar stress. Numerical modeling was then used to analyze a two-dimensional cross section of the overburden and mine, and provide an independent estimate of stresses. Based on published data for floor bearing capacity and pillar load capacity, GIS was used to perform a mine-wide classification of pillars according to stress level. An example of this analysis and classification is presented in this paper for an abandoned coal mine in the Illinois Basin. The mine had been operated in the Herrin No. 6 Seam at a depth of 60 in with an average overburden stress of 1.4 MPa. It was found that pillars with estimated stresses greater than 5 MPa correlated with historical subsidence events. Due to the greater detail considered in this approach, it provides a fundamental basis for the assessment of subsidence risk since it incorporates the geometry of mine pillars and entries as well as the ultimate strength of the pillars and floor.

O`Connor, K.M. [GeoTDR, Inc., Apple Valley, MN (United States); Siekmeier, J.A. [Braun Intertec Corp., Minneapolis, MN (United States); Stache, J.

1996-12-31T23:59:59.000Z

208

A numerical model of non-equilibrium thermal plasmas. I. Transport properties  

SciTech Connect

A self-consistent and complete numerical model for investigating the fundamental processes in a non-equilibrium thermal plasma system consists of the governing equations and the corresponding physical properties of the plasmas. In this paper, a new kinetic theory of the transport properties of two-temperature (2-T) plasmas, based on the solution of the Boltzmann equation using a modified Chapman-Enskog method, is presented. This work is motivated by the large discrepancies between the theories for the calculation of the transport properties of 2-T plasmas proposed by different authors in previous publications. In the present paper, the coupling between electrons and heavy species is taken into account, but reasonable simplifications are adopted, based on the physical fact that m{sub e}/m{sub h} Much-Less-Than 1, where m{sub e} and m{sub h} are, respectively, the masses of electrons and heavy species. A new set of formulas for the transport coefficients of 2-T plasmas is obtained. The new theory has important physical and practical advantages over previous approaches. In particular, the diffusion coefficients are complete and satisfy the mass conversation law due to the consideration of the coupling between electrons and heavy species. Moreover, this essential requirement is satisfied without increasing the complexity of the transport coefficient formulas. Expressions for the 2-T combined diffusion coefficients are obtained. The expressions for the transport coefficients can be reduced to the corresponding well-established expressions for plasmas in local thermodynamic equilibrium for the case in which the electron and heavy-species temperatures are equal.

Zhang XiaoNing; Xia WeiDong [Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Li HePing [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Murphy, Anthony B. [CSIRO Materials Science and Engineering, PO Box 218, Lindfield NSW 2070 (Australia)

2013-03-15T23:59:59.000Z

209

A numerical model of convective heat transfer in a three dimensional channel with baffles  

E-Print Network (OSTI)

to minimize the effects of the temperature. Chandrupatla and Sastri (1977) used a finite difference method to study laminar heat transfer and fluid flow for Non-Newtonian fluids. In the limiting case of Newtonian fluids their results showed good agreement... and Sastri (1977) for developing laminar flow in a rectangular smooth channel. Figure 4. 1 shows the numerically predicted centerline axial velocity compared with the experimental data of Goldstein and Kreid (1967). The agreement between the numerical...

Lopez Buso, Jorge Ricardo

2012-06-07T23:59:59.000Z

210

Sensitivity of Optimal Operation of an Activated Sludge Process Model  

E-Print Network (OSTI)

Sensitivity of Optimal Operation of an Activated Sludge Process Model Antonio Araujo, Simone sensitivity analysis of optimal operation conducted on an activated sludge process model based on the test.[7] applied a systematic procedure for control structure design of an activated sludge process

Skogestad, Sigurd

211

Numerical modeling of the transient behavior of a thermoelectric Electromagnetic Self-Induced Pump  

E-Print Network (OSTI)

. IMPROVED PUMP MODELS Momentum model theory Transient thermoelectric model theory CHAPTER IV MODELING METHODS AND RESULTS Lumped parameter model Hydraulic model Page ln tv v11 v111 14 18 21 24 29 29 . " 41 41 43 Thermoelectric model Full... " " " " " 17 Magnetic core structure 20 Momentum model component assembly illustration 32 10 Illustration of the effects that act on the thermoelectric elements " """" 37 12 Lumped parameter model flow chart Hydraulic model flow chart 42 44 13 Flow...

Djordjevic, Vladimir

2012-06-07T23:59:59.000Z

212

Modeling and Optimizing Ergonomic Activities in Automobile Product Development  

E-Print Network (OSTI)

Modeling and Optimizing Ergonomic Activities in Automobile Product Development João Ferreira Anna.silva@acm.org Abstract We collect ergonomic rules and normative rules considerations for automobile business and modeled these activities with a special UML language created for automobile business, VDML (Vehicle Development Modeling

da Silva, Alberto Rodrigues

213

Activity Stream - Brazil Direct Normal Solar Radiation Model...  

Open Energy Info (EERE)

Dataset Activity Stream Activity Stream Jay Huggins updated the dataset Brazil Direct Normal Solar Radiation Model (10km) from INPE and LABSOLAR 6 days ago Jay Huggins added the...

214

Numerical simulation of fluid flow and heat transfer inside a rotating disk-cylinder configuration by a lattice Boltzmann model  

Science Journals Connector (OSTI)

A simple lattice Boltzmann model for numerical simulation of fluid flow and heat transfer inside a rotating disk-cylinder configuration, which is of fundamental interest and practical importance in science as well as in engineering, is proposed in this paper. Unlike existing lattice Boltzmann models for such flows, which were based on “primitive-variable” Navier-Stokes equations, the target macroscopic equations of the present model for the flow field are vorticity–stream function equations, inspired by our recent work designed for nonrotating flows [S. Chen, J. Tölke, and M. Krafczyk, Phys. Rev. E 79, 016704 (2009); S. Chen, J. Tölke, S. Geller, and M. Krafczyk, Phys. Rev. E 78, 046703 (2008)]. The flow field and the temperature field both are solved by the D2Q5 model. Compared with the previous models, the present model is more efficient, more stable, and much simpler. It was found that, even though with a relatively low grid resolution, the present model can still work well when the Grashof number is very high. The advantages of the present model are validated by numerical experiments.

Sheng Chen; Jonas Tölke; Manfred Krafczyk

2009-07-14T23:59:59.000Z

215

Physical modeling and numerical simulation of subcooled boiling in one- and three-dimensional representation of bundle geometry  

SciTech Connect

Numerical simulation of subcooled boiling in one-dimensional geometry with the Homogeneous Equilibrium Model (HEM) may yield difficulties related to the very low sonic velocity associated with the HEM. These difficulties do not arise with subcritical flow. Possible solutions of the problem include introducing a relaxation of the vapor production rate. Three-dimensional simulations of subcooled boiling in bundle geometry typical of fast reactors can be performed by using two systems of conservation equations, one for the HEM and the other for a Separated Phases Model (SPM), with a smooth transition between the two models.

Bottoni, M.; Lyczkowski, R.; Ahuja, S.

1995-07-01T23:59:59.000Z

216

Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)  

SciTech Connect

Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

2014-06-01T23:59:59.000Z

217

PNNL Support of the DOE GTO Model Comparison Activity  

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

PNNL Support of the DOE GTO Model Comparison Activity presentation at the April 2013 peer review meeting held in Denver, Colorado.

218

NUMERICAL MODELING OF SPACE PLASMA FLOWS: ASTRONUM-2009 ASP Conference Series, Vol. 4xx, 2010  

E-Print Network (OSTI)

regions in the cold star forming molecular gas on scales from 50 pc down to a few astronomical units operating in the energy cascade in the inertial range of scales (e.g., Kritsuk et al. 2007a). The effective by numerical diffusivity of purely artificial nature. In simulations in- volving magnetic fields, the magnetic

Kritsuk, Alexei

219

Numerical model to determine the composition of H2ONaClCaCl2 fluid inclusions based on  

E-Print Network (OSTI)

Numerical model to determine the composition of H2O­NaCl­CaCl2 fluid inclusions based 2010 Abstract Natural fluids approximated by the H2O­NaCl­CaCl2 system are common in a wide range the compositions of fluid inclusions in the H2O­NaCl­CaCl2 sys- tem based on microthermometric and microanalytical

Bodnar, Robert J.

220

Advanced Numerical Weather Prediction Techniques for Solar Irradiance Forecasting : : Statistical, Data-Assimilation, and Ensemble Forecasting  

E-Print Network (OSTI)

Multiscale numerical weather prediction model. Progress inassimilating numerical weather prediction model for solarwith numerical weather prediction models. In: Solar Energy

Mathiesen, Patrick James

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Theory and numerical modeling of the accelerated expansion of laser-ablated materials near a solid surface  

Science Journals Connector (OSTI)

A self-similar theory and numerical hydrodynamic modeling is developed to investigate the effects of dynamic source and partial ionization on the acceleration of the unsteady expansion of laser-ablated material near a solid target surface. The dynamic source effect accelerates the expansion in the direction perpendicular to the target surface, while the dynamic partial ionization effect accelerates the expansion in all directions. The vaporized material during laser ablation provides a nonadiabatic dynamic source at the target surface into the unsteady expanding fluid. For studying the dynamic source effect, the self-similar theory begins with an assumed profile of plume velocity, u=v/vm=?+(1-?)?, where vm is the maximum expansion velocity, ? is a constant, and ?=x/vmt. The resultant profiles of plume density and plume temperature are derived. The relations obtained from the conservations of mass, momentum, and energy, respectively, all show that the maximum expansion velocity is inversely proportional to ?, where 1-? is the slope of plume velocity profile. The numerical hydrodynamic simulation is performed with the Rusanov method and the Newton Raphson method. The profiles and scalings obtained from numerical hydrodynamic modeling are in good agreement with the theory. The dynamic partial ionization requires ionization energy from the heat at the expansion front, and thus reduces the increase of front temperature. The reduction of thermal motion would increase the flow velocity to conserve the momentum. This dynamic partial ionization effect is studied with the numerical hydrodynamic simulation including the Saha equation. With these effects, ? is reduced from its value of conventional free expansion. This reduction on ? increases the flow velocity slope, decreases the flow velocity near the surface, and reduces the thermal motion of plume, such that the maximum expansion velocity is significantly increased over that found from conventional models. The result may provide an explanation for experimental observations of high-expansion front velocities even at low-laser fluence.

K. R. Chen; T. C. King; J. H. Hes; J. N. Leboeuf; D. B. Geohegan; R. F. Wood; A. A. Puretzky; J. M. Donato

1999-09-15T23:59:59.000Z

222

A three-dimensional numerical model of dry convection in an ambient wind field  

E-Print Network (OSTI)

effects of the ambient wind field on convection. Nost of the numerical results are shown to correspond to empirical observations, while some results are unexpected but reasonable. Nechanical and thermal energy equations have been developed... to investigate the effects on convection of an The citations on the following pages follow the tyl of th J* J of ~At * h ' f ambient wind with a vertical shear He also examined the energy interactions between convective flow and nean flows. There were many...

Burgeson, John Carl

2012-06-07T23:59:59.000Z

223

An Efficient Numerical Scheme for Simulating Unidirectional Irregular Waves Based on a Hybrid Wave Model  

E-Print Network (OSTI)

................................................................................ 40 Table 4 NREL 5-MW wind turbine characteristics ................................................ 41 Table 5 Hywind-OC3 Spar dimensions .................................................................. 41 Table 6 Mooring system properties...) for computing the wind loads on a wind turbine. A 5MW wind turbine installed on the top of a classical Spar (Hywind-OC3 Spar) is employed to demonstrate the simulation. The 39 numerical results derived in this study may provide crucial information...

Jia, Dongxing 1984-

2012-11-15T23:59:59.000Z

224

Numerical Modeling of Speckle Fields: Catching the Visible and the Invisible  

Science Journals Connector (OSTI)

The present paper deals with the numerical simulation of the diffracted field emanating from an optically rough surface illuminated by a spatially coherent white?light source. The colored speckle pattern which can be observed under these circumstances visualizes the 3D structure of the diffracted speckle field and what’s more it allows us appreciate the differences between diffraction regimes i.e. Fresnel rather than Fraunhofer regime. In the paper the 3D structure of near? and far?field diffraction fully developed speckle fields will be explored by numerical simulation in the Mathematica™ environment by using few highly?optimized functions implementing the Rayleigh?Sommerfeld formulation into the built?in FFT (Fast Fourier Transform) algorithm. In the applicability range of the Fresnel approximation the dimensionless Fresnel number fully describes the diffraction regime and the results of the numerical simulation can be simply mapped into the physical world by the appropriate scaling parameters at diffraction plane and along the propagation direction.

Andrea Poggialini; Luigi Bruno

2010-01-01T23:59:59.000Z

225

Mathematical formulation and numerical modeling of wax deposition in pipelines from enthalpy–porosity approach and irreversible thermodynamics  

Science Journals Connector (OSTI)

In the last 10 years, there have been a number of studies in modeling of the deposition processes in flowlines. Most of these models: (1) assume empirical or semi-empirical correlations to predict the pressure drop and temperature profile, (2) ignore the radial convection flow in the layer composed of the two-phase wax and oil (that is the gel layer), and (3) use Fick’s law to describe the diffusion flux of species towards the wall by using the chain rule to relate concentration gradient to temperature gradient. In this work, a rigorous mathematical model for the prediction of wax deposition in pipelines is presented for laminar flow. The transient deposition of each component is calculated from the solution of the coupled momentum, energy and, species balance equations, and a thermodynamic wax precipitation model at the local level. An enthalpy formulation based on a fixed-grid approach is used to approximate the convection flow in the gel layer. We do not use the chain rule to relate composition gradient to temperature gradient in Fick’s law to avoid violating the laws of irreversible thermodynamics. Our diffusion flux expression includes molecular diffusion (concentration gradient is driving force) and thermal diffusion (temperature gradient is driving force) with appropriate diffusion coefficients. This work also includes the description of the numerical solution of the governing equations. Numerical results and features of wax deposition as well as model verification with experimental data are presented in a separate paper.

R. Banki; H. Hoteit; A. Firoozabadi

2008-01-01T23:59:59.000Z

226

Adjoint Sensitivity Analysis for Numerical Weather Prediction  

E-Print Network (OSTI)

Sep 2, 2011 ... Adjoint Sensitivity Analysis for Numerical Weather Prediction: Applications to ... weather variables using numerical weather prediction models.

Alexandru Cioaca

2011-09-02T23:59:59.000Z

227

EMEP Intercomparison Study of Numerical Models for Long-Range Atmospheric Transport of Mercury  

E-Print Network (OSTI)

............................... Denmark...NERI G. Petersen, R. Ebinghaus .................. Germany...GKSS J. Pacyna and Oxidants Model, GKSS Research Center, GermanyADOM MSC-E heavy metal regional model, EMEP MSC

228

Simulation of a Polar Low Case in the North Atlantic with different regional numerical models  

E-Print Network (OSTI)

Matthias Zahn, Hans von Storch University of Hamburg/ GKSS, Matthias.Zahn@gkss.de ABSTRACT In this paper (REgional MOdel) and CLM (CLimate Model) simulations performed at the GKSS with spectral nudging (Feser et

Zahn, Matthias

229

Initial Testing of a Numerical Ocean Circulation Model Using a Hybrid (Quasi-Isopycnic) Vertical Coordinate  

Science Journals Connector (OSTI)

An ocean circulation model, developed for the study of mesoscale to gyre-scale circulation and heat transport, is described and tested. The model employs density as vertical coordinate except in the immediate vicinity of possible coordinate ...

Rainer Bleck; Douglas B. Boudra

1981-06-01T23:59:59.000Z

230

A Blended Soundproof-to-Compressible Numerical Model for Small- to Mesoscale Atmospheric Dynamics  

Science Journals Connector (OSTI)

A blended model for atmospheric flow simulations is introduced that enables seamless transition from fully compressible to pseudo-incompressible dynamics. The model equations are written in nonperturbation form and integrated using a well-balanced ...

Tommaso Benacchio; Warren P. O’Neill; Rupert Klein

2014-12-01T23:59:59.000Z

231

Numerical Modeling At Neal Hot Springs Geothermal Area (U.S....  

Open Energy Info (EERE)

model was created. The model was created on March 24th 2011 by a consulting reservoir engineer and presented to the DOE's independent reservoir engineer. Upon review the final...

232

THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES  

E-Print Network (OSTI)

improving production by hydraulic fracturing 8 the focus otfor fractures. (d) Hydraulic Fracturing: The model has been

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

233

THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES  

E-Print Network (OSTI)

geothermal reservoir and wellbore model was used in the history-matching simulations for test wells in Cerro Prieto, Mexico,

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

234

Time-dependent restricted-active-space self-consistent-field theory for laser-driven many-electron dynamics. II. Extended formulation and numerical analysis  

E-Print Network (OSTI)

The time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method is formulated based on the TD variational principle. In analogy with the configuration-interaction singles (CIS), singles-and-doubles (CISD), singles-doubles-and-triples (CISDT) methods in quantum chemistry, the TD-RASSCF-S, -SD, and -SDT methods are introduced as extensions of the TD-RASSCF dou- bles (-D) method [Phys. Rev. A 87, 062511 (2013)]. Based on an analysis of the numerical cost and test calculations for one-dimensional (1D) models of atomic helium, beryllium, and carbon, it is shown that the TD-RASSCF-S and -D methods are computationally feasible for systems with many electrons and more accurate than the TD Hartree-Fock (TDHF) and TDCIS methods. In addition to the discussion of methodology, an analysis of electron dynamics in the high-order harmonic generation (HHG) process is presented. For the 1D beryllium atom, a state-resolved analysis of the HHG spectrum based on the time-independent HF orbitals shows that while only single-orbital excitations are needed in the region below the cutoff, single- and double-orbital excitations are es- sential beyond, where accordingly the single-active-electron (SAE) approximation and the TDCIS method break down. On the other hand, the TD-RASSCF-S and -D methods accurately describe the multi-orbital excitation processes throughout the entire region of the HHG spectrum. For the 1D carbon atom, our calculations show that multi-orbital excitations are essential in the HHG process even below the cutoff. Hence, in this test system a very accurate treatment of electron correlation is required. The TD-RASSCF-S and -D approaches meet this demand, while the SAE approximation and the TDCIS method are inadequate.

Haruhide Miyagi; Lars Bojer Madsen

2014-05-21T23:59:59.000Z

235

Numerical Modeling of Nonlinear Coupling between Lines/Beams with Multiple Floating Bodies  

E-Print Network (OSTI)

spring model and the three(3) dimensional FE beam model. The coupling of the TLP motion with the reaction force at the tie-down clamp is considered by using exact nonlinear dynamic equations of the motion with the reaction forces modeled with the spring...

Yang, Chan K.

2010-07-14T23:59:59.000Z

236

NUMERICAL EXPERIMENTS USING MESONH/FOREFIRE COUPLED ATMOSPHERIC-FIRE MODEL  

E-Print Network (OSTI)

model inputting the wind fields and outputting heat and vapour fluxes to the atmospheric model. Fore mesh. Another originality of the approach is the fire rate of spread model that integrates wind effect of has been developed to add locale atmosphere interaction to the family of fire area simulators

Boyer, Edmond

237

Atmospheric transmittance model for photosynthetically active radiation  

SciTech Connect

A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)

2013-11-13T23:59:59.000Z

238

Evaluation of the numerical stability and sensitivity to material parameter variations for several unified constitutive models  

E-Print Network (OSTI)

Material Constants Used In Bodner's Model For Hastelloy-X at 1800' F . Naterial Constants Used In Walker's Model For Hastelloy-X at 1800' F . Material Constants Used In Krieg's Model For Hastelloy-X at 1800 F . Material Constants Used In Miller...'s Model For Hastelloy-X at 1800' F . Page 18 26 30 35 LIST OF FIGURES Fi gure Plots Used to Obtain Material Parameters For Bodner's Model . Page T6 Back Stress and True Stress-Strain Curve Used in Walker's Theory. Plot Used to Determine...

Imbrie, Peter Kenneth

1985-01-01T23:59:59.000Z

239

Learning Active Basis Model for Object Detection and Recognition  

Science Journals Connector (OSTI)

This article proposes an active basis model, a shared sketch algorithm, and a computational architecture of sum-max maps for representing, learning, and recognizing deformable templates. In our generative model, a deformable template is in the form of ... Keywords: Deformable template, Generative model, Shared sketch algorithm, Sum maps and max maps, Wavelet sparse coding

Ying Nian Wu; Zhangzhang Si; Haifeng Gong; Song-Chun Zhu

2010-11-01T23:59:59.000Z

240

Evaluation of models for numerical simulation of the non-neutral region of sheath plasma  

SciTech Connect

Four different electron models are used to simulate the nonequilibrium plasma flow around a representative cylindrical Faraday probe geometry. Each model is implemented in a two-dimensional axisymmetric hybrid electron fluid and particle in cell method. The geometric shadowing model is derived from kinetic theory on the basis that physical obstruction of part of the velocity distribution leads to many of the expected sheath features. The Boltzmann electron fluid model relates the electron density to the plasma potential through the Boltzmann relation. The non-neutral detailed electron fluid model is derived from the electron conservation equations under the assumption of neutrality, and then modified to include non-neutral effects through the electrostatic Poisson equation. The Poisson-consistent detailed electron fluid model is also derived from the conservation equations and the electrostatic Poisson equation, but uses an alternative method that is inherently non-neutral from the outset. Simulations using the geometric shadowing and non-neutral detailed models do not yield satisfactory sheath structures, indicating that these models are not appropriate for sheath simulations. Simulations using the Boltzmann and Poisson-consistent models produce sheath structures that are in excellent agreement with the planar Bohm sheath solution near the centerline of the probe. The computational time requirement for the Poisson-consistent model is much higher than for the Boltzmann model and becomes prohibitive for larger domains.

Boerner, Jeremiah J.; Boyd, Iain D. [Department of Aerospace Engineering, University of Michigan, Ann Arbor, FXB Building, 1320 Beal Avenue, Ann Arbor, Michigan 48109 (United States)

2009-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical modelling of ground water flow using MODFLOW, Indian Journal of Science, 2013, 2(4), 86-92, www.discovery.org.in  

E-Print Network (OSTI)

management approaches. However, there should be no expectation of a single `true' model, and model outputsRESEARCH Kumar, Numerical modelling of ground water flow using MODFLOW, Indian Journal of Science management or impact of new development scenarios. However, if the modelling studies are not well designed

Kumar, C.P.

242

E-Print Network 3.0 - activated sludge model Sample Search Results  

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

model Search Powered by Explorit Topic List Advanced Search Sample search results for: activated sludge model...

243

E-Print Network 3.0 - activated sludge models Sample Search Results  

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

models Search Powered by Explorit Topic List Advanced Search Sample search results for: activated sludge models...

244

AMPS, a real-time mesoscale modeling system, has provided a decade of service for scientific and logistical needs and has helped advance polar numerical weather prediction  

E-Print Network (OSTI)

and logistical needs and has helped advance polar numerical weather prediction as well as understanding support for the USAP. The concern at the time was the numerical weather prediction (NWP) guidance-time implementation of the Weather Research and Forecasting model (WRF; Skamarock et al. 2008) to support the U

Howat, Ian M.

