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1

Numerical Modeling  

Science Conference Proceedings (OSTI)

Feb 28, 2011... or field repair, durability, weight and cost efficiency, and extreme climate. ... Cohesive zone model is implemented to investigate the interfacial ...

2

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

3

NUMERICAL MODELING OF THE INITIATION OF CORONAL MASS EJECTIONS IN ACTIVE REGION NOAA 9415  

SciTech Connect

Coronal mass ejections (CMEs) and solar flares are the main drivers of weather in space. Understanding how these events occur and what conditions might lead to eruptive events is of crucial importance for up to date and reliable space weather forecasting. The aim of this paper is to present a numerical magnetohydrodynamic (MHD) data-inspired model suitable for the simulation of the CME initiation and their early evolution. Starting from a potential magnetic field extrapolation of the active region (AR) NOAA 9415, we solve the full set of ideal MHD equations in a non-zero plasma-{beta} environment. As a consequence of the applied twisting motions, a force-free-magnetic field configuration is obtained, which has the same chirality as the investigated AR. We investigate the response of the solar corona when photospheric motions resembling the ones observed for AR 9415 are applied at the inner boundary. As a response to the converging shearing motions, a flux rope is formed that quickly propagates outward, carrying away the plasma confined inside the flux rope against the gravitational attraction by the Sun. Moreover, a compressed leading edge propagating at a speed of about 550 km s{sup -1} and preceding the CME is formed. The presented simulation shows that both the initial magnetic field configuration and the plasma-magnetic-field interaction are relevant for a more comprehensive understanding of the CME initiation and early evolution phenomenon.

Zuccarello, F. P.; Poedts, S. [Centre for Mathematical Plasma-Astrophysics, KU Leuven, Celestijnenlaan 200B, B-3001 Leuven (Belgium); Meliani, Z., E-mail: Francesco.Zuccarello@wis.kuleuven.be, E-mail: Stefaan.Poedts@wis.kuleuven.be, E-mail: zakaria.meliani@obspm.fr [Observatoire de Paris, LUTh, F-92190 Meudon (France)

2012-10-20T23:59:59.000Z

4

Numerical simulation of the active magnetic regenerator  

Science Conference Proceedings (OSTI)

A time-dependent one-dimensional model of the active magnetic regenerator (AMR) that takes into account most of the physical and practical design problems for the AMR is developed as a highly nonlinear system of partial differential equations. The adequateness ... Keywords: Active magnetic regenerator, Magnetic refrigerator, Modeling and numerical scheme, Numerical simulation, Passive regenerator

B. M. Siddikov; B. A. Wade; D. H. Schultz

2005-05-01T23:59:59.000Z

5

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

6

Numerical Modeling and Optimization of Microstructure Evolution ...  

Science Conference Proceedings (OSTI)

Presentation Title, Numerical Modeling and Optimization of Microstructure Evolution ... A Hybrid Model on Low Energy Ion Beam Processing Leading to Phase ...

7

A Numerical Model of the Ventilated Thermocline  

Science Conference Proceedings (OSTI)

A steady state numerical solution is found for an idealized, rectangular ocean basin driven by wind and surface buoyancy flux. A three-dimensional primitive equation model is used. In agreement with recent analytical modeling, the thermocline in ...

Michael D. Cox; Kirk Bryan

1984-04-01T23:59:59.000Z

8

3D Temperature distribution and numerical modeling of heat transfers in an active fault zone: Eugene Island 330, Offshore Louisiana.  

E-Print Network (OSTI)

temperature distributions by using some of the most commonly recorded data in modern oil field exploration sensitive to the movement of strong seismic events such as oil/water and gas/oil contacts on the scale for the dynamics of active oil fields. Here, Plio- Pleistocene sandstone reservoirs are supplied with mature

Guerin, Gilles

9

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

10

Numerical wind speed simulation model  

DOE Green Energy (OSTI)

A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.

Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.

1981-09-01T23:59:59.000Z

11

Waste glass melter numerical and physical modeling  

SciTech Connect

Results of physical and numerical simulation modeling of high-level liquid waste vitrification melters are presented. Physical modeling uses simulant fluids in laboratory testing. Visualization results provide insight into convective melt flow patterns from which information is derived to support performance estimation of operating melters and data to support numerical simulation. Numerical simulation results of several melter configurations are presented. These are in support of programs to evaluate melter operation characteristics and performance. Included are investigations into power skewing and alternating current electric field phase angle in a dual electrode pair reference design and bi-modal convective stability in an advanced design. 9 refs., 9 figs., 1 tab.

Eyler, L.L.; Peters, R.D.; Lessor, D.L.; Lowery, P.S.; Elliott, M.L.

1991-10-01T23:59:59.000Z

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

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.

14

Numerical modeling of liquid geothermal systems  

DOE Green Energy (OSTI)

A mathematical model describing the physical behavior of hot-water geothermal systems is presented. The model consists of a set of coupled partial differential equations for heat and mass transfer in porous media and an equation of state relating fluid density to temperature and pressure. The equations are solved numerically using an integrated finite difference method which can treat arbitrary nodal configurations in one, two, or three dimensions. The model is used to analyze cellular convection in permeable rock layers heated from below. Results for cases with constant fluid and rock properties are in good agreement with numerical and experimental results from other authors.

Sorey, M.L.

1978-01-01T23:59:59.000Z

15

Microcomputer Numerical Ocean Surface Wave Model  

Science Conference Proceedings (OSTI)

A numerical wean surface wave model has been developed specifically to operate on desktop super micro-computers. The model uses one or more local and moving grids within which waves of importance at a location of interest are generated. Within ...

Marshall D. Earle

1989-02-01T23:59:59.000Z

16

Efficient numerical modeling of borehole heat exchangers  

Science Conference Proceedings (OSTI)

This paper presents a finite element modeling technique for double U-tube borehole heat exchangers (BHE) and the surrounding soil mass. Focus is placed on presenting numerical analyses describing the capability of a BHE model, previously reported, to ... Keywords: BHE, Geothermal heat pumps, Geothermic, Heat transfer, Space heating

R. Al-Khoury; T. Kölbel; R. Schramedei

2010-10-01T23:59:59.000Z

17

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

18

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

19

Numerical simulation of micro-fluidic passive and active mixers  

E-Print Network (OSTI)

Numerical simulations of mixing using passive and active techniques are performed. For passive mixing, numerical modeling of a micro-fluidic device, build by Holden and Cremer, was performed. The micro-fluidic device consists of a Y-junction that allows inflow of two different species of fluid into a main-channel. The main-channel eventually splits into eleven smaller output micro-channels. This device enables control of molecular diffusion from one fluid stream into the other by regulating the flow rate. Hence, output channels exhibit predetermined concentration values, which allow concentration dependent chemistry experiments in each output channel. Convective diffusive transport in this micro mixer is studied numerically and theoretically. Our model prediction are compared with the experimental data. Numerical simulations of a peristaltically driven micro mixer is studied as a function of the travelling wave amplitude and the Reynolds number. First the numerical scheme was verified for small deformation cases for moderate and large Reynolds numbers. Kinematics of large deformation conditions are studied for various Reynolds numbers.

Kumar, Saurabh

2002-01-01T23:59:59.000Z

20

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

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

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

22

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

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 OF CATHODE CONTACT MATERIAL DENSIFICATION  

Science Conference Proceedings (OSTI)

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

26

Numerical Model Studies of Long-Period Edge Waves  

Science Conference Proceedings (OSTI)

A numerical modeling study of aspects of the generation and propagation of long-period edge waves along a continental shelf is described. The numerical model is based on the traditional shallow-water dynamics. A scale analysis indicates that ...

F. A. Shillington; D. Van Foreest

1986-08-01T23:59:59.000Z

27

A Numerical Model for Combustion of Bubbling Thermoplastic ...  

Science Conference Proceedings (OSTI)

... the highly viscous nature of softening coal, the model ... unity in the region close to the ... dependent numerical model of burning thermoplastic materials ...

2004-12-27T23:59:59.000Z

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

Numerical models for high beta magnetohydrodynamic flow  

Science Conference Proceedings (OSTI)

The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs.

Brackbill, J.U.

1987-01-01T23:59:59.000Z

30

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"

31

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

Open Energy Info (EERE)

Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A...

32

A Benchmark Simulation for Moist Nonhydrostatic Numerical Models  

Science Conference Proceedings (OSTI)

A benchmark solution that facilitates testing the accuracy, efficiency, and efficacy of moist nonhydrostatic numerical model formulations and assumptions is presented. The solution is created from a special configuration of moist model processes ...

George H. Bryan; J. Michael Fritsch

2002-12-01T23:59:59.000Z

33

A Numerical Model for Low-Frequency Equatorial Dynamics  

Science Conference Proceedings (OSTI)

A fast, efficient numerical procedure for modeling the linear low-frequency motions on an equatorial beta plane is developed. The model is capable of simulating the seasonal and interannual variability in realistically shaped ocean basins forced ...

Mark A. Cane; Randall J. Patton

1984-12-01T23:59:59.000Z

34

The Fleet Numerical Oceanography Center Global Spectral Ocean Wave Model  

Science Conference Proceedings (OSTI)

The Spectral Ocean Wave Model (SOWM) has been an operational product at Fleet Numerical Oceanography Center since the mid 1970s; the Global Spectral Ocean Wave Model (GSOWM) was developed to replace it. An operational test of GSOWM, using buoy, ...

R. M. Clancy; J. E. Kaitala; L. F. Zambresky

1986-05-01T23:59:59.000Z

35

Numerical Simulation and Modelling of Electronic and Biochemical Systems  

Science Conference Proceedings (OSTI)

Numerical simulation and modelling are witnessing a resurgence. Designing systems with integrated wireless components, mixed-signal blocks and nanoscale, multi-GHz "digital" circuits is requiring extensive low-level modelling and simulation. Analysis ...

Jaijeet Roychowdhury

2009-02-01T23:59:59.000Z

36

Pacific Hindcast Performance of Three Numerical Wave Models  

Science Conference Proceedings (OSTI)

Although mean or integral properties of wave spectra are typically used to evaluate numerical wave model performance, one must look into the spectral details to identify sources of model deficiencies. This creates a significant problem, as basin-...

Jeffrey L. Hanson; Barbara A. Tracy; Hendrik L. Tolman; R. Douglas Scott

2009-08-01T23:59:59.000Z

37

Linear Spectral Numerical Model for Internal Gravity Wave Propagation  

Science Conference Proceedings (OSTI)

A three-dimensional linear spectral numerical model is proposed to simulate the propagation of internal gravity wave fluctuations in a stably stratified atmosphere. The model is developed to get first-order estimations of gravity wave ...

J. Marty; F. Dalaudier

2010-05-01T23:59:59.000Z

38

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

39

Numerical Modeling of Centrifugally Cast HSS Rolls  

Science Conference Proceedings (OSTI)

This model will help to further understand the complex solidification behavior of the HSS roll. Performance of the HSS roll requires proper formation and ...

40

Numerical Modeling of Orographically Forced Postfrontal Rain  

Science Conference Proceedings (OSTI)

A nonhydrostatic mesoscale model is used to simulate the dynamics and microphysics of postfrontal flow in the mountainous region of southeastern Australia. The aim of the paper is to determine if it is possible to use 2D models to simulate the ...

Deborah J. Abbs; Jřrgen B. Jensen

1993-01-01T23:59:59.000Z

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.


41

A Lightning Parameterization for Numerical Cloud Models  

Science Conference Proceedings (OSTI)

A new lightning parameterization has been developed to enable cloud models to simulate the location and structure of individual lightning flashes more realistically. To do this, three aspects of previous parameterizations have been modified: 1) ...

Donald R. MacGorman; Jerry M. Straka; Conrad L. Ziegler

2001-03-01T23:59:59.000Z

42

Radiation Boundary Conditions in Numerical Modeling  

Science Conference Proceedings (OSTI)

A two-dimensional anelastic model is used to study the propagation of errors arising from the use of open lateral boundaries. Reference experiments were performed using very large horizontal domains. Other experiments were carried out in smaller ...

Mark Hedley; M. K. Yau

1988-09-01T23:59:59.000Z

43

A Numerical Study of Cirrus Clouds. Part I: Model Description  

Science Conference Proceedings (OSTI)

This article, the first of a two-part series, presents a detailed description of a two-dimensional numerical cloud model directed toward elucidating the physical processes governing the evolution of cirrus clouds. The two primary scientific ...

Hui-Chun Liu; Pao K. Wang; Robert E. Schlesinger

2003-04-01T23:59:59.000Z

44

Numerical Modeling of the Atmosphere with an Isentropic Vertical Coordinate  

Science Conference Proceedings (OSTI)

In constructing a numerical model of the atmosphere, we must choose an appropriate vertical coordinate. Among the various possibilities, isentropic vertical coordinates such as the ?-coordinate seem to have the greatest potential, in spite of the ...

Yueh-Jiuan G. Hsu; Akio Arakawa

1990-10-01T23:59:59.000Z

45

Hurricane Track Prediction Using a Statistical Ensemble of Numerical Models  

Science Conference Proceedings (OSTI)

A new statistical ensemble prediction system for tropical cyclone tracks is presented. The system is based on a statistical analysis of the annual performance of numerical track prediction models, assuming that their position errors are ...

Harry C. Weber

2003-05-01T23:59:59.000Z

46

Numerical Modeling Studies of a Process of Lee Cyclogenesis  

Science Conference Proceedings (OSTI)

A process of lee cyclogenesis associated with backsheared baroclinic flow is studied using a fully nonlinear, primitive equation numerical model. A region of low pressure and a narrow baroclinic zone develop to the southwest of the mountain in ...

Yuh-Lang Lin; Donald J. Perkey

1989-12-01T23:59:59.000Z

47

Energy Trapping near the Equator in a Numerical Ocean Model  

Science Conference Proceedings (OSTI)

The trapped equatorial standing modes described theoretically by Gent (1979) are reproduced in a single vertical-mode numerical ocean model. integrations are carried out in domains whose longitudinal extents are characteristic of the widths of ...

Peter R. Gent; Albert J. Semtner Jr.

1980-06-01T23:59:59.000Z

48

Two-Time-Step Oscillations in Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

Spurious, nonamplifying, two-time-step oscillations are present in several numerical models of the atmosphere where the vertical diffusion is parameterized using a nonlinear diffusion equation. The problems become particularly pronounced when the ...

Ulla Hammarstrand

1997-12-01T23:59:59.000Z

49

Numerical Modeling of Gravity Wave Generation by Deep Tropical Convection  

Science Conference Proceedings (OSTI)

Although convective clouds are known to generate internal gravity waves, the mechanisms responsible are not well understood. The present study seeks to clarify the dynamics of wave generation using a high-resolution numerical model of deep ...

Todd P. Lane; Michael J. Reeder; Terry L. Clark

2001-05-01T23:59:59.000Z

50

Free Planetary Waves in Finite-Difference Numerical Models  

Science Conference Proceedings (OSTI)

The effects of spatial finite-differencing, viscosity and diffusion on unbounded planetary waves in numerical models are investigated using a quasi-geostrophic approximation to the midlatitude, ?-plane, shallow-water equations. The two-...

Roxana C. Wajsowicz

1986-04-01T23:59:59.000Z

51

An Eddy Resolving Numerical Model of the Ventilated Thermocline  

Science Conference Proceedings (OSTI)

A three-dimensional, primitive equation numerical model is used to study the effects of mesoscale eddies within the subtropical thermocline. Solutions are obtained for an ocean bounded by idealized topography are driven by simple wind and ...

Michael D. Cox

1985-10-01T23:59:59.000Z

52

Geothermal: Sponsored by OSTI -- A numerical model ofhydro-thermo...  

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

A numerical model of hydro-thermo-mechanical coupling in a fractured rock mass Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic...

53

Gulf of Mexico numerical model. Project summary  

DOE Green Energy (OSTI)

An efficient three-dimensional, time dependent prognostic model of the Gulf of Mexico has been developed. The model is driven by winds and surface heat flux derived from climatological, atmospheric surface data, the result of an intensive data analysis study. Mean velocity, temperature, salinity, turbulence kinetic energy and turbulence macroscale are the prognostic variables. Lateral boundary conditions for temperature and salinity and geostrophically derived velocity at the Straits of Yucatan and Florida are obtained from climatological ocean data. An analytical second moment turbulence closure scheme embedded within the model provides realistic surface mixed layer dynamics. Free surface elevation distributions are calculated with an algorithm which calculates the external (tidal) mode separately from the internal mode. The external mode, an essentially two-dimensional calculation, requires a short integrating timestep whereas the more costly, three-dimensional, internal mode can be executed with a long step. The result is a fully three-dimensional code which includes a free surface at no sacrifice in computer cost compared to rigid lid models.