245

A GIS tool for the evaluation of the precipitation forecasts of a numerical weather prediction model using satellite data  

Science Journals Connector (OSTI)

In this study, the possibility of implementing Geographic Information Systems (GIS) for developing an integrated and automatic operational system for the real-time evaluation of the precipitation forecasts of the numerical weather prediction model BOLAM (BOlogna Limited Area Model) in Greece, is examined. In fact, the precipitation estimates derived by an infrared satellite technique are used for real-time qualitative and quantitative verification of the precipitation forecasts of the model BOLAM through the use of a GIS tool named as precipitation forecasts evaluator (PFE). The application of the developed tool in a case associated with intense precipitation in Greece, suggested that PFE could be a very important support tool for nowcasting and very short-range forecasting of such events.

Haralambos Feidas; Themistoklis Kontos; Nikolaos Soulakellis; Konstantinos Lagouvardos

2007-01-01T23:59:59.000Z

246

Kinetics of intrachain reactions of supercoiled DNA: Theory and numerical modeling  

E-Print Network (OSTI)

. Klenin and Jo¨rg Langowskia) Division Biophysics of Macromolecules, German Cancer Research Center, Im analytical approach has yet been found. It is clear that the rate of a very slow reaction is deter- mined that the activity

Langowski, Jörg

247

Generation of baroclinic tide energy in a global three-dimensional numerical model with different spatial grid resolutions  

Science Journals Connector (OSTI)

Abstract We examine the global distribution of energy conversion rates from barotropic to baroclinic tides using a hydrostatic sigma-coordinate numerical model with a special attention to the dependence on the model grid resolution as well as the model topography resolution. A series of numerical experiments shows that the baroclinic tidal energy conversion rate increases almost exponentially with the decrease of the horizontal grid spacing, namely, from 1/5° to 1/20°. The baroclinic tidal energy conversion rates for the semidiurnal tidal constituents (M2, S2) are more sensitive to the horizontal grid spacing than those for the diurnal tidal constituents (K1, O1), reflecting the difference of their horizontal wavelengths. The sensitivity of the baroclinic tidal energy conversion rate to the horizontal grid spacing is also dependent on the generation sites of baroclinic tides; it becomes very sensitive in the regions characterized by geologically young seafloor having numerous small-scale rough topographic features such as the Mid-Atlantic Ridges, the eastern Pacific Ridges, and the Mid-Indian Ocean Ridges, whereas it is less sensitive in the regions such as the Indonesian Archipelago, and the western Pacific Ocean. The difference of the sensitivity can be best explained in terms of the value of the forcing function that is proportional to the square of the vertical velocity caused by barotropic tidal currents interacting with high-pass filtered bottom topography. Using the extrapolated value of the forcing function that takes into account all the topographic features generating baroclinic tides, we present the global distribution of the baroclinic tidal energy conversion rates in the limit of zero horizontal grid spacing.

Yoshihiro Niwa; Toshiyuki Hibiya

2014-01-01T23:59:59.000Z

248

Coalescing neutron stars - a step towards physical models III. Improved numerics and different neutron star masses and spins  

E-Print Network (OSTI)

(Abridged) In this paper we present a compilation of results from our most advanced neutron star merger simulations, including a description of the employed numerical procedures and a more complete overview over a large number of computed models. The three-dimensional hydrodynamic simulations were done with a code based on the Piecewise Parabolic Method with up to five levels of nested Cartesian grids. The simulations are basically Newtonian, but gravitational-wave emission and the corresponding back-reaction are taken into account. The use of a physical nuclear equation of state allows us to follow the thermodynamic history of the stellar medium and to compute the energy and lepton number loss due to the emission of neutrinos. The computed models differ concerning the neutron star masses and mass ratios, the neutron star spins, the numerical resolution expressed by the cell size of the finest grid and the number of grid levels, and the calculation of the temperature from the solution of the entropy equation instead of the energy equation. Our simulations show that the details of the gravitational-wave emission are still sensitive to the numerical resolution, even in our highest-quality calculations. The amount of mass which can be ejected from neutron star mergers depends strongly on the angular momentum of the system. Our results do not support the initial conditions of temperature and proton-to-nucleon ratio assumed in recent work for producing a solar r-process pattern for nuclei around and above the A approx 130 peak. The improved models confirm our previous conclusion that gamma-ray bursts are not powered by neutrino emission during the dynamical phase of the merging of two neutron stars.

M. Ruffert; H. -Th. Janka

2001-06-13T23:59:59.000Z

249

THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES  

E-Print Network (OSTI)

Doughty, 1979a, Aquifer thermal energy storage--a numericalical modeling of thermal energy storage in aquifers.Presented at the Thermal Energy Storage in Aquifers

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

250

Analysis of vadose zone tritium transport from an underground storage tank release using numerical modeling and geostatistics  

SciTech Connect

Numerical and geostatistical analyses show that the artificial smoothing effect of kriging removes high permeability flow paths from hydrogeologic data sets, reducing simulated contaminant transport rates in heterogeneous vadose zone systems. therefore, kriging alone is not recommended for estimating the spatial distribution of soil hydraulic properties for contaminant transport analysis at vadose zone sites. Vadose zone transport if modeled more effectively by combining kriging with stochastic simulation to better represent the high degree of spatial variability usually found in the hydraulic properties of field soils. However, kriging is a viable technique for estimating the initial mass distribution of contaminants in the subsurface.

Lee, K.H.

1997-09-01T23:59:59.000Z

251

Numerical modeling of quasitransient backward Raman amplification of laser pulses in moderately undercritical plasmas with multicharged ions  

SciTech Connect

It was proposed recently that powerful optical laser pulses could be efficiently compressed through backward Raman amplification in ionized low density solids, in spite of strong damping of the resonant Langmuir wave. It was argued that, even for nonsaturated Landau damping of the Langmuir wave, the energy transfer from the pump laser pulse to the amplified seed laser pulse can nevertheless be highly efficient. This work numerically examines such regimes of strong damping, called quasitransient regimes, within the simplest model that takes into account the major effects. The simulations indicate that compression of powerful optical laser pulses in ionized low density solids indeed can be highly efficient.

Balakin, A. A.; Fraiman, G. M. [Institute of Applied Physics RAS, Nizhnii Novgorod 603950 (Russian Federation); Fisch, N. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540 (United States); Malkin, V. M. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540 (United States); Toroker, Z. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2011-10-15T23:59:59.000Z

252

Establishment of Stress-Permeabilty relationship of fractured rock mass by numerical modeling  

Office of Scientific and Technical Information (OSTI)

Accepted for publication in International Journal of Rock Mechanics & Mining Sciences Accepted for publication in International Journal of Rock Mechanics & Mining Sciences Stress-Dependent Permeability of Fractured Rock Masses: A Numerical Study Ki-Bok Min *1 , J Rutqvist 2 , Chin-Fu Tsang 2 , and Lanru Jing 1 1 Engineering Geology and Geophysics Research Group, Royal Institute of Technology (KTH), Stockholm, Sweden 2 Earth Sciences Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA, USA * corresponding author. Tel.: +46-8-790-7919; fax: +46-8-790-6810. E-mail address: kibok@kth.se (Ki-Bok Min) 1 Abstract We investigate the stress-dependent permeability issue in fractured rock masses considering the effects of nonlinear normal deformation and shear dilation of fractures using a two-dimensional

253

Intercomparison of Single-Column Numerical Models for the Prediction of Radiation Fog  

E-Print Network (OSTI)

layers of the atmosphere. Current NWP models poorly forecast the life cycle of fog, and improved NWP models exist in the surface boundary layer before the fog onset, particularly in cases with light winds before improving the analysis and prediction of fog (e.g., Benjamin et al. 2004; Fowler et al. 2006

Ribes, Aurélien

254

Geothermics 33 (2004) 457476 Numerical modeling of transient Basin and Range  

E-Print Network (OSTI)

.Drillingindicateshightemperatures(>190 C)at2.5­3.0 kmdepth along a strike length of at least 20 km along the west side of the valley model consists of two mountain ranges (1 km relief from the valley floor) separated by a thick sequence exist on a steady-state basis. The models show some features seen in Dixie Valley, Naveda

Southern Methodist University

255

A two-dimensional numerical model of dry convection with three-dimensional dynamics  

E-Print Network (OSTI)

symmetric model to simulate a bucyant mass of fluid embedded in an ambient The format and style of this thesis follow those of the Journal of Atmos heric Sciences. fluid of uniform density. The results from Ogura's model exhibited the shape preserving...

Weyman, James Charles

1978-01-01T23:59:59.000Z

256

NUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA-HIGH  

E-Print Network (OSTI)

, hydro-chemo- mechanical coupling ABSTRACT Cracks, caused by shrinkage or external loading, reduce. In this study, a hydro-chemo-mechanical model was developed to simulate autogenous healing by further hydration into water was modelled based on micro-mechanical observations. The diffusion process has been simulated

Boyer, Edmond

257

A generative model for activations in functional MRI  

E-Print Network (OSTI)

Detection of brain activity and selectivity using functional magnetic resonance imaging (fMRI) provides unique insight into the underlying functional properties of the brain. We propose a generative model that jointly ...

Sridharan, Ramesh

2011-01-01T23:59:59.000Z

258

White Paper on DOE-HEP Accelerator Modeling Science Activities  

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

White Paper on DOE-HEP Accelerator Modeling Science Activities J.-L. Vay, C. G. R. Geddes, A. Koniges - Lawrence Berkeley National Laboratory A. Friedman, D. P. Grote - Lawrence...

259

Coupled numerical modelling of power loss generation in busbar system of low-voltage switchgear  

Science Journals Connector (OSTI)

Abstract This paper presents a coupled mathematical model of the heat transfer processes in an electric switchgear. The considered problem required the computation of the detailed distribution of the power losses and all the heat transfer modes (radiation, convection, and conduction) within a unit. In this complex thermal analysis, different definitions of electric busbar heating were considered and compared. The most advanced model, which couples the thermal and electromagnetic fields in two ways, was also compared with the simplified approaches. First, the direct current loading of the busbar, which neglected the alternating current effects, was considered. Second, models that included only one method of coupling were calculated for different assumed average busbar temperatures. Finally, the model with the two-way coupling, which took the eddy currents and proximity effects into account, was simulated using an iteration loop between the electromagnetic and fluid flow solvers. This study employed a geometrical model of industrial low-voltage switchgear. The presented mathematical model was also validated against temperature measurements carried out by a certified laboratory. The obtained results show that a fully coupled model produces very satisfactory agreement between computed and experimental data.

Mateusz Bedkowski; Jacek Smolka; Krzysztof Banasiak; Zbigniew Bulinski; Andrzej J. Nowak; Tomasz Tomanek; Adam Wajda

2014-01-01T23:59:59.000Z

260

A general formulation of Bead Models applied to flexible fibers and active filaments at low Reynolds number  

E-Print Network (OSTI)

This contribution provides a general framework to use Lagrange multipliers for the simulation of low Reynolds number fiber dynamics based on Bead Models (BM). This formalism provides an efficient method to account for kinematic constraints. We illustrate, with several examples, to which extent the proposed formulation offers a flexible and versatile framework for the quantitative modeling of flexible fibers deformation and rotation in shear flow, the dynamics of actuated filaments and the propulsion of active swimmers. Furthermore, a new contact model called Gears Model is proposed and successfully tested. It avoids the use of numerical artifices such as repulsive forces between adjacent beads, a source of numerical difficulties in the temporal integration of previous Bead Models.

Delmotte, Blaise; Plouraboue, Franck

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Efficient Conservative Numerical Schemes for 1D Nonlinear Spherical Diffusion Equations with Applications in Battery Modeling  

E-Print Network (OSTI)

Mathematical models of batteries which make use of the intercalation of a species into a solid phase need to solve the corresponding mass transfer problem. Because solving this equation can significantly add to the ...

Zeng, Yi

262

Numerical simulations and predictive models of undrained penetration in soft soils  

E-Print Network (OSTI)

of rateindependent finite element analyses of pre-embedded penetration depths, and validate the results by upper and lower bound solutions from classical plasticity theory. Furthermore, strain rate effects are modeled by finite element simulations within a framework...

Shi, Han

2005-11-01T23:59:59.000Z

263

NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES  

E-Print Network (OSTI)

though, that nutrient limitation coupled with fluid motion may play a key role as a physical control. Under this model, competitions of nutrients were setup among growing microbial communities, which later evolve into specially arranged, 3D mats. However...

Patel, Harsh Jay

2013-09-27T23:59:59.000Z

264

Mathematical Modelling and Numerical Simulation of Marine Ecosystems With Applications to Ice Algae.  

E-Print Network (OSTI)

??Sea-ice ecosystem modelling is a novel field of research. In this thesis, the main organism studied is sea-ice algae. A basic introduction to algae and… (more)

Wickramage, Shyamila Iroshi Perera

2013-01-01T23:59:59.000Z

265

Numerical modeling of the ignition of a liquid hydrocarbon layer by a radiant heat pulse  

Science Journals Connector (OSTI)

A gas-phase model of radiative ignition of a flammable liquid is developed, allowing for absorption of the radiant flux in the gas phase. Using motor fuels (gasoline and diesel fuel), as examples, we demonstra...

Yu. V. Agabekov; F. G. Yagafarov

266

Detailed numerical modeling of chemical and thermal nonequilibrium in hypersonic flows  

SciTech Connect

Interest in hypersonic flows has created a large demand for physicochemical models for air flow computations around reentry bodies. Detailed physicochemical models for air in chemical and thermal nonequilibrium are needed for a realistic prediction of hypersonic flowfields. In this paper we develop a model, based on elementary physicochemical processes, for a detailed description of chemical nonequilibrium together with the excitation of internal DOFs. This model is implemented in a 2D Navier-Stokes code in order to show the strong influence of thermal nonequilibrium on the flowfields. The algorithm presented here is based on a fully conservative discretization of the inviscid fluxes in the conservation equations and uses the chain rule conservation law form for the viscous fluxes. The large system of ordinary differential and algebraic equations resulting from the spatial discretization is solved by a time-accurate semiimplicit extrapolation method. 34 refs.

Riedel, U.; Maas, U.; Warnatz, J. (Stuttgart Univ. (Germany))

1993-03-01T23:59:59.000Z

267

A numerical model for ultimate soil resistance to an untrenched pipeline under ocean currents  

Science Journals Connector (OSTI)

One of the main concerns for pipeline on-bottom stability design is to properly predict ultimate soil resistance in severe ocean environments. A plane-strain finite element model ... the partially-embedded pipeli...

Fu-ping Gao ???; Xi-ting Han ???; Shu-ming Yan ???

2012-06-01T23:59:59.000Z

268

Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers  

E-Print Network (OSTI)

installation separation range. Non-homogenous media were modeled by varying backfill thermal conductivity. Maximum heat transfer was achieved with a fictitious backfill thermal conductivity of 1,000 W/m-K, while measured bentonite backfill conductivities were...

Muraya, Norman K.

269

Photochemical Numerics for Global-Scale Modeling: Fidelity and GCM Testing  

Science Journals Connector (OSTI)

Atmospheric photochemistry lies at the heart of global-scale pollution problems, but it is a nonlinear system embedded in nonlinear transport and so must be modeled in three dimensions. Total earth grids are massive and kinetics require dozens of ...

Scott Elliott; Xuepeng Zhao; Richard P. Turco; Chih-Yue Jim Kao; Mei Shen

1995-03-01T23:59:59.000Z

270

Development and numerical implementation of nonlinear viscoelastic-viscoplastic model for asphalt materials  

E-Print Network (OSTI)

pavements is illustrated using finite element simulations. The constitutive model developed in this study can describe the behavior of asphalt materials (asphalt binder, asphalt mastic and mixtures) under various testing conditions. This study also achieved...

Huang, Chien-Wei

2009-05-15T23:59:59.000Z

271

Evaluation of Precipitation from Numerical Weather Prediction Models and Satellites Using Values Retrieved from Radars  

Science Journals Connector (OSTI)

Precipitation is evaluated from two weather prediction models and satellites, taking radar-retrieved values as a reference. The domain is over the central and eastern United States, with hourly accumulated precipitation over 21 days for the ...

Slavko Vasi?; Charles A. Lin; Isztar Zawadzki; Olivier Bousquet; Diane Chaumont

2007-11-01T23:59:59.000Z

272

NUMERICAL MODEL OF TRANSIENT TWO-PHASE FLOW IN A WELLBORE  

E-Print Network (OSTI)

Wellbore storage in geothermal wells: presented at 1979two-phase flow in a geothermal well has been modelled with asteam water flow in geothermal wells: Journal of Petroleum

Miller, Constance W.

2012-01-01T23:59:59.000Z

273

Numerical and analytical modeling of heat transfer between fluid and fractured rocks  

E-Print Network (OSTI)

Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...

Li, Wei, S.M. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

274

The numerical solution of a nickel-cadmium battery cell model using the method of lines  

E-Print Network (OSTI)

systems of ODE's, this scheme may be preferable. 3. Conduction in Two Connected Slabs with Different Thermal Conductivities The mathematical modeling of the Ni-Cd battery cell results in a multi-domain problem. Solution of multi domain PDE's using... systems of ODE's, this scheme may be preferable. 3. Conduction in Two Connected Slabs with Different Thermal Conductivities The mathematical modeling of the Ni-Cd battery cell results in a multi-domain problem. Solution of multi domain PDE's using...

Hailu, Teshome

2012-06-07T23:59:59.000Z

275

Short term performance comparisons between a solar thermosyphon water heater and two numerical models  

SciTech Connect

An experimental study of a solar thermosyphon domestic water heater was conducted in the indoor solar simulator facility at Colorado State University (Bickford, 1994). The system consisted of a closed-loop collector circuit filled with propylene glycol and water solution and a horizontal storage tank with an annular tank-in-tank heat exchanger. Short-term irradiated tests with and without timed draws were performed to assess overall performance and monitor collector flow rate, storage tank stratification, and heat exchanger temperature distribution. The measured performance was compared with the ``standard`` thermosyphon model in TRNSYS 13.1 (transient system simulation program). A revised TRNSYS model was developed by Graham Morrison at the University of New South Wales, Australia. The revised model specifically addressed the horizontal tank, closed-loop configuration. The standard TRNSYS version predicted solar gain within 17% of the measured values and differed dramatically from experimental collector temperatures, closed-loop flow rate, and tank stratification. This is not surprising since this model does not include the tank and tank heat exchanger. The revised TRNSYS model agreed more closely with experimental results. It predicted closed-loop flow at 8% lower than observed flow and collector temperature rise that was higher than the observed flow by approximately the same amount, resulting in extremely accurate prediction of collector output energy. Losses from the storage tank and piping were significantly underpredicted in both models, however.

Bickford, C.; Hittle, D.C. [Colorado State Univ., Fort Collins, CO (United States). Solar Energy Applications Lab.

1995-11-01T23:59:59.000Z

276

A Global Time-Dependent Model of Thunderstorm Electricity. Part I: Mathematical Properties of the Physical and Numerical Models  

Science Journals Connector (OSTI)

A time-dependent model that simulates the interaction of a thunderstorm with its electrical environment is introduced. The model solves the continuity equation of the Maxwell current density that includes conduction, displacement, and source ...

G. L. Browning; I. Tzur; R. G. Roble

1987-08-01T23:59:59.000Z

277

Satellite Data Assimilation in Numerical Weather Prediction Models. Part I: Forward Radiative Transfer and Jacobian Modeling in Cloudy Atmospheres  

Science Journals Connector (OSTI)

Satellite data assimilation requires rapid and accurate radiative transfer and radiance gradient models. For a vertically stratified scattering and emitting atmosphere, the vector discrete-ordinate radiative transfer model (VDISORT) was developed ...

Fuzhong Weng; Quanhua Liu

2003-11-01T23:59:59.000Z

278

Effects of Localized Energy Extraction in an Idealized, Energetically Complete Numerical Model of an Ocean-Estuary Tidal System  

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

localized energy extraction in an localized energy extraction in an idealized, energetically complete numerical model of an ocean-estuary tidal system MHK Instrumentation, Measurement & Computer Modeling Workshop, Broomfield CO, July 10 2012 Mitsuhiro Kawase and Marisa Gedney Northwest National Marine Renewable Energy Center / School of Oceanography University of Washington Seattle WA 98195 United States * Far-field (Estuary-wide) - Changes in the tidal range - Changes in tidal currents  Near-field (Vicinity of the Device)  Flow redirection  Interaction with marine life  Impact on bottom sediments and benthos Environmental Effects of Tidal Energy Extraction * Reduction in tidal range can permanently expose/submerge tidal flats, altering nearshore habitats * Reduction in kinetic energy of

279

Numerical modelling of the electrical activity of the atria and the pulmonary veins.  

E-Print Network (OSTI)

Post-processing Medical or biological ensight Monodomaine : (CmtV + Iion(V )) electrophy. + divD V. ­ Asymptotic analysis Se- cond order convergence. (CmtVk + Iion(Vk) electrophy. ) - divD Vk coupling + (-1)k JUNCTIONS NON LINEAR DYNAMICS ­ GJ conductance: GGJ = Gmaxw0 tw0 = w(V )-w0 (V ) (Cmt0 + Iion(0)) - x (~(w0

Boyer, Edmond

280

Synthesis of Numerical Methods for Modeling Wave Energy Converter-Point Absorbers: Preprint  

SciTech Connect

During the past few decades, wave energy has received significant attention among all ocean energy formats. Industry has proposed hundreds of prototypes such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber as the technology to extract wave energy. Several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. However, no standardized method has been decided. To assist the development of wave energy conversion technologies, this report reviews the methods for modeling the floating-point absorber.

Li, Y.; Yu, Y. H.

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Mathematical Modeling and Numerical Simulation of Methane Production in a Hydrate Reservoir  

Science Journals Connector (OSTI)

Contrary to more traditional reservoir simulations, the set of model unknowns or primary variables in HydrateResSim changes throughout the simulation as a result of the formation or dissociation of ice and hydrate phases during the simulation. ... For example, in the petroleum industry, CFD models have been developed since the 1970s to help optimize oil production by steam flooding. ... (2) Since the 1980s, an increasing number of problems in environmental engineering, such as the contamination of groundwater due to subsurface leakage of petroleum products, has been a concern for governments and industries that has led to the development of multiphase multicomponent models to simulate the transport of contaminants in the subsurface. ...

Isaac K. Gamwo; Yong Liu

2010-03-10T23:59:59.000Z

282

Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits  

E-Print Network (OSTI)

. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control robots is still a challenge. For a given gait pattern, landing time and point of each leg are prescribed, i.e. they depend on parameters. The trajectory of each joint between lift-off and landing

Stryk, Oskar von

283

Numerical Modelling of Tide-Surge Interaction in the Bay of Bengal  

Science Journals Connector (OSTI)

...tropical cyclone led to severe inland flooding. This is one of the few events for which...response are correctly reproduced. A model simulation is also made of the surge that occurred...level and eyewitness accounts of inland flooding. The principal requirement for the operational...