Blumberg, A. F.; Mellor, G. L.; Herring, H. J.

1981-02-01T23:59:59.000Z

54

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

55

Mathematical Models in Landscape Ecology: Stability Analysis and Numerical Tests  

Science Conference Proceedings (OSTI)

In the present paper a review of some mathematical models for the ecological evaluation of environmental systems is considered. Moreover a new model, capable to furnish more detailed information at the level of landscape units, is proposed. Numerical ... Keywords: 34D05, 92F05, Landscape ecology, Mathematical models, Stability analysis

Federica Gobattoni; Giuliana Lauro; Roberto Monaco; Raffaele Pelorosso

2013-06-01T23:59:59.000Z

56

On a numerical model for gasification of biomass materials  

Science Conference Proceedings (OSTI)

In this paper, a thermochemical equilibrium model is used to predict the performance of a downdraft gasifier. Numerical results are shown to be in good agreement with those of the experiments. Different biomass materials are tested using the model and ... Keywords: biomass, gasification, mathematical modeling, renewable energy, thermochemical equilibrium

Mahdi Vaezi; Mohammad Passandideh-Fard; Mohammad Moghiman

2007-12-01T23:59:59.000Z

57

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

58

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

E-Print Network (OSTI)

of numerical weather prediction solar irradiance forecasts of numerical weather prediction for intra?day solar numerical weather prediction model for solar irradiance 

Mathiesen, Patrick; Collier, Craig; Kleissl, Jan

2013-01-01T23:59:59.000Z

59

A Numerical Model for Prediction of Road Temperature and Ice  

Science Conference Proceedings (OSTI)

A numerical model for the prediction of road temperature and ice has been tested on data from a Danish road station. The model is based on the solution of the equation of heat conduction in the ground and the surface energy-balance equation.

Bent H. Sass

1992-12-01T23:59:59.000Z

60

Introduction Application of numerical models of ground water flow  

E-Print Network (OSTI)

Introduction Application of numerical models of ground water flow almost always involves some sort (Yeh 1986; Poeter and Hill 1997; Hill et al. 1998). Other data beside hydraulic head have been used in calibration of ground water models, including rates of ground water exchange with streams and other surface

Saiers, James

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 geomagnetic secularvariation timescale in observations and numerical dynamo models  

E-Print Network (OSTI)

The geomagnetic secularvariation timescale in observations and numerical dynamo models Florian March 2011; published 5 May 2011. [1] The knowledge of the spatial power spectra of the main geomagnetic for recent satellite field models. In the broader context of geomagnetic data assimilation, tSV could provide

Aubert, Julien

62

Numerical models for the evaluation of geothermal systems  

DOE Green Energy (OSTI)

We have carried out detailed simulations of various fields in the USA (Bada, New Mexico; Heber, California); Mexico (Cerro Prieto); Iceland (Krafla); and Kenya (Olkaria). These simulation studies have illustrated the usefulness of numerical models for the overall evaluation of geothermal systems. The methodology for modeling the behavior of geothermal systems, different approaches to geothermal reservoir modeling and how they can be applied in comprehensive evaluation work are discussed.

Bodvarsson, G.S.; Pruess, K.; Lippmann, M.J.

1986-08-01T23:59:59.000Z

63

Physical and numerical modeling of Joule-heated melters  

SciTech Connect

The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

1985-10-01T23:59:59.000Z

64

Forecasting the Skill of a Regional Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

It is demonstrated that the skill of short-term regional numerical forecasts can be predicted on a day-to-day basis. This was achieved by using a statistical regression scheme with the model forecast errors (MFE) as the predictands and the ...

L. M. Leslie; K. Fraedrich; T. J. Glowacki

1989-03-01T23:59:59.000Z

65

Numerical Ocean Prediction Models—Goal for the 1980s  

Science Conference Proceedings (OSTI)

Based on the experience of numerical weather prediction during the 1950s and 1960s as a model, a case is presented for the development of an ocean prediction capability during the 1980s. Examples selected from recent research at the Naval ...

Russell L. Elsberry; Roland W. Garwood Jr.

1980-12-01T23:59:59.000Z

66

Numerical Discretization of Rotated Diffusion Operators in Ocean Models  

Science Conference Proceedings (OSTI)

A method to improve the behavior of the numerical discretization of a rotated diffusion operator such as, for example, the isopycnal diffusion parameterization used in large-scale ocean models based on the so-called z-coordinate system is ...

J-M. Beckers; H. Burchard; E. Deleersnijder; P. P. Mathieu

2000-08-01T23:59:59.000Z

67

Numerical Modeling of Internal Tide Generation along the Hawaiian Ridge  

Science Conference Proceedings (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

68

The Free Kelvin Wave in Finite-Difference Numerical Models  

Science Conference Proceedings (OSTI)

The effects of viscosity and finite- differencing on free Kelvin waves in numerical models (which employ the Arakawa B- or C-grid difference schemes) are investigated using the f-plane shallow-water equations with offshore finite-difference grids,...

William W. Hsieh; Michael K. Davey; Roxana C. Wajsowicz

1983-08-01T23:59:59.000Z

69

Thesis A Numerical Model of Hydro-Thermo- Mechanical Coupling...  

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

1 31 53-T Thesis A Numerical Model of Hydro-Thermo- Mechanical Coupling in a Fractured Rock Mass ECEIVED Los Alamos N A T I O N A L L A B O R A T O R Y Los Alamos National...

70

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

Science Conference Proceedings (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

71

Integrating Numerical Computation into the Modeling Instruction Curriculum  

E-Print Network (OSTI)

We describe a way to introduce physics high school students with no background in programming to computational problem-solving experiences. Our approach builds on the great strides made by the Modeling Instruction reform curriculum. This approach emphasizes the practices of "Developing and using models" and "Computational thinking" highlighted by the NRC K-12 science standards framework. We taught 9th-grade students in a Modeling-Instruction-based physics course to construct computational models using the VPython programming environment. Numerical computation within the Modeling Instruction curriculum provides coherence among the curriculum's different force and motion models, links the various representations which the curriculum employs, and extends the curriculum to include real-world problems that are inaccessible to a purely analytic approach.

Caballero, Marcos D; Aiken, John M; Douglas, Scott S; Scanlon, Erin M; Thoms, Brian; Schatz, Michael F

2012-01-01T23:59:59.000Z

72

Modelling geomagnetic activity data  

Science Conference Proceedings (OSTI)

Strong geomagnetic activity is a hazard to electronics and electric power facilities. Assessment of the actual geomagnetic activity level from local magnetometer monitoring therefore is of importance for risk assessment but also in earth sciences and ... Keywords: geomagnetism, neuro fuzzy modelling, self organizing map, signal processing, wavelets

Ernst D. Schmitter

2008-01-01T23:59:59.000Z

73

Numerical modeling of injection experiments at The Geysers  

DOE Green Energy (OSTI)

Data from injection experiments in the southeast Geysers are presented that show strong interference (both negative and positive) with a neighboring production well. Conceptual and numerical models are developed that explain the negative interference (decline of production rate) in terms of heat transfer limitations and water-vapor relative permeability effects. Recovery and over-recovery following injection shut-in are attributed to boiling of injected fluid, with heat of vaporization provided by the reservoir rocks.

Pruess, K. [Lawrence Berkeley Lab., CA (United States); Enedy, S. [Northern California Power Agency, Middletown, CA (United States)

1993-01-01T23:59:59.000Z

74

ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS  

Science Conference Proceedings (OSTI)

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

75

Thermoinertial bouncing of a relativistic collapsing sphere: A numerical model  

Science Conference Proceedings (OSTI)

We present a numerical model of a collapsing radiating sphere, whose boundary surface undergoes bouncing due to a decreasing of its inertial mass density (and, as expected from the equivalence principle, also of the 'gravitational' force term) produced by the 'inertial' term of the transport equation. This model exhibits for the first time the consequences of such an effect, and shows that under physically reasonable conditions this decreasing of the gravitational term in the dynamic equation may be large enough as to revert the collapse and produce a bouncing of the boundary surface of the sphere.

Herrera, L.; Di Prisco, A.; Barreto, W. [Centro de Fisica Teorica y Computacional, Facultad de Ciencias, Universidad Central de Venezuela, Caracas (Venezuela); Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de los Andes, Merida (Venezuela)

2006-01-15T23:59:59.000Z

76

Numerical Model for Conduction-Cooled Current Lead Heat Loads  

SciTech Connect

Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world; however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal intercepts. The model is validated by comparing the numerical model results to ideal cases where analytical equations are valid. In addition, the XFEL (X-Ray Free Electron Laser) prototype current leads are modeled and compared to the experimental results from testing at DESY's XFEL Magnet Test Stand (XMTS) and Cryomodule Test Bench (CMTB).

White, M.J.; Wang, X.L.; /Fermilab; Brueck, H.D.; /DESY

2011-06-10T23:59:59.000Z

77

SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION  

SciTech Connect

Active capping involves the use of capping materials that react with sediment contaminants to reduce their toxicity or bioavailability. Although several amendments have been proposed for use in active capping systems, little is known about their long-term ability to sequester metals. Recent research has shown that the active amendment apatite has potential application for metals contaminated sediments. The focus of this study was to evaluate the effectiveness of apatite in the sequestration of metal contaminants through the use of short-term laboratory column studies in conjunction with predictive, numerical modeling. A breakthrough column study was conducted using North Carolina apatite as the active amendment. Under saturated conditions, a spike solution containing elemental As, Cd, Co, Se, Pb, Zn, and a non-reactive tracer was injected into the column. A sand column was tested under similar conditions as a control. Effluent water samples were periodically collected from each column for chemical analysis. Relative to the non-reactive tracer, the breakthrough of each metal was substantially delayed by the apatite. Furthermore, breakthrough of each metal was substantially delayed by the apatite compared to the sand column. Finally, a simple 1-D, numerical model was created to qualitatively predict the long-term performance of apatite based on the findings from the column study. The results of the modeling showed that apatite could delay the breakthrough of some metals for hundreds of years under typical groundwater flow velocities.

Dixon, K.; Knox, A.

2012-02-13T23:59:59.000Z

78

Optimal numerical realization of the energy balance equation for wind wave models  

Science Conference Proceedings (OSTI)

The optimal numerical realization of the energy balance equation in wind wave models is proposed. The scheme is separated into two parts: the numerical source term integration and the energy propagation numerical realization. The first one is based on ...

Igor V. Lavrenov

2003-06-01T23:59:59.000Z

79

A Split Explicit Reformulation of the Regional Numerical Weather Prediction Model of the Japan Meteorological Agency  

Science Conference Proceedings (OSTI)

The split explicit integration scheme for numerical weather prediction models is employed in a version of the regional numerical weather prediction model of the Japan Meteorological Agency. The finite-difference scheme of the model is designed in ...

Dean G. Duffy

1981-05-01T23:59:59.000Z

80

Numerical Modeling of Complex Porous Media For Borehole Applications  

E-Print Network (OSTI)

The diffusion/relaxation behavior of polarized spins of pore filling fluid, as often probed by NMR relaxometry, is widely used to extract information on the pore-geometry. Such information is further interpreted as an indicator of the key transport property of the formation in the oil industry. As the importance of reservoirs with complex pore geometry grows, so does the need for deeper understanding of how these properties are inter-related. Numerical modeling of relevant physical processes using a known pore geometry promises to be an effective tool in such endeavor. Using a suite of numerical techniques based on random-walk (RW) and Lattice-Boltzmann (LB) algorithms, we compare sandstone and carbonate pore geometries in their impact on NMR and flow properties. For NMR relaxometry, both laboratory measurement and simulation were done on the same source to address some of the long-standing issues in its borehole applications. Through a series of "numerical experiments" in which the interfacial relaxation properties of the pore matrix is varied systematically, we study the effect of a variable surface relaxivity while fully incorporating the complexity of the pore geometry. From combined RW and LB simulations, we also obtain diffusion-convection propagator and compare the result with experimental and network-simulation counterparts.

Seungoh Ryu; Weishu Zhao; Gabriela Leu; Philip M. Singer; Hyung Joon Cho; Youngseuk Keehm

2009-08-13T23:59:59.000Z

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.


81

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

82

Numerical modeling of dish-Stirling reflux solar receivers  

DOE Green Energy (OSTI)

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

83

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

84

Progress report on LBL's numerical modeling studies on Cerro Prieto  

DOE Green Energy (OSTI)

An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.

Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.

1989-04-01T23:59:59.000Z

85

Numerical modeling of a true in situ oil shale retort  

DOE Green Energy (OSTI)

A numerical model has been developed to simulate the true in situ retorting process. The retort is assumed to be a low-porosity fractured bed composed of large seams of competent shale separated at intervals by open fractures. Kerogen and carbonate decomposition and char, oil, and gas combustion, as well as other reactions, are considered. In contrast to the results of rubbled-bed models, the retorting of seams thicker than one meter is characterized by incomplete retorting and significant oil combustion (10 to 40% of that retorted). The amount of shale retorted can, however, be maximized by proper control of air and steam injection rates, with the injected gas being optimally 40 to 50% steam. The oil available for recovery from a two meter seam can then be, for example, as high as 50% of Fischer Assay.

Tyner, C.E.; Hommert, P.J.

1979-01-01T23:59:59.000Z

86

A numerical model simulation of longshore transport for Galveston Island  

E-Print Network (OSTI)

The shoreline changes, deposition patterns, and longshore transport rates were calculated for the coast of Galveston Island using a numerical model simulation. The model only simulated changes due to waves creating longshore currents. East Beach showed a net accretion pattern, with erosion confined to the eastern section of the area. Large accretion was found near the first groin indicating transport from east to west. The groin field fluctuated with erosion and accretion, with a net gain of shoreline. The unprotected beach in front of the seawall eroded almost completely away. West Beach had a net loss of shoreline overall. This was largely due to the shoreline erosion found at San Luis Pass. The majority of West Beach was frequently unstable, fluctuating between erosion and accretion.

Gilbreath, Stephen Alexander

1995-01-01T23:59:59.000Z

87

Effects of Numerics on the Physics in a Third-Generation Wind-Wave Model  

Science Conference Proceedings (OSTI)

Numerical errors in third-generation ocean wave models can result in a misinterpretation of the physics in the model. Using idealized situations, it is shown that numerical errors significantly influence the initial growth, the response of wave ...

Hendrik L. Tolman

1992-10-01T23:59:59.000Z

88

Numeric modeling of fire suppression by organophosphorous inhibitors  

E-Print Network (OSTI)

Numerical calculations of the effect of organophosphorous inhibitor (CF3CH2O)3P and its mixtures with carbon dioxide on propane flames are carried out using the three dimensional Reynolds-averaged Navier-Stokes (RANS) equations in the low Mach number approximation. The k-e model of turbulence, the EDC combustion model and the weighted-sum-of-gray-gases model of radiation are used. The Westbrook global-kinetic scheme with fractional order of reaction was used for the calculation of chemical reaction rate of propane combustion. The empirical expression for the correction factor for the chemical reaction rate was used to model the effect of organophosphorous inhibitor no the reaction. Two series of test calculations for different values of the correction factor are carried out. Dependences of the minimum extinguishing concentration of the inhibitor per carbon dioxide volume concentration in the extinguishing mixtures were obtained. The results of test calculations are shown to agree reasonably with the experimen...

Makhviladze, G M; Zykov, A P

2008-01-01T23:59:59.000Z

89

CDIAC catalog of numeric data packages and computer model packages  

Science Conference Proceedings (OSTI)

The Carbon Dioxide Information Analysis Center acquires, quality-assures, and distributes to the scientific community numeric data packages (NDPs) and computer model packages (CMPs) dealing with topics related to atmospheric trace-gas concentrations and global climate change. These packages include data on historic and present atmospheric CO{sub 2} and CH{sub 4} concentrations, historic and present oceanic CO{sub 2} concentrations, historic weather and climate around the world, sea-level rise, storm occurrences, volcanic dust in the atmosphere, sources of atmospheric CO{sub 2}, plants` response to elevated CO{sub 2} levels, sunspot occurrences, and many other indicators of, contributors to, or components of climate change. This catalog describes the packages presently offered by CDIAC, reviews the processes used by CDIAC to assure the quality of the data contained in these packages, notes the media on which each package is available, describes the documentation that accompanies each package, and provides ordering information. Numeric data are available in the printed NDPs and CMPs, in CD-ROM format, and from an anonymous FTP area via Internet. All CDIAC information products are available at no cost.

Boden, T.A. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; O`Hara, F.M. Jr. [O`Hara (Fred M., Jr.), Oak Ridge, TN (US); Stoss, F.W. [Univ. of Tennessee, Knoxville, TN (US). Energy, Environment, and Resources Center

1993-05-01T23:59:59.000Z

90

Coupling geological and numerical models to simulate groundwater flow and contaminant transport in fractured media  

Science Conference Proceedings (OSTI)

A new modeling approach is presented to improve numerical simulations of groundwater flow and contaminant transport in fractured geological media. The approach couples geological and numerical models through an intermediate mesh generation phase. As ... Keywords: Fractures, Geomodel, Influence coefficient technique, Numerical modeling, Tetrahedra

Daniela Blessent; René Therrien; Kerry MacQuarrie

2009-09-01T23:59:59.000Z

91

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

92

Numerical modeling and experimental testing of a solar grill  

SciTech Connect

The sun provides a free, nonpolluting and everlasting source of energy. Considerable research has been carried out to utilize solar energy for purposes such as water heating, high temperature ovens, and conversion to electrical energy. One of the interesting forms for utilizing solar energy is cooking. The main disadvantage of solar energy systems has been the low efficiency attained in most of its practical applications. It is expected, however, that due to continuing decreases in the availability of other energy sources such as oil and coal, along with the safety problems associated with nuclear energy, man's need for utilization of solar energy will increase, thus leading him to find the ways and means to develop adequate and efficient solar-powered systems. In camps, where tents are used to accommodate people, cooking is done via conventional gas stoves. This usually takes place in extremely crowded areas which become highly fireprone. Solar oven cookers seem to be a viable alternative considering both economy and safety. Among the various forms of solar cookers, the oven-type solar cooker is known to be the best in terms of efficiency. One of the most practical and efficient forms of solar oven cookers is the outdoor portable solar grill (Bar-B-Q), developed by Khalifa et al. The solar grill is a light and portable unit that utilizes solar energy to grill meat. One of the best types of grilling with this cooker is the well-known Shish Kebab or Bar-B-Q. A detailed description for the design of the solar grill is provided as follows. This paper is aimed at providing experimental results and formulating a numerical model for the solar grill. Results of the two approaches are then compared to verify the validity of the numerical simulation. An experimental and theoretical investigation was conducted on the solar grill in order to study the factors that affect its design and performance.

Olwi, I.; Khalifa, A. (King Abdulaziz Univ., Jeddah (Saudi Arabia))

1993-02-01T23:59:59.000Z

93

Numerical Modeling of Hailstorms and Hailstone Growth. Part I: Preliminary Model Verification and Sensitivity Tests  

Science Conference Proceedings (OSTI)

This paper is the first in a three part series describing numerical simulations of hailstorms and hailstone growth using a two-dimensional, time-dependent cloud model. In this model. cloud water, cloud ice and rain are treated via standard ...

R. D. Farley; H. D. Orville

1986-12-01T23:59:59.000Z

94

Passive millimeter-wave retrieval of global precipitation utilizing satellites and a numerical weather prediction model  

E-Print Network (OSTI)

This thesis develops and validates the MM5/TBSCAT/F([lambda]) model, composed of a mesoscale numerical weather prediction (NWP) model (MM5), a two-stream radiative transfer model (TBSCAT), and electromagnetic models for ...

Surussavadee, Chinnawat

2007-01-01T23:59:59.000Z

95

Numerical investigations of the Schwinger model and selected quantum spin models  

E-Print Network (OSTI)

Numerical investigations of the XY model, the Heisenberg model and the J-J' Heisenberg model are conducted, using the exact diagonalisation, the numerical renormalisation and the density matrix renormalisation group approach. The low-lying energy levels are obtained and finite size scaling is performed to estimate the bulk limit values. The results are found to be consistent with the exact values. The DMRG results are found to be most promising. The Schwinger model is also studied using the exact diagonalisation and the strong coupling expansion. The massless, the massive model and the model with a background electric field are explored. Ground state energy, scalar and vector particle masses and order parameters are examined. The achieved values are observed to be consistent with previous results and theoretical predictions. Path to the future studies is outlined.

Marcin Szyniszewski

2013-03-03T23:59:59.000Z

96

Numerical Forecasting of Radiation Fog. Part I: Numerical Model and Sensitivity Tests  

Science Conference Proceedings (OSTI)

To improve the forecast of dense radiative fogs, a method has been developed using a one-dimensional model of the nocturnal boundary layer forced by the mesoscale fields provided by a 3D limited-area operational model. The 1D model involves a ...

Thierry Bergot; Daniel Guedalia

1994-06-01T23:59:59.000Z

97

An Open Boundary Condition for Numerical Coastal Circulation Models  

Science Conference Proceedings (OSTI)

Open boundaries (OBs) are usually unavoidable in numerical coastal circulation simulations. At OBs, an appropriate open boundary condition (OBC) is required so that outgoing waves freely pass to the exterior without creating reflections back into ...

Peifeng Ma; Ole Secher Madsen

2011-12-01T23:59:59.000Z

98

The Maximum Intensity of Tropical Cyclones in Axisymmetric Numerical Model Simulations  

Science Conference Proceedings (OSTI)

An axisymmetric numerical model is used to evaluate the maximum possible intensity of tropical cyclones. As compared with traditionally formulated nonhydrostatic models, this new model has improved mass and energy conservation in saturated ...

George H. Bryan; Richard Rotunno

2009-06-01T23:59:59.000Z

99

An evaluation of tropical cyclone genesis forecasts from global numerical models  

Science Conference Proceedings (OSTI)

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

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

100

Laboratory–Numerical Model Comparisons of Flow over a Coastal Canyon  

Science Conference Proceedings (OSTI)

Different modeling approaches are applied to the same geophysical flow in order to assess the ability of laboratory models to provide useful benchmarks in the development of oceanic numerical models. The test case considered here—that of the flow ...

Nicolas Pérenne; Dale B. Haidvogel; Don L. Boyer

2001-02-01T23:59:59.000Z

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.
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101

An Evaluation of Tropical Cyclone Genesis Forecasts from Global Numerical Models  

Science Conference Proceedings (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

102

Parameterization of Convective Precipitation in Mesoscale Numerical Models: A Critical Review  

Science Conference Proceedings (OSTI)

Current approaches for incorporating cumulus convection into mesoscale numerical models are divided into three groups. The traditional approach utilizes cumulus parameterization at convectively unstable points and explicit (nonparameterized) ...

John Molinari; Michael Dudek

1992-02-01T23:59:59.000Z

103

Field-Object Design of a Numerical Weather Prediction Model for Uni- and Multiprocessors  

Science Conference Proceedings (OSTI)

The performance of a numerical weather model constructed from scalar, vector, and tensor field objects is evaluated on several workstation computers and on a message-passing multiprocessor.

D. K. Purnell; M. J. Revell; P. N. McGavin

1995-02-01T23:59:59.000Z

104

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

105

Decoupled overlapping grids for the numerical modeling of oil wells  

Science Conference Proceedings (OSTI)

Accurate computation of time-dependent well bore pressure is important in well test analysis - a branch of petroleum engineering where reservoir properties are estimated by comparing measured pressure responses at an oil well to results from a mathematical ... Keywords: Numerical well test analysis, Overlapping grids, Reservoir simulation

Nneoma Ogbonna; Dugald B. Duncan

2012-01-01T23:59:59.000Z

106

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

Science Conference Proceedings (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

107

Fractional Calculus in Hydrologic Modeling: A Numerical Perspective  

Science Conference Proceedings (OSTI)

Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.

David A. Benson; Mark M. Meerschaert; Jordan Revielle

2012-01-01T23:59:59.000Z

108

Operational Convective-Scale Numerical Weather Prediction with the COSMO Model: Description and Sensitivities  

Science Conference Proceedings (OSTI)

Since April 2007, the numerical weather prediction model, COSMO (Consortium for Small Scale Modelling), has been used operationally in a convection-permitting configuration, named COSMO-DE, at the Deutscher Wetterdienst (DWD; German weather ...

Michael Baldauf; Axel Seifert; Jochen Förstner; Detlev Majewski; Matthias Raschendorfer; Thorsten Reinhardt

2011-12-01T23:59:59.000Z

109

Convective Building of a Pycnocline: A Two-Dimensional Nonhydrostatic Numerical Model  

Science Conference Proceedings (OSTI)

The convective building of a pycnocline is examined using a two-dimensional nonhydrostatic numerical model forced by a balanced salinity dipole (source and sink). Although the forcing fields are steady, the model develops oscillations that renew ...

David W. Pierce; Peter B. Rhines

1997-06-01T23:59:59.000Z

110

Numerical Investigations with a Hybrid Isentropic–Sigma Model. Part I: Normal-Mode Characteristics  

Science Conference Proceedings (OSTI)

In a validation experiment of a hybrid isentropic–sigma coordinate primitive equation model developed at the University of Wisconsin (the UW ??? model), an initial value technique is used to investigate numerically the normal-mode characteristics ...

R. Bradley Pierce; Fred M. Reames; Tom H. Zapotocny; Donald R. Johnson; Bart J. Wolf

1991-09-01T23:59:59.000Z

111

Localized Precipitation Forecasts from a Numerical Weather Prediction Model Using Artificial Neural Networks  

Science Conference Proceedings (OSTI)

Although the resolution of numerical weather prediction models continues to improve, many of the processes that influence precipitation are still not captured adequately by the scales of present operational models, and consequently precipitation ...

Robert J. Kuligowski; Ana P. Barros

1998-12-01T23:59:59.000Z

112

Cumulus Entrainment and Cloud Droplet Spectra: A Numerical Model within a Two-Dimensional Dynamical Framework  

Science Conference Proceedings (OSTI)

A simple numerical model designed to predict the evolution of cloud droplet spectra with special emphasis on the role of entrainment is developed for a case of nonprecipitating cloud. The model assumes that the cloud water mixing ratio at any ...

Jean-Louis Brenguier; Wojciech W. Grabowski

1993-01-01T23:59:59.000Z

113

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

Science Conference Proceedings (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

114

Numerical Model Simulations of a Mesoscale Gravity Wave Event: Sensitivity Tests and Spectral Analyses  

Science Conference Proceedings (OSTI)

This study presents numerical model experiments and spectral investigations involving a mesoscale gravity wave event. Its purposes are to determine the sensitivity of mesoscale gravity wave simulation to model configuration and physics and to ...

Jordan G. Powers

1997-08-01T23:59:59.000Z

115

Numerical Simulation of Organized Convection. Part I: Model Description and Preliminary Comparisons with Squall Line Observations  

Science Conference Proceedings (OSTI)

A numerical model designed for the simulations of mesoscale flows perturbed by deep convective clouds is discussed. It is based on the time dependent coupling between a three-dimensional nonhydrostatic mesoscale model and a quasi-one-dimensional ...

Yves Pointin

1985-01-01T23:59:59.000Z

116

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

Science Conference Proceedings (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

117

A Vertically Nested Regional Numerical Weather Prediction Model with Second-Order Closure Physics  

Science Conference Proceedings (OSTI)

The model we describe involves a unique strategy in which a high vertical resolution grid is nested within the coarse vertical resolution grid of a regional numerical weather prediction (NWP) model. Physics computations performed on the high ...

Stephen D. Burk; William T. Thompson

1989-11-01T23:59:59.000Z

118

The model of information retrieval based on the theory of hypercomplex numerical systems  

E-Print Network (OSTI)

The paper provided a description of a new model of information retrieval, which is an extension of vector-space model and is based on the principles of the theory of hypercomplex numerical systems. The model allows to some extent realize the idea of fuzzy search and allows you to apply in practice the model of information retrieval practical developments in the field of hypercomplex numerical systems.

Lande, D V; Boyarinova, Yu E

2012-01-01T23:59:59.000Z

119

Numerical modelling of current transfer in nonlinear anisotropic conductive media  

E-Print Network (OSTI)

load vector and components of f jiM,M global damping matrix and components of M U nodal points of W Index of abbreviations HTS high temperature superconductor Bi-2212 Bi2Sr2CaCu2Ox Y-123 YBa2Cu3Ox EJ the electric field dependence upon the local current... experimental technique is presented. A mathematical analysis is also outlined that enables part of the magnetic field profile to be deduced directly from transport measurements. Chapter 4 discusses the principal approaches used in the numerical solution...

Baranowski, Robert Paul

120

A Hierarchy of Nonlinear Filtered Models—Numerical Solutions  

Science Conference Proceedings (OSTI)

Five filtered models, including two that are intermediate between the balanced and the primitive equations, are studied using actual weather data. The iterative method of solution works well in most cases. The two more general models are solved ...

Trond Iversen; Thor Erik Nordeng

1984-10-01T23:59:59.000Z

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

Numerical Experiments with a Stochastic Zonal Climate Model  

Science Conference Proceedings (OSTI)

A zonally averaged energy balance climate model is used to generate zonal temperature variability through fluctuating meridional energy transports. In the base model, stochastic transport fluctuations are introduced by multiplying the eddy ...

H. Nuzhet Dalfes; S. H. Schneider; Starley L. Thompson

1983-07-01T23:59:59.000Z

122

Numerical Modelling for Characterising the Flammability of Natural ...  

Science Conference Proceedings (OSTI)

... Modelling for Characterising the Flammability of Natural Fibre Reinforced Composites .... Influenced Corrosion of Pipeline Steels used in Oil & Gas Industry .

123

Numerical modeling of geothermal systems with applications to Krafla, Iceland and Olkaria, Kenya  

SciTech Connect

The use of numerical models for the evaluation of the generating potential of high temperature geothermal fields has increased rapidly in recent years. In the present paper a unified numerical approach to the modeling of geothermal systems is discussed and the results of recent modeling of the Krafla geothermal field in Iceland and the Olkaria, Kenya, are described. Emphasis is placed on describing the methodology using examples from the two geothermal fields.

Bodvarsson, G.S.

1987-08-01T23:59:59.000Z

124

A Numerical Model for Combustion of Bubbling Thermoplastic ...  

Science Conference Proceedings (OSTI)

... [8] Wichman, IS, "A Model Describing the Steady-State Gasification of ... and Chemical Processes During Pyrolysis of a Large Biomass Particle," Fuel ...

2004-12-27T23:59:59.000Z

125

Numerical Model of a Tensioner System and Flex Joint  

E-Print Network (OSTI)

Top Tensioned Riser (TTR) and Steel Catenary Riser (SCR) are often used in a floating oil/gas production system deployed in deep water for oil transport. This study focuses on the improvements to the existing numerical code, known as CABLE3D, to allow for static and dynamic simulation of a TTR connected to a floating structure through a tensioner system or buoyancy can, and a SCR connected to a floating structure through a flex joint. A tensioner system usually consists of three to four cylindrical tensioners. Although the stiffness of individual tensioner is assumed to be linear, the resultant stiffness of a tensioner system may be nonlinear. The vertical friction at a riser guide is neglected assuming a roller is installed there. Near the water surface, a TTR is forced to move due to the motion of the upper deck of a floating structure as well as related riser guides. Using the up-dated CABLE3D, the dynamic simulation of TTRs will be made to reveal their motion, tension, and bending moment, which is important for the design. A flex joint is approximated by a rotational spring with linear stiffness, which is used as a connection between a SCR and a floating structure or a connection between a TTR and the sea floor. The improved CABLE3D will be integrated into a numerical code, known as COUPLE, for the simulation of the dynamic interaction among the hull of a floating structure, such as SPAR or TLP, its mooring system and riser system under the impact of wind, current and waves. To demonstrate the application of the improved CABLE3D and its integration with COUPLE, the related simulation is made for ‘Constitution’ SPAR under the met-ocean conditions of hurricane ‘Ike’. The mooring system of the Spar consists of nine mooring lines and the riser system consists of six TTRs and two SCRs.