1985-01-01T23:59:59.000Z

284

Mathematical Modelling and Numerical Analysis Will be set by the publisher Modelisation Mathematique et Analyse Numerique  

E-Print Network (OSTI)

´ematique et Analyse Num´erique A NULL CONTROLLABILITY DATA ASSIMILATION METHODOLOGY APPLIED TO A LARGE SCALE assimilation refers to any methodology that uses partial observational data and the dynamics of a system for estimating the model state or its parameters. We consider here a non classical approach to data assimilation

Osses, Axel

285

Model Validation and Spatial Interpolation by Combining Observations with Outputs from Numerical  

E-Print Network (OSTI)

""r,c,rn The authors are for hel]JfuI #12;Abstract Constructing maps of pollution levels is vital for air quality concentrations. Key tlJords: air pollution, Ba~yesian inference, change of support, likelihood approaches, Matern Resolutions 2.5 Modeling a Nonstationary Covariance . 3 Estimation 3.1 Algorithm 4 Application: Air Pollution

Washington at Seattle, University of

286

Development and validation of a vertically two-dimensional mesoscale numerical model  

E-Print Network (OSTI)

because the model is dry. The equations are as follows: dv " ? 1 1 d dv f k X V ? ? Vp ? g Vz + ? ~ ? (pK ? ), (2) dt P pH ds m ds pgH do dn d o + 'it ~ pV + ? (ns) + p V ~ VH = 0 dt ds P H (4) dT . H Q sg ? + d t C p C p pRT The symbols... of the model. The remaining variables have been previously defined. 15 The finite difference equations are as follows: ~ H (o V (i, k) = H(i+1) * ( p(i+1, k) + p(i, k) ) * u(i+1, k) ? H(i) * ( p(i, k) + p (i-l, k) ) * u(i, k) / ( 2 a DX ) = DV(i k) (I...

Walters, Michael Kent

2012-06-07T23:59:59.000Z

287

Storm surge analysis using numerical and statistical techniques and comparison with NWS model SLOSH  

E-Print Network (OSTI)

. Most of the coastal basins that make up the estuaries along the Texas Gulf coast are very shallow, with depths that are often no more than a meter. In addition to the shallow bay depths, the topography of coastal lands is that of flat coastal plains... stress for a well-developed hurricane moving towards Texas coast ........................................................................................ 28 Fig. 3-1 SLOSH model basins for the East and Gulf coastlines of the U...

Aggarwal, Manish

2005-11-01T23:59:59.000Z

288

Numerical modeling of a thermohydrochemical (T-H-C) coupling and the implications to radionuclide transport.  

SciTech Connect

Thermohydrochemical (T-H-C) processes result from the placement of heat-generating radioactive materials in unsaturated, fractured geologic materials. The placement of materials in the proposed Yucca Mountain repository will result in complex environmental conditions. Simple models are developed liking the thermohydrological effects simulated with TOUGHZ to system chemistry, with an example presented for chloride. Perturbations to near-field chemistry could have a significant impact on the migration of actinides and fission products in geologic materials. Various conceptual models to represent fractures are utilized in TOUGHZ simulations of thermohydrological processes. The simulated moisture redistribution is then coupled to simple chemical models to demonstrate the potential magnitude of T-H-C processes. The concentration of chloride in solution (returning to the engineered barrier system) is demonstrated, in extreme cases, to exceed 100,000 mg/L. The implication is that the system (typically ambient chemical and hydrological conditions) in which radionuclide transport is typically simulated and measured may be significantly different from the perturbed system.

Esh, D. W.; Scheetz, B. E.

1999-09-21T23:59:59.000Z

289

Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers  

E-Print Network (OSTI)

In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force dis...

Sraj, Ihab; Marr, David W M; Eggleton, Charles D

2015-01-01T23:59:59.000Z

290

Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers  

E-Print Network (OSTI)

In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force distribution on the cell surface and the net deformation. Scattering and gradient forces are reported for different nucleus sizes and the effect of nucleus size on the cell deformation is discussed.

Ihab Sraj; Joshua Francois; David W. M. Marr; Charles D. Eggleton

2015-01-15T23:59:59.000Z

291

Mixture Preparation and Nitric Oxide Formation in a GDI Engine studied by Combined Laser Diagnostics and Numerical Modeling  

SciTech Connect

Through the combination of advanced imaging laser diagnostics with multi-dimensional computer models, a new understanding of the performance of direct-injection gasoline engines is pursuit. The work focuses on the fuel injection process, the breakup of the liquid into a fine spray and the mixing of the fuel with the in-cylinder gases. Non-intrusive laser diagnostics will be used to measure the spatial distribution of droplets and vaporized fuel with very high temporal resolution. These data along with temperature measurements will be used to validate a new spray breakup model for gasoline direct-injection. Experimental data on near wall fuel distributions will be used for comparison with a model that predicts the spray-wall interaction and the dynamics of the liquid film on the surface. Quantitative measurements of local nitric oxide concentrations inside the combustion chamber will provide a critical test for a numerical simulation of the nitric oxide formation process. This model is based on a modified flamelet approach and will be used to study the effects of exhaust gas recirculation.

Volker Sick; Dennis N. Assanis

2002-11-27T23:59:59.000Z

292

The preparation of landslide map by Landslide Numerical Risk Factor (LNRF) model and Geographic Information System (GIS)  

Science Journals Connector (OSTI)

Abstract One of the risks to threaten mountainous areas is that hillslope instability caused damage to lands. One of the most dangerous instabilities is mass movement and much movement occurs due to slip. The aim of this study is zonation of landslide hazards in a basin of the Ardebil province, the eastern slopes of Sabalan, Iran. Geological and geomorphologic conditions, climate and type of land use have caused susceptibility of this watershed to landslides. Firstly, maps of the main factors affecting landslide occurrence including slope, distance from faults, lithology, elevation and precipitation were prepared and digitized. Then, by using interpretation of aerial photos and satellite images and field views, the ground truth map of landslides was prepared. Each basic layer (factor) and landslide map were integrated to compute the numeric value of each factor with the help of a Landslide Numerical Risk Factor (LNRF) model and landslide occurrence percent obtained in different units from each of the maps. Finally, with overlapping different data layers, a landslide hazard zonation map was prepared. Results showed that 67.85% of the basin has high instability, 7.76% moderate instability and 24.39% low instability.

Ali Mohammadi Torkashvand; Akram Irani; Jaliledin Sorur

2014-01-01T23:59:59.000Z

293

Numerical modelling of salinity variations due to wind and thermohaline forcing in the Persian Gulf  

Science Journals Connector (OSTI)

Salinity is an important component of the marine system. Due to shallow nature of the Persian Gulf, the salinity has been influenced by both wind driven and surface thermohaline fluxes (heat and moisture fluxes). In this study, the seasonal distribution of salinity and its variations due to wind stress and thermohaline forcing are investigated by using a three-dimensional hydrodynamic model, Coupled Hydrodynamical–Ecological Model for Regional and Shelf Seas (COHERENS). The simulation results show that the salinity in the Persian Gulf experiences dramatic spatial and temporal variations. The influence of the thermohaline forcing is considerably more than the wind stress on the salinity. The effect of the surface thermohaline fluxes over the salinity field is generally to increase the salinity for almost all the water column during the year. This effect is high during September–November where the evaporative surface salinity flux dominates over inflow of low-salinity values of Indian Ocean Surface Water. The wind forcing at the most regions of the Persian Gulf, in particular at the United Arab Emirate (UAE) coast and Bahrain–Qatar shelf, freshens the water all the year round. The wind and thermohaline forcing in March–June have strong potential to generate stratification in salinity structure. The model predictions, which are successful in simulating many features of observed pattern, indicate that the surface water of the Gulf is saltier in winter than that in spring and early summer. Both heat fluxes and wind stress play an important role for this seasonal cycle of the surface salinity.

S. Hassanzadeh; F. Hosseinibalam; A. Rezaei-Latifi

2011-01-01T23:59:59.000Z

294

E-Print Network 3.0 - activities including modelling Sample Search...  

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

models. We analyse five different developments, viz., Coordination Theory, Activity... Theory, Task Manager model, ActionInteraction Theory and Object-Oriented Activity Support...

295

CDA6530: Performance Models of Computers and Networks (Fall 2013) Project 2: Using Matlab Simulink to derive numerical solution for differential equations  

E-Print Network (OSTI)

CDA6530: Performance Models of Computers and Networks (Fall 2013) Project 2: Using Matlab Simulink matlab simulink from the example of the simple worm propagation modeling in class. Now you are asked to derive the numerical solutions for more complicated differential equations. If you cannot access Matlab

Zou, Cliff C.

296

Carbon monoxide in the solar atmosphere I. Numerical method and two-dimensional models  

E-Print Network (OSTI)

The radiation hydrodynamic code CO5BOLD has been supplemented with the time-dependent treatment of chemical reaction networks. Advection of particle densities due to the hydrodynamic flow field is also included. The radiative transfer is treated frequency-independently, i.e. grey, so far. The upgraded code has been applied to two-dimensional simulations of carbon monoxide (CO) in the non-magnetic solar photosphere and low chromosphere. For this purpose a reaction network has been constructed, taking into account the reactions which are most important for the formation and dissociation of CO under the physical conditions of the solar atmosphere. The network has been strongly reduced to 27 reactions, involving the chemical species H, H2, C, O, CO, CH, OH, and a representative metal. The resulting CO number density is highest in the cool regions of the reversed granulation pattern at mid-photospheric heights and decreases strongly above. There, the CO abundance stays close to a value of 8.3 on the usual logarithmic abundance scale with [H]=12 but is reduced in hot shock waves which are a ubiquitous phenomenon of the model atmosphere. For comparison, the corresponding equilibrium densities have been calculated, based on the reaction network but also under assumption of instantaneous chemical equilibrium by applying the Rybicki & Hummer (RH) code by Uitenbroek (2001). Owing to the short chemical timescales, the assumption holds for a large fraction of the atmosphere, in particular the photosphere. In contrast, the CO number density deviates strongly from the corresponding equilibrium value in the vicinity of chromospheric shock waves. Simulations with altered reaction network clearly show that the formation channel via hydroxide (OH) is the most important one under the conditions of the solar atmosphere.

S. Wedemeyer-Boehm; I. Kamp; J. Bruls; B. Freytag

2005-03-23T23:59:59.000Z

297

Optimization of numerical weather/wave prediction models based on information geometry and computational techniques  

Science Journals Connector (OSTI)

The last years a new highly demanding framework has been set for environmental sciences and applied mathematics as a result of the needs posed by issues that are of interest not only of the scientific community but of today's society in general: global warming renewable resources of energy natural hazards can be listed among them. Two are the main directions that the research community follows today in order to address the above problems: The utilization of environmental observations obtained from in situ or remote sensing sources and the meteorological-oceanographic simulations based on physical-mathematical models. In particular trying to reach credible local forecasts the two previous data sources are combined by algorithms that are essentially based on optimization processes. The conventional approaches in this framework usually neglect the topological-geometrical properties of the space of the data under study by adopting least square methods based on classical Euclidean geometry tools. In the present work new optimization techniques are discussed making use of methodologies from a rapidly advancing branch of applied Mathematics the Information Geometry. The latter prove that the distributions of data sets are elements of non-Euclidean structures in which the underlying geometry may differ significantly from the classical one. Geometrical entities like Riemannian metrics distances curvature and affine connections are utilized in order to define the optimum distributions fitting to the environmental data at specific areas and to form differential systems that describes the optimization procedures. The methodology proposed is clarified by an application for wind speed forecasts in the Kefaloniaisland Greece.

2014-01-01T23:59:59.000Z

298

Analysis of mid-tropospheric carbon monoxide data using a three- dimensional Global atmospheric Chemistry numerical Model  

SciTech Connect

The GChM atmospheric chemistry and transport model has been used to analyze the mid-tropospheric CO dataset obtained from NASA`s Measurement of Air Pollution by Satellites (MAPS) program. Fourteen simulations with a 3.75 horizontal resolution have been performed, including a base case and 13 sensitivity runs. The model reproduces many, but not all, of the major features of the MAPS dataset. Locations of peak CO mixing ratios associated with biomass burning as observed in the MAPS experiment are slightly farther south than the model result, indicating either greater horizontal transport than present in the model representation or a spatial difference between the location of modeled biomass fires and actual fires. The current version of GChM was shown to be relatively insensitive to the magnitude of the prescribed NO{sub x} and O{sub 3} global distributions and very insensitive to the depth of the mixed layer as parameterized in the model. Cloud convective transport was shown to play an important role in venting boundary layer CO to the free troposphere. This result agrees with prior meteorological analyses of the MAPS dataset that have-indirectly inferred the presence of convective activity through satellite-based information. Work is continuing to analyze the results of these simulations further and to perform more detailed comparisons between model results and MAPS data.

Easter, R.C.; Saylor, R.D.; Chapman, E.G.

1993-12-01T23:59:59.000Z

299

Multi-Assay-Based Structure?Activity Relationship Models: Improving Structure?Activity Relationship Models by Incorporating Activity Information from Related Targets  

Science Journals Connector (OSTI)

In this paper, we present a new class of methods for building SAR models, referred to as multi-assay based, that utilize activity information from different targets. ... Depending on the method, this SAR model will be built using either its own activity information (baseline SAR model) or additional information obtained from its set of related targets (multi-assay-based SAR model). ... To illustrate the cross-family nature of the multi-assay-based methods, Figure 3 shows the set of related proteins for the different proteins within and across the different families (Ktkligs and m = 3). ...

Xia Ning; Huzefa Rangwala; George Karypis

2009-10-20T23:59:59.000Z

300

Spindles and active vortices in a model of confined filament-motor mixtures  

E-Print Network (OSTI)

Robust self-organization of subcellular structures is a key principle governing the dynamics and evolution of cellular life. In fission yeast cells undergoing division, the mitotic spindle spontaneously emerges from the interaction of microtubules, motor proteins and the confining cell walls, and asters and vortices have been observed to self-assemble in quasi-two dimensional microtubule-kinesin assays. Their is no clear microscopic picture of the role of the active motors driving this pattern formation, and the relevance of continuum modeling to filament-scale structures remains uncertain. Here we present results of numerical simulations of a discrete filament-motor protein model confined to a pressurised cylindrical box. Stable spindles, nematic configurations, asters and high-density semi-asters spontaneously emerge, the latter pair having also been observed in cytosol confined within emulsion droplets. State diagrams are presented delineating each stationary state as the pressure, motor speed and motor de...

Head, David A; Gompper, Gerhard

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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301

A model for the formation of the active region corona driven by magnetic flux emergence  

E-Print Network (OSTI)

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a 3D radiation MHD simulation of the emergence of an active region through the upper convection zone and the photosphere as a lower boundary for a 3D MHD coronal model. The latter accounts for the braiding of the magnetic fieldlines, which induces currents in the corona heating up the plasma. We synthesize the coronal emission for a direct comparison to observations. Starting with a basically field-free atmosphere we follow the filling of the corona with magnetic field and plasma. Numerous individually identifiable hot coronal loops form, and reach temperatures well above 1 MK with densities comparable to observations. The footpoints of these loops are found where small patches of magnetic flux concentrations move into the sunspots. The loop formation is triggered by an incr...

Chen, F; Bingert, S; Cheung, M C M

2014-01-01T23:59:59.000Z

302

ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS  

SciTech Connect

Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.

Chiswell, S

2009-01-11T23:59:59.000Z

303

Exploiting Active Subspaces to Quantify Uncertainty in the Numerical Simulation of the HyShot II Scramjet  

E-Print Network (OSTI)

We present a computational analysis of the reactive flow in a hypersonic scramjet engine with emphasis on effects of uncertainties in the operating conditions. We employ a novel methodology based on active subspaces to characterize the effects of the input uncertainty on the scramjet performance. The active subspace re-parameterizes the operating conditions from seven well characterized physical parameters to a single derived active variable. This dimension reduction enables otherwise intractable---given the cost of the simulation---computational studies to quantify uncertainty; bootstrapping provides confidence intervals on the studies' results. In particular we (i) identify the parameters that contribute the most to the variation in the output quantity of interest, (ii) compute a global upper and lower bound on the quantity of interest, and (iii) classify sets of operating conditions as safe or unsafe corresponding to a threshold on the output quantity of interest. We repeat this analysis for two values of ...

Constantine, Paul; Larsson, Johan; Iaccarino, Gianluca

2014-01-01T23:59:59.000Z

304

Wind resource assessment using numerical weather prediction models and multi-criteria decision making technique: case study (Masirah Island, Oman)  

Science Journals Connector (OSTI)

The Authority for Electricity Regulation in Oman has recently announced the implementation of a 500 kW wind farm pilot project in Masirah Island. Detailed wind resource assessment is then required to identify the most suitable location for this project. This paper presents wind resource assessment using nested ensemble numerical weather prediction (NWP) model's approach at 2.8 km resolution and multi-criteria decision making (MCDM) technique. A case study based on the proposed approach is conducted over Masirah Island, Oman. The resource assessment over the island was based on the mean wind speed and wind power distribution over the entire island at different heights. In addition, important criteria such as turbulence intensity and peak hour matching are also considered. The NWP model results were verified against the available 10 m wind data observations from the meteorological station in the northern part of the island. The resource assessment criteria were evaluated using MCDM technique to score the locations over the island based on their suitability for wind energy applications. Two MCDM approaches namely equally weighted and differently weighted criteria were implemented in this paper.

Sultan Al-Yahyai; Yassine Charabi; Abdullah Al-Badi; Adel Gastli

2013-01-01T23:59:59.000Z

305

A Model for Minimizing Active Processor Time Jessica Chang1  

E-Print Network (OSTI)

, the problem often becomes NP-complete.) We propose a simple model for measuring energy usage on a parallel consumes a fixed amount of energy per active timeslot, regardless of the number of jobs scheduled to finding a triangle-free 2-matching on a special graph. We extend the algorithm of Babenko et. al. [3

Khuller, Samir

306

A Model for Minimizing Active Processor Time Jessica Chang  

E-Print Network (OSTI)

#12;We propose a simple model for measuring energy usage on a parallel machine. Rather than focusing consumes a fixed amount of energy per active timeslot, regardless of the number of jobs scheduled, the problem amounts to finding a triangle-free 2-matching on a special graph. We extend the algorithm

Khuller, Samir

307

MODELING OF A NEW SMA MICRO-ACTUATOR FOR ACTIVE  

E-Print Network (OSTI)

memory alloys, active endoscopy, thermo-electricity, modeling. 1. INTRODUCTION Microtechnology. It produces unexpected behaviour and low dy- namic response. A technic consist in using thermo- electric coolers (Kyu-Jin and Asada, 2005). The control of the SMA phases transformations, and then the mechanical

Paris-Sud XI, Université de

308

Numerical Analyses of CERN 200GeV/A Heavy-Ion Collisions Based on a Hydrodynamical Model with Phase Transition  

E-Print Network (OSTI)

We numerically analyze recent high energy heavy-ion collision experiments based on a hydrodynamical model with phase transition and discuss a systematic change of initial state of QGP-fluid depending on colliding-nuclei's mass. In a previous paper, we formulated a (3+1)-dimensional hydrodynamical model for quark-gluon plasma with phase transition and discussed numerically the space-time evolution in detail. We here compare the numerical solution with the hadronic distributions given by CERN WA80 and NA35. Systematic analyses of the experiments with various colliding nuclei enable us to discuss the dependences of the initial parameters of the hydrodynamical model on colliding nuclei's mass. Furthermore, extrapolating the present experiments, we derive the possible hadronic distributions for lead-lead 150GeV/A collision.

Shin Muroya; Hiroki Nakamura; Mikio Namiki

1995-02-02T23:59:59.000Z

309

Numerical Modelling of Oxy-Fuel Combustion in a Full-Scale Tangentially-Fired Pulverised Coal Boiler  

Science Journals Connector (OSTI)

Abstract This paper presents a computational fluid dynamics (CFD) modelling study to investigate Victorian brown coal combustion in a 550 MW utility boiler under the air-fired (standard) and three oxy-fuel-fired cases. The standard case was modelled based on the real operating conditions of Loy Yang A power plant located in the state of Victoria, Australia. A level of confidence of the present CFD model was achieved validating four parameters of the standard combustion case, as well as the previous preliminary CFD studies which were conducted on a lab-scale (100 kW) unit firing lignite and propane under oxy-fuel-fired scenarios. The oxy-fuel combustion cases are known as OF25 (25vol. % O2 concentration), OF27 (27vol. % O2 concentration), and OF29 (29vol. % O2 concentration). The predictions of OF29 combustion case were considerably similar to the standard firing results in terms of gas temperature levels and radiative heat transfer compared with OF25 and OF27 combustion scenarios. This similarity was because of increasing the residence time of pulverised coal (PC) in the combustion zone and O2 concentration in feed oxidizer gases. Furthermore, a significant increase in the CO2 concentrations and a noticeable decrease in the nitric oxides (NOx) formation were noted under all oxy-fuel combustion conditions. This numerical study of oxy-fuel combustion in a full-scale tangentially-fired PC boiler is important prior to its execution in real-life power plants.

Audai Hussein Al-Abbas; Jamal Naser; David Dodds; Aaron Blicblau

2013-01-01T23:59:59.000Z

310

Active shape model with inter-profile modeling paradigm for cardiac right ventricle segmentation  

Science Journals Connector (OSTI)

In this work, a novel active shape model (ASM) paradigm is proposed to segment the right ventricle (RV) in cardiac magnetic resonance image sequences. The proposed paradigm includes modifications to two fundamental steps in the ASM algorithm. The first ...

Mohammed S. ElBaz; Ahmed S. Fahmy

2012-10-01T23:59:59.000Z

311

Numerical studies of the high power microwave breakdown in gas using the fluid model with a modified electron energy distribution function  

SciTech Connect

A modified electron energy distribution function (EEDF) is introduced into the fluid model and its effects on the high power microwave (HPM) breakdown in air and argon are investigated. A proper numerical scheme for the finite-difference time-domain method is employed to solve the fluid model. Numerical simulations show that the HPM breakdown time in argon predicted by the fluid model with the modified EEDF agrees well with the results of Particle-in-cell-Monte Carlo collision simulations, while the Maxwellian EEDF results in faster HPM breakdown when the mean electron energy is less than 20 eV. We also confirm that the Maxwellian EEDF can be used in the fluid model for simulating the air breakdown at the low frequencies based on the reported experiments.

Zhao Pengcheng; Liao Cheng; Lin Chenbin; Chang Lei; Fu Haijun [Institute of Electromagnetics, Southwest Jiaotong University, Chengdu 610031 (China)

2011-10-15T23:59:59.000Z

312

Discrimination between 1/f noise models in junctions field effect transistors and metal?oxide?semiconductor field effect transistors: Numerical results  

Science Journals Connector (OSTI)

The integrals given by Park e t a l. in an earlier paper [J. Appl. Phys. 52 296 (1981)] on 1/f noise are expressed in closed forms and evaluated numerically. The results show how the field dependent mobility affects the number fluctuation model and how the field dependent mobility and the field dependence of Hooge’s parameter ? affects the mobility fluctuation model. The latter effect is very strong and results in a large decrease in the noise spectrum at larger values of drain bias when compared with the elementary theory that neglects these field dependences. For relatively short channels the mobility fluctuation model gives a peak in the noise well before saturation in agreement with the experiments of Park e t a l. The effects of the field dependent mobility and of the field dependent ? on the noise resistance at saturation are evaluated numerically.