Huang, Han

2013-08-01T23:59:59.000Z

126

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

127

Numerical simulation of a lattice polymer model at its integrable point  

E-Print Network (OSTI)

We revisit an integrable lattice model of polymer collapse using numerical simulations. This model was first studied by Bl\\"ote and Nienhuis in J. Phys. A. {\\bf 22}, 1415 (1989) and it describes polymers with some attraction, providing thus a model for the polymer collapse transition. At a particular set of Boltzmann weights the model is integrable and the exponents $\

A. Bedini; A. L. Owczarek; T. Prellberg

2012-11-01T23:59:59.000Z

128

Numerical Algorithms of the Lawrence--Doniach Model for Layered Superconductors and their Parallel Implementation  

Science Conference Proceedings (OSTI)

The Lawrence--Doniach model is often used for studying vortex dynamics in superconductors which exhibit a layered structure. In solving these model equations numerically, the added degrees of complexity due to the coupling and nonlinearity of the model ... Keywords: Lawrence--Doniach model, layered superconductors, parallel computing, parallel virtual machine, superconductivity

Qiang Du; Paul Gray

1999-05-01T23:59:59.000Z

129

Three-Dimensional Numerical Simulation of Plume Downwash with a k–? Turbulence Model  

Science Conference Proceedings (OSTI)

Plume downwash at a large oil-gathering facility in the Prudhoe Bay, Alaska oil-field reservation was simulated in a series of numerical experiments. The purpose of this study was to investigate the potential of the numerical model as a means of ...

Alex Guenther; Brian Lamb; David Stock

1990-07-01T23:59:59.000Z

130

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

131

A Numerical Model for the Equilibrium Shape of Electrified Raindrops  

Science Conference Proceedings (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

132

A Global Numerical Weather Prediction Model with Variable Resolution  

Science Conference Proceedings (OSTI)

A conformal transformation suggested by F. Schmidt is followed to implement a global spectral model with variable resolution. A conformal mapping is defined from a physical sphere (like the earth) to a transformed (computational) sphere. The ...

Vivek Hardiker

1997-01-01T23:59:59.000Z

133

Parameterization of Bulk Condensation in Numerical Cloud Models  

Science Conference Proceedings (OSTI)

The accuracy of the moist saturation adjustment scheme has been evaluated using a three-dimensional explicit microphysical cloud model. It was found that the error in saturation adjustment depends strongly on the CCN concentration in the ambient ...

Yefim L. Kogan; William J. Martin

1994-06-01T23:59:59.000Z

134

Ductile fracture modeling : theory, experimental investigation and numerical verification  

E-Print Network (OSTI)

The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...

Xue, Liang, 1973-

2007-01-01T23:59:59.000Z

135

Numerical modeling of hydrofracturing in a multilayer coal seam  

Science Conference Proceedings (OSTI)

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

136

Numerical heat transfer attic model using a radiant barrier system  

Science Conference Proceedings (OSTI)

A two-dimensional, steady-state finite-element model was developed to simulate the thermal effects of the application of an attic radiant barrier system (ARBS) inside a ventilated residential attic. The attic is ventilated using the exhaust air from an evaporative cooler. The study uses a {kappa}-{epsilon} turbulent model to describe the velocity and temperature distributions in the attic. The ambient temperature and solar isolation densities on the outside inclined attic surfaces are used as driving functions for the model. The model also included the appropriate heat exchange modes of convection and radiation on these outside surfaces. Several recirculation zones were visually observed in the attic flow pattern. Also, the use of the ARBS seems to lower the heat transfer through the ceiling by 25--30%, but this effect decreases significantly as the outside ventilation rates are increased through the attic space. The 2D model revealed some interesting temperature distributions along the attic surfaces that could not have been predicted by the one-dimensional models. The lower emissivity ARBS seems to raise the temperature of the inclined attic surfaces as well as the temperature of the exhausted ventilation air.

Moujaes, S.F.; Alsaiegh, N.T.

2000-04-01T23:59:59.000Z

137

Numerical modeling of the wind flow over a transverse dune  

E-Print Network (OSTI)

Transverse dunes, which form under unidirectional winds and have fixed profile in the direction perpendicular to the wind, occur on all celestial objects of our solar system where dunes have been detected. Here we perform a numerical study of the average turbulent wind flow over a transverse dune by means of computational fluid dynamics simulations. We find that the length of the zone of recirculating flow at the dune lee --- the {\\em{separation bubble}} --- displays a surprisingly strong dependence on the wind shear velocity, $u_{\\ast}$: it is nearly independent of $u_{\\ast}$ for shear velocities within the range between $0.2\\,$m$$s and $0.8\\,$m$$s but increases linearly with $u_{\\ast}$ for larger shear velocities. Our calculations show that transport in the direction opposite to dune migration within the separation bubble can be sustained if $u_{\\ast}$ is larger than approximately $0.39\\,$m$$s, whereas a larger value of $u_{\\ast}$ (about $0.49\\,$m$$s) is required to initiate this reverse transport.

Ascânio D. Araújo; Eric J. R. Parteli; Thorsten Poeschel; José S. Andrade Jr.; Hans J. Herrmann

2013-07-26T23:59:59.000Z

138

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

139

Bayesian Estimation of Stochastic Parameterizations in a Numerical Weather Forecasting Model  

Science Conference Proceedings (OSTI)

Parameterizations in numerical models account for unresolved processes. These parameterizations are inherently difficult to construct and as such typically have notable imperfections. One approach to account for this uncertainty is through ...

Yong Song; Christopher K. Wikle; Christopher J. Anderson; Steven A. Lack

2007-12-01T23:59:59.000Z

140

A New Visibility Parameterization for Warm-Fog Applications in Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

The objective of this work is to suggest a new warm-fog visibility parameterization scheme for numerical weather prediction (NWP) models. In situ observations collected during the Radiation and Aerosol Cloud Experiment, representing boundary ...

I. Gultepe; M. D. Müller; Z. Boybeyi

2006-11-01T23:59:59.000Z

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.


141

Operational Assimilation of GPS Zenith Total Delay Observations into the Met Office Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

Zenith total delay (ZTD) observations derived from ground-based GPS receivers have been assimilated operationally into the Met Office North Atlantic and European (NAE) numerical weather prediction (NWP) model since 2007. Assimilation trials were ...

Gemma V. Bennitt; Adrian Jupp

2012-08-01T23:59:59.000Z

142

Impulsively Started Flow in a Submarine Canyon: Comparison of Results from Laboratory and Numerical Models  

Science Conference Proceedings (OSTI)

Intercomparisons have been made of results from laboratory experiments and a numerical model for the flow in the vicinity of an idealized submarine canyon located along an otherwise continuous shelf. Motion in the rotating and continuously ...

Nicolas Pérenne; J. William Lavelle; David C. Smith IV; Don L. Boyer

2001-10-01T23:59:59.000Z

143

A Spectral Cumulus Parameterization for Use in Numerical Models of the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

The spectral cumulus parameterization theory of Arakawa and Schubert is presented in the convective flux form as opposed to the original detrainment form. This flux form is more convenient for use in numerical prediction models. The equations are ...

James J. Hack; Wayne H. Schubert; Pedro L. Silva Dias

1984-04-01T23:59:59.000Z

144

Global Data on Land Surface Parameters from NOAA AVHRR for Use in Numerical Climate Models  

Science Conference Proceedings (OSTI)

This paper reviews satellite datasets from the NOAA Advanced Very High Resolution Radiometer that could be employed in support of numerical climate modeling at regional and global scales. Presently available NOAA operational and research datasets ...

G. Garik Gutman

1994-05-01T23:59:59.000Z

145

Use of Medium-Range Numerical Weather Prediction Model Output to Produce Forecasts of Streamflow  

Science Conference Proceedings (OSTI)

This paper examines an archive containing over 40 years of 8-day atmospheric forecasts over the contiguous United States from the NCEP reanalysis project to assess the possibilities for using medium-range numerical weather prediction model output ...

Martyn P. Clark; Lauren E. Hay

2004-02-01T23:59:59.000Z

146

An Eddy-Resolving Numerical Model of the Ventilated Thermocline: Time Dependence  

Science Conference Proceedings (OSTI)

A primitive equation, eddy-resolving numerical model is used to study the inherent time scales of variability in the subtropical ocean, assuming temporally constant surface forcing. Three primary scales arise: mesoscale variability of roughly 50-...

Michael D. Cox

1987-07-01T23:59:59.000Z

147

Estimates of Cn2 from Numerical Weather Prediction Model Output and Comparison with Thermosonde Data  

Science Conference Proceedings (OSTI)

Area-averaged estimates of Cn2 from high-resolution numerical weather prediction (NWP) model output are produced from local estimates of the spatial structure functions of refractive index with corrections for the inherent smoothing and filtering ...

Rod Frehlich; Robert Sharman; Francois Vandenberghe; Wei Yu; Yubao Liu; Jason Knievel; George Jumper

2010-08-01T23:59:59.000Z

148

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

Science Conference Proceedings (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

149

A Comprehensive Radiation Scheme for Numerical Weather Prediction Models with Potential Applications in Climate Simulations  

Science Conference Proceedings (OSTI)

A comprehensive scheme for the parameterization of radiative transfer in numerical weather Prediction (NWP) models has been developed. The scheme is based on the solution of the ?-two-stream version of the radiative transfer equation ...

Bodo Ritter; Jean-Francois Geleyn

1992-02-01T23:59:59.000Z

150

Data Mining Numerical Model Output for Single-Station Cloud-Ceiling Forecast Algorithms  

Science Conference Proceedings (OSTI)

Accurate cloud-ceiling-height forecasts derived from numerical weather prediction (NWP) model data are useful for aviation and other interests where low cloud ceilings have an impact on operations. A demonstration of the usefulness of data-mining ...

Richard L. Bankert; Michael Hadjimichael

2007-10-01T23:59:59.000Z

151

The Impact of Satellite Sounding Data on the Systematic Error of a Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

The impact of satellite sounding data on the systematic errors of the numerical weather prediction model of the Israel Meteorological Service has been investigated. In general, satellite data have been shown to reduce systematic error, and in ...

Noah Wolfson; Albert Thomasell; Arnold Gruber; George Ohring

1985-06-01T23:59:59.000Z

152

Microscale Numerical Prediction over Montreal with the Canadian External Urban Modeling System  

Science Conference Proceedings (OSTI)

The Canadian urban and land surface external modeling system (known as urban GEM-SURF) has been developed to provide surface and near-surface meteorological variables to improve numerical weather prediction and to become a tool for environmental ...

Sylvie Leroyer; Stéphane Bélair; Jocelyn Mailhot; Ian B. Strachan

2011-12-01T23:59:59.000Z

153

An Upper Boundary Condition Permitting Internal Gravity Wave Radiation in Numerical Mesoscale Models  

Science Conference Proceedings (OSTI)

A radiative upper boundary condition is proposed for numerical mesoscale models which allows vertically propagating internal gravity waves to pass out of the computational domain with minimal reflection. In this formulation, the pressure along ...

Joseph B. Klemp; Dale R. Durran

1983-03-01T23:59:59.000Z

154

Numerical Experiments on Consistent Horizontal and Vertical Resolution for Atmospheric Models and Observing Systems  

Science Conference Proceedings (OSTI)

Simple numerical experiments are performed in order to determine the effects of inconsistent combinations of horizontal and vertical resolution in both atmospheric models and observing systems. In both cases, we find that inconsistent spatial ...

Michael S. Fox-Rabinovitz; Richard S. Lindzen

1993-01-01T23:59:59.000Z

155

A Numerical Model of Internal Tides with Application to the Australian North West Shelf  

Science Conference Proceedings (OSTI)

A nonlinear, primitive equation, finite-difference numerical model is applied to the problem of the generation, propagation, and dissipation of internal tides over a cross section of the continental slope and shelf topography of a region on the ...

Peter E. Holloway

1996-01-01T23:59:59.000Z

156

The Effects of Subgrid Model Mixing and Numerical Filtering in Simulations of Mesoscale Cloud Systems  

Science Conference Proceedings (OSTI)

Using the newly developed Weather Research and Forecasting (WRF) model, this study investigates the effects of subgrid mixing and numerical filtering in mesoscale cloud simulations by examining the sensitivities to the parameters in turbulence-...

Tetsuya Takemi; Richard Rotunno

2003-09-01T23:59:59.000Z

157

A Numerical Modeling Study of Warm Offshore Flow over Cool Water  

Science Conference Proceedings (OSTI)

Numerical simulations of boundary layer evolution in offshore flow of warm air over cool water are conducted and compared with aircraft observations of mean and turbulent fields made at Duck, North Carolina. Two models are used: a two-dimensional,...

Eric D. Skyllingstad; Roger M. Samelson; Larry Mahrt; Phil Barbour

2005-02-01T23:59:59.000Z

158

Systematic Biases in the Microphysics and Thermodynamics of Numerical Models That Ignore Subgrid-Scale Variability  

Science Conference Proceedings (OSTI)

A grid box in a numerical model that ignores subgrid variability has biases in certain microphysical and thermodynamic quantities relative to the values that would be obtained if subgrid-scale variability were taken into account. The biases are ...

Vincent E. Larson; Robert Wood; Paul R. Field; Jean-Christophe Golaz; Thomas H. Vonder Haar; William R. Cotton

2001-05-01T23:59:59.000Z

159

Direct Numerical Simulation of the Turbulent Ekman Layer: Evaluation of Closure Models  

Science Conference Proceedings (OSTI)

A direct numerical simulation (DNS) at a Reynolds number of 1000 was performed for the neutral atmospheric boundary layer (ABL) using the Ekman layer approximation. The DNS results were used to evaluate several closure approximations that model ...

Stuart Marlatt; Scott Waggy; Sedat Biringen

2012-03-01T23:59:59.000Z

160

The Sensitivity of Numerically Simulated Cyclic Mesocyclogenesis to Variations in Model Physical and Computational Parameters  

Science Conference Proceedings (OSTI)

In a previous paper, a three-dimensional numerical model was used to study the evolution of successive mesocyclones produced by a single supercell storm, that is, cyclic mesocyclogenesis. Not all supercells, simulated or observed, exhibit this ...

Edwin J. Adlerman; Kelvin K. Droegemeier

2002-11-01T23:59:59.000Z

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.


161

A New Diffusion Scheme for Numerical Models Based on Full Irreversibility  

Science Conference Proceedings (OSTI)

In this work, the forecast accuracy of a numerical weather prediction model is improved by emulating physical dissipation as suggested by the second law of thermodynamics, which controls the irreversible evolutionary direction of a many-body ...

C. Liu; Y. Liu; H. Xu

2009-04-01T23:59:59.000Z

162

Estimation of Meteorological Parameters for Air Quality Management: Coupling of Sodar Data with Simple Numerical Models  

Science Conference Proceedings (OSTI)

In this paper an attempt is made to couple sodar data and simple numerical models to calculate the wind field and the boundary layer parameters that are relevant to air quality monitoring and studies. For this purpose, a diagnostic, mass-...

Dimitrios Melas; Giulia Abbate; Dias Haralampopoulos; Alexandros Kelesidis

2000-04-01T23:59:59.000Z

163

Subjective Verification of Numerical Models as a Component of a Broader Interaction between Research and Operations  

Science Conference Proceedings (OSTI)

Systematic subjective verification of precipitation forecasts from two numerical models is presented and discussed. The subjective verification effort was carried out as part of the 2001 Spring Program, a seven-week collaborative experiment ...

John S. Kain; Michael E. Baldwin; Paul R. Janish; Steven J. Weiss; Michael P. Kay; Gregory W. Carbin

2003-10-01T23:59:59.000Z

164

Human equivalent antenna model for HF exposures: analytical versus numerical approach  

Science Conference Proceedings (OSTI)

In this paper, the human exposure to HF radiation is analyzed using the simplified human equivalent antenna model featuring analytical and numerical approach, respectively. Namely, the human body is represented by an equivalent receiving straight thin ...

Dragan Poljak; Silvestar Sesnic; Ivana Zulim

2009-09-01T23:59:59.000Z

165

Using Temporal Modes of Rainfall to Evaluate the Performance of a Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

The authors demonstrate that much can be learned about the performance of a numerical weather prediction (NWP) model by examining the temporal modes of its simulated rainfall. Observations from the Weather Surveillance Radar-1988 Doppler (WSR-88D)...

Jason C. Knievel; David A. Ahijevych; Kevin W. Manning

2004-12-01T23:59:59.000Z

166

Generation and Propagation of 30-Day Waves in a Numerical Model of the Pacific  

Science Conference Proceedings (OSTI)

A multilevel numerical model is applied to the equatorial Pacific Ocean, driven by long-term averaged, monthly varying winds. In agreement with satellite-observed sea surface temperatures, the solution is unstable at certain times of year and ...

Michael D. Cox

1980-08-01T23:59:59.000Z

167

Parameterization and Impact of Ice initiation Processes Relevant to Numerical Model Simulations of Cirrus Clouds  

Science Conference Proceedings (OSTI)

An effort to improve descriptions of ice initiation processes of relevance to cirrus clouds for use in regional-scale numerical cloud models with bulk microphysical schemes is described. This is approached by deriving practical parameterizations ...

Paul J. DeMott; Michael P. Meyers; William R. Cotton

1994-01-01T23:59:59.000Z

168

Explosive East Coast Cyclogenesis: Numerical Experimentation and Model-Based Diagnostics  

Science Conference Proceedings (OSTI)

Numerical experimentation of explosive East Coast cyclogenesis is performed using the Florida State University Global Spectral Model (FSUGSM). The three cases examined here are the Presidents'Day storm of 18–19 February 1979 and the North ...

John Manobianco

1989-11-01T23:59:59.000Z

169

Numerical Modeling of Meander and Eddy Formation in the Azores Current Frontal Zone  

Science Conference Proceedings (OSTI)

Numerical experiments with an 11-level primitive equation, finite-difference model in a periodic channel are performed to analyze the properties of unstable finite-amplitude disturbances in an idealized Azores Current. Release of available ...

Jürgen Kielmann; Rolf H. Käse

1987-04-01T23:59:59.000Z

170

Laboratory–Numerical Model Comparisons of Canyon Flows: A Parameter Study  

Science Conference Proceedings (OSTI)

An integrated set of laboratory and numerical-model experiments has been conducted to understand the development of residual circulation surrounding a coastal canyon and to explore further the degree to which laboratory experiments can provide ...

Don L. Boyer; Dale B. Haidvogel; Nicolas Pérenne

2004-07-01T23:59:59.000Z

171

Numerical modeling of hydrogen-fueled internal combustion engines  

DOE Green Energy (OSTI)

The planned use of hydrogen as the energy carrier of the future introduces new challenges and opportunities, especially to the engine design community. Hydrogen is a bio-friendly fuel that can be produced from renewable resources and has no carbon dioxide combustion products; and in a properly designed ICE, almost zero NO{sub x} and hydrocarbon emissions can be achieved. Because of the unique properties of hydrogen combustion - in particular the highly wrinkled nature of the laminar flame front due to the preferential diffusion instability - modeling approaches for hydrocarbon gaseous fuels are not generally applicable to hydrogen combustion. This paper reports on the current progress to develop a engine design capability based on KIVA family of codes for hydrogen-fueled, spark-ignited engines in support of the National Hydrogen Program. A turbulent combustion model, based on a modified eddy-turnover model in conjunction with an intake flow valve model, is found to describe well the efficiency and NO{sub x} emissions of this engine satisfy the Equivalent Zero Emission Vehicle (EZEV) standard established by the California Resource Board. 26 refs., 10 figs., 1 tab.

Johnson, N.L.; Amsden, A.A.

1996-12-31T23:59:59.000Z

172

Numerical modeling of interaction of a current with a circular cylinder near a rigid bed  

Science Conference Proceedings (OSTI)

The numerical modeling of 2D turbulent flow around a smooth horizontal circular cylinder near a rigid bed with gap ratio G/D=0.3 at Reynolds number Re"D=9500 is investigated. Ansys^(R) 10.0-FLOTRAN program package is used to solve the governing equations ... Keywords: Circular cylinder, Numerical model, Particle image velocimetry, Steady flow, Strouhal number, Velocity field

M. Salih Kirkgoz; A. Alper Oner; M. Sami Akoz

2009-11-01T23:59:59.000Z

173

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

Recanati, Catherine

174

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

Science Conference Proceedings (OSTI)

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

175

Numerical Models of Broad-Bandwidth Nanosecond Optical Parametric Oscillators  

SciTech Connect

We present three new methods for modeling broad-bandwidth, nanosecond optitcal parametric oscillators in the plane-wave approximation. Each accounts for the group-velocity differences that determine the operating linewidth of unseeded optical parametric oscillators, and each allows the signal and idler waves to develop from quantum noise. The first two methods are based on split-step integration methods in which nonlinear mixing and propagation are calculated separately on alternate steps. One method relies on Fourier transforming handle propagation, wiih mixing integrated over a the fields between t and u to Az step: the other transforms between z and k= in the propagation step, with mixing integrated over At. The third method is based on expansion of the three optical fields in terms of their respective longitudinal empty cavity modes, taking into account the cavity boundary condi- tions. Equations describing the time development of the mode amplitudes are solved to yield the time dependence of the three output fields. These plane-wave models exclude diffractive effects, but can be readily extended to include them.

Bowers, M.S.; Gehr. R.J.; Smith, A.V.

1998-10-22T23:59:59.000Z

176

Sensitivity of numerical dispersion modeling to explosive source parameters  

Science Conference Proceedings (OSTI)

The calculation of downwind concentrations from non-traditional sources, such as explosions, provides unique challenges to dispersion models. The US Department of Energy has assigned the Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) the task of estimating the impact of accidental radiological releases to the atmosphere anywhere in the world. Our experience includes responses to over 25 incidents in the past 16 years, and about 150 exercises a year. Examples of responses to explosive accidents include the 1980 Titan 2 missile fuel explosion near Damascus, Arkansas and the hydrogen gas explosion in the 1986 Chernobyl nuclear power plant accident. Based on judgment and experience, we frequently estimate the source geometry and the amount of toxic material aerosolized as well as its particle size distribution. To expedite our real-time response, we developed some automated algorithms and default assumptions about several potential sources. It is useful to know how well these algorithms perform against real-world measurements and how sensitive our dispersion model is to the potential range of input values. In this paper we present the algorithms we use to simulate explosive events, compare these methods with limited field data measurements, and analyze their sensitivity to input parameters. 14 refs., 7 figs., 2 tabs.

Baskett, R.L. (EG and G Energy Measurements, Inc., Pleasanton, CA (USA)); Cederwall, R.T. (Lawrence Livermore National Lab., CA (USA))

1991-02-13T23:59:59.000Z

177

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

178

Numerical modeling of water injection into vapor-dominatedgeothermal reservoirs  

SciTech Connect

Water injection has been recognized as a powerful techniquefor enhancing energy recovery from vapor-dominated geothermal systemssuch as The Geysers. In addition to increasing reservoir pressures,production well flow rates, and long-term sustainability of steamproduction, injection has also been shown to reduce concentrations ofnon-condensible gases (NCGs) in produced steam. The latter effectimproves energy conversion efficiency and reduces corrosion problems inwellbores and surface lines.This report reviews thermodynamic andhydrogeologic conditions and mechanisms that play an important role inreservoir response to water injection. An existing general-purposereservoir simulator has been enhanced to allow modeling of injectioneffects in heterogeneous fractured reservoirs in three dimensions,including effects of non-condensible gases of different solubility.Illustrative applications demonstrate fluid flow and heat transfermechanisms that are considered crucial for developing approaches to insitu abatement of NCGs.

Pruess, Karsten

2006-11-06T23:59:59.000Z

179

Numerical modeling of a solid particle solar central receiver  

Science Conference Proceedings (OSTI)

The flow of air and particles and the heat transfer inside a solar heated, open cavity containing a falling cloud of 100 to 1000 micron solid particles have been studied. Two-way momentum and thermal coupling between the particles and the air is included in the analysis along with the effects of radiative transport within the particle cloud, among the cavity surfaces, and between the cloud and the surfaces. The flow field is assumed to be two dimensional with steady mean quantities. The PSI-Cell (particle source in cell) computer code is used to describe the gas-particle interaction. The method of discrete ordinates is used to obtain the radiative transfer within the cloud. The results include the velocity and temperature profiles of the particles and the air. In addition, the thermal performance of the solid particle solar receiver has been determined as a function of the following particle parameters: size, mass flow rate, absorptivity, and infrared scattering albedo. Other parameters which have been varied include the incident solar flux (both magnitude and distribution) and receiver size. A forced flow, applied across the cavity aperture, has also been investigated as a means of decreasing convective heat loss from the cavity. Comparison of the results from the model has been made with an experiment performed at the radiant heat facility in Albuquerque. The model has also been used to predict the entrainment of air and the decrease in particle drag which has been observed when measurements were made of particle velocity in a cloud of particles in free fall.

Evans, G.H.; Houf, W.G.; Greif, R.; Crowe, C.

1985-12-01T23:59:59.000Z

180

Analytical and numerical models of uranium ignition assisted by hydride formation  

DOE Green Energy (OSTI)

Analytical and numerical models of uranium ignition assisted by the oxidation of uranium hydride are described. The models were developed to demonstrate that ignition of large uranium ingots could not occur as a result of possible hydride formation during storage. The thermodynamics-based analytical model predicted an overall 17 C temperature rise of the ingot due to hydride oxidation upon opening of the storage can in air. The numerical model predicted locally higher temperature increases at the surface; the transient temperature increase quickly dissipated. The numerical model was further used to determine conditions for which hydride oxidation does lead to ignition of uranium metal. Room temperature ignition only occurs for high hydride fractions in the nominally oxide reaction product and high specific surface areas of the uranium metal.

Totemeier, T.C.; Hayes, S.L. [Argonne National Lab., Idaho Falls, ID (United States). Engineering Div.

1996-05-01T23:59:59.000Z

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.


181

Horizontal Heat Fluxes over Complex Terrain Computed Using a Simple Mixed-Layer Model and a Numerical Model  

Science Conference Proceedings (OSTI)

The thermally induced local circulation over a periodic valley is simulated by a two-dimensional numerical model that does not include condensational processes. During the daytime of a clear, calm day, heat is transported from the mountainous ...

Fujio Kimura; Tuneo Kuwagata

1995-02-01T23:59:59.000Z

182

Model Documentation Report: Macroeconomic Activity Module (MAM ...  

U.S. Energy Information Administration (EIA)

Model Documentation Report: Macroeconomic Activity Module (MAM) of the National Energy Modeling System April 2013 Independent Statistics & ...

183

A Quasi-Geostrophic Circulation Model of the Northeast Pacific. Part I: A Preliminary Numerical Experiment  

Science Conference Proceedings (OSTI)

A limited-area quasi-geostrophic numerical model with mesoscale resolution is developed to study the circulation in the northeast (NE) Pacific Ocean. The model domain extends from the British Columbia-Alaska coast out to 170°W and down to 45°N, ...

Patrick F. Cummins; Lawrence A. Mysak

1988-09-01T23:59:59.000Z

184

Numerical Simulation of Polar Lows and Comma Clouds Using Simple Dry Models  

Science Conference Proceedings (OSTI)

Linear and nonlinear numerical channel models are used to simulate polar low/comma cloud evolution. The purpose of this study is to see how much realism can be obtained using models that do not include water vapor. The study was inspired by ...

Stephen E. Mudrick

1987-12-01T23:59:59.000Z

185

Numerical Model-Reality Intercomparison Tests Using Small-Sample Statistics  

Science Conference Proceedings (OSTI)

When a numerical model's representation of a physical field is to be compared with a corresponding real observed field, it is usually the case that the numbers of realizations of model and observed field are relatively small, so that the natural ...

Rudolph W. Preisendorfer; Tim P. Barnett

1983-08-01T23:59:59.000Z

186

A numerical method for solving convection-reaction-diffusion multivalued equations in fire spread modelling  

Science Conference Proceedings (OSTI)

A numerical method is developed for fire spread simulation modelling. The two-dimensional surface model presented takes into account moisture content, radiation, wind and slope effects, which are by far the most important mechanisms in fire spread. We ... Keywords: 02.60.Cb, 02.60.Lj, 02.70.Dh, Fire, Moisture, Pyrolysis, Radiation, Slope, Wind

L. Ferragut; M. I. Asensio; S. Monedero

2007-06-01T23:59:59.000Z

187

Evaluation of a Simple Numerical Model as a Mesoscale Weather Forecasting Tool  

Science Conference Proceedings (OSTI)

During the America's Cup race series of 1986–1987, a numerical sea breeze model was used to assist offshore forecasts. The exercise has provided a detailed insight into the extent to which such a model may assist the forecasting process the ...

P. J. Rye

1989-12-01T23:59:59.000Z

188

Cluster cross sections for strong lensing: analytic and numerical lens models  

E-Print Network (OSTI)

The statistics of gravitationally lensed arcs was recognised earlier as a potentially powerful cosmological probe. However, while fully numerical models find orders of magnitude difference between the arc probabilities in different cosmological models, analytic models tend to find markedly different results. We introduce in this paper an analytic cluster lens model which improves upon existing analytic models in four ways. (1) We use the more realistic Navarro-Frenk-White profile instead of singular isothermal spheres, (2) we include the effect of cosmology on the compactness of the lenses, (3) we use elliptical instead of axially symmetric lenses, and (4) we take the intrinsic ellipticity of sources into account. While these improvements to the analytic model lead to a pronounced increase of the arc probability, comparisons with numerical models of the same virial mass demonstrate that the analytic models still fall short by a substantial margin of reproducing the results obtained with numerical models. Using multipole expansions of cluster mass distributions, we show that the remaining discrepancy can be attributed to substructure inside clusters and tidal fields contributed by the cluster surroundings, effects that cannot reasonably and reliably be mimicked in analytic models.

Massimo Meneghetti; Matthias Bartelmann; Lauro Moscardini

2002-01-30T23:59:59.000Z

189

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

190

Numerical Classical and Quantum Mechanical simulations of Charge Density wave models  

E-Print Network (OSTI)

We first present how to do a computer simulation of Charge Density Waves using a driven harmonic oscillator model by a numerical scheme as initially formulated by Littlewood, and then afterwards use this to present how the dielectric model as presented by this proceedure leads to a blow up at the initialization of a threshold field ET. We find that this is highly unphysical and this initiated our inquiry as to alternative models. Afterwards, we then investigate hwo to present this transport problem of CDW quantum mechanically, threough a numerical simulation of the massive Schwinger model. We find that this single chaing quantum mechanical simulation uwed to formulate solutions to CDW transport in itself is insufficient for transport of solitons(anti-solitons) through a pinning gap model of CDW. We show that a model Hamiltonian with Peierls condensation energy used to couple adjacent chains (or transverse wave vectors) permits formation of solitons (anti- solitons) which can be used to transport CDW through a potential barrier. This addition of the Peierls condensation energy term is essential for any quantum model of Charge Density Waves to give tunneling behavior as seen via a numerical simulation.

A. W. Beckwith

2004-09-13T23:59:59.000Z

191

Fluid Temperature and Power Estimation of Geothermal Power Plants by a Simplified Numerical Model  

Science Conference Proceedings (OSTI)

This paper presents an estimation of power generated in a given geothermal heat pipe system. Such power generation is basically controlled by the ultimate temperature of fluid flowing through the u-shape pipes and could also be affected by power consumption ... Keywords: energy, geothermal power plant, numerical model, heat conduction, optimum design

Ge Ou; Itai Einav

2010-08-01T23:59:59.000Z

192

Local Mass Conservation and Velocity Splitting in PV-Based Balanced Models. Part II: Numerical Results  

Science Conference Proceedings (OSTI)

The effects of enforcing local mass conservation on the accuracy of non-Hamiltonian potential-vorticity- based balanced models (PBMs) are examined numerically for a set of chaotic shallow-water f-plane vortical flows in a doubly periodic square ...

Ali R. Mohebalhojeh; Michael E. McIntyre

2007-06-01T23:59:59.000Z

193

Numerical Modeling of a Line of Towering Cumulus on Day 226 of GATE  

Science Conference Proceedings (OSTI)

A three-dimensional numerical model with warm rain bulk cloud physics is used to investigate the shallow convection observed on day 226 of GATE. This convection had cloud tops at 3.0 km, cloud bases at 0.4 km and approximately 0.1 cm of rain at ...

Frank B. Lipps; Richard S. Hemler

1988-09-01T23:59:59.000Z

194

The Parameterization of Radiation for Numerical Weather Prediction and Climate Models  

Science Conference Proceedings (OSTI)

This paper presents a review of the various methods used to compute both the fluxes and the rate of heating and/or cooling due to atmospheric radiation for use in numerical models of atmospheric circulation. The paper does not follow, step by ...

Graeme L. Stephens

1984-04-01T23:59:59.000Z

195

A Numerical Model of the Formation and Evolution of a Low-Level Jet  

Science Conference Proceedings (OSTI)

A one-layer. one-dimensional numerical model is described which simulates the life cycle of the extratropical low-level jet (LLJ). The LLJ starts as an isallobaric wind near the point of maximum pressure tall. Subsequently, the LLJ expands over a ...