A. van der Ziel; R. J. J. Zijlstra; H. S. Park

1981-01-01T23:59:59.000Z

313

Evaluation of numerical weather prediction for intra-day solar forecasting in the continental United States  

E-Print Network (OSTI)

for numerical weather prediction and climate models.   Abstract:  Numerical weather prediction (NWP) models are Model output statistics (MOS), Numerical Weather Prediction (

Mathiesen, Patrick; Kleissl, Jan

2011-01-01T23:59:59.000Z

314

Modeling polychlorinated biphenyl mass transfer after amendment of contaminated sediment with activated carbon  

SciTech Connect

The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). The authors extend their evaluation of a model based on intraparticle diffusion by including a biomimetic semipermeable membrane device (SPMD) and a first-order degradation rate for the aqueous phase. The model predictions are compared with the previously reported experimental PCB concentrations in the bulk water phase and in SPMDs. The simulated scenarios comprise a marine and a freshwater sediment, four PCB congeners, two AC grain sizes, four doses of AC, and comparison with laboratory experiments. The modeling approach distinguishes between two different sediment particles types: a light-density fraction representing carbonaceous particles such as charcoal, coal, coke, cenospheres, or wood, and a heavy-density fraction representing the mineral phase with coatings of organic matter. A third particle type in the numerical model is AC. The model qualitatively reproduces the observed shifts in the PCB distribution during repartitioning after AC amendment but overestimates the overall effect of the treatment in reducing aqueous and SPMD concentrations of PCBs by a factor of 2-6. For the AC application in sediment, competitive sorption of the various solutes apparently requires a reduction by a factor of 16 of the literature values for the AC-water partitioning coefficient measured in pure aqueous systems. With this correction, model results and measurements agree within a factor of 3. After AC amendment is homogeneously mixed into the sediment and then left undisturbed, aqueous PCB concentrations tend toward the same reduction after 5 years. 19 refs., 5 figs., 4 tabs.

David Werner; Upal Ghosh; Richard G. Luthy [University of Newcastle upon Tyne, Newcastle (United Kingdom)

2006-07-01T23:59:59.000Z

315

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.

Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences

2013-11-13T23:59:59.000Z

316

Groningen Active Living Model (GALM): stimulating physical activity in sedentary older adults; validation of the behavioral change model  

Science Journals Connector (OSTI)

Background A significant proportion of older adults in The Netherlands do not participate regularly in leisure-time physical activity. The Groningen Active Living Model (GALM) was developed to change this situation for the better. Longitudinal results of the validation of the GALM behavioral change model are presented. Methods We obtained data on potentially mediating variables of physical activity behavior change (self-efficacy, social support, perceived fitness, and enjoyment) from 96 participants in a prospective study during the 18 months the GALM strategy lasted. Results Prospective analyses revealed significant differences in several potentially mediating variables, although some of these differences were contrary to our hypothesis. Discriminant analysis resulted in canonical correlations of 0.50 after 6 months and 0.66 after 18 months of program participation between adherers and nonadherers, respectively; 73.8 and 80.0% of the subjects were classified correctly. Conclusions Based on the results, it can be concluded that we partially succeeded in manipulating the potentially mediating variables by means of our GALM strategy. Several mediating variables were identified that reliably discriminated long-term adherers from nonadherers, expanding the generalizability of social cognitive theory-driven variables to a Dutch population.

Martin Stevens; Koen A.P.M Lemmink; Marieke J.G van Heuvelen; Johan de Jong; Piet Rispens

2003-01-01T23:59:59.000Z

317

E-Print Network 3.0 - active fracture model Sample Search Results  

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

fracture model Search Powered by Explorit Topic List Advanced Search Sample search results for: active fracture model Page: << < 1 2 3 4 5 > >> 1 THELEADINGEDGESeptember2007Vol.26,...

318

Theoretical and Numerical Analysis of a Class of Semi-Implicit Semi-Lagrangian Schemes Potentially Applicable to Atmospheric Models  

Science Journals Connector (OSTI)

In this paper, theoretical and numerical analyses of the properties of some complex semi-Lagrangian methods are performed to deal with the issues of the instability associated with the treatment of the nonlinear part of the forcing term. A class ...

Abdelaziz Beljadid; Abdolmajid Mohammadian; Martin Charron; Claude Girard

2014-12-01T23:59:59.000Z

319

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluate CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends

Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping

2013-03-14T23:59:59.000Z

320

Statistical and Realistic Numerical Model Investigations of Anthropogenic and Climatic Factors that Influence Hypoxic Area Variability in the Gulf of Mexico  

E-Print Network (OSTI)

, Steven DiMarco George Jackson Committee Members, Robert Hetland Thomas Bianchi Piers Chapman Steven Davis Head of Department, Piers Chapman May 2012 Major Subject: Oceanography iii ABSTRACT Statistical and Realistic Numerical Model... Investigations of Anthropogenic and Climatic Factors that Influence Hypoxic Area Variability in the Gulf of Mexico. (May 2012) Yang Feng, B. S., Ocean University of China; M.S., Ocean University of China Co?Chairs of Advisory Committee: Dr. Steven Di...

Feng, Yang

2012-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical modeling of buoyancy-driven flows in a rotating cylindrical cavity: Comparison of a finite element model with a spectral model  

SciTech Connect

A finite element model is developed for the prediction of the motion of rotating Boussinesq fluid driven by buoyancy. The computations are performed for the axisymmetric regime in an annular cavity for Reynolds number varying from 0 to 2,500. The results are compared with those of an earlier study of this problem using a spectral Tau-Chebyshev method. The good agreement found assesses the finite element model. Finally, a complementary convergence analysis gives the sensitivity of the model to mesh refinement.

Jaeger, M.; Medale, M.; Randriamanpianina, A. [Centre National de la Recherche Scientifique, Marseille (France)

1996-12-01T23:59:59.000Z

322

Ising models for neural activity inferred via Selective Cluster Expansion: structural and coding  

E-Print Network (OSTI)

Ising models for neural activity inferred via Selective Cluster Expansion: structural and coding) of the entropy, a method for inferring an Ising model which describes the correlated activity of populations: statistical inference, neuronal networks #12;Ising models for neural activity inferred via Selective Cluster

Cocco, Simona

323

Numerical investigation of the physical model of a high-power electromagnetic wave in a magnetically insulated transmission line  

SciTech Connect

An efficient numerical code for simulating the propagation of a high-power electromagnetic pulse in a vacuum transmission line is required to study the physical phenomena occurring in such a line, to analyze the operation of present-day megavolt generators at an {approx}10-TW power level, and to design such new devices. The main physical theoretical principles are presented, and the stability of flows in the near-threshold region at the boundary of the regime of magnetic self-insulation is investigated based on one-dimensional telegraph equations with electron losses. Numerical (difference) methods-specifically, a method of characteristics and a finite-difference scheme-are described and their properties and effectiveness are compared by analyzing the high-frequency modes.

Samokhin, A. A. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

2010-02-15T23:59:59.000Z

324

Application of the distributed activation energy model to blends devolatilisation  

Science Journals Connector (OSTI)

In this study, an investigation was carried out into the thermal behaviour of coal, petcoke and their blend as a generic feedstock in combustion and IGCC plants for energy production. The samples were pyrolysed in a TG analyzer in nitrogen atmosphere (constant flow of 0.0335 m/s) at several heating rates with temperatures ranging from 300 to 1223 K. The distributed activation energy model was applied to study the effects of heating rates on the reactions of single solids. The results obtained were used in the calculation of curves mass loss vs. temperature at more realistic heating rates. The algorithm used to obtain the distribution of reactivities for single solids was successfully implemented to allow the prediction of blends performance.

M.V. Navarro; A. Aranda; T. Garcia; R. Murillo; A.M. Mastral

2008-01-01T23:59:59.000Z

325

Boron-10 ABUNCL Prototype Models And Initial Active Testing  

SciTech Connect

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.

Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

2013-04-23T23:59:59.000Z

326

Model-based Controllers for Semi-active Control  

E-Print Network (OSTI)

damper Base isolation TLCD Semi-active Control Active mass driver Active tendon Variable orifice damper/13/2012Page 11 Linearized explicit approximation Small perturbations Accuracy of the assumed rappresentation

327

Numerical modelling and experimental studies of thermal behaviour of building integrated thermal energy storage unit in a form of a ceiling panel  

Science Journals Connector (OSTI)

AbstractObjective The paper presents a new concept of building integrated thermal energy storage unit and novel mathematical and numerical models of its operation. This building element is made of gypsum based composite with microencapsulated PCM. The proposed heat storage unit has a form of a ceiling panel with internal channels and is, by assumption, incorporated in a ventilation system. Its task is to reduce daily variations of ambient air temperature through the absorption (and subsequent release) of heat in PCM, without additional consumption of energy. Methods The operation of the ceiling panel was investigated experimentally on a special set-up equipped with temperature sensors, air flow meter and air temperature control system. Mathematical and numerical models of heat transfer and fluid flow in the panel account for air flow in the panel as well as real thermal properties of the PCM composite, i.e.: thermal conductivity variation with temperature and hysteresis of enthalpy vs. temperature curves for heating and cooling. Proposed novel numerical simulator consists of two strongly coupled sub models: the first one – 1D – which deals with air flowing through the U-shaped channel and the second one – 3D – which deals with heat transfer in the body of the panel. Results Spatial and temporal air temperature variations, measured on the experimental set-up, were used to validate numerical model as well as to get knowledge of thermal performance of the panel operating in different conditions. Conclusion Preliminary results of experimental tests confirmed the ability of the proposed heat storage unit to effectively control the air temperature inside the building. However, detailed measurement of the temperature of PCM composite have shown some disadvantages of the panel used in the study, e.g. thickness of the walls and distribution of PCM should be optimized. This can be achieved with the aid of the numerical simulator developed in this research. Practical implications The proposed ceiling panel, optimised from the point of view of thermal performance in a given environmental conditions, can be used as a part of ventilation systems in residential and office buildings.

Maciej Jaworski; Piotr ?apka; Piotr Furma?ski

2014-01-01T23:59:59.000Z

328

Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model  

E-Print Network (OSTI)

with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

Schuh, Harald

329

Numerical studies of a one-dimensional three-spin spin-glass model with long-range interactions  

E-Print Network (OSTI)

We study a p-spin spin-glass model to understand if the finite-temperature glass transition found in the mean-field regime of p-spin models, and used to model the behavior of structural glasses, persists in the nonmean-field regime. By using a three...

Larson, Derek; Katzgraber, Helmut G.; Moore, M. A.; Young, A. P.

2010-01-01T23:59:59.000Z

330

Temporal characteristics of resonant surface polaritons in superlensing planar double-negative slabs: Development of analytical schemes and numerical models  

Science Journals Connector (OSTI)

The temporal behavior of electric fields in arbitrary double-negative planar slabs is systematically investigated in this paper, from both analytical and numerical perspectives. Concerning infinite slabs, a set of exact expressions for an exponential current excitation is derived through an efficient complex analysis, and an integrated study of surface polariton frequencies is performed. Subsequently, the significant case of a source with a random spatial profile is explored in order to obtain rigorous relations for the field and transient phenomena damping time with respect to problem parameters. On the other hand, a robust finite-difference time-domain methodology is introduced for the comprehensive examination of finite slabs, whose numerical simulations dictate the adoption of a resonatorlike discipline. This inevitable, yet very instructive, convention is physically justified by the almost perfect surface mode reflections at the edges of the slab. In this manner, the proposed formulation reveals a prominent increase in the excited polariton amplitude, relative to the corresponding infinite arrangements, which leads to larger transient times.

Dimitrios L. Sounas; Nikolaos V. Kantartzis; Theodoros D. Tsiboukis

2007-10-17T23:59:59.000Z

331

Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models  

E-Print Network (OSTI)

compressible numerical weather prediction model incompressible numerical weather prediction model withcompressible numerical weather prediction model in

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

332

Modeling of activation data in the BrainMap TM database: Detection of outliers  

E-Print Network (OSTI)

Modeling of activation data in the BrainMap TM database: Detection of outliers Finn š Arup Nielsen@imm.dtu.dk 1 #12; ABSTRACT We describe a system for meta­analytical modeling of activation foci from functional neuroimaging studies. Our main vehicle is a set of density models in Talairach space capturing the distribution

Nielsen, Finn Ã?rup

333

A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification  

E-Print Network (OSTI)

A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification Ilenia of the Activated Sludge Models (ASM) [Henze, M., Gujer, W., Mino, T., van Loosdrecht, M.C.M., 2000. Ac- tivated Sludge Models ASM1, ASM2, ASM2d, and ASM3. IWA Scientific and Technical Report No. 9. IWA Publishing

334

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic Controlled Variable Selection  

E-Print Network (OSTI)

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no structure that leads to optimal economic operation, while promptly rejecting disturbances at lower layers

Skogestad, Sigurd

335

Current Challenges for Modeling Enzyme Active Sites by Biomimetic Synthetic Diiron Complexes  

E-Print Network (OSTI)

This tutorial review describes recent progress in modeling the active sites of carboxylate-rich non-heme diiron enzymes that activate dioxygen to carry out several key reactions in Nature. The chemistry of soluble methane ...

Friedle, Simone

336

Enhanced activity of Pt foil model catalysts thermally treated under UHV conditions  

Science Journals Connector (OSTI)

The thermal treatment of Pt foil model catalysts under UHV conditions leads to an enhanced activity for...2-D2 exchange. For the enhanced activity, the UHV atmosphere, a temperature of 1073 K and ... surface roug...

Satoru Nishiyama; Masahiro Akemoto…

1996-09-01T23:59:59.000Z

337

Amending Numerical Weather Prediction forecasts using GPS  

E-Print Network (OSTI)

. Satellite images and Numerical Weather Prediction (NWP) models are used together with the synoptic surfaceAmending Numerical Weather Prediction forecasts using GPS Integrated Water Vapour: a case study to validate the amounts of humidity in Numerical Weather Prediction (NWP) model forecasts. This paper presents

Stoffelen, Ad

338

Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1  

SciTech Connect

Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.

Gupta, Prabhat Kumar [Raja Ramanna Centre for Advanced Technology (RRCAT), Indore (MP), India; Rabehl, Roger [FNAL

2014-07-01T23:59:59.000Z

339

Numerical simulation of detonation structures using a thermodynamically consistent and fully conservative reactive flow model for multi-component computations  

Science Journals Connector (OSTI)

...there have been many advances in detonation modelling...apparent in figure 7 c. Recent experimental investigation...support by the Natural Sciences and Engineering Research...mixtures. In 42nd AIAA Aerospace Science Meeting and Exhibit...

2009-01-01T23:59:59.000Z

340

Numerical Simulation of the Meso-? Scale Structure and Evolution of the 1977 Johnstown Flood. Part I: Model Description and Verification  

Science Journals Connector (OSTI)

The Pennsylvania State University/NCAR mesoscale model, originally developed by Anthes and Warner, is modified to simulate the meso-? scale structure and evolution of convectively driven weather systems. The modifications include: (i) two-way ...

Da-Lin Zhang; J. Michael Fritsch

1986-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Assessment of the ocean circulation in the Azores region as predicted by a numerical model assimilating altimeter data  

E-Print Network (OSTI)

) on the new perspectives in data assimilation). In the SIMAN project (SIMulation de l'Atlantique Nord Stream area (Blayo et al., 1996). It has been shown that the model is able to reproduce

Paris-Sud XI, Université de

342

Numerical modeling of in-flight characteristics of inconel 625 particles during high-velocity oxy-fuel thermal spraying  

Science Journals Connector (OSTI)

A computational fluid dynamics (CFD) model is developed to predict particle dynamic behavior in a high-velocity oxyfuel (HVOF) thermal spray gun in which premixed oxygen and propylene are ... 20 to 40 µm. At a pa...

S. Gu; D. G. McCartney; C. N. Eastwick; K. Simmons

2004-01-01T23:59:59.000Z

343

Development of analytical and numerical models predicting the deposition rate of electrically charged particles in turbulent channel flows  

E-Print Network (OSTI)

An analytical model is established to predict an electrostatically charged particle deposition as a function of particle size in fully-developed turbulent pipe flow. The convectivediffusion flux equation is solved for the particle concentration as a...

Ko, Hanseo

2012-06-07T23:59:59.000Z

344

Comparison of Snow Cover from Satellite and Numerical Weather Prediction Models in the Northern Hemisphere and Northern Europe  

Science Journals Connector (OSTI)

Snow cover has a strong effect on the surface and lower atmosphere in NWP models. Because the progress of in situ observations has stalled, satellite-based snow analyses are becoming increasingly important. Currently, there exist several products ...

Otto Hyvärinen; Kalle Eerola; Niilo Siljamo; Jarkko Koskinen

2009-06-01T23:59:59.000Z

345

A three-layer ocean circulation model application to numerical studies on the North Pacific Ocean circulation  

Science Journals Connector (OSTI)

The formulation and justification of a three-layer baroclinic ocean model developed to simulate the general circulation of the ocean are described in this paper. Test of ... the annual mean circulation patterns i...

Zhang Li-ping; Qin Zeng-hao

1994-09-01T23:59:59.000Z

346

Numerical modeling of time-lapse seismic data from fractured reservoirs including fluid flow and geochemical processes  

E-Print Network (OSTI)

Discrete Fracture Network (DFN) models. My seismic simulation study suggests that CO2 saturated reservoir shows approximately ten times more attenuation than brine saturated reservoir. Similarly, large P-wave velocity variation in CO2 saturated reservoir...

Shekhar, Ravi

2009-05-15T23:59:59.000Z

347

RECIPIENT:Desert Research Institute STATE:NV PROJECT Tall Tower Wind Energy Monitoring and Numerical Model Validation in Southern Nevada; NREl Tracking  

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

Desert Research Institute STATE:NV Desert Research Institute STATE:NV PROJECT Tall Tower Wind Energy Monitoring and Numerical Model Validation in Southern Nevada; NREl Tracking TITLE: No. 11-012 Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number CID Number NREl-11-012 G010337 Based on my review of the information concerning the proposed action, as NEPA CompHance Officer (authorized under DOE Order 451.1A), I have made the following determination: CX, EA, EIS APPENDIX AND NUMBER: Description: A9 Information gathering (including, but not limited to, literature surveys, inventories, audits), data analYSis (including computer modeling), document preparation (such as conceptual deSign or feasibility studies, analytical energy supply and demand studies), and dissemination (including, but not limited to, document mailings, publication, and distribution;

348

Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 episodic events in southern Lake Michigan  

SciTech Connect

A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive+noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically-based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are 1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and 2) the settling velocity of sediment flocs which controls the deposition location.

Lee, Cheegwan; Schwab, David J.; Beletsky, Dmitry; Stroud, Jonathan; Lesht, B. M.

2007-02-17T23:59:59.000Z

349

Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 episodic events in southern Lake Michigan.  

SciTech Connect

A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are (1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and (2) the settling velocity of sediment flocs which controls the deposition location.

Lee, C.; Schwab, D. J.; Beletsky, D.; Stroud, J.; Lesht, B.; PNNL; NOAA; Univ. of Michigan; Univ. of Pennsylvania

2007-02-17T23:59:59.000Z

350

Model Realization and Numerical Studies of a Three-Dimensional Bosonic Topological Insulator and Symmetry-Enriched Topological Phases  

E-Print Network (OSTI)

We study a topological phase of interacting bosons in (3+1) dimensions which is protected by charge conservation and time-reversal symmetry. We present an explicit lattice model which realizes this phase and which can be studied in sign-free Monte Carlo simulations. The idea behind our model is to bind bosons to topological defects called hedgehogs. We determine the phase diagram of the model and identify a phase where such bound states are proliferated. In this phase we observe a Witten effect in the bulk whereby an external monopole binds half of the elementary boson charge, which confirms that it is a bosonic topological insulator. We also study the boundary between the topological insulator and a trivial insulator. We find a surface phase diagram which includes exotic superfluids, a topologically ordered phase, and a phase with a Hall effect quantized to one-half of the value possible in a purely two-dimensional system. We also present models that realize symmetry-enriched topologically-ordered phases by binding multiple hedgehogs to each boson; these phases show charge fractionalization and intrinsic topological order as well as a fractional Witten effect.

Scott Geraedts; Olexei Motrunich

2014-08-05T23:59:59.000Z

351

A fully nonlinear, dynamically consistent numerical model for solid-body ship motion. I. Ship motion with fixed heading  

Science Journals Connector (OSTI)

...surface and the buoyancy effect from the underwater volume of the actual ship hull with a hybrid finite-difference...strongly nonlinear effects in ship motion; and (iii...Kuang2007Modeling the effects of ship appendages on the six-degree...

2011-01-01T23:59:59.000Z

352

Physical Modeling of the Motions of a Container Ship Moored to a Dock with Comparison to Numerical Simulation  

E-Print Network (OSTI)

ship moored to a dock, a 1:50 scale model is moored to two types of dock, solid wall dock and pile supported dock. Irregular waves of TMA spectrum with various periods, heights, and directions are generated in the wave basin to induce the motions...

Zhi, Yuanzhe

2013-07-11T23:59:59.000Z

353

Modeling - Scale-Bridging Simulations Active Materials in Li...  

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

& Publications Microscale Electrode Design Using Coupled Kinetic, Thermal and Mechanical Modeling Overview of the Batteries for Advanced Transportation Technologies (BATT)...

354

Numerical Modeling Studies of The Dissolution-Diffusion-Convection ProcessDuring CO2 Storage in Saline Aquifers  

SciTech Connect

For purposes of geologic storage, CO2 would be injected into saline formations at supercritical temperature and pressure conditions, and would form a separate phase that is immiscible with the aqueous phase (brine). At typical subsurface temperature and pressure conditions, supercritical CO2 (scCO2) has lower density than the aqueous phase and would experience an upward buoyancy force. Accordingly, the CO2 is expected to accumulate beneath the caprock at the top of the permeable interval, and could escape from the storage formation wherever (sub-)vertical pathways are available, such as fractures or faults through the caprock, or improperly abandoned wells. Over time, an increasing fraction of CO2 may dissolve in the aqueous phase, and eventually some of the aqueous CO2 may react with rock minerals to form poorly soluble carbonates. Dissolution into the aqueous phase and eventual sequestration as carbonates are highly desirable processes as they would increase permanence and security of storage. Dissolution of CO2 will establish phase equilibrium locally between the overlying CO2 plume and the aqueous phase beneath. If the aqueous phase were immobile, CO2 dissolution would be limited by the rate at which molecular diffusion can remove dissolved CO2 from the interface between CO2-rich and aqueous phases. This is a slow process. However, dissolution of CO2 is accompanied by a small increase in the density of the aqueous phase, creating a negative buoyancy force that can give rise to downward convection of CO2-rich brine, which in turn can greatly accelerate CO2 dissolution. This study explores the process of dissolution-diffusion-convection (DDC), using high-resolution numerical simulation. We find that geometric features of convection patterns are very sensitive to small changes in problem specifications, reflecting self-enhancing feedbacks and the chaotic nature of the process. Total CO2 dissolution rates on the other hand are found to be quite robust against modest changes in problem parameters, and are essentially constant as long as no dissolved CO2 reaches the lower boundary of the system.

Pruess, Karsten; Zhang, Keni

2008-11-17T23:59:59.000Z

355

Coupled axisymmetric finite element model of a hydraulically amplified magnetostrictive actuator for active powertrain mounts  

Science Journals Connector (OSTI)

A coupled axisymmetric finite element model is formulated to describe the dynamic performance of a hydraulically amplified magnetostrictive actuator for active powertrain mounts. The formulation is based on the weak form representations of Maxwell's ... Keywords: Active powertrain mount, Actuator, Axisymmetric model, Magnetostriction, Terfenol-D

Suryarghya Chakrabarti; Marcelo J. Dapino

2012-11-01T23:59:59.000Z

356

Categories and Functional Units: An Infinite Hierarchical Model for Brain Activations  

E-Print Network (OSTI)

Categories and Functional Units: An Infinite Hierarchical Model for Brain Activations Danial present a model that describes the structure in the responses of different brain areas to a set of stimuli encodes the relationship between brain activations and fMRI time courses. A variational inference

Golland, Polina

357

Modeling and characterization of potato quality by active thermography  

E-Print Network (OSTI)

This research focuses on characterizing a potato with extra sugar content and identifying the location and depth of the extra sugar content using the active thermography imaging technique. The extra sugar content of the potato is an important...