Dušan Djuri?

1981-02-01T23:59:59.000Z

196

A Note on the Sea Surface Temperature Sensitivity of a Numerical Model of Tropical Storm Genesis  

Science Conference Proceedings (OSTI)

In a three-dimensional numerical model of a tropical disturbance, a spectrum of development stages, from a weakening wave to a mature tropical storm, was obtained with a 5 K range (298 to 303 K) sea surface temperature (SST). However, the ...

Robert E. Tuleya; Yoshio Kurihara

1982-12-01T23:59:59.000Z

197

Shallow water numerical model of the wave generated by the Vajont landslide  

Science Conference Proceedings (OSTI)

On October 9th 1963 a huge landslide fell into the Vajont artificial reservoir in Northern Italy, and displaced the water which overtopped the dam and produced a destructive wave that inundated the valley causing about 2000 casualties and complete devastation. ... Keywords: Finite volume scheme, Moving boundary condition, Numerical model, Shallow water equations, Vajont landslide

Silvia Bosa; Marco Petti

2011-04-01T23:59:59.000Z

198

Sea-Breeze Interactions along a Concave Coastline in Southern Australia: Observations and Numerical Modeling Study  

Science Conference Proceedings (OSTI)

Observations and numerical modeling of the bay and ocean breezes of Port Phillip Bay show that the interaction of these two breezes produces features undocumented in previous sea-breeze studies. The first of these is the formation of a mesoscale ...

Deborah J. Abbs

1986-05-01T23:59:59.000Z

199

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

Science Conference Proceedings (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

200

Numerical simulation of sloshing in LNG tanks with a compressible two-phase model  

E-Print Network (OSTI)

The study of liquid dynamics in LNG tanks is getting more and more important with the actual trend of LNG tankers sailing with partially filled tanks. The effect of sloshing liquid in the tanks on pressure levels at the tank walls and on the overall ship motion indicates the relevance of an accurate simulation of the fluid behaviour. This paper presents the simulation of sloshing LNG by a compressible two-phase model and the validation of the numerical model on model-scale sloshing experiments. The details of the numerical model, an improved Volume Of Fluid (iVOF) method, are presented in the paper. The program has been developed initially to study the sloshing of liquid fuel in spacecraft. The micro-gravity environment requires a very accurate and robust description of the free surface. Later, the numerical model has been used for calculations for different offshore applications, including green water loading. The model has been extended to take two-phase flow effects into account. These effects are particularly important for sloshing in tanks. The complex mixture of the liquid and gas phase around

Rik Wemmenhove; Arthur E. P. Veldman; Tim Bunnik

2007-01-01T23:59:59.000Z

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

Physical and Numerical Models of Pore-Scale Trapping of CO2  

Science Conference Proceedings (OSTI)

Numerical simulations of deep geological carbon sequestration are being used to design field-scale implementations, predict their long-term performance, and evaluate associated risks. However, conventional field-scale simulators are unable to explicitly resolve the pore-scale processes that exert significant control on the migration and fate of supercritical CO2 in the subsurface. A combination of physical and numerical experiments with explicit pore-scale resolution are being performed in order to identify conditions under which continuum model approximations may fail, and to propose alternative simulation approaches that can be used in such cases.

Scheibe, Timothy D.; Tartakovsky, Alexandre M.; Bandara, Uditha C.; Palmer, Bruce J.; Oostrom, Martinus; Zhang, Changyong; Bonneville, Alain HR

2011-11-18T23:59:59.000Z

202

Numerical prediction of aerodynamic characteristics of prismatic cylinder by finite element method with Spalart-Allmaras turbulence model  

Science Conference Proceedings (OSTI)

Aerodynamic characteristic of prismatic cylinders is numerically investigated by using finite element method with Spalart-Allmaras turbulence model. The developed model is verified against the available experimental and numerical results for turbulent ... Keywords: Aerodynamic characteristic, Afterbody shape, Finite element method, Prismatic cylinder, Turbulent flow, Unsteady S-A model

Yan Bao; Dai Zhou; Cheng Huang; Qier Wu; Xiang-qiao Chen

2011-02-01T23:59:59.000Z

203

Activity based surveillance video content modelling  

Science Conference Proceedings (OSTI)

This paper tackles the problem of surveillance video content modelling. Given a set of surveillance videos, the aims of our work are twofold: firstly a continuous video is segmented according to the activities captured in the video; secondly a model ... Keywords: Activity recognition, Dynamic Bayesian networks, Dynamic scene modelling, Surveillance video segmentation, Unusual activity detection, Video content analysis

Tao Xiang; Shaogang Gong

2008-07-01T23:59:59.000Z

204

Improving the performance of mass-consistent numerical models using optimization techniques  

DOE Green Energy (OSTI)

This report describes a technique of using a mass-consistent model to derive wind speeds over a microscale region of complex terrain. A serious limitation in the use of these numerical models is that the calculated wind field is highly sensitive to some input parameters, such as those specifying atmospheric stability. Because accurate values for these parameters are not usually known, confidence in the calculated winds is low. However, values for these parameters can be found by tuning the model to existing wind observations within a microscale area. This tuning is accomplished by using a single-variable, unconstrained optimization procedure that adjusts the unknown parameters so that the error between the observed winds and model calculations of these winds is minimized. Model verification is accomplished by using eight sets of hourly averaged wind data. These data are obtained from measurements made at approximately 30 sites covering a wind farm development in the Altamont Pass area. When the model is tuned to a small subset of the 30 sites, an accurate determination of the wind speeds was made for the remaining sites in six of the eight cases. (The two that failed were low wind speed cases.) Therefore, when this technique is used, numerical modeling shows great promise as a tool for microscale siting of wind turbines in complex terrain.

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

1985-09-01T23:59:59.000Z

205

Generation of an Hourly Meteorological Time Series for an Alpine Basin in British Columbia for Use in Numerical Hydrologic Modeling  

Science Conference Proceedings (OSTI)

Spatially distributed numerical hydrologic models are useful tools for examining the long-term impact of forest harvesting in mountainous basins on streamflow regime properties. Such models require the input of long-duration subdaily ...

Markus Schnorbus; Younes Alila

2004-10-01T23:59:59.000Z

206

A Model Comparison: Numerical Simulations of the North and Equatorial Atlantic Oceanic Circulation in Depth and Isopycnic Coordinates  

Science Conference Proceedings (OSTI)

A series of medium-resolution (1°) numerical simulations for the equatorial and North Atlantic basin have been performed with two primitive equation models, one employing depth and the other density as the vertical coordinate. The models have ...

Eric P. Chassignet; Linda T. Smith; Rainer Bleck; Frank O. Bryan

1996-09-01T23:59:59.000Z

207

Electrification of Stratiform Regions in Mesoscale Convective Systems. Part II: Two-Dimensional Numerical Model Simulations of a Symmetric MCS  

Science Conference Proceedings (OSTI)

Model simulations of a symmetric mesoscale convective system (MCS; observations discussed in Part I) were conducted using a 2D, time-dependent numerical model with bulk microphysics. A number of charging mechanisms were considered based on ...

Terry J. Schuur; Steven A. Rutledge

2000-07-01T23:59:59.000Z

208

Estimates of Turbulence from Numerical Weather Prediction Model Output with Applications to Turbulence Diagnosis and Data Assimilation  

Science Conference Proceedings (OSTI)

Estimates of small-scale turbulence from numerical model output are produced from local estimates of the spatial structure functions of model variables such as the velocity and temperature. The key assumptions used are the existence of a ...

Rod Frehlich; Robert Sharman

2004-10-01T23:59:59.000Z

209

A Numerical Modeling System of the Hydrological Cycle for Estimation of Water Fluxes in the Huaihe River Plain Region, China  

Science Conference Proceedings (OSTI)

To analyze the water budget under human influences in the Huaihe River plain region in China, the authors have developed a numerical modeling system that integrates water flux algorithms into a platform created by coupling a soil moisture model ...

Xi Chen; Yongqin David Chen; Zhicai Zhang

2007-08-01T23:59:59.000Z

210

Numerical modeling of boiling due to production in a fractured reservoir and its field application  

Science Conference Proceedings (OSTI)

Numerical simulations were carried out to characterize the behaviors of fractured reservoirs under production which causes in-situ boiling. A radial flow model with a single production well, and a two-dimensional geothermal reservoir model with several production and injection wells were used to study the two-phase reservoir behavior. The behavior can be characterized mainly by the parameters such as the fracture spacing and matrix permeability. However, heterogeneous distribution of the steam saturation in the fracture and matrix regions brings about another complicated feature to problems of fractured two-phase reservoirs.

Yusaku Yano; Tsuneo Ishido

1995-01-26T23:59:59.000Z

211

Numerical modeling of plasma plume evolution against ambient background gas in laser blow off experiments  

Science Conference Proceedings (OSTI)

Two dimensional numerical modelling based on simplified hydrodynamic evolution for an expanding plasma plume (created by laser blow off) against an ambient background gas has been carried out. A comparison with experimental observations shows that these simulations capture most features of the plasma plume expansion. The plume location and other gross features are reproduced as per the experimental observation in quantitative detail. The plume shape evolution and its dependence on the ambient background gas are in good qualitative agreement with the experiment. This suggests that a simplified hydrodynamic expansion model is adequate for the description of plasma plume expansion.

Patel, Bhavesh G.; Das, Amita; Kaw, Predhiman; Singh, Rajesh; Kumar, Ajai [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2012-07-15T23:59:59.000Z

212

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

213

Problem-orientable numerical algorithm for modelling multi-dimensional radiative MHD flows in astrophysics -- the hierarchical solution scenario  

E-Print Network (OSTI)

We present a hierarchical approach for enhancing the robustness of numerical solvers for modelling radiative MHD flows in multi-dimensions. This approach is based on clustering the entries of the global Jacobian in a hierarchical manner that enables employing a variety of solution procedures ranging from a purely explicit time-stepping up to fully implicit schemes. A gradual coupling of the radiative MHD equation with the radiative transfer equation in higher dimensions is possible. Using this approach, it is possible to follow the evolution of strongly time-dependent flows with low/high accuracies and with efficiency comparable to explicit methods, as well as searching quasi-stationary solutions for highly viscous flows. In particular, it is shown that the hierarchical approach is capable of modelling the formation of jets in active galactic nuclei and reproduce the corresponding spectral energy distribution with a reasonable accuracy.

A. A. Hujeirat

2004-10-26T23:59:59.000Z

214

Influence of Air-Conditioning Waste Heat on Air Temperature in Tokyo during Summer: Numerical Experiments Using an Urban Canopy Model Coupled with a Building Energy Model  

Science Conference Proceedings (OSTI)

A coupled model consisting of a multilayer urban canopy model and a building energy analysis model has been developed to investigate the diurnal variations of outdoor air temperature in the office areas of Tokyo, Japan. Observations and numerical ...

Yukitaka Ohashi; Yutaka Genchi; Hiroaki Kondo; Yukihiro Kikegawa; Hiroshi Yoshikado; Yujiro Hirano

2007-01-01T23:59:59.000Z

215

Approximations to the Distributed Activation Energy Model  

E-Print Network (OSTI)

Approximations to the Distributed Activation Energy Model for Pyrolysis C.P. Please, 1 M.J. Mc, then resubmitted after minor revisions in September 2002. Abstract The Distributed Activation Energy Model (DAEM effective method for estimating kinetic parameters and the distribution of activation energies. Comparison

McGuinness, Mark

216

A reaction-based river/stream water quality model Part I: Model development and numerical schemes  

SciTech Connect

This paper presents the conceptual and mathematical development of a numerical model of sediment and reactive chemical transport in river/streams. The distribution of mobile suspended sediments and immobile bed sediments is controlled by hydrologic transport as well as erosion and deposition processes. The fate and transport of water quality constituents involving a variety of chemical and physical processes is mathematically described by a system of reaction equations for immobile constituents and advective-dispersive-reactive transport equations for constituents. To circumvent stiffness associated with equilibrium reactions, matrix decomposition is performed via Gauss-Jordan column reduction. After matrix decomposition, the system of water quality constituent reactive transport equations is transformed into a set of thermodynamic equations representing equilibrium reactions and a set of transport equations involving no equilibrium reactions. The decoupling of equilibrium and kinetic reactions enables robust numerical integration of the partial differential equations for non-equilibrium-variables. Solving non-equilibrium-variable transport equations instead of individual water quality constituent transport equations also reduces the number of PDEs. A variety of numerical methods are investigated for solving the mixed differential and algebraic equations. Two verification examples are compared with analytical solutions to demonstrate the correctness of the code and to illustrate the importance of employing application-dependent numerical methods to solve specific problems.

Zhang, Fan [ORNL; Gour-Tsyh, Yeh [University of Central Florida, Orlando; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Jardine, Philip M [ORNL

2008-01-01T23:59:59.000Z

217

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators  

E-Print Network (OSTI)

A new generation of laser wakefield accelerators, supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modeling for further understanding of the underlying physics and identification of optimal regimes, but large scale modeling of these scenarios is computationally heavy and requires efficient use of state-of-the-art Petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed / shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modeling of LWFA, demonstrating speedups of over 1 order of magni...

Fonseca, Ricardo A; Fiúza, Frederico; Davidson, Asher; Tsung, Frank S; Mori, Warren B; Silva, Luís O

2013-01-01T23:59:59.000Z

218

A particle numerical model for wall film dynamics in port-injected engines  

DOE Green Energy (OSTI)

To help predict hydrocarbon emissions during cold-start conditions the authors are developing a numerical model for the dynamics and vaporization of the liquid wall films formed in port-injected spark-ignition engines and incorporating this model in the KIVA-3 code for complex geometries. This paper summarizes the current status of the project and presents illustrative example calculations. The dynamics of the wall film is influenced by interactions with the impinging spray, the wall, and the gas flow near the wall. The spray influences the film through mass, tangential momentum, and energy addition. The wall affects the film through the no-slip boundary condition and heat transfer. The gas alters film dynamics through tangential stresses and heat and mass transfer in the gas boundary layers above the films. New wall functions are given to predict transport in the boundary layers above the vaporizing films. It is assumed the films are sufficiently thin that film flow is laminar and that liquid inertial forces are negligible. Because liquid Prandtl numbers are typically about then, unsteady heating of the film should be important and is accounted for by the model. The thin film approximation breaks down near sharp corners, where an inertial separation criterion is used. A particle numerical method is used for the wall film. This has the advantages of compatibility with the KIVA-3 spray model and of very accurate calculation of convective transport of the film. The authors have incorporated the wall film model into KIVA-3, and the resulting combined model can be used to simulate the coupled port and cylinder flows in modern spark-ignition engines. They give examples by comparing computed fuel distributions with closed- and open-valve injection during the intake and compression strokes of a generic two-valve engine.

O`Rourke, P.J.; Amsden, A.A.

1996-09-01T23:59:59.000Z

219

TOUGH: a numerical model for nonisothermal unsaturated flow to study waste canister heating effects  

Science Conference Proceedings (OSTI)

The physical processes modeled and the mathematical and numerical methods employed in a simulator for non-isothermal flow of water, vapor, and air in permeable media are briefly summarized. The simulator has been applied to study thermo-hydrological conditions in the near vicinity of high-level nuclear waste packages emplaced in unsaturated rocks. The studies reported here specifically address the question whether or not the waste canister environment will dry up in the thermal phase. 13 references, 8 figures, 2 tables.

Pruess, K.; Wang, J.S.Y.

1983-12-01T23:59:59.000Z

220

Leaking method approach to surface transport in the Mediterranean Sea from a numerical ocean model  

E-Print Network (OSTI)

We use Lagrangian diagnostics (the leaking and the exchange methods) to characterize surface transport out of and between selected regions in the Western Mediterranean. Velocity fields are obtained from a numerical model. Residence times of water of Atlantic origin in the Algerian basin, with a strong seasonal dependence, are calculated. Exchange rates between these waters and the ones occupying the northern basin are also evaluated. At surface, northward transport is dominant, and involves filamental features and eddy structures that can be identified with the Algerian eddies. The impact on these results of the presence of small scale turbulent motions is evaluated by adding Lagrangian diffusion.