Sun, Chih-Chen

2009-05-15T23:59:59.000Z

358

Numerical Modeling of Footpoint-driven Magneto-acoustic Wave Propagation in a Localized Solar Flux Tube  

Science Journals Connector (OSTI)

In this paper, we present and discuss results of two-dimensional simulations of linear and nonlinear magneto-acoustic wave propagation through an open magnetic flux tube embedded in the solar atmosphere expanding from the photosphere through to the transition region and into the low corona. Our aim is to model and analyze the response of such a magnetic structure to vertical and horizontal periodic motions originating in the photosphere. To carry out the simulations, we employed our MHD code SAC (Sheffield Advanced Code). A combination of the VALIIIC and McWhirter solar atmospheres and coronal density profiles were used as the background equilibrium model in the simulations. Vertical and horizontal harmonic sources, located at the footpoint region of the open magnetic flux tube, are incorporated in the calculations, to excite oscillations in the domain of interest. To perform the analysis we have constructed a series of time-distance diagrams of the vertical and perpendicular components of the velocity with respect to the magnetic field lines at each height of the computational domain. These time-distance diagrams are subject to spatio-temporal Fourier transforms allowing us to build ?-k dispersion diagrams for all of the simulated regions in the solar atmosphere. This approach makes it possible to compute the phase speeds of waves propagating throughout the various regions of the solar atmosphere model. We demonstrate the transformation of linear slow and fast magneto-acoustic wave modes into nonlinear ones, i.e., shock waves, and also show that magneto-acoustic waves with a range of frequencies efficiently leak through the transition region into the solar corona. It is found that the waves interact with the transition region and excite horizontally propagating surface waves along the transition region for both types of drivers. Finally, we estimate the phase speed of the oscillations in the solar corona and compare it with the phase speed derived from observations.

V. Fedun; S. Shelyag; R. Erdélyi

2011-01-01T23:59:59.000Z

359

Multiple solutions and numerical analysis to the dynamic and stationary models coupling a delayed energy balance model involving latent heat and discontinuous albedo with a deep ocean  

Science Journals Connector (OSTI)

...variability of an energy-balance model with...instability in an energy balance model. Clim...differential equations. New York, NY: Springer...of some diffusive energy balance climate models...pp. 101-156. New York, NY: Academic Press...

2014-01-01T23:59:59.000Z

360

Numerical Modeling of Hydrate Formation in Sand Sediment Simulating Sub-Seabed CO2 Storage in the form of Gas Hydrate  

Science Journals Connector (OSTI)

Abstract Among several methods for CO2 capture and storage, we focus on CO2 sequestration in the form of gas hydrate under the seafloor, mainly for many sequestration sites offshore Japan and for little risk of CO2 leakage from the sediment. However, it is difficult to evaluate the precise storage potential and cost of this method due to the lack of the relevant information. Here, in order to do feasibility studies of this technique so as to make an effective storage method, we made a 3-dimentional gas water flow simulator with kinetic hydrate formation. The new design of CO2 hydrate formation in porous media under two-phase flow condition was implemented in this simulator, and unknown parameters in necessary mathematical models for gas-water flow in sand sediments were verified from the comparison between the results of the numerical simulations and the experimental measurements from the previous study.

Takuya Nakashima; Toru Sato; Masayuki Inui

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Comparison of unsaturated flow and solute transport through waste rock at two experimental scales using temporal moments and numerical modeling  

Science Journals Connector (OSTI)

Abstract This study analyzed and compared unsaturated flow response and tracer breakthrough curves from a 10-m high constructed pile experiment (CPE) in the field (Antamina, Peru) and two 0.8 m high laboratory-based columns. Similar materials were used at both experimental scales, with the exception of a narrower grain size distribution range for the smaller column tests. Observed results indicate flow and solute transport regimes between experimental scales were comparable, dominated by flow and solute migration through granular matrix materials. These results are supported by: analogous breakthrough curves (normalized to cross-sectional area and flow path length) that suggest observation- or smaller- scale heterogeneities within the porous media have been homogenized or smoothed at the transport-scale, long breakthrough tails, and similar recovered tracer mass fractions (i.e., 0.72 – 0.80) at the end of the experiment. CPE breakthrough curves do indicate a portion of the fluid flow follows rapid flow paths (open void or film flow); however, this portion accounts for a minor (i.e., ~ 0.1%) component of the overall flow and transport regime. Flow-corrected temporal moment analysis was used to estimate flow and transport parameter values, however large temporal variations in flow indicate this method is better suited for conceptualizing transport regimes. In addition, a dual-porosity mobile-immobile (MIM), rate-limited mass-transfer approach was able to simulate tracer breakthrough and the dominant transport regimes from both scales. Dispersivity values used in model simulations reflect a scale-dependency, whereby column values were approximately 2x smaller than those values applied in CPE simulations. The mass-transfer coefficient, for solute transport between mobile and immobile regions, was considered as a model calibration factor. Column experiments are characterized by a larger ‘mobile to immobile’ porosity ratio and a shorter experimental duration and flow path, which supports larger mass-transfer coefficient values (relative to the CPE). These results demonstrate that laboratory-based experiments may be able to mimic flow regimes observed in the field; however, the requirement of scale-dependent dispersivities and in particular mass-transfer coefficients indicates these tests may be more limited in understanding larger-scale solute transport between regions of different mobility. Nevertheless, the results of this study suggest that the reasonably simplistic modeling approaches utilized in this study may be applied at other field sites to estimate parameters and conceptualize dominant transport processes through highly heterogeneous, unsaturated material.

Sharon Blackmore; Leslie Smith; K. Ulrich Mayer; Roger D. Beckie

2014-01-01T23:59:59.000Z

362

APPLYING ACTIVITY PATTERNS FOR DEVELOPING AN INTELLIGENT PROCESS MODELING TOOL  

E-Print Network (OSTI)

attracting the interest of both BPM researchers and BPM tool vendors. Frequently, process models can Process Management (BPM) tools as well as emerging patterns for process modeling and change. BPM processes of an enterprise. Moreover, through Web service technology, the benefits of BPM can be created

Ulm, Universität

363

A depth-averaged debris-flow model that includes the effects of evolving dilatancy. II. Numerical predictions and experimental tests  

Science Journals Connector (OSTI)

...satisfies numerical conservation by using a similarity...details). Numerical conservation of quantities transported...include a motionless pool of water lying over variable...2003 Shallow-water theory for arbitrary...1960 Systems of conservation laws. Comm. Pure...

2014-01-01T23:59:59.000Z

364

numerical models & information Systems, Nice: France (2013)" Environmental impact for offshore wind farms: Geolocalized Life Cycle Assessment (LCA) approach  

E-Print Network (OSTI)

Abstract. This paper presents an approach for Environmental Impact Assessment through the use of geolocalized LCA approach, for fixed and floating offshore wind farms. This work was undertaken within the EUsponsored EnerGEO project, aiming at providing a versatile modeling platform for stakeholders allowing calculation, forecasting and monitoring of environmental impacts of different sources of energy. This paper described the geolocalized LCA approach, and its use for the evaluation of environmental impacts of wind energy. The effects of offshore wind farms on global environnemental impacts are evaluated though the LCA approach. It takes into account the type of wind farm, the construction phase, all technical aspects, the operation and maintenance scheme and the decommissioning. It also includes geolocalized information such as wind resources, bathymetry, accessibility … Environmental impact parameters are accessible through a web service helping the decision makers in assessing the environnemental impacts. 1

Catherine Guermont; Lionel Ménard; Isabelle Blanc

2013-01-01T23:59:59.000Z

365

Near-Infrared and X-ray Quasi-Periodic Oscillations in Numerical Models of Sgr A*  

E-Print Network (OSTI)

We report transient quasi-periodic oscillations (QPOs) on minute timescales in relativistic, radiative models of the galactic center source Sgr A*. The QPOs result from nonaxisymmetric $m=1$ structure in the accretion flow excited by MHD turbulence. Near-infrared (NIR) and X-ray power spectra show significant peaks at frequencies comparable to the orbital frequency at the innermost stable circular orbit (ISCO) $f_o$. The excess power is associated with inward propagating magnetic filaments inside the ISCO. The amplitudes of the QPOs are sensitive to the electron distribution function. We argue that transient QPOs appear at a range of frequencies in the neighborhood of $f_o$ and that the power spectra, averaged over long times, likely show a broad bump near $f_o$ rather than distinct, narrow QPO features.

Joshua C. Dolence; Charles F. Gammie; Hotaka Shiokawa; Scott C. Noble

2012-01-09T23:59:59.000Z

366

Numerical study on convection diffusion for gasification agent in underground coal gasification. Part I: establishment of mathematical models and solving method  

SciTech Connect

The aim of this article is to discuss the distribution law of the gasification agent concentration in a deep-going way during underground coal gasification and the new method of solving the problem for the convection diffusion of the gas. In this paper, the basic features of convection diffusion for the gas produced in underground coal gasification are studied. On the basis of the model experiment, through the analysis of the distribution and patterns of variation for the fluid concentration field in the process of the combustion and gasification of the coal seams within the gasifier, the 3-D non-linear unstable mathematical models on the convection diffusion for oxygen are established. In order to curb such pseudo-physical effects as numerical oscillation and surfeit which frequently occurred in the solution of the complex mathematical models, the novel finite unit algorithm, the upstream weighted multi-cell balance method is advanced in this article, and its main derivation process is introduced.

Yang, L.H.; Ding, Y.M. [China University of Mining & Technology, Xuzhou (China). College of Resources and Geoscience

2009-07-01T23:59:59.000Z

367

Numerical simulations of particle growth in a silicon-CVD fluidized bed reactor via a CFD–PBM coupled model  

Science Journals Connector (OSTI)

Abstract A Eulerian–Eulerian two-fluid model coupled with population balance equations was applied to simulate the evolution of silicon particle growth by chemical vapor deposition of silane pyrolysis in a three-dimensional slugging fluidized bed reactor using FLUENT. The simulation of the particle growth considering surface deposition, cluster scavenging, aggregation and wall deposition was carried out after the verification of flow and heat transfer characteristics based on the well-accepted correlations. The results showed that the scavenging effect was responsible for the particle growth, and the growth rate agreed well with the experimental data by Tejero-Ezpeleta et al. (2004) when the scavenging factor was set to 0.1 under the condition of 923 K and atmospheric pressure. Moreover, the formation of light silicon hydrides by silane homogeneous pyrolysis in the dilute phase was also investigated in the form of CHMEKIN mechanism, which showed that disilane turned to be the main silicon hydride and the silane conversion was underestimated by 12.5%. Finally, the effects of operating conditions on the growth rate were studied in detail with the observation of defluidization phenomenon during the evolution of particle growth.

Si-Si Liu; Wen-De Xiao

2014-01-01T23:59:59.000Z

368

FiltrationinPorousMediaandIndustrialApplications(Cetraro,Italy1998),9-77,LectureNotesinMath.,1734,Springer,Berlin,2000 NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON  

E-Print Network (OSTI)

-oil model is commonly used to describe water injection. This model works well in simulating water flooding to the construction and analysis of large time step operator splitting algorithms for the numerical simulation. Reservoir Simulation. 8. Acknowledgement. 1. Introduction The flow in subsurface hydrology

Karlsen, Kenneth Hvistendahl

369

turbulent heat International Journal of Numerical  

E-Print Network (OSTI)

Enhanced turbulent heat transfer 47 International Journal of Numerical Methods for Heat & Fluid, Hsinchu,Taiwan Keywords Heat transfer, Fluids, Flow, Turbulence, Numerical methods Abstract This study evaluates low Reynolds number models of turbulence for numerical computations on the heat transfer and fluid

Lin, Wen-Wei

370

Multiple solutions and numerical analysis to the dynamic and stationary models coupling a delayed energy balance model involving latent heat and discontinuous albedo with a deep ocean  

Science Journals Connector (OSTI)

...6. Funding statement The research of J.I.D. and L.T...2014 Parameter estimation for energy balance models with memory...Diaz, and II Vrabie. 2001 An abstract approximate controllability...analysis of some diffusive energy balance climate models. Mathematics...

2014-01-01T23:59:59.000Z

371

Integrated Modeling and Design of Lightweight, Active Mirrors for Launch Survival and On-Orbit  

E-Print Network (OSTI)

Integrated Modeling and Design of Lightweight, Active Mirrors for Launch Survival and On-Orbit Performance Lucy E. Cohan and David W. Miller June 2010 SSL# 2-10 #12;#12;Integrated Modeling and Design-based design and evolutionary models to guide the technology development program. This methodology is applied

372

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING Int. J. Numer. Meth. Biomed. Engng. 2014; 30:15971613  

E-Print Network (OSTI)

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING Int. J. Numer. Meth. Biomed BIOMEDICAL ENGINEERING 2013 A finite strain nonlinear human mitral valve model with fluid. © 2014 The Authors. International Journal for Numerical Methods in Biomedical Engineering published

Luo, Xiaoyu

373

Mixing Cell Model: A One-Dimensional Numerical Model for Assessment of Water Flow and Contaminant Transport in the Unsaturated Zone  

SciTech Connect

This report describes the Mixing Cell Model code, a one-dimensional model for water flow and solute transport in the unsaturated zone under steady-state or transient flow conditions. The model is based on the principles and assumptions underlying mixing cell model formulations. The unsaturated zone is discretized into a series of independent mixing cells. Each cell may have unique hydrologic, lithologic, and sorptive properties. Ordinary differential equations describe the material (water and solute) balance within each cell. Water flow equations are derived from the continuity equation assuming that unit-gradient conditions exist at all times in each cell. Pressure gradients are considered implicitly through model discretization. Unsaturated hydraulic conductivity and moisture contents are determined by the material-specific moisture characteristic curves. Solute transport processes include explicit treatment of advective processes, first-order chain decay, and linear sorption reactions. Dispersion is addressed through implicit and explicit dispersion. Implicit dispersion is an inherent feature of all mixing cell models and originates from the formulation of the problem in terms of mass balance around fully mixed volume elements. Expressions are provided that relate implicit dispersion to the physical dispersion of the system. Two FORTRAN codes were developed to solve the water flow and solute transport equations: (1) the Mixing-Cell Model for Flow (MCMF) solves transient water flow problems and (2) the Mixing Cell Model for Transport (MCMT) solves the solute transport problem. The transient water flow problem is typically solved first by estimating the water flux through each cell in the model domain as a function of time using the MCMF code. These data are stored in either ASCII or binary files that are later read by the solute transport code (MCMT). Code output includes solute pore water concentrations, water and solute inventories in each cell and at each specified output time, and water and solute fluxes through each cell and specified output time. Computer run times for coupled transient water flow and solute transport were typically several seconds on a 2 GHz Intel Pentium IV desktop computer. The model was benchmarked against analytical solutions and finite-element approximations to the partial differential equations (PDE) describing unsaturated flow and transport. Differences between the maximum solute flux estimated by the mixing-cell model and the PDE models were typically less than two percent.

A. S. Rood

2009-04-01T23:59:59.000Z

374

Mixing Cell Model: A One-Dimensional Numerical Model for Assessment of Water Flow and Contaminant Transport in the Unsaturated Zone  

SciTech Connect

This report describes the Mixing Cell Model code, a one-dimensional model for water flow and solute transport in the unsaturated zone under steady-state or transient flow conditions. The model is based on the principles and assumptions underlying mixing cell model formulations. The unsaturated zone is discretized into a series of independent mixing cells. Each cell may have unique hydrologic, lithologic, and sorptive properties. Ordinary differential equations describe the material (water and solute) balance within each cell. Water flow equations are derived from the continuity equation assuming that unit-gradient conditions exist at all times in each cell. Pressure gradients are considered implicitly through model discretization. Unsaturated hydraulic conductivity and moisture contents are determined by the material-specific moisture characteristic curves. Solute transport processes include explicit treatment of advective processes, first-order chain decay, and linear sorption reactions. Dispersion is addressed through implicit and explicit dispersion. Implicit dispersion is an inherent feature of all mixing cell models and originates from the formulation of the problem in terms of mass balance around fully mixed volume elements. Expressions are provided that relate implicit dispersion to the physical dispersion of the system. Two FORTRAN codes were developed to solve the water flow and solute transport equations: (1) the Mixing-Cell Model for Flow (MCMF) solves transient water flow problems and (2) the Mixing Cell Model for Transport (MCMT) solves the solute transport problem. The transient water flow problem is typically solved first by estimating the water flux through each cell in the model domain as a function of time using the MCMF code. These data are stored in either ASCII or binary files that are later read by the solute transport code (MCMT). Code output includes solute pore water concentrations, water and solute inventories in each cell and at each specified output time, and water and solute fluxes through each cell and specified output time. Computer run times for coupled transient water flow and solute transport were typically several seconds on a 2 GHz Intel Pentium IV desktop computer. The model was benchmarked against analytical solutions and finite-element approximations to the partial differential equations (PDE) describing unsaturated flow and transport. Differences between the maximum solute flux estimated by the mixing-cell model and the PDE models were typically less than two percent.

A. S. Rood

2010-10-01T23:59:59.000Z

375

NUMERICAL MODELING OF THE DISRUPTION OF COMET D/1993 F2 SHOEMAKER-LEVY 9 REPRESENTING THE PROGENITOR BY A GRAVITATIONALLY BOUND ASSEMBLAGE OF RANDOMLY SHAPED POLYHEDRA  

SciTech Connect

We advance the modeling of rubble-pile solid bodies by re-examining the tidal breakup of comet Shoemaker-Levy 9, an event that occurred during a 1.33 R encounter with Jupiter in 1992 July. Tidal disruption of the comet nucleus led to a chain of sub-nuclei {approx}100-1000 m diameter; these went on to collide with the planet two years later. They were intensively studied prior to and during the collisions, making SL9 the best natural benchmark for physical models of small-body disruption. For the first time in the study of this event, we use numerical codes treating rubble piles as collections of polyhedra. This introduces forces of dilatation and friction, and inelastic response. As in our previous studies we conclude that the progenitor must have been a rubble pile, and we obtain approximately the same pre-breakup diameter ({approx}1.5 km) in our best fits to the data. We find that the inclusion of realistic fragment shapes leads to grain locking and dilatancy, so that even in the absence of friction or other dissipation we find that disruption is overall more difficult than in our spheres-based simulations. We constrain the comet's bulk density at {rho}{sub bulk} {approx} 300-400 kg m{sup -3}, half that of our spheres-based predictions and consistent with recent estimates derived from spacecraft observations.

Movshovitz, Naor; Asphaug, Erik; Korycansky, Donald, E-mail: nmovshov@ucsc.edu [Department of Earth and Planetary Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

2012-11-10T23:59:59.000Z

376

Reduced Activity of AMP-Activated Protein Kinase Protects against Genetic Models of Motor Neuron Disease  

E-Print Network (OSTI)

A growing body of research indicates that amyotrophic lateral sclerosis (ALS) patients and mouse models of ALS exhibit metabolic dysfunction. A subpopulation of ALS patients possesses higher levels of resting energy ...

Lim, M. A.

377

Activity synchrony and social cohesion: a fission-fusion model  

Science Journals Connector (OSTI)

...constant probability (fusion rate) which is equal for both group types. Since the model...The ssion and fusion of groups is a dynamic...groups of di erent types with time can be...are of the ssion^fusion type (i.e. animals...

2000-01-01T23:59:59.000Z

378

Variability in active galactic nuclei: confrontation of models with observations  

Science Journals Connector (OSTI)

......flux. The time-scale of the light variation corresponds to the...However, observations of quasar light curves imply time-scales of...parameter sets to produce simulated light curves from which they can evaluate...had come to be known as the Christmas tree model (Pica Smith 1983......

M.R.S. Hawkins

2002-01-01T23:59:59.000Z

379

A fully resolved active musculo-mechanical model for esophageal transport  

E-Print Network (OSTI)

Esophageal transport is a physiological process that mechanically transports an ingested food bolus from the pharynx to the stomach via the esophagus, a multi-layered muscular tube. This process involves interactions between the bolus, the esophagus, and the neurally coordinated activation of the esophageal muscles. In this work, we use an immersed boundary (IB) approach to simulate peristaltic transport in the esophagus. The bolus is treated as a viscous fluid that is actively transported by the muscular esophagus, which is modeled as an actively contracting, fiber-reinforced tube. A simplified version of our model is verified by comparison to an analytic solution to the tube dilation problem. Three different complex models of the multi-layered esophagus, which differ in their activation patterns and the layouts of the mucosal layers, are then extensively tested. To our knowledge, these simulations are the first of their kind to incorporate the bolus, the multi-layered esophagus tube, and muscle activation i...

Kou, Wenjun; Griffith, Boyce E; Pandolfino, John E; Kahrilas, Peter J; Patankar, Neelesh A

2015-01-01T23:59:59.000Z

380

(MIRU2011) 2011 7 ActiveAppearanceModel  

E-Print Network (OSTI)

Appearance Models AAM ) 2. 2. 1 1 Experimental environment . 1 IS2-11 : 572 #12;webcam 2. 2 2 System flow . 2, y1, z1, x2, y2, z2, ..., xn, yn, zn)T (21) 4. 3 Pose (8) Pose yaw pitch p = [yaw pitch roll scale = Trans Scale RotZ RotY RotX pb (23) (24) (28) yaw pitch roll T rans = ( 1 0 0 trans x 0 1 0 trans y 0

Takiguchi, Tetsuya

Note: This page contains sample records for the topic "activity numerical modeling" 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

Undefined 21-4 (2010) 1 1 Towards Automated Models of Activities of  

E-Print Network (OSTI)

-setting episodes. Keywords: Activity Modeling, Knowledge-based Action Analysis, Human Motion Tracking 1 observations of the same per- son allows to assess changes in the behavior. Also, powerful predictive

Cremers, Daniel

382

Modeling Polychlorinated Biphenyl Mass Transfer after Amendment of Contaminated Sediment with Activated Carbon  

Science Journals Connector (OSTI)

The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). We extend our evaluation of ...

David Werner; Upal Ghosh; Richard G. Luthy

2006-05-24T23:59:59.000Z

383

Numerical Modeling of HCCI Combustion  

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

Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs.

384

An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions  

E-Print Network (OSTI)

Article An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions, sounds that are known as spontaneous otoacoustic emissions. They are a signature of the active amplification mechanism in the cochlea. Emissions occur at frequencies that are unique for an individual

Juelicher, Frank

385

Highly Unstable Double-Diffusive Finger Convection in a Hele-Shaw Cell: Baseline Experimental Data for Evaluation of Numerical Models  

SciTech Connect

An experimental investigation was conducted to study double-diffusive finger convection in a Hele-Shaw cell by layering a sucrose solution over a more-dense sodium chloride (NaCl) solution. The solutal Rayleigh numbers were on the order of 60,000, based upon the height of the cell (25 cm), and the buoyancy ratio was 1.2. A full-field light transmission technique was used to measure a dye tracer dissolved in the NaCl solution. They analyze the concentration fields to yield the temporal evolution of length scales associated with the vertical and horizontal finger structure as well as the mass flux. These measures show a rapid progression through two early stages to a mature stage and finally a rundown period where mass flux decays rapidly. The data are useful for the development and evaluation of numerical simulators designed to model diffusion and convection of multiple components in porous media. The results are useful for correct formulation at both the process scale (the scale of the experiment) and effective scale (where the lab-scale processes are averaged-up to produce averaged parameters). A fundamental understanding of the fine-scale dynamics of double-diffusive finger convection is necessary in order to successfully parameterize large-scale systems.

PRINGLE,SCOTT E.; COOPER,CLAY A.; GLASS JR.,ROBERT J.

2000-12-21T23:59:59.000Z

386

Threedimensional numerical simulation for various geometries  

E-Print Network (OSTI)

Three­dimensional numerical simulation for various geometries of solid oxide fuel cells J.R. Ferguson 1 , J.M. Fiard 2 , and R. Herbin 3 Abstract A 3D mathematical model of a Solid Oxide Fuel Cell modelling and numerical simulation of natural gas­fed solid oxide cells (Solid Oxide Fuel Cell, SOFC

Herbin, Raphaèle

387

A Theory of Travel Decision-Making with Applications for Modeling Active Travel Demand  

E-Print Network (OSTI)

A Theory of Travel Decision-Making with Applications for Modeling Active Travel Demand by Patrick interdisciplinary framework for a theory of travel decision-making with applications for travel demand modeling behavior that have a large influence on the development of the theory of travel decision

Bertini, Robert L.

388

Numerical Simulation of Surfactant-Polymer Flooding  

Science Journals Connector (OSTI)

We propose a mathematical model (numerical simulation) of surfactant-polymer flooding for a three-phase six-component system. ... model takes into account various phenomena inherent to flooding, the effect of sur...

Baoguang Jin; Hanqiao Jiang; Xiansong Zhang…

2014-03-01T23:59:59.000Z

389

Models of transcription factor binding: Sensitivity of activation functions to model assumptions  

E-Print Network (OSTI)

on statistical physics, a Markov-chain model and a computational simulation. Comparison of these models suggests for cooperativity. The simulation model suggests that direct interactions between TFs are unlikely to be the main in this contribution, the assumption of the cell being a well stirred reactor makes a qualitative difference

Kent, University of

390

Model Products Available  

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

Available Available Archiving environmental data products has become recognized as a vital research practice: it improves our ability to reproduce results and perform additional analyses while saving the cost of redundant data collection activities. The same rationale applies to archiving numerical models. Archived models will provide the methodological detail of numerical modeling studies to recreate published modeling results, enabling the synthesis of results across modeling studies and the investigation of new hypotheses. In addition, archived models will allow determination of uncertainties for comparison with results from other models in assessment / policy studies. The model source code will also allow others to see how models treat individual processes. We are creating a two-tiered archive for numerical models. The first tier

391

A New Model to Study ICT Adoption in Connection with Physical Activity – The TAMPA-Model  

Science Journals Connector (OSTI)

Physical inactivity is one of the leading risks for mortality worldwide. One of future main drivers for physical activity could be information and communication technology (ICT) gadgets and services that suppo...

Eija Koskivaara; Raija Laukkanen; Olli J. Heinonen

2011-01-01T23:59:59.000Z

392

Crosstalk and transitions between multiple spatial maps in an attractor neural network model of the hippocampus: Collective motion of the activity  

Science Journals Connector (OSTI)

The dynamics of a neural model for hippocampal place cells storing spatial maps is studied. In the absence of external input, depending on the number of cells and on the values of control parameters (number of environments stored, level of neural noise, average level of activity, connectivity of place cells), a “clump” of spatially localized activity can diffuse or remains pinned due to crosstalk between the environments. In the single-environment case, the macroscopic coefficient of diffusion of the clump and its effective mobility are calculated analytically from first principles and corroborated by numerical simulations. In the multienvironment case the heights and the widths of the pinning barriers are analytically characterized with the replica method; diffusion within one map is then in competition with transitions between different maps. Possible mechanisms enhancing mobility are proposed and tested.

R. Monasson and S. Rosay

2014-03-11T23:59:59.000Z

393

An international land-biosphere model benchmarking activity for the IPCC Fifth Assessment Report (AR5)  

SciTech Connect

The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Project (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.

Hoffman, Forrest M [ORNL; Randerson, James T [ORNL; Thornton, Peter E [ORNL; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Erickson III, David J [ORNL; Fung, Inez [University of California, Berkeley

2009-12-01T23:59:59.000Z

394

Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease  

SciTech Connect

Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

Wu, Weibin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China) [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China); Zhu, Bo; Peng, Xiaomin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China)] [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China)] [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Jia, Dongwei, E-mail: jiadongwei@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China)] [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China) [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China)

2014-01-03T23:59:59.000Z

395

Activities  

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

Activities and events provide Residential Network members the opportunity to discuss similar needs and challenges, and to collectively identify effective strategies and useful resources.

396

Mean First-Passage Time Calculations for the Coil-to-Helix Transition:? The Active Helix Ising Model  

Science Journals Connector (OSTI)

Mean First-Passage Time Calculations for the Coil-to-Helix Transition:? The Active Helix Ising Model† ... The kinetics and thermodynamics of the coil-to-helix transition is studied using a one-dimensional “Zimm?Bragg” Ising model. ... 4. Mean First-Passage Time for the Active-Helix Ising Model ...

Nicolae-Viorel Buchete; John E. Straub

2001-06-20T23:59:59.000Z

397

Numerical investigation of transient hydrothermal processes around intrusions: heat-transfer and fluid-  

E-Print Network (OSTI)

Numerical investigation of transient hydrothermal processes around intrusions: heat the intrusion. Keywords: Hydrothermal processes, numerical modelling, magmatic intrusion, permeability- depth around magmatic intrusions have been obtained through coupled hydrothermal numerical modelling that takes

Paris-Sud XI, Université de

398

A quantum cascade laser in a transverse magnetic field. A model of the open triple-barrier active region  

Science Journals Connector (OSTI)

A theory of spectral parameters and active dynamic conductivity of the quantum cascade laser is proposed in the model of a triple-barrier active region of an individual cascade in a transverse magnetic field. In ...

N. V. Tkach; I. V. Boyko; Ju. A. Seti; G. G. Zegrya

2013-06-01T23:59:59.000Z

399

Modeling the Dispersal of an Active Region: Quantifying Energy Input into the Corona  

Science Journals Connector (OSTI)

In this paper, a new technique for modeling nonlinear force-free fields directly from line-of-sight magnetogram observations is presented. The technique uses sequences of magnetograms directly as lower boundary conditions to drive the evolution of coronal magnetic fields between successive force-free equilibria over long periods of time. It is illustrated by applying it to SOHO: MDI observations of a decaying active region, NOAA AR 8005. The active region is modeled during a four-day period around its central meridian passage. Over this time, the dispersal of the active region is dominated by random motions due to small-scale convective cells. Through studying the buildup of magnetic energy in the model, it is found that such small-scale motions may inject anywhere from (2.5-3) ? 1025 erg s–1 of free magnetic energy into the coronal field. Most of this energy is stored within the center of the active region in the low corona, below 30 Mm. After four days, the buildup of free energy is 10% that of the corresponding potential field. This energy buildup is sufficient to explain the radiative losses at coronal temperatures within the active region. Small-scale convective motions therefore play an integral part in the energy balance of the corona. This new technique has wide ranging applications with the new high-resolution, high-cadence observations from the SDO:HMI and SDO:AIA instruments.

Duncan H. Mackay; L. M. Green; Aad van Ballegooijen

2011-01-01T23:59:59.000Z

400

A MODEL FOR TIME-AND BUDGET-CONSTRAINED ACTIVITY DEMAND ANALYSIS  

E-Print Network (OSTI)

the derivation of a system of demands for activity participation by applying microeconomic theory in a time-price to be of discrete choices (e.g., Train et al. 1987); many models of jointly estimated demand responses lack-time demand elasticities, values of time, and other behavioral properties. METHODOLOGY Microeconomic

Kockelman, Kara M.

Note: This page contains sample records for the topic "activity numerical modeling" 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

Hybrid correlation models based on active-space partitioning: Seeking accurate O,,N5  

E-Print Network (OSTI)

Hybrid correlation models based on active-space partitioning: Seeking accurate O,,N5 ... ab initio and doubles coupled cluster CCSD method to produce a hybrid method that retains the computational scaling of MP2 and improves dramatically the shape of the MP2 curves. In this work we expand the hybrid

Sherrill, David

402

Aligning context-based statistical models of language with brain activity during reading  

E-Print Network (OSTI)

Aligning context-based statistical models of language with brain activity during reading Leila for incoming words given the context. On the other hand, brain imaging studies have sug- gested that during reading, the brain (a) continu- ously builds a context from the successive words and every time

Knight, Kevin

403

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction  

E-Print Network (OSTI)

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction

Zollman, Dean

404

Towards Model-Based Estimation of the Cardiac Electro-Mechanical Activity from ECG Signals  

E-Print Network (OSTI)

Towards Model-Based Estimation of the Cardiac Electro-Mechanical Activity from ECG Signals by comparing the actual patient's ECG with computational results and the deformation of the biomechani- cal-to-access measurements on a patient: the ECG (Electrocardiogram), and a time sequence of volumetric ultrasound images

Coudière, Yves

405

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2012; 68:377402  

E-Print Network (OSTI)

exhibit similarity in terms of various error metrics to the full 4D Var results, but are obtained using of its extension to operational 3-D numerical weather prediction models. Copyright 2011 John Wiley & Sons complicated Numerical Weather Prediction (NWP) models. Therefore, derivation and testing of various algorithms

Navon, Michael

406

Fast Geodesic Active Contours Roman Goldenberg, Ron Kimmel,  

E-Print Network (OSTI)

Fast Geodesic Active Contours Roman Goldenberg, Ron Kimmel, Ehud Rivlin, and Michael Rudzsky use an unconditionally stable numerical scheme to im­ plement a fast version of the geodesic active objects by a dynamic model known as the `geodesic active contour' introduced in [4--7], see also [18, 28

Kimmel, Ron

407

Sandia National Laboratories: Numerical Manufacturing And Design...  

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

NuMAD (Numerical Manufacturing And Design) is an open-source software tool written in Matlab which simplifies the process of creating a three-dimensional model of a wind turbine...

408

Distributed Numerical Weather Prediction via Satellite  

Science Journals Connector (OSTI)

This paper describes a recent undertaking in distributed numerical weather prediction via high data rate networks. The governing project involved the operation of a coupled mesoscale modeling system on widely separated supercomputers, and ...

Jordan G. Powers; Mark T. Stoelinga; William S. Boyd

1997-12-01T23:59:59.000Z

409

Jordan Form Numerical. . .  

E-Print Network (OSTI)

Similarity Jordan Form Numerical. . . Applications Proofs Basis change A short proof Home Page, Alabama, USA Oct 3, 2007 Jordan Normal Form Revisited Speaker: Tin-Yau Tam Graduate Student Seminar tamtiny@auburn.edu #12;Similarity Jordan Form Numerical. . . Applications Proofs Basis change A short

Tam, Tin-Yau

410

Numerical simulations of a vertical tail of a commercial aircraft...  

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

of a commercial aircraft with active flow control Authors: Rasquin, M., Martin, J., Jansen, K. A series of numerical simulations of a realistic vertical tail of a commercial...

411

Numerical Analyses of CERN 200 GeV/A Heavy-Ion Collisions Based on a Hydrodynamical Model with Phase Transition  

Science Journals Connector (OSTI)

......A Heavy-Ion Collisions...Model with Phase Transition Shin Muroya...A Heavy-Ion Collisions...Model with Phase Transition Shin MUROYA...model with phase- transition to the recent heavy-ion experiments......

Shin Muroya; Hiroki Nakamura; Mikio Namiki

1995-03-01T23:59:59.000Z

412

Numerical Test of a Mapping Theory for the IBM3  

Science Journals Connector (OSTI)

......for obtaining enough number of energy levels at low energy. Numerical analysis also indicates...Thompson M. J. Shell Model and Nuclear Structure (1989) World Scientific...for obtaining enough number of energy levels at low energy. Numerical......

Munetake Hasegawa

1991-01-01T23:59:59.000Z

413

Modeling the recharge kinetics of the positive electrode active mass of a lead-acid battery  

SciTech Connect

A mathematical model has been developed and compared with experimental data from the literature. A characteristic fourfold increase in the Tafel slope with increasing current density found in the experimental polarization curves is predicted by the model. The model is based on the assumption that the positive active mass has a structure with microporous agglomerates forming a macroporous skeleton. During charging, lead ions dissolve from the surface of the lead sulfate crystals, diffuse through the skeleton and into the agglomerates, and finally react on the PbO/sub 2/-surface. The fourfold increase of the Tafel slope is attributed to the combined effect of strong pore diffusion resistance in both macro- and micropores. In other respects as well, the model is consistent with published kinetic data.

Bjornbom, P.

1987-07-01T23:59:59.000Z

414

An improved lake model for climate simulations: Model structure, evaluation, and sensitivity analyses in CESM1  

E-Print Network (OSTI)

into the numerical weather prediction model COSMO, BorealCurrent numerical weather prediction (NWP) models, regionalof lakes in numerical weather prediction and climate models:

Subin, Z.M.

2013-01-01T23:59:59.000Z

415

Activity based travel demand models as a tool for evaluating sustainable transportation policies  

Science Journals Connector (OSTI)

India is in the course of an economic transition. The economic growth nurtured the life in the cities and cities have become a major livelihood destination for everyone. This migration of people contributed to the increased urbanization of Indian cities. The booming economy fostered the well-being and shaped the lifestyle of people in such a way that the dependency on private vehicle has become an unavoidable affair. Along with population growth, the increased vehicle ownership gave rise to overall spurt in travel demand. But the supply side lagged behind the demand adding to many of the transport related externalities such as accidents, congestion, pollution, inequity etc. The importance of sustainability is understood in the current urban transport scenario leading to the development and promotion of sustainable transport polices. The core agenda of these polices is to target the travel behavior of people and change the way they travel by creating a different travel environment. However, the impacts of many such policies are either unknown or complex. Hence, before adopting and implementing such policies, it is important for the decision makers to be aware of the impacts of them. The role of travel demand models comes here as they predict the future travel demand under different policy scenarios. This paper reviews the ability of travel demand models applied in India in analyzing the sustainable transport policies. The study found that the conventional model system in India, which is trip based four step aggregate methodology, is inadequate in analyzing the sustainable transport policies. A review of alternative approach, known as activity based travel demand modeling found that they are capable of handling such policies better than conventional models and are assistive to the decision makers in arriving at right mix of polices specific to the situations. Since there is no operational activity based travel demand model system developed in India, the study at the end envisaged a conceptual framework of an integrated activity based travel demand model based on the requirements identified from the review. This can potentially replace the existing travel demand models and can be used for planning applications once the modification & validation have been done according to the existing activity-travel behavior of individuals.

Manoj Malayath; Ashish Verma

2013-01-01T23:59:59.000Z

416

The Groningen Active Living Model, an example of successful recruitment of sedentary and underactive older adults  

Science Journals Connector (OSTI)

Objective Many physical activity interventions do not reach those people who would benefit the most from them. The Groningen Active Living Model (GALM) was successful in recruiting sedentary and underactive older adults. Method In the fall of 2000 older adults in three municipalities in the Netherlands received written information, were visited at home and, if eligible according to the GALM recruitment criteria, filled in the Stages of Change questionnaire and the Voorrips physical activity questionnaire. Results By using the strategy we succeeded in including 12.3% of the older adults (315 of the 2551 qualifying participants), 79.4% of whom could be indeed regarded as sedentary or underactive. These results can be considered in line with results described in the literature. The cost of successfully recruiting an older adult was estimated at $84. Conclusions The GALM recruitment strategy is a potentially useful and effective method for reaching community-dwelling sedentary and underactive older adults.

Martin Stevens; Johan de Jong; Koen A.P.M. Lemmink

2008-01-01T23:59:59.000Z

417

External kink modes as a model for MHD activity associated with ELMs  

SciTech Connect

Tokamak plasmas in the high confinement mode of operation are known to exhibit edge localized activity referred to as ELMs. A model is proposed for the underlying cause in terms of the external kink mode. The build up of the current density near the plasma edge is shown to decrease the shear in the safety-factor, q, profile and lead to destabilization of the kink mode. The role of the plasma geometry and equilibrium profiles is discussed.

Manickam, J.

1992-01-01T23:59:59.000Z

418

A mathematical model for countercurrent moving-bed activated carbon adsorption  

E-Print Network (OSTI)

the carbon column was divided into ten sections and the activated carbon flow rate was such that its detention time was fifty hours. Also, during this fifty hours one thousand gallons of water were treated. Thus the water volume of each section would... be one thou- sand gallons divided by ten sections or 100 gallons. One practical difficulty with the model is that an acti- vated carbon volume must be assumed, tests made, and calculations performed to determine if the effluent quality...

Anderson, Douglas Harold

1976-01-01T23:59:59.000Z

419

A Numerical Evaluation Of Electromagnetic Methods In Geothermal Exploration  

Open Energy Info (EERE)

GEOTHERMAL ENERGYGeothermal Home GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Evaluation Of Electromagnetic Methods In Geothermal Exploration Details Activities (0) Areas (0) Regions (0) Abstract: The size and low resistivity of the clay cap associated with a geothermal system create a target well suited for electromagnetic (EM) methods and also make electrical detection of the underlying geothermal reservoir a challenge. Using 3-D numerical models, we evaluate four EM techniques for use in geothermal exploration: magnetotellurics (MT), controlled-source audio magnetotellurics (CSAMT), long-offset time-domain EM (LOTEM), and short-offset time-domain EM (TEM). Our results show that all of these techniques can delineate the clay cap, but none can be said to unequivocally detect the reservoir. We do find, however, that the EM

420

LAB #8 Numerical Methods  

E-Print Network (OSTI)

Required tools: Matlab routine dfield ; numerical routines eul, rk2, rk4; m-files. Discussion ... You should get a piecewise linear graph made up .... in the matrix y

2005-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Design, Modeling and Numerical Analysis of Microwave and Optical Devices: The Multi-band Patch Antenna, Ultra Wideband Ring Filter and Plasmonic Waveguide Coupler  

E-Print Network (OSTI)

The Transmission Line Model .................................................................................. 13 Reconfigurable Antennas ......................................................................................... 20 Multiband Frequency.... ................... 22 Figure 2-13. Transmission line model of the reconfigurable antenna shown in Figure 2-12. ............................................................................................................. 23 Figure 2-14. VSWR for the frequency...

Liu, Ya-Chi

2014-01-14T23:59:59.000Z

422

Modeling high-pressure adsorption of gas mixtures on activated carbon and coal using a simplified local-density model  

SciTech Connect

The simplified local-density (SLD) theory was investigated regarding its ability to provide accurate representations and predictions of high-pressure supercritical adsorption isotherms encountered in coalbed methane (CBM) recovery and CO{sub 2} sequestration. Attention was focused on the ability of the SLD theory to predict mixed-gas adsorption solely on the basis of information from pure gas isotherms using a modified Peng-Robinson (PR) equation of state (EOS). An extensive set of high-pressure adsorption measurements was used in this evaluation. These measurements included pure and binary mixture adsorption measurements for several gas compositions up to 14 MPa for Calgon F-400 activated carbon and three water-moistened coals. Also included were ternary measurements for the activated carbon and one coal. For the adsorption of methane, nitrogen, and CO{sub 2} on dry activated carbon, the SLD-PR can predict the component mixture adsorption within about 2.2 times the experimental uncertainty on average solely on the basis of pure-component adsorption isotherms. For the adsorption of methane, nitrogen, and CO{sub 2} on two of the three wet coals, the SLD-PR model can predict the component adsorption within the experimental uncertainties on average for all feed fractions (nominally molar compositions of 20/80, 40/60, 60/40, and 80/20) of the three binary gas mixture combinations, although predictions for some specific feed fractions are outside of their experimental uncertainties.

Fitzgerald, J.E.; Robinson, R.L.; Gasem, K.A.M. [Oklahoma State University, Stillwater, OK (United States). School of Chemical Engineering

2006-11-07T23:59:59.000Z

423

Distribution of oceanic 137Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model  

Science Journals Connector (OSTI)

Radioactive materials were released to the environment from the Fukushima Dai-ichi Nuclear Power Plant as a result of the reactor accident after the Tohoku earthquake and tsunami of 11 March 2011. The measured 137Cs concentration in a seawater sample near the Fukushima Dai-ichi Nuclear Power Plant site reached 68 kBq L?1 (6.8 × 104 Bq L?1) on 6 April. The two major likely pathways from the accident site to the ocean existed: direct release of high radioactive liquid wastes to the ocean and the deposition of airborne radioactivity to the ocean surface. By analysis of the 131I/137Cs activity ratio, we determined that direct release from the site contributed more to the measured 137Cs concentration than atmospheric deposition did. We then used a regional ocean model to simulate the 137Cs concentrations resulting from the direct release to the ocean off Fukushima and found that from March 26 to the end of May the total amount of 137Cs directly released was 3.5 ± 0.7 PBq ((3.5 ± 0.7) × 1015 Bq). The simulated temporal change in 137Cs concentrations near the Fukushima Daini Nuclear Power Plant site agreed well with observations. Our simulation results showed that (1) the released 137Cs advected southward along the coast during the simulation period; (2) the eastward-flowing Kuroshio and its extension transported 137C during May 2011; and (3) 137Cs concentrations decreased to less than 10 Bq L?1 by the end of May 2011 in the whole simulation domain as a result of oceanic advection and diffusion. We compared the total amount and concentration of 137Cs released from the Fukushima Dai-ichi reactors to the ocean with the 137Cs released to the ocean by global fallout. Even though the measured 137Cs concentration from the Fukushima accident was the highest recorded, the total released amount of 137Cs was not very large. Therefore, the effect of 137Cs released from the Fukushima Dai-ichi reactors on concentration in the whole North Pacific was smaller than that of past release events such as global fallout, and the amount of 137Cs expected to reach other oceanic basins is negligible comparing with the past radioactive input.

Daisuke Tsumune; Takaki Tsubono; Michio Aoyama; Katsumi Hirose

2012-01-01T23:59:59.000Z

424

Numerical and physical modelling of microstructure evolution – new approach to the development and optimisation of cold rolling and annealing technology of IF steel strips  

Science Journals Connector (OSTI)

Modelling of cold rolling and continuous annealing of the IF steel is the objective of the paper. Experimental plastometric tests were performed to determine flow stress in the temperature range characteristic for cold rolling. Physical simulations of the annealing were performed at various heating rates to various temperatures. The kinetics of recrystallization model based on the additivity rule was identified on the basis of the experimental results. In connection with the finite element model of cold rolling, the complex model for the whole manufacturing cycle is obtained. This model can be used for optimisation of cold rolling and annealing technology of IF steel strips.

R. KUZIAK; R. MOLENDA; M. PIETRZYK

2008-01-01T23:59:59.000Z

425

Mean First-Passage Time Calculations for the Coil-to-Helix Transition: The Active Helix Ising Model  

E-Print Network (OSTI)

Mean First-Passage Time Calculations for the Coil-to-Helix Transition: The Active Helix Ising Model of the coil-to-helix transition is studied using a one-dimensional "Zimm- Bragg" Ising model. The mean first-dimensional Ising model for arbitrary spin-spin coupling (J) and external field (H) where J and H are expressed

Straub, John E.

426

Multigrid methods for improving the variational data assimilation in numerical weather prediction  

E-Print Network (OSTI)

conditions are needed to solve numerical weather prediction models: initial condition and boundary conditionMultigrid methods for improving the variational data assimilation in numerical weather prediction: numerical weather prediction, variational data assimilation, minimization procedure, multigrid methods, cell

Kwak, Do Young

427

activities  

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

Detecting Things We Cannot See: Learning the Concepts of Control and Detecting Things We Cannot See: Learning the Concepts of Control and Variable in an Experiment Submitted by Anita Brook-Dupree, 1996 TRAC teacher at Fermilab, Teacher, Alternative Middle Years School, Philadelphia, PA. Particle physicists at Fermilab in Batavia, Illinois are faced with the problem of detecting the presence of sub-atomic particles they cannot see. During my summer as a TRAC teacher at Fermilab, I tried to think of ways to teach middle school students about things we cannot see. I want to thank my nine-year-old daughter Gia for the idea for the following activity. I was lamenting that I could not come up with ideas of how to relate the work of Fermilab scientists to anything that my students would understand. Then I was reminded by my daughter, that when I brought her to school on the

428

Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data  

SciTech Connect

The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.

Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.

2009-08-15T23:59:59.000Z

429

CDA6530: Performance Models of Computers and Networks (Fall 2012) Project 2: Using Matlab Simulink to derive numerical solution for differential equations  

E-Print Network (OSTI)

CDA6530: Performance Models of Computers and Networks (Fall 2012) Project 2: Using Matlab SimulinkCourse) You have learned matlab simulink from the example of the simple worm propagation modeling in class. If you cannot access Matlab Simulink, you can use an equivalent free software 'Xcos' (similar to Simulink

Zou, Cliff C.

430

CDA6530: Performance Models of Computers and Networks (Fall 2011) Project 2: Using Matlab Simulink to derive numerical solution for differential equations  

E-Print Network (OSTI)

CDA6530: Performance Models of Computers and Networks (Fall 2011) Project 2: Using Matlab Simulink learned matlab simulink from the example of the simple worm propagation modeling in class. Now you submit this project assignment via webcourse. You should attach a Winzip file containing a document (such

Zou, Cliff C.

431

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

SciTech Connect

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

Pohlmann Karl,Ye Ming

2012-03-01T23:59:59.000Z

432

Disruptive Innovation in Numerical Hydrodynamics  

SciTech Connect

We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.

Waltz, Jacob I. [Los Alamos National Laboratory

2012-09-06T23:59:59.000Z

433

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part II: Model application and results  

Science Journals Connector (OSTI)

The present model and methodology described in Part I of this work are applied to perform a comprehensive risk analysis of the dam-break flood of five reservoirs in the Haihe River ... The results indicate that t...

Zhengyin Zhou; Xiaoling Wang; Ruirui Sun; Xuefei Ao; Xiaopei Sun…

2014-06-01T23:59:59.000Z

434

Design and Synthesis of a Novel Triptycene-Based Ligand for Modeling Carboxylate-Bridged Diiron Enzyme Active Sites  

E-Print Network (OSTI)

A novel triptycene-based ligand with a preorganized framework was designed to model carboxylate-bridged diiron active sites in bacterial multicomponent monooxygenase (BMM) hydroxylase enzymes. The synthesis of the ...

Li, Yang

435

Modeling and controller synthesis for the cascaded H-bridge multilevel active power filter with ADALINE-based identifiers  

Science Journals Connector (OSTI)

This paper presents the averaged state-space modeling and controller synthesis methodology for the cascaded H-bridge multilevel active power filters (CHB-APFs). ... compensation and dc-link stabilization among th...

Yang Han; Lin Xu; Muhammad Mansoor Khan; Chen Chen

2011-06-01T23:59:59.000Z

436

Modeling the cathode compartment of polymer electrolyte fuel cells: Dead and active reaction zones  

SciTech Connect

A two-dimensional model of the cathode compartment of a polymer electrolyte fuel cell has been developed. The existence of gas channels in the current collector is taken into account. The model is based on continuity equations for concentrations of the gases and Poisson's equations for potentials of membrane and carbon phase, coupled by Tafel relation for reaction kinetics. Stefan-Maxwell and Knudsen diffusion of gases are taken into account. The simulations were performed for high and low values of carbon phase conductivity. The results revealed (i) for a low value of carbon phase conductivity, a dead zone in the active layer in front of the gas channel is formed, where the reaction rate is small. The catalyst may be removed from this zone without significant loss in cell performance; (ii) For a high carbon phase conductivity value, such a zone is absent, but removal of the catalyst from the same part of the active layer forces the reaction to proceed more rapidly in the remaining parts, with only marginal losses in performance. This conclusion is valid for high diffusivity of oxygen. For low diffusivity, dead zones are formed in front of the current collector, so that catalyst can be removed from these zones. The results, thus, show the possibilities for a considerable reduction of the amount of catalyst.

Kulikovsky, A.A.; Divisek, J.; Kornyshev, A.A.

1999-11-01T23:59:59.000Z

437

A nanoflare model for active region radiance: application of artificial neural networks  

E-Print Network (OSTI)

Context. Nanoflares are small impulsive bursts of energy that blend with and possibly make up much of the solar background emission. Determining their frequency and energy input is central to understanding the heating of the solar corona. One method is to extrapolate the energy frequency distribution of larger individually observed flares to lower energies. Only if the power law exponent is greater than 2, is it considered possible that nanoflares contribute significantly to the energy input. Aims. Time sequences of ultraviolet line radiances observed in the corona of an active region are modelled with the aim of determining the power law exponent of the nanoflare energy distribution. Methods. A simple nanoflare model based on three key parameters (the flare rate, the flare duration time, and the power law exponent of the flare energy frequency distribution) is used to simulate emission line radiances from the ions Fe XIX, Ca XIII, and Si iii, observed by SUMER in the corona of an active region as it rotates around the east limb of the Sun. Light curve pattern recognition by an Artificial Neural Network (ANN) scheme is used to determine the values. Results. The power law exponents, alpha 2.8, 2.8, and 2.6 for Fe XIX, Ca XIII, and Si iii respectively. Conclusions. The light curve simulations imply a power law exponent greater than the critical value of 2 for all ion species. This implies that if the energy of flare-like events is extrapolated to low energies, nanoflares could provide a significant contribution to the heating of active region coronae.

M. Bazarghan; H. Safari; D. E. Innes; E. Karami; S. K. Solanki

2008-08-28T23:59:59.000Z

438

Numerical prediction of heat-flux to massive calorimeters engulfed in regulatory fires with the cask analysis fire environment (CAFE) model  

SciTech Connect

Recent observations show that the thermal boundary conditions within large-scale fires are significantly affected by the presence of thermally massive objects. These objects cool the soot and gas near their surfaces, and these effects reduce the incoming radiant heat-flux to values lower than the levels expected from simple {sigma}T{sub fire}{sup 4} models. They also affect the flow and temperature fields in the fire far from their surfaces. The Cask Analysis Fire Environment (CAFE) code has been developed at Sandia National Laboratories to provide an enhanced fire boundary condition for the design of radioactive material packages. CAFE is a set of computer subroutines that use computational fluid mechanics methods to predict convective heat transfer and mixing. It also includes models for fuel and oxygen transport, chemical reaction, and participating-media radiation heat transfer. This code uses two-dimensional computational models so that it has reasonably short turnaround times on standard workstations and is well suited for design and risk studies. In this paper, CAFE is coupled with a commercial finite-element program to model a large cylindrical calorimeter fully engulfed in a pool fire. The time-dependent heat-flux to the calorimeter and the calorimeter surface temperature are determined for several locations around the calorimeter circumference. The variation of heat-flux with location is determined for calorimeters with different diameters and wall thickness, and the observed effects discussed.

KOSKI,JORMAN A.; SUO-ANTITLA,AHTI; KRAMER,M. ALEX; GREINER,MILES

2000-05-11T23:59:59.000Z

439

CDA6530: Performance Models of Computers and Networks (Fall 2010) Project 2: Using Matlab Simulink to derive numerical solution for differential equations  

E-Print Network (OSTI)

CDA6530: Performance Models of Computers and Networks (Fall 2010) Project 2: Using Matlab Simulink submission deadline: 11/02 midnight) You have learned matlab simulink from the example of the simple worm differential equations. Submission: please submit this project assignment via webcourse. You should attach

Zou, Cliff C.

440

Efficient numerical surface wave propagation through the optimization of discrete crustal models—a technique based on non-linear dispersion curve matching (DCM)  

Science Journals Connector (OSTI)

......and 8) are the least constrained. 4 Methodology The modification of discrete earth models...and (13), with their respective subsidiary conditions, exist. 4.2 Non-Linear...Schoenberg M. , Muir F., 1989. A calculus for finely layered anisotropic media......

Andreas Fichtner; Heiner Igel

2008-05-01T23:59:59.000Z

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


441

BABAR searches for New Physics in B decays to invisible final states The Standard Model (SM) of particle physics has been proven by numerous experiments over  

E-Print Network (OSTI)

BABAR searches for New Physics in B decays to invisible final states The Standard Model (SM for invisible decays of neutral B mesons, where unobservable particles are created in the final state, either exclusively or accompanied by a single photon. The invisible decay products are neutral particles

Wechsler, Risa H.

442

Model-Evaluation Tools for Three-Dimensional Cloud Verification via Spaceborne Active Sensors  

Science Journals Connector (OSTI)

Clouds pose many operational hazards to the aviation community in terms of ceilings and visibility, turbulence, and aircraft icing. Realistic descriptions of the three-dimensional (3D) distribution and temporal evolution of clouds in numerical ...

Steven D. Miller; Courtney E. Weeks; Randy G. Bullock; John M. Forsythe; Paul A. Kucera; Barbara G. Brown; Cory A. Wolff; Philip T. Partain; Andrew S. Jones; David B. Johnson

2014-09-01T23:59:59.000Z

443

IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 10, NO. 10, OCTOBER 2001 1467 Fast Geodesic Active Contours  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 10, NO. 10, OCTOBER 2001 1467 Fast Geodesic Active stable numerical scheme to implement a fast version of the geodesic active contour model. The proposed method for tracking in color movies. Index Terms--Additive operator splitting, color, geodesic active

Rivlin, Ehud

444

Fast Geodesic Active Contours Roman Goldenberg, Ron Kimmel, Ehud Rivlin, Michael Rudzsky  

E-Print Network (OSTI)

1 Fast Geodesic Active Contours Roman Goldenberg, Ron Kimmel, Ehud Rivlin, Michael Rudzsky Abstract--- We use an unconditionally stable numerical scheme to implement a fast version of the geodesic active by a dynamic model known as the `geodesic active contour' introduced in [4], [5], [6], [7], see also [19], [30

Kimmel, Ron

445

A numerical soil-water-balance (SWB) model was used to estimate groundwater recharge in the Williston and Powder River structural basins in the Northern Great Plains.  

E-Print Network (OSTI)

in the Williston and Powder River structural basins in the Northern Great Plains. The SWB model consisted of 1 km2 to 2011. Average calculated recharge in the Williston basin was 0.190 in/yr (1,281 ft3 /sec) and ranged.1 percent of precipitation in the Williston basin. Average recharge in the Powder River basin was 0.136 in

Torgersen, Christian

446

Numerical modelling of the energy balance and the englacial temperature of the Greenland Ice Sheet. Calculations for the ETH-Camp location (West Greenland, 1155 m a.s.l.)  

Science Journals Connector (OSTI)

In the present work, a numerical model that calculates the surface energy blance, mass balance and temperature in the uppermost 25 m of ice at a single location on a glacier is presented. The model is forced by five “basic” meteorological elements: air temperature and humidity, wind speed, cloud amount and precipitation. The model was developed for studies of the Greenland Ice Sheet. Parameterizations of the surface energy fluxes were optimised with data mainly from the ETH Camp, West Greenland (1155 m a.s.l.). The model was tested on data collected during the summer of 1990 in the ETH Camp. In this case measurements of the radiative fluxes could be used. A reasonable fit between measurements and calculations of mass balance and englacial temperature could be obtained. The energy balance of this summer is discussed. In a second application, the annual cycle of the energy and mass balance and the englacial temperature at the location of the ETH Camp was simulated. In this case long term average values of the input variables were estimated from measurements at other locations and the radiative fluxes were computed with the parameterizations. The effect of model uncertainties on the calculated mass balance and 10 m ice temperature is discussed. The energy balance and the relation between air and ice temperature are analysed. The uncertainty in the calculated ablation is so large (500–1000 mm w.e./yr) that the contribution of ablation on the Greenland Ice Sheet to sea-level rise cannot be calculated with sufficient accuracy (i.e. 60 mm w.e./yr) with this kind of model. However, the model should be appropriate for the determination of the sensitivity of ablation to climate change. It is predicted that at the ETH Camp the mass balance will decrease by 610 mm w.e./yr after a temperature increase of 1°C.

Wouter Greuell; Thomas Konzelmann

1994-01-01T23:59:59.000Z

447

Numerical simulation of contaminant flow in a wool scour  

Science Journals Connector (OSTI)

Wool scouring is the process of washing dirty wool after shearing. Our model numerically simulates contaminant movement in a wool scour bowl using the advection-dispersion equation. This is the first wool scour model to give time-dependent results and ... Keywords: Finite differences, Numerical simulation, Wool scouring

J. F. Caunce; S. I. Barry; G. N. Mercer; T. R. Marchant

2007-08-01T23:59:59.000Z

448

Numerical Simulation of Wave Loads on Static Offshore Structures  

E-Print Network (OSTI)

Numerical Simulation of Wave Loads on Static Offshore Structures Hrvoje Jasak, Inno Gatin, Vuko Workshop, Cambridge, 30 July 2014 Numerical Simulation of Wave Loads on Static Offshore Structures ­ p. #12 of Wave Loads on Static Offshore Structures ­ p. #12;VOF Free Surface Flow Model Modelling of Free Surface

449

Experimental and numerical analysis of a deepwater mini-TLP  

E-Print Network (OSTI)

As the quest for oil and gas resources drives the industry to ever deeper waters, model testing still represents an essential step after numerical modeling when designing offshore platforms in these hostile environments. In an attempt to better...

Guichard, Aurelien

2012-06-07T23:59:59.000Z

450

Numerical Investigation of Solar Chimney Power Plant in UAE  

Science Journals Connector (OSTI)

This paper presents a numerical simulation results for a steady air flow inside a solar chimney power plant. A standard k-epsilon turbulence model is used to model a prototype solar chimney that was built in Al A...

Mohammad O. Hamdan; Saud Khashan

2014-01-01T23:59:59.000Z

451

Numerical modeling of the aerodynamics, heat exchange, and combustion of a polydisperse ensemble of coke-ash particles in ascending axisymmetric two-phase flow  

SciTech Connect

A two-dimensional stationary model of motion, heat and mass exchange, and chemical reaction of polydisperse coke and ash particles in ascending gas-suspension flow has been constructed with allowance for the turbulent and pseudo turbulent mechanisms of transfer in the dispersed phase. The system of equations that describes motion and heat transfer in the solid phase has been closed at the level of the equations for the second moments of velocity and temperature pulsations, whereas the momentum equations of the carrying medium have been closed using the equation for turbulent gas energy, which allows for the influence of the particles and heterogeneous reactions.

B.B. Rokhman [National Academy of Sciences of Ukraine, Kiev (Ukraine). Institute of Coal Power Technologies

2009-07-15T23:59:59.000Z

452

Thermal model of water and CO activity of Comet C/1995 O1 (Hale-Bopp)  

Science Journals Connector (OSTI)

An investigation of the activity of Comet C/1995 O1 (Hale-Bopp) with a thermophysical nucleus model that does not rely on the existence of amorphous ice is presented. Our approach incorporates recent observations allowing to constrain important parameters that control cometary activity. The model accounts for heat conduction, heat advection, gas diffusion, sublimation, and condensation in a porous ice–dust matrix with moving boundaries. Erosion due to surface sublimation of water ice leads to a moving boundary. The movement of the boundary is modeled by applying a temperature remapping technique which allows us to account for the loss in the internal energy of the eroded surface material. These kind of problems are commonly referred to as Stefan problems. The model takes into account the diurnal rotation of the nucleus and seasonal effects due to the strong obliquity of Hale-Bopp as reported by Jorda et al. (Jorda, L., Rembor, K., Lecacheux, J., Colom, P., Colas, F., Frappa, E., Lara, L.M. [1997]. Earth Moon Planets 77, 167–180). Only bulk sublimation of water and CO ice are considered without further assumptions such as amorphous ices with certain amount of occluded CO gas. Confined and localized activity patterns are investigated following the reports of Lederer and Campins (Lederer, S.M., Campins, H. [2002]. Earth Moon Planets 90, 381–389) about the chemical heterogeneity of Hale-Bopp and of Bockelée-Morvan et al. (Bockelée-Morvan, D., Henry, F., Biver, N., Boissier, J., Colom, P., Crovisier, J., Despois, D., Moreno, R., Wink, J. [2009]. Astron. Astrophys. 505, 825–843) about a strong CO source at a latitude of 20°. The best fit to the observations of Biver et al. (Biver, N. et al. [2002]. Earth Moon Planets 90, 5–14) is obtained with a low thermal conductivity of 0.01 W m?1 K?1. This is in agreement with recent results of the Deep Impact mission to 9P/Tempel 1 (Groussin, O., A’Hearn, M.F., Li, J.-Y., Thomas, P.C., Sunshine, J.M., Lisse, C.M., Meech, K.J., Farnham, T.L., Feaga, L.M., Delamere, W.A. [2007]. Icarus 187, 16–25) and with previous thermal simulations (Kührt, E. [1999]. Space Sci. Rev. 90, 75–82). The water production curve matches the production rates well from ?4 AU pre-perihelion to the outgoing leg while the model does not reproduce so well the water production beyond 4 AU pre-perihelion. The CO production curve is a good fit to the measurements of Biver et al. (2002) over the whole measured heliocentric range from ?7 AU pre- to 15 AU post-perihelion.

N. Gortsas; E. Kührt; U. Motschmann; H.U. Keller

2011-01-01T23:59:59.000Z

453

NUMERICAL SIMULATIONS OF THE MAGNETIC RAYLEIGH-TAYLOR INSTABILITY IN THE KIPPENHAHN-SCHLUeTER PROMINENCE MODEL. II. RECONNECTION-TRIGGERED DOWNFLOWS  

SciTech Connect

The launch of the Hinode satellite has allowed high-resolution observations of supersonic bright downflows in quiescent prominences, known as prominence knots. We present observations in the Ca II H spectral line using the Solar Optical Telescope on board the Hinode satellite of a descending plasma knot of size {approx}900 km. The knot initially undergoes ballistic motion before undergoing impulsive accelerations at the same time as experiencing increases in intensity. We also present a subset of our three-dimensional magnetohydrodynamic simulations, performed to investigate the nonlinear stability of the Kippenhahn-Shlueter prominence model to the magnetic Rayleigh-Taylor instability in which interchange reconnection occurs. The interchange reconnection in the model breaks the force balance along the field lines which initiates the downflows. The downflows propagate with a downward fluid velocity of {approx}15 km s{sup -1} and a characteristic size of {approx}700 km. We conclude that the observed plasma blob and the simulated downflow are driven by the breaking of the force balance along the magnetic field as a result of a change in magnetic topology caused by reconnection of the magnetic field.

Hillier, Andrew; Isobe, Hiroaki; Shibata, Kazunari [Kwasan and Hida Observatories, Kyoto University, Kyoto (Japan); Berger, Thomas [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA (United States)

2012-09-10T23:59:59.000Z

454

Ion-heated thermal Comptonization models and x-ray spectral correlations in active galactic nuclei  

SciTech Connect

Recent Ginga observations of the Seyfert 1 galaxies NGC 4051 and MCG 6-30-15 show a positive correlation between the 2-10 keV luminosity and photon spectral index {alpha}. Similar behavior has also been reported in Exosat and Einstein observations of other active galactic nuclei, and is suggested in hard x-ray low-state data of the galactic black-hole candidate Cygnus X-1. A two-temperature thermal Comptonization model with internal soft-photon production provides a simple explanation for this correlation. The electron temperature, determined by a balance between ion heating and radiative cooling, decreases in response to an enhancement of the soft photon flux, resulting in a softening of the spectrum and an increase in the soft x-ray luminosity. The bulk of the soft photons are produced through pion production in collisions between the hot ions. Pivoting of the spectrum at photon energies {var epsilon} > 50 keV is a consequence of variations in the ion temperature. An important test of the model would be time correlations between soft and hard x-ray bands. 17 refs., 9 figs., 1 tab.

Dermer, C.D.

1989-11-01T23:59:59.000Z

455

A direct comparison of X-ray spectral models for tori in active galactic nuclei  

E-Print Network (OSTI)

Several X-ray spectral models for tori in active galactic nuclei (AGNs) are available to constrain the properties of tori; however, the accuracy of these models has not been verified. We recently construct a code for the torus using Geant4, which can easily handle different geometries (Liu & Li 2014). Thus, we adopt the same assumptions as Murphy & Yaqoob (2009, hereafter MY09) and Brightman & Nandra (2011, hereafter BN11) and try to reproduce their spectra. As a result, we can reproduce well the reflection spectra and the strength of the Fe K$\\alpha$ line of MY09, for both $\\NH=10^{24}$ and $10^{25}$ cm$^{-2}$. However, we cannot produce the strong reflection component of BN11 in the low-energy band. The origin of this component is the reflection from the visible inner wall of the torus, and it should be very weak in the edge-on directions under the geometry of BN11. Therefore, the behaviour of the reflection spectra in BN11 is not consistent with their geometry. The strength of the Fe K$\\alpha$ ...

Liu, Yuan

2015-01-01T23:59:59.000Z

456

Composite repair of pipelines, considering the effect of live pressure-analytical and numerical models with respect to ISO/TS 24817 and ASME PCC-2  

Science Journals Connector (OSTI)

Abstract Wrapping composite material around the defected pipe is a recent method in pipeline rehabilitation. ISO-24817 and ASME PCC-2 are the only available design codes for the design of this repair system. For the case when the corroded pipe contributes to the load carrying capacity, the two codes suggest calculating the repair thickness for a special design pressure based on the pipe diameter, remaining wall thickness, pipe and composite material properties, composite allowable strain, and the live pressure, which is the internal pressure in the pipe at the time of repair application. In this study, a range of design scenarios are modelled using analytical equations and finite element method in order to assess the validity of including live pressure in the design. Results indicate that the repair thickness is independent of the live pressure and hence an appropriate modification is proposed to the existing design equation.

Nariman Saeed; Hamid Ronagh; Amandeep Virk

2014-01-01T23:59:59.000Z

457

A Numerical Method for Extended Boussinesq  

E-Print Network (OSTI)

A Numerical Method for Extended Boussinesq Shallow-Water Wave Equations by Mark Andrew Walkley and diffraction, and nonlinear wave interactions such as the generation of harmonic waves. The Boussinesq, shallow water envi- ronment. There are a variety of Boussinesq-type mathematical models

Walkley, Mark

458

GPU Acceleration of Numerical Weather John Michalakes  

E-Print Network (OSTI)

GPU Acceleration of Numerical Weather Prediction John Michalakes National Center for Atmospheric parallelism will prove ineffective for many scenarios. We present an alternative method of scaling model Exponentially increasing processor power has fueled fifty years of continuous improvement in weather and climate

Colorado at Boulder, University of

459

BIT Numerical Mathematics 2005, to appear  

E-Print Network (OSTI)

. AKRIVIS AND S. LARSSON This system models the electric heating of a conductive body, with u being­DEPENDENT JOULE HEATING PROBLEM # G. AKRIVIS 1+ and S. LARSSON 2 June 27, 2005 1 Computer Science Department@chalmers.se Abstract. Completely discrete numerical methods for a nonlinear elliptic­parabolic system, the time

Larsson, Stig

460

Presented by High Fidelity Direct Numerical  

E-Print Network (OSTI)

Presented by High Fidelity Direct Numerical Simulations of Turbulent Combustion Jacqueline H. Chen (PI), Chun Sang Yoo, Gaurav Bansal, Hongfeng Yu, Ajith Mascarenhas Combustion Research Facility Sandia) of turbulent combustion DNS approach and role � Fully resolve all continuum scales without using subgrid models

Note: This page contains sample records for the topic "activity numerical modeling" 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

Numerical control user experience  

SciTech Connect

AUTOCON is an acronym for Automatic Contouring, a program which generates a contour toolpath for the external profile of printed writing boards (PWB) using ICEM DDN. AUTOCON originates from the Computer Aided Process Planning (CAPP) Procedure developed by Electrical Manufacturing at Allied Bendix. The CAPP program uses electronically transmitted graphics files received from a design agency to generate automatic panel layouts and travellers for Process Engineers. The objective of AUTOCON is to utilize the information from the CAPP program to generate Numerical Control tapes. If the CAPP program can be utilized to its full potential, it is estimated that a good portion of the 60 to 90 PWB tapes shipped each month from our Numerical Control Department could be eliminated from conventional N/C Programming. The purpose of AUTOCON is to automatically generate a toolpath around the external profile of a PWB with no user intervention. The Process Engineer can generate a profile contour N/C tape after he has completed the panel layout and traveller through CAPPS for a part. After the layout and traveller illustrations have been completed, the same geometry can then be utilized again for the N/C tape. An N/C Analysist then reviews the listing for a final checkout of the job. 13 figs.

Butler, J.

1985-10-01T23:59:59.000Z

462

WEC Model Development at Sandia  

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

2C 2C Marine and Hydrokinetic Instrumentation, Measurement & Computer Modeling Workshop - Broomfield, CO July 9 th , 2012 Wave Energy Converter Model Development at Sandia Outline  Overview of SNL's WEC Modeling Activities * Wave Energy Development Roadmap * MHK Reference Models - Diana Bull * WEC Model Tool Development - Kelley Ruehl Reference Models and SNL Array Modeling presented in next session Wave Energy Development Roadmap Overall Goal and Motivation  Goal: Develop a suggested path for WEC development from design to commercialization.  Motivation: Guide industry towards successful design optimizations, prototype deployments, and utility scale commercialization by providing a roadmap incorporating numerical modeling and experimentation.

463

A charging control strategy for active building-integrated thermal energy storage systems using frequency domain modeling  

Science Journals Connector (OSTI)

Abstract Primary space conditioning can be provided through active building-integrated thermal energy storage (BITES) systems, such as radiant space heating through concrete slabs. This approach can reduce peak space conditioning demand and energy costs while satisfying thermal comfort. However, thermal charging rates need to be predictively controlled due to the slow thermal response of BITES systems. This paper presents a charge control strategy using frequency domain models and room air temperature set-point profile as input. The models were previously verified with full-scale experiment data. The calculation procedures are demonstrated on active BITES systems with and without airflow to zone. Results show that the calculated charging rates satisfy the desired room air temperature set-point profiles. This control strategy is important for integrating the design and operation of active BITES systems because frequency domain models also provide important design information.

Yuxiang Chen; Andreas K. Athienitis; Khaled E. Galal

2014-01-01T23:59:59.000Z

464

Functional role of tropomyosin on thin filament activation and cross bridge kinetics in transgenic cardiac muscle: a model study  

E-Print Network (OSTI)

. Hunter (Member) Way Kuo (Head ol Department) December 1999 Major Subject: Biomedical Engineering ABSTRACT Functional Role of Tropomyosin on Thin Filament Activation and Cross Bridge Kinetics in Transgenic Cardiac Muscle: A Model Study. (December... 1999) Gayathri Krishnamoorthy, B. E. , University of Mumbai, India Co-Chairs of Advisory Committee: Dr. Sohi Rastegar Dr. Mariappan Muthuchamy Regulation of contractile activity in cardiac muscle is a cooperative interaction between thick and thin...

Krishnamoorthy, Gayathri

2012-06-07T23:59:59.000Z

465

Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.  

SciTech Connect

The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.

Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk

2013-08-22T23:59:59.000Z

466

Physical Constraints on, and a Model for, the Active Regions in Seyfert Galaxies  

E-Print Network (OSTI)

We discuss several physical constraints on the nature of the Active Regions (AR) in Seyfert 1 Galaxies, and show that a plausible model consistent with these constraints is one in which the ARs are magnetically confined and ``fed''. The unique X-ray index of these sources points to a large compactness parameter ($l\\gg 1$). This, together with the conditions required to account for the observed optical depth being close to unity, suggests that the magnetic energy density in the AR should be comparable to the equipartition value in the accretion disk, and that it should be released in a flare-like event above the surface of the cold accretion disk. We consider the various issues pertaining to magnetic flares and attempt to construct a coherent picture, including a reason for the optical depth in the AR being $\\sim 1$, and an understanding of the characteristics of the X-ray reflection component and the power density spectra associated with this high-energy emission.

Sergei Nayakshin; Fulvio Melia

1997-05-30T23:59:59.000Z

467

Design of Predictive Control Strategies for Active BITIES Systems Using Frequency Domain Models  

E-Print Network (OSTI)

Active building-integrated thermal energy storage (BITES) systems, such as ventilated concrete slabs, are able to effectively store and release abundant of thermal energy to assist space conditioning. Since active BITES systems are strongly thermal...

Chen, Y.; Athienitis, A. K.; Gala, K. E.

2013-01-01T23:59:59.000Z

468

Numerical aspects of 3D stellar winds  

E-Print Network (OSTI)

This paper explores and compares the pitfalls of modelling the three-dimensional wind of a spherical star with a cartesian grid. Several numerical methods are compared, using either uniform and stretched grid or adaptative mesh refinement (AMR). An additional numerical complication is added, when an orbiting planet is considered. In this case a rotating frame is added to the model such that the orbiting planet is at rest in the frame of work. The three-dimensional simulations are systematically compared to an equivalent two-dimensional, axisymmetric simulation. The comparative study presented here suggests to limit the rotation rate of the rotating frame below the rotating frame of the star and provides guidelines for further three-dimensional modelling of stellar winds in the context of close-in star-planet interactions.

Strugarek, A; Matt, S P; Reville, V

2014-01-01T23:59:59.000Z

469

E-Print Network 3.0 - activity model validation Sample Search...  

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

Rutgers University Collection: Computer Technologies and Information Sciences 50 Enabling Modeling and Simulation-based Science in the Classroom: Agent-Based Models, Real-World...

470

Critical Simulation Based Evaluation of Thermally Activated Building Systems (TABS) Design Models  

E-Print Network (OSTI)

19 Figure 3.1 Sketchup model of the simulated officemodel simulated. Figure 3.1 Sketchup model of the simulated

Basu, Chandrayee

2012-01-01T23:59:59.000Z

471

Solute-Solvent Interactions From Gas Chromatographic Activity Coefficients and the Solvation Parameter Model for Nitrogen-Containing Stationary Phases  

Science Journals Connector (OSTI)

......analyte injected into a gas chromatographic...Interactions From Gas Chromatographic Activity...Parameter Model for Nitrogen-Containing Stationary...mol), R is the gas con- stant (taken...pressure of saturated water vapor at ambient...the Ost- wald solubility coefficient (or......

José M. Santiuste

2003-04-01T23:59:59.000Z

472

Modeling and analysis of early events in T-lymphocyte antigen-activated intracellular-signaling pathways  

Science Journals Connector (OSTI)

The T-cell antigen-activated signaling pathway is a highly regulated intracellular biochemical system that is crucial for initiating an appropriate adaptive immune response. To improve the understanding of the complex regulatory mechanisms controlling ... Keywords: Bistability, Feedback regulation, Hysteresis, Mathematical modeling, T-cell signaling

Yanan Zheng; Venkataramanan Balakrishnan; Greg Buzzard; Robert Geahlen; Marietta Harrison; Ann Rundell

2005-12-01T23:59:59.000Z

473

Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases  

E-Print Network (OSTI)

met many nice people and developed numerous precious friendships. I would like to take this opportunity to acknowledge help and support that I received. First, I wish to thank my advisor, Professor Marcetta Y. Darensbourg, for mentoring me through... of you taught or mentored me in some form by shaping my scientific development and maturity: Drs. Joy Chiang, Marilyn Rampersad, Jesse Tye, Kayla Green, Elky Almaraz, Stephen Jeffery and Christine Thomas. I thank the current members of the MYD group...

Liu, Tianbiao

2011-02-22T23:59:59.000Z

474

Numerical simulation of wind effects: a probabilistic perspective Ahsan Kareem  

E-Print Network (OSTI)

Numerical simulation of wind effects: a probabilistic perspective Ahsan Kareem NatHaz Modeling Laboratory, University of Notre Dame, Notre Dame, IN 46556 ABSTRACT: Numerical simulations of wind loads and their effects are critical in the design of structures to ensure their safety under winds. The simulations range

Kareem, Ahsan

475

Numerical Simulation of a Natural Circulation Steam Generator  

E-Print Network (OSTI)

Numerical Simulation of a Natural Circulation Steam Generator W. Linzer \\Lambda , K. Ponweiser circulation steam generator. We focus on a model with a simple geometry consisting of two vertical pipes properties of water and steam. We present a numerical algorithm based on an explicit upwind discretization

Weinmüller, Ewa B.

476

A numerical model of perturbation gas chromatography  

E-Print Network (OSTI)

37 38 39 10. 12. 13. 14. 15. 16. 17. 18. Species Profile for a Positive Benzene Perturbation in System 1 Species Profile for a Positive Cyclohexane Perturbation in System 1 Species Profile for a Positive n-Hexane Perturbation in System... 1 Species Profile for a Cyclohexane Perturbation in System 3 Species Profile for a Positive n ? Hexane Perturbation in System 2 Species Profile for a Positive Benzene Perturbation in System 2 Species Profile for a Positive Cyclohexane...

DeBarro, Marc Joseph

2012-06-07T23:59:59.000Z

477

Numerical Models of Extragalactic Radio Sources  

Science Journals Connector (OSTI)

...OF BOUNDARY-CONDITIONS AND GRID RESOLUTION, ASTRONOMY AND...national observatories provided an infrastructure that resulted in high-quality...of ideal MHD on an Eulerian grid in time and space using a battery...ARTICLES 523 magnetic field is a hybrid of the constrained transport...

JACK O. BURNS; MICHAEL L. NORMAN; DAVID A. CLARKE

1991-08-02T23:59:59.000Z

478

Numerical Models of Extragalactic Radio Sources  

Science Journals Connector (OSTI)

...WITH A CONTINUOUS ENERGY SUPPLY FROM A CENTRAL...observatories provided an infrastructure that resulted in...gravitational potential energy into bulk outflow...momen-tum, and energy, along with an...MHD on an Eulerian grid in time and space...magnetic field is a hybrid of the constrained...

JACK O. BURNS; MICHAEL L. NORMAN; DAVID A. CLARKE

1991-08-02T23:59:59.000Z

479

Numerical simulation and modeling of carbon nanotubes.  

E-Print Network (OSTI)

??The discovery of carbon nanotubes has triggered a significant amount of interest. Since then, much research has been done on these new forms of carbon… (more)

Wong, Chee How.

2008-01-01T23:59:59.000Z

480

Numerical Wave Modeling and Wave Energy Estimation  

Science Journals Connector (OSTI)

In a rapidly evolving operational and research framework concerning the global energy resources, new frontiers have been set for ... the scientific community working on environmental and renewable energy issues. ...

G. Galanis; G. Zodiatis; D. Hayes…

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "activity numerical modeling" 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

Thermally activated dislocation creep model for primary water stress corrosion cracking of NiCrFe alloys  

SciTech Connect

There is a growing awareness that awareness that environmentally assisted creep plays an important role in integranular stress corrosion cracking (IGSCC) of NiCrFe alloys in the primary coolant water environment of a pressurized water reactor (PWR). The expected creep mechanism is the thermally activated glide of dislocations. This mode of deformation is favored by the relatively low temperature of PWR operation combined with the large residual stresses that are most often identified as responsible for the SCC failure of plant components. Stress corrosion crack growth rate (CGR) equations that properly reflect the influence of this mechanism of crack tip deformation are required for accurate component life predictions. A phenomenological IGSCC-CGR model, which is based on an apriori assumption that the IGSCC-CGR is controlled by a low temperature dislocation creep mechanism, is developed in this report. Obstacles to dislocation creep include solute atoms such as carbon, which increase the lattice friction force, and forest dislocations, which can be introduced by cold prestrain. Dislocation creep also may be environmentally assisted due to hydrogen absorption at the crack tip. The IGSCC-CGR model developed here is based on an assumption that crack growth occurs by repeated fracture events occurring within an advancing crack-tip creep-fracture zone. Thermal activation parameters for stress corrosion cracking are obtained by fitting the CGR model to IGSCC-CGR data obtained on NiCrFe alloys, Alloy X-750 and Alloy 600. These IGSCC-CGR activation parameters are compared to activation parameters obtained from creep and stress relaxation tests. Recently reported CGR data, which exhibit an activation energy that depends on yield stress and the applied stress intensity factor, are used to benchmark the model. Finally, the effects of matrix carbon concentration, grain boundary carbides and absorbed hydrogen concentration are discussed within context of the model.

Hall, M.M., Jr

1995-12-31T23:59:59.000Z

482

Stephanie von Numers | Department of Energy  

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

Stephanie von Numers About Us Stephanie von Numers - Communications and Web Coordinator, Education & Workforce Development Stephanie von Numers joined the U.S. Department of...

483

Midwest Numerical Analysis Day 2011  

E-Print Network (OSTI)

Group Photos: Link. The 2011 Midwest Numerical Analysis Day ... (Free parking across street during the weekend). The organizers are Jie Shen (Chair), Peijun ...

484

E-Print Network 3.0 - active walk model Sample Search Results  

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

transition in human gait from walking to running as walking speed Summary: the ankle plantar flexors. Despite an increase in muscle activation with walking speed, the...

485

E-Print Network 3.0 - activity indicator model Sample Search...  

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

on the GUI. The pur- pose of this work is to explore how... observation streams from sensors, activities can be ... Source: Modayil, Joseph - Department of Computing Science,...

486

E-Print Network 3.0 - active region model Sample Search Results  

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

Collection: Physics 72 The main rationale In the 21st Summary: development in the ASEAN region. Chapter 3: The Space Activities of ASEAN Countries investigates the...

487

Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b  

E-Print Network (OSTI)

Numerical study of high heat ¯ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings

Maruyama, Shigeo

488

Temporal Changes in Wind as Objects for Evaluating Mesoscale Numerical Weather Prediction  

E-Print Network (OSTI)

a method of evaluating numerical weather prediction models by comparing the characteristics of temporal for biases in features forecast by the model. 1. Introduction Verification of numerical weather predictionTemporal Changes in Wind as Objects for Evaluating Mesoscale Numerical Weather Prediction DARAN L

Knievel, Jason Clark

489

Noninvasive three-dimensional activation time imaging of ventricular excitation by means of a heart-excitation model  

Science Journals Connector (OSTI)

We propose a new method for imaging activation time within three-dimensional (3D) myocardium by means of a heart-excitation model. The activation time is estimated from body surface electrocardiograms by minimizing multiple objective functions of the measured body surface potential maps (BSPMs) and the heart-model-generated BSPMs. Computer simulation studies have been conducted to evaluate the proposed 3D myocardial activation time imaging approach. Single-site pacing at 24 sites throughout the ventricles, as well as dual-site pacing at 12 pairs of sites in the vicinity of atrio-ventricular ring, was performed. The present simulation results show that the average correlation coefficient (CC) and relative error (RE) for single-site pacing were 0.9992 ± 0.0008/0.9989 ± 0.0008 and 0.05 ± 0.02/0.07 ± 0.03, respectively, when 5 µV/10 µV Gaussian white noise (GWN) was added to the body surface potentials. The average CC and RE for dual-site pacing were 0.9975 ± 0.0037 and 0.08 ± 0.04, respectively, when 10 µV GWN was added to the body surface potentials. The present simulation results suggest the feasibility of noninvasive estimation of activation time throughout the ventricles from body surface potential measurement, and suggest that the proposed method may become an important alternative in imaging cardiac electrical activity noninvasively.

Bin He; Guanglin Li; Xin Zhang

2002-01-01T23:59:59.000Z

490

SimHydro 2014:Modelling of rapid transitory flows,11-13 June 2014, Sophia Antipolis Marechal E., Khelladi S., Ravelet F., Delepierre-Massue O,. Bakir F Towards numerical simulation of snow showersin jet-engine fuel systems.  

E-Print Network (OSTI)

-engine fuel systems. TOWARDS NUMERICAL SIMULATION OF SNOW SHOWERS IN JET- ENGINE FUEL SYSTEMS Ewen MARECHAL1 investigations over past years. Jet engines fuel system components may sensitive to clogging. When a snow shower., Delepierre-Massue O,. Bakir F ­ Towards numerical simulation of snow showersin jet-engine fuel systems. Jet

Boyer, Edmond

491

Tailoring real-time physical activity coaching systems: a literature survey and model  

Science Journals Connector (OSTI)

Technology mediated healthcare services designed to stimulate patients' self-efficacy are widely regarded as a promising paradigm to reduce the burden on the healthcare system. The promotion of healthy, active living is a topic of growing interest in ... Keywords: Personalization, Physical activity, Real time coaching, Tailoring, Telemedicine, eHealth

Harm Akker, Valerie M. Jones, Hermie J. Hermens

2014-12-01T23:59:59.000Z

492

C/1995 O1 Hale-Bopp: Short and Long Distance Activity From a Theoretical Model  

Science Journals Connector (OSTI)

A theoretical model of the nucleus thermal evolution and differentiation is used to simulate the evolution along the orbit of the gas and dust emissions of comet Hale-Bopp. The model was already applied to ... an...

Maria Teresa Capria; Angioletta Coradini…

2002-01-01T23:59:59.000Z

493

Numerical Simulations of Water Wave Propagation and Flooding  

Science Journals Connector (OSTI)

In this paper we present main points in the process of application of numerical schemes for hyperbolic balance laws to water wave propagation and flooding. The appropriate mathematical models are the one ... two-...

Luka Sopta; Nelida ?rnjari?-Žic…

2005-01-01T23:59:59.000Z

494

Numerical Implementation of the Wave Energy Balance Equation  

Science Journals Connector (OSTI)

Successful solution of the problem of hindcasting and forecasting a sea wind wave depends on the quality of the physical model, the numerical implementation of the wave energy balance equation and the accuracy of...

Professor Dr. Igor V. Lavrenov

2003-01-01T23:59:59.000Z

495

Modeling and Field Test Planning Activities in Support of Disposal of Heat-Generating Waste in Salt  

SciTech Connect

The modeling efforts in support of the field test planning conducted at LBNL leverage on recent developments of tools for modeling coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. This work includes development related to, and implementation of, essential capabilities, as well as testing the model against relevant information and published experimental data related to the fate and transport of water. These are modeling capabilities that will be suitable for assisting in the design of field experiment, especially related to multiphase flow processes coupled with mechanical deformations, at high temperature. In this report, we first examine previous generic repository modeling results, focusing on the first 20 years to investigate the expected evolution of the different processes that could be monitored in a full-scale heater experiment, and then present new results from ongoing modeling of the Thermal Simulation for Drift Emplacement (TSDE) experiment, a heater experiment on the in-drift emplacement concept at the Asse Mine, Germany, and provide an update on the ongoing model developments for modeling brine migration. LBNL also supported field test planning activities via contributions to and technical review of framework documents and test plans, as well as participation in workshops associated with field test planning.

Rutqvist, Jonny; Blanco Martin, Laura; Mukhopadhyay, Sumit; Houseworth, Jim; Birkholzer, Jens

2014-09-26T23:59:59.000Z

496

CFD Numerical Simulation of Vortex-Induced Vibration of a Stay Cable under a Wind Profile  

Science Journals Connector (OSTI)

VIV (Vortex-induced vibration) of a stay cable subjected to a wind profile is numerically simulated through combining CFD ... numerical model. Under a profile of mean wind speed, unsteady aerodynamic lift coeffic...

Wenli Chen; Hui Li

2009-01-01T23:59:59.000Z

497

Numerical evidence of turbulence generated by non-breaking surface waves  

Science Journals Connector (OSTI)

Numerical simulation of monochromatic surface waves propagating over a turbulent field is conducted to reveal the mechanism of turbulence production by non-breaking waves. The numerical model solves the primitive equations subject to the fully ...

Wu-ting Tsai; Shi-ming Chen; Guan-hung Lu

498

A study of a two-stroke free piston linear engine using numerical analysis  

Science Journals Connector (OSTI)

We studied a two-stroke free piston linear engine by numerical models and simulation. The numerical ... ratio, reciprocating mass, spark timing, and spring stiffness on the operating characteristics as well as pe...

Nguyen Ba Hung; Ock Taeck Lim

2014-04-01T23:59:59.000Z

499

Two-bath model for activated surface diffusion of interacting adsorbates  

E-Print Network (OSTI)

The diffusion and low vibrational motions of adsorbates on surfaces can be well described by a purely stochastic model, the so-called interacting single adsorbate model, for low-moderate coverages (\\theta \\lesssim 0.12). Within this model, the effects of thermal surface phonons and adsorbate-adsorbate collisions are accounted for by two uncorrelated noise functions which arise in a natural way from a two-bath model based on a generalization of the one-bath Caldeira-Leggett Hamiltonian. As an illustration, the model is applied to the diffusion of Na atoms on a Cu(001) surface with different coverages.

R. Martinez-Casado; A. S. Sanz; G. Rojas-Lorenzo; S. Miret-Artes

2008-10-10T23:59:59.000Z

500

Characterization and activity of ferric-sulfide-based catalyst in model reactions of direct coal liquefaction: Effect of preparation conditions  

SciTech Connect

The authors studied the activity of various ferric-sulfide-based catalysts in model hydrogenation and cracking reactions under conditions typical of direct coal liquefaction (DCL). The catalysts used were mixtures of FeS{sub 2} (pyrite, PY) and nonstoichiometric FeS{sub x} (pyrrhotite, PH) obtained by high-temperature disproportionation of ferric sulfide in a nitrogen atmosphere or a hydrogen atmosphere. The structural changes in the catalyst were also examined, both before and after the model reactions. The cracking functionality of the catalysts was studied by using cumene, and the hydrocracking functionality was studied by using diphenylmethane. Phenanthrene was used as a model compound for hydrogenation and hydrogen shuttling. Phenanthrene hydrogenation was studied in the presence of H{sub 2}(g), and hydrogen shuttling was studied when a hydrogen donor (tetralin) was present in the absence of H{sub 2}(g). All the model reactions were performed under conditions typical of DCL: 400 C and 1,000 psig for 30 min. The surface and bulk of the catalysts were characterized by Auger electron spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and atomic absorption spectroscopy. The performance of the catalysts was found to vary with the type of reaction, the initial ratio of FeS{sub x} to FeS{sub 2} (PH/PY) found in the catalyst, and the catalyst age. Catalysts freshly prepared in a nitrogen atmosphere were most active for model hydrogenation and hydrocracking runs. Catalysts freshly prepared in hydrogen were most active in shuttling. A simple model was developed to explain changes in the surface and bulk of the catalysts.

Chadha, A.; Stinespring, C.D.; Stiller, A.H.; Zondlo, J.W.; Dadyburjor, D.B. [West Virginia Univ., Morgantown, WV (United States). Dept. of Chemical Engineering] [West Virginia Univ., Morgantown, WV (United States). Dept. of Chemical Engineering

1997-02-01T23:59:59.000Z