Judit Schneider; Vicente Fernandez; Emilio Hernandez-Garcia

2004-10-01T23:59:59.000Z

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

Original article: Comparison of numerical models in radiative heat transfer with application to circuit-breaker simulations  

Science Conference Proceedings (OSTI)

Two different modeling approaches for the numerical computation of the radiation energy exchange in the context of the simulation of high-voltage circuit breakers are investigated. These are the basic Radiative Transfer Equation method and the P1 model ... Keywords: CFD modeling, Circuit breakers, Finite volume discretization, P1 model, Radiative heat transfer

Matthieu Melot; Jean-Yves TréPanier; Ricardo Camarero; Eddy Petro

2012-08-01T23:59:59.000Z

222

Numerical model to characterize the thermal comfort in new ecodistricts: methodology and validation through the canyon street case  

Science Conference Proceedings (OSTI)

In built-up areas, the urban structures affect the radiative and thermal environment. The numerical simulation models provide informations about urban thermal performance for many ranges of urban configurations. This paper presents a validation of a ... Keywords: CFD model, building heat transfers, coupling model, street canyon, thermo-radiative model

Khaled Athamena; Jean Francois Sini; Julien Guilhot; Jerome Vinet; Maeva Sabre; Jean-Michel Rosant

2011-01-01T23:59:59.000Z

223

Numerical model to characterize the thermal comfort in new eco-districts: methodology and validation through the canyon street case  

Science Conference Proceedings (OSTI)

In built-up areas, the urban structures affect the radiative and thermal environment. The numerical simulation models provide informations about urban thermal performance for many ranges of urban configurations. This paper presents a validation of a ... Keywords: CFD model, building heat transfers, coupling model, street canyon, thermo-radiative model

Khaled Athamena; Jean Francois Sini; Julien Guilhot; Jerome Vinet; Maeva Sabre; Jean-Michel Rosant

2011-01-01T23:59:59.000Z

224

A Three-Dimensional Numerical Model of an Isolated Thunderstorm. Part II: Dynamics of Updraft Splitting and Mesovortex Couplet Evolution  

Science Conference Proceedings (OSTI)

This study analyzes the dynamics of an isolated convective storm embedded within marked ambient vertical wind shear dominated by low-level veering, as simulated by a three-dimensional anelastic numerical modeling experiment. Two particular ...

Robert E. Schlesinger

1980-02-01T23:59:59.000Z

225

High-Order Numerics in an Unstaggered Three-Dimensional Time-Split Semi-Lagrangian Forecast Model  

Science Conference Proceedings (OSTI)

Traditional finite-difference numerical forecast models usually employ relatively low-order approximations on grids staggered in both the horizontal and the vertical. In a previous study, Purser and Leslie (1988) demonstrated that high-order ...

L. M. Leslie; R. J. Purser

1991-07-01T23:59:59.000Z

226

Mesoscale Numerical Weather Prediction Models Used in Support of Infrared Hyperspectral Measurement Simulation and Product Algorithm Development  

Science Conference Proceedings (OSTI)

A novel application of numerical weather prediction (NWP) models within an end-to-end processing system used to demonstrate advanced hyperspectral satellite technologies and instrument concepts is presented. As part of this system, sophisticated ...

Jason A. Otkin; Derek J. Posselt; Erik R. Olson; Hung-Lung Huang; James E. Davies; Jun Li; Christopher S. Velden

2007-04-01T23:59:59.000Z

227

On the Numerical Implementation of Advection Schemes for Use in Conjunction with Various Mixing Parameterizations in the GFDL Ocean Model  

Science Conference Proceedings (OSTI)

The results from ocean model experiments conducted with isopycnal and isopycnal thickness diffusion parameterizations for subgrid-scale mixing associated with mesoscale eddies are examined from a numerical standpoint. It is shown that when the ...

Andrew J. Weaver; Michael Eby

1997-02-01T23:59:59.000Z

228

Mapping Frost-Sensitive Areas with a Three-Dimensional Local-Scale Numerical Model. Pad II: Comparison with Observations  

Science Conference Proceedings (OSTI)

A three-dimensional numerical model was developed to predict the microclimate near the ground surface of local-scale domains during radiative frost events. Its performances are compared with an observational topo-climatological survey of minimum ...

R. Avissar; Y. Mahrer

1988-04-01T23:59:59.000Z

229

Numerical Sensitivity Experiments of Varying Model Physics on the Structure, Evolution and Dynamics of Two Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

The effects of different model physics and different convective and boundary layer parameterization schemes are investigated using an 18-h nested-grid numerical simulation of the mesoscale convective systems (MCSs) that were responsible for the ...

Da-Lin Zhang; J. Michael Fritsch

1988-01-01T23:59:59.000Z

230

A High-Resolution Topographic Correction Method for Clear-Sky Solar Irradiance Derived with a Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

Rugged terrain is a source of variability in the incoming solar radiation field, but the influence of terrain is still not properly included by most current numerical weather prediction (NWP) models. In this work, a downscaling postprocessing ...

José A. Ruiz-Arias; David Pozo-Vázquez; Vicente Lara-Fanego; Francisco J. Santos-Alamillos; J. Tovar-Pescador

2011-12-01T23:59:59.000Z

231

Fast 2D non-LTE radiative modelling of prominences I. Numerical methods and benchmark results  

E-Print Network (OSTI)

New high-resolution spectropolarimetric observations of solar prominences require improved radiative modelling capabilities in order to take into account both multi-dimensional - at least 2D - geometry and complex atomic models. This makes necessary the use of very fast numerical schemes for the resolution of 2D non-LTE radiative transfer problems considering freestanding and illuminated slabs. The implementation of Gauss-Seidel and successive over-relaxation iterative schemes in 2D, together with a multi-grid algorithm, is thoroughly described in the frame of the short characteristics method for the computation of the formal solution of the radiative transfer equation in cartesian geometry. We propose a new test for multidimensional radiative transfer codes and we also provide original benchmark results for simple 2D multilevel atom cases which should be helpful for the further development of such radiative transfer codes, in general.

L. Leger; L. Chevallier; F. Paletou

2007-03-27T23:59:59.000Z

232

A Numerical Model for Chemical and Meteorological Processes in the Atmospheric Boundary Layer. Part I: A Model Description and a One-Dimensional Parameter Study  

Science Conference Proceedings (OSTI)

A numerical flow model is presented for the atmospheric boundary layer, including dispersion and chemical transformations of air pollutants. The model is a three-dimensional time-dependent one for the mesoscale based on the conservation equations ...

Gunilla Svensson

1996-06-01T23:59:59.000Z

233

Simulation models for photogate active pixel sensor  

Science Conference Proceedings (OSTI)

The constant reduction in the transistors sizes for the design and the integration of smart sensors on chip requires accurate simulations of electrical characteristics. To this end, new simulation models of photogate active pixel sensor for CMOS imagers ... Keywords: modelling and simulation, optoelectronic devices, photogate active pixel sensor

B. Casadei; C. Dufaza; L. Martin

2005-07-01T23:59:59.000Z

234

A Markov Chain Model of Tornadic Activity  

Science Conference Proceedings (OSTI)

Tornadic activity in four U.S. regions is stochastically modeled based on data on tornado counts over the years 1953–98. It is shown that tornadic activity on a given day is mostly affected by the activity on the previous day. Hence, the process ...

Mathias Drton; Caren Marzban; Peter Guttorp; Joseph T. Schaefer

2003-12-01T23:59:59.000Z

235

Numerical Models of Boundary Layer Processes over and around the Gulf of Mexico during a Return-Flow Event  

Science Conference Proceedings (OSTI)

The return-flow of low-level air from the Gulf of Mexico over the southeast United States during the cool season is studied using numerical models. The key models are a newly developed airmass transformation (AMT) model and a one-dimensional ...

A. Birol Kara; James B. Elsner; Paul H. Ruscher

1998-12-01T23:59:59.000Z

236

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

237

Development of analytical and numerical models for the assessment and interpretation of hydrogeological field tests  

Science Conference Proceedings (OSTI)

Mathematical models of the flow and tracer tests in fractured aquifers are being developed for the further study of radioactive wastes migration in round water at the Lake Area, which is associated with one of the waste disposal site in Russia. The choice of testing methods, tracer types (chemical or thermal) and the appropriate models are determined by the nature of the ongoing ground-water pollution processes and the hydrogeological features of the site under consideration. Special importance is attached to the increased density of wastes as well as to the possible redistribution of solutes both in the liquid phase and in the absorbed state (largely, on fracture surfaces). This allows for studying physical-and-chemical (hydrogeochemical) interaction parameters which are hard to obtain (considering a fractured structure of the rock mass) in laboratory. Moreover, a theoretical substantiation is being given to the field methods of studying the properties of a fractured stratum aimed at the further construction of the drainage system or the subsurface flow barrier (cutoff wall), as well as the monitoring system that will evaluate the reliability of these ground-water protection measures. The proposed mathematical models are based on a tight combination of analytical and numerical methods, the former being preferred in solving the principal (2D axisymmetrical) class of the problems. The choice of appropriate problems is based on the close feedback with subsequent field tests in the Lake Area. 63 refs.

Mironenko, V.A.; Rumynin, V.G.; Konosavsky, P.K. [St. Petersburg Mining Inst. (Russian Federation); Pozdniakov, S.P.; Shestakov, V.M. [Moscow State Univ. (Russian Federation); Roshal, A.A. [Geosoft-Eastlink, Moscow (Russian Federation)

1994-07-01T23:59:59.000Z

238

Original article: Estimation of spatially varying open boundary conditions for a numerical internal tidal model with adjoint method  

Science Conference Proceedings (OSTI)

The adjoint data assimilation technique is applied to the estimation of the spatially varying open boundary conditions (OBCs) for a numerical internal tidal model. The spatial variation of the OBCs is realized by the so-called 'independent point scheme' ... Keywords: Adjoint method, Internal tidal model, Open boundary conditions, Parameter estimation, Spatial variation

Haibo Chen, Anzhou Cao, Jicai Zhang, Chunbao Miao, Xianqing Lv

2014-03-01T23:59:59.000Z

239

Efficient Numerical Methods for an Anisotropic, Nonisothermal, Two-Phase Transport Model of Proton Exchange Membrane Fuel Cell  

Science Conference Proceedings (OSTI)

We carry out model and numerical studies for a three-dimensional, anisotropic, nonisothermal, two-phase steady state transport model of proton exchange membrane fuel cell (PEMFC) in this paper. Besides fully addressing the conservation equations of mass, ... Keywords: Anisotropy, Combined finite element-upwind finite volume, Kirchhoff transformation, Newton's linearization, Nonisothermality, Proton exchange membrane fuel cell (PEMFC), Two-phase transport

Pengtao Sun

2012-04-01T23:59:59.000Z

240

On business activity modeling using grammars  

Science Conference Proceedings (OSTI)

Web based applications offer a mainstream channel for businesses to manage their activities. We model such business activity in a grammar-based framework. The Backus Naur form notation is used to represent the syntax of a regular grammar corresponding ... Keywords: data mining, web log analysis

Savitha Srinivasan; Arnon Amir; Prasad Deshpande; Vladimir Zbarsky

2005-05-01T23:59:59.000Z

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.


241

Development of a numerical computer code and circuit element models for simulation of firing systems  

SciTech Connect

Numerical simulation of firing systems requires both the appropriate circuit analysis framework and the special element models required by the application. We have modified the SPICE circuit analysis code (version 2G.6), developed originally at the Electronic Research Laboratory of the University of California, Berkeley, to allow it to be used on MSDOS-based, personal computers and to give it two additional circuit elements needed by firing systems--fuses and saturating inductances. An interactive editor and a batch driver have been written to ease the use of the SPICE program by system designers, and the interactive graphical post processor, NUTMEG, supplied by U. C. Berkeley with SPICE version 3B1, has been interfaced to the output from the modified SPICE. Documentation and installation aids have been provided to make the total software system accessible to PC users. Sample problems show that the resulting code is in agreement with the FIRESET code on which the fuse model was based (with some modifications to the dynamics of scaling fuse parameters). In order to allow for more complex simulations of firing systems, studies have been made of additional special circuit elements--switches and ferrite cored inductances. A simple switch model has been investigated which promises to give at least a first approximation to the physical effects of a non ideal switch, and which can be added to the existing SPICE circuits without changing the SPICE code itself. The effect of fast rise time pulses on ferrites has been studied experimentally in order to provide a base for future modeling and incorporation of the dynamic effects of changes in core magnetization into the SPICE code. This report contains detailed accounts of the work on these topics performed during the period it covers, and has appendices listing all source code written documentation produced.

Carpenter, K.H. (Kansas State Univ., Manhattan, KS (USA). Dept. of Electrical and Computer Engineering)

1990-07-02T23:59:59.000Z

242

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

E-Print Network (OSTI)

Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non-ideal fracture geometries and coupled primary-secondary fracture interactions on reservoir performance in these unconventional gas reservoirs. This thesis provides a grid construction tool to generate high-resolution unstructured meshes using Voronoi grids, which provides the flexibility required to accurately represent complex geologic domains and fractures in three dimensions. Using these Voronoi grids, the interaction between propped hydraulic fractures and secondary "stress-release" fractures were evaluated. Additionally, various primary fracture configurations were examined, where the fractures may be non-planar or non-orthogonal. For this study, a numerical model was developed to assess the potential performance of tight gas and shale gas reservoirs. These simulations utilized up to a half-million grid-blocks and consider a period of up to 3,000 years in some cases. The aim is to provide very high-definition reference numerical solutions that will exhibit virtually all flow regimes we can expect in these unconventional gas reservoirs. The simulation results are analyzed to identify production signatures and flow regimes using diagnostic plots, and these interpretations are confirmed using pressure maps where useful. The coupled primary-secondary fracture systems with the largest fracture surface areas are shown to give the highest production in the traditional "linear flow" regime (which occurs for very high conductivity vertical fracture cases). The non-ideal hydraulic fracture geometries are shown to yield progressively lower production as the angularity of these fractures increases. Hence, to design optimum fracture completions, we should endeavor to keep the fractures as orthogonal to the horizontal well as possible. This work expands the current understanding of flow behavior in fractured tight-gas and shale-gas systems and may be used to optimize fracture and completion design, to validate analytical models and to facilitate more accurate reserves estimation.

Olorode, Olufemi Morounfopefoluwa

2011-12-01T23:59:59.000Z

243

Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations  

E-Print Network (OSTI)

We present the first numerical, N-body, hydrodynamical, chemical simulations of cosmic structure formation in the framework of non-Gaussian models. We study the impact of primordial non-Gaussianities on early chemistry (e, H, H+, H-, He, He+, He++, H2, H2+, D, D+, HD, HeH+), molecular and atomic gas cooling, star formation, metal (C, O, Si, Fe, Mg, S) enrichment, population III (popIII) and population II-I (popII) transition, and on the evolution of "visible" objects. We find that non-Gaussianities can have some consequences on baryonic structure formation at very early epochs, but the subsequent evolution at later times washes out any difference among the various models. When assuming reasonable values for primordial non-Gaussian perturbations, it turns out that they are responsible for: (i) altering early molecular fractions in the cold, dense gas phase of ~10 per cent; (ii) inducing small temperature fluctuations of ~15, and of the popIII/popII transition of up to some 10^7yr; (iv) determining variations of history of the Universe. We stress, though, that purely non-Gaussian effects might be difficult to address, since they are strictly twisted with additional physical phenomena (e.g. primordial gas bulk flows, unknown primordial popIII stellar mass function, etc.) that have similar or stronger impact on the behaviour of the baryons.

Umberto Maio; Francesca Iannuzzi

2011-03-16T23:59:59.000Z

244

Numerical modeling of the elution peak profiles of retained solutes in supercritical fluid chromatography  

Science Conference Proceedings (OSTI)

In supercritical fluid chromatography (SFC), the significant expansion of the mobile phase along the column causes the formation of axial and radial gradients of temperature. Due to these gradients, the mobile phase density, its viscosity, its velocity, its diffusion coefficients, etc. are not constant throughout the column. This results in a nonuniform flow velocity distribution, itself causing a loss of column efficiency in certain cases, even at low flow rates, as they do in HPLC. At high flow rates, an important deformation of the elution profiles of the sample components may occur. The model previously used to account satisfactorily for the retention of an unsorbed solute in SFC is applied to the modeling of the elution peak profiles of retained compounds. The numerical solution of the combined heat and mass balance equations provides the temperature and the pressure profiles inside the column and values of the retention time and the band profiles of retained compounds that are in excellent agreement with independent experimental data for large value of mobile phase reduced density. At low reduced densities, the band profiles can strongly depend on the column axial distribution of porosity.

Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL

2011-01-01T23:59:59.000Z

245

Numerical study of the disordered Poland-Scheraga model of DNA denaturation  

E-Print Network (OSTI)

We numerically study the binary disordered Poland-Scheraga model of DNA denaturation, in the regime where the pure model displays a first order transition (loop exponent $c=2.15>2$). We use a Fixman-Freire scheme for the entropy of loops and consider chain length up to $N=4 \\cdot 10^5$, with averages over $10^4$ samples. We present in parallel the results of various observables for two boundary conditions, namely bound-bound (bb) and bound-unbound (bu), because they present very different finite-size behaviors, both in the pure case and in the disordered case. Our main conclusion is that the transition remains first order in the disordered case: in the (bu) case, the disorder averaged energy and contact densities present crossings for different values of $N$ without rescaling. In addition, we obtain that these disorder averaged observables do not satisfy finite size scaling, as a consequence of strong sample to sample fluctuations of the pseudo-critical temperature. For a given sample, we propose a procedure to identify its pseudo-critical temperature, and show that this sample then obeys first order transition finite size scaling behavior. Finally, we obtain that the disorder averaged critical loop distribution is still governed by $P(l) \\sim 1/l^c$ in the regime $l \\ll N$, as in the pure case.

Thomas Garel; Cecile Monthus

2005-04-05T23:59:59.000Z

246

Active curve axis Gaussian mixture models  

Science Conference Proceedings (OSTI)

Gaussian Mixture Models (GMM) have been broadly applied for the fitting of probability density function. However, due to the intrinsic linearity of GMM, usually many components are needed to appropriately fit the data distribution, when there are curve ... Keywords: AcaG, AcaGMM, Active curve axis, EM, Finite mixture models, GMM, Unsupervised learning

Baibo Zhang; Changshui Zhang; Xing Yi

2005-12-01T23:59:59.000Z

247

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

E-Print Network (OSTI)

The Unidirectional Hybrid Wave Model (UHWM) predicts irregular wave kinematics and pressure accurately in comparison with its linear counterpart and modification, especially near the free surface. Hence, in using the Morrison equation it has been employed in the computation of wave loads on a moored floating structure, such as Spar or TLP (Tension Leg Platform), which can be approximated by a slender body or a number of slender components. Dr. Jun Zhang, with his former and current graduate students, have developed a numerical code, known as COUPLE, over the past two decades, simulating 6 Degree Of Freedom (DOF) motions of a moored floating structures interacting with waves, current and wind. COUPLE employs UHWM as a module for computing wave loads on a floating structure. However, when the duration of simulating the wave-structure interaction is long, say 3 hours (typically required by the offshore industry for extreme storm cases), the computation time of using UHWM increases significantly in comparisons with the counterpart based upon linear wave theory. This study is to develop a numerical scheme which may significantly reduce the CPU time in the use of UHWM and COUPLE. In simulating irregular (or random) waves following a JONSWAP spectrum of a given cut off frequency, the number of free wave components in general grows linearly with the increase of the simulation duration. The CPU time for using a linear spectral method to simulate irregular waves is roughly proportion to N2, where N is the number of free wave components used in simulating irregular waves, while that for using a nonlinear wave model, such as UHWM, it is roughly proportional to N3. Therefore, to reduce the CPU time, the total simulation duration is divided into a number of segments. However, due to the nature of Fast Fourier Transform (FFT), the connection between the two neighboring surface elevations segments is likely discontinuous. To avoid the discontinuity, an overlapped duration between the two neighboring segments is adopted. For demonstration, a free-wave spectrum is input to COUPLE for simulating the 6 DOF motions of a floating 5-MW wind turbine installed on an OC3 moored Spar and tensions in the mooring lines. It is shown that the CPU time for the above simulation for duration of 2048 seconds is reduced from more than16 hours when the irregular wave elevation and kinematics are calculated without dividing into segments to less than three hours when those are calculated by dividing into five segments.

Jia, Dongxing 1984-

2012-12-01T23:59:59.000Z

248

A Numerical Examination of the Castro-Mahecha Supersymmetric Model of the Riemann Zeros  

E-Print Network (OSTI)

The unknown parameters of the recently-proposed (Int J. Geom. Meth. Mod. Phys. 1, 751 [2004]) Castro-Mahecha model of the imaginary parts (lambda_{j}) of the nontrivial Riemann zeros are the phases (alpha_{k}) and the frequency parameter (gamma) of the Weierstrass function of fractal dimension D=3/2 and the turning points (x_{j}) of the supersymmetric potential-squared Phi^2(x) -- which incorporates the smooth Wu-Sprung potential (Phys. Rev. E 48, 2595 [1993]), giving the average level density of the Riemann zeros. We conduct numerical investigations to estimate/determine these parameters -- as well as a parameter (sigma) we introduce to scale the fractal contribution. Our primary analyses involve two sets of coupled equations: one set being of the form Phi^{2}(x_{j}) = lambda_{j}, and the other set corresponding to the fractal extension -- according to an ansatz of Castro and Mahecha -- of the Comtet-Bandrauk-Campbell (CBC) quasi-classical quantization conditions for good supersymmetry. Our analyses suggest the possibility strongly that gamma converges to its theoretical lower bound of 1, and the possibility that all the phases (alpha_{k}) should be set to zero. We also uncover interesting formulas for certain fractal turning points.

Paul B. Slater

2005-11-07T23:59:59.000Z

249

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

DOE Green Energy (OSTI)

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

250

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

E-Print Network (OSTI)

Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed with two dimensional horizontal cross sectional models. The heat transfer and temperature distributions yielded excess errors less than 6% and 3%, respectively, when compared to analytical solutions. Two constant temperature sources performed equivalent heating as one constant temperature source having twice the radius. For constant heat flux sources, the equivalent radius was found to be increased by ?2. A heat flux equivalent radius (tau_h,eqv) was developed and shown to be more consistent than the geometric radius (tau_g,eqv). All equivalent radii varied with time and source separation. A heat exchanger effectiveness for two sources, (epsilon_A), was introduced based on an earlier definition for one source. Effectiveness was found to be independent of a dimensionless temperature variable that included temperatures of the tubes and soil, and varied only with separation distance at steady state. Thermal short circuiting was defined as 1 – epsilon_A and ranged from 38% to 47% in the reasonable 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 less than 2 W/m-K. The overall heat transfer increased with backfill thermal conductivity but epsilon_A decreased. Therefore, the backfill effectiveness of Couvillion was used to rank backfill performance. The range of the backfill effectiveness was from 45% for touching bentonite backfill tubes to 60% for the fictitious backfill at a separation of seven l/Do. Moisture migration was incorporated into the numerical finite element model by formulating coupled partial differential equations for non-linear heat and mass transfer. Simulations with decreasing soil moisture contents resulted in lower thermal conductivity and performance degradation. Increasing the bore hole size improved the efficiency (decreased thermal short circuiting) by as much as 20%. In addition, higher conductivity fictitious backfills improved efficiency by up to an additional 20%. However, cost savings in both cases had a negligible effect compared to the bore hole cost.

Muraya, Norman K.

1994-12-01T23:59:59.000Z

251

Numerical modeling of species transport in turbulent flow and experimental study on aerosol sampling  

E-Print Network (OSTI)

Numerical simulations were performed to study the turbulent mixing of a scalar species in straight tube, single and double elbow flow configurations. Different Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) models were used to model the turbulence in the flow. Conventional and dynamic Smagorinsky sub-grid scale models were used for the LES simulations. Wall functions were used to resolve the near wall boundary layer. These simulations were run with both two-dimensional and three-dimensional geometries. The velocity and tracer gas concentration Coefficient of Variations were compared with experimental results. The results from the LES simulations compared better with experimental results than the results from the RANS simulations. The level of mixing downstream of a S-shaped double elbow was higher than either the single elbow or the U-shaped double elbow due to the presence of counter rotating vortices. Penetration of neutralized and non-neutralized aerosol particles through three different types of tubing was studied. The tubing used included standard PVC pipes, aluminum conduit and flexible vacuum hose. Penetration through the aluminum conduit was unaffected by the presence or absence of charge neutralization, whereas particle penetrations through the PVC pipe and the flexible hosing were affected by the amount of particle charge. The electric field in a space enclosed by a solid conductor is zero. Therefore charged particles within the conducting aluminum conduit do not experience any force due to ambient electric fields, whereas the charged particles within the non-conducting PVC pipe and flexible hose experience forces due to the ambient electric fields. This increases the deposition of charged particles compared to neutralized particles within the 1.5� PVC tube and 1.5� flexible hose. Deposition 2001a (McFarland et al. 2001) software was used to predict the penetration through transport lines. The prediction from the software compared well with experiments for all cases except when charged particles were transported through non-conducting materials. A Stairmand cyclone was designed for filtering out large particles at the entrance of the transport section.

Vijayaraghavan, Vishnu Karthik

2006-12-01T23:59:59.000Z

252

Numerical modelling of dynamical interaction between seismic radiation and near-surface geological structures: a parallel approach  

Science Conference Proceedings (OSTI)

We investigate a faster and easier way to parallelise seismological codes able to simulate the dynamical interaction between seismic radiation and near-surface geological structures. This is important in assessing strong ground motion, in the mitigation ... Keywords: HPF, numerical modelling, openMP, parallel computing, seismic site effects

A. Caserta; V. Ruggiero; P. Lanucara

2002-11-01T23:59:59.000Z

253

Numerical identification of parameters for a strongly degenerate convection--diffusion problem modelling centrifugation of flocculated suspensions  

Science Conference Proceedings (OSTI)

This paper presents the identification of parameters in the flux and diffusion functions for a quasilinear strongly degenerate parabolic equation which models the centrifugation of flocculated suspensions. We consider both a rotating tube and a basket ... Keywords: Degenerate parabolic differential equation, Inverse problem, Numerical methods

S. Berres; R. Bürger; A. Coronel; M. Sepúlveda

2005-03-01T23:59:59.000Z

254

The Numerical Solution of the Mellor-Yamada Level 2.5 Turbulent Kinetic Energy Equation in the Eta Model  

Science Conference Proceedings (OSTI)

A new method is presented for obtaining the numerical solution of the production-dissipation component of the turbulent kinetic energy equation that arises in the Mellor-Yamada level 2.5 turbulent closure model. The development of this new method ...

Joseph P. Gerrity Jr.; Thomas L. Black; Russell E. Treadon

1994-07-01T23:59:59.000Z

255

A Numerical Study of Breaking Kelvin-Helmholtz Billows using a Reynolds-Stress Turbulence Closure Model  

Science Conference Proceedings (OSTI)

A two-dimensional numerical study of breaking Kelvin-Helmholtz billows is presented. The turbulent breaking process is modeled using second-order closure methods to describe the small-wale turbulence, while the large-scale billow itself is ...

R. I. Sykes; W. S. Lewellen

1982-07-01T23:59:59.000Z

256

Numerical methods for instability mitigation in the modeling of laser wakefield accelerators in a Lorentz-boosted frame  

Science Conference Proceedings (OSTI)

Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [1] has been shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups required mitigation of a high-frequency instability ... Keywords: Boosted frame, Laser wakefield acceleration, Numerical instability, Particle-in-cell, Plasma simulation, Special relativity

J. -L. Vay; C. G. R. Geddes; E. Cormier-Michel; D. P. Grote

2011-07-01T23:59:59.000Z

257

Numerical Modeling of an Orographically Enhanced Precipitation Event Associated with Tropical Storm Rachel over Taiwan  

Science Conference Proceedings (OSTI)

An orographic rainfall event that occurred on 6–7 August 1999 during the passage of Tropical Storm (TS) Rachel over Taiwan is investigated by performing triply nested, nonhydrostatic numerical simulations using the Naval Research Laboratory's (...

Sen Chiao; Yuh-Lang Lin

2003-04-01T23:59:59.000Z

258

A Local Minimum Aliasing Method for Use in Nonlinear Numerical Models  

Science Conference Proceedings (OSTI)

The local spectral method is a minimum aliasing technique for the discretization and numerical integration of prognostic systems consisting of nonlinear partial differential equations. The technique embodies many features of both spectral ...

John R. Anderson

1989-07-01T23:59:59.000Z

259

The Fleet Numerical Oceanography Center Suite of Oceanographic Models and Products  

Science Conference Proceedings (OSTI)

Fleet Numerical Oceanography Center (FLENUMOCEANCEN) is the navy's real-time prediction center for global-scale and open-ocean regional-scale oceanographic products, having filled this role for over 25 years. FLENUMOCEANCEN provides operational ...

R. M. Clancy; LCDR W. D. Sadler

1992-06-01T23:59:59.000Z

260

Transient heat transfer through walls and thermal bridges. numerical modelling: methodology and validation  

Science Conference Proceedings (OSTI)

The current advanced numerical codes for the energy audits carry out 0-dimensional simulation (i.e., one computational node representing the thermal zone), underestimating the effects of thermal bridges on the seasonal heating demand of buildings. The ...

Fabrizio Ascione; Filippo de' Rossi; Nicola Bianco; Giuseppe Peter Vanoli

2012-12-01T23:59:59.000Z

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261

Landscape-Induced Atmospheric Flow and its Parameterization in Large-Scale Numerical Models  

Science Conference Proceedings (OSTI)

Extensive numerical simulations are performed to demonstrate that the landscape-induced mesoscale sensible heat, moisture, and momentum fluxes associated with spatially heterogeneous convective boundary layers can be larger than, and have a ...

Xubin Zeng; Roger A. Pielke

1995-05-01T23:59:59.000Z

262

Three-Dimensional Numerical Model Simulations of Airflow Over Mountainous Terrain: A Comparison with Observations  

Science Conference Proceedings (OSTI)

Numerical simulations of airflow over two different choices of mountainous terrain and the comparisons of results with aircraft observations are presented. Two wintertime casts for flow over Elk Mountain, Wyoming where surface heating is assumed ...

Terry L. Clark; Robert Gall

1982-07-01T23:59:59.000Z

263

Coupling between Sea Surface Temperature and Low-Level Winds in Mesoscale Numerical Models  

Science Conference Proceedings (OSTI)

This study evaluates the impacts of sea surface temperature (SST) specification and grid resolution on numerical simulations of air–sea coupling near oceanic fronts through analyses of surface winds from the European Centre for Medium-Range ...

Qingtao Song; Dudley B. Chelton; Steven K. Esbensen; Nicolai Thum; Larry W. O’Neill

2009-01-01T23:59:59.000Z

264

Real &me numerical forecast of global epidemic spreading using large-scale computa&onal models  

E-Print Network (OSTI)

Real &me numerical forecast of global epidemic spreading using large conditions). Forecast = best prediction given the present knowledge on the system. Projection = attempt functionalities) #12;Real time forecast for the H1N1pdm (2009) Key parameters

Cattuto, Ciro

265

Direct Numerical Simulations of a Smoke Cloud–Top Mixing Layer as a Model for Stratocumuli  

Science Conference Proceedings (OSTI)

A radiatively driven cloud-top mixing layer is investigated using direct numerical simulations. This configuration mimics the mixing process across the inversion that bounds the stratocumulus-topped boundary layer. The main focus of this paper is ...

Alberto de Lozar; Juan Pedro Mellado

2013-08-01T23:59:59.000Z

266

A Numerical Modeling Study of the Upwelling Source Waters along the Oregon Coast during 2005  

Science Conference Proceedings (OSTI)

Regional ocean circulation along the Oregon coast is studied numerically for forcing fields derived from year 2005 and climatological-mean conditions. The primary object is to study directly the Lagrangian pathways by which fluid arrives in the ...

David Rivas; R. M. Samelson

2011-01-01T23:59:59.000Z

267

The Formation of Comma Vortices in a Tropical Numerical Simulation Model  

Science Conference Proceedings (OSTI)

A detailed analysis of a numerically simulated tropical disturbance displays a comma-shaped pattern at the mature stage in the low-level vorticity, surface convergence, mid-level upward motion and precipitation fields.

Robert E. Tuleya; Yoshio Kurihara

1984-03-01T23:59:59.000Z

268

Diagnosis and Correction of Systematic Humidity Error in a Global Numerical Weather Prediction Model  

Science Conference Proceedings (OSTI)

Accuracy of humidity forecasts has been considered relatively unimportant to much of the operational numerical weather prediction (NWP) community. However, the U.S. Air Force is interested in accurate water vapor and cloud forecasts as end ...

Donald C. Norquist; Sam S. Chang

1994-11-01T23:59:59.000Z

269

Extending the Numerical Stability Limit of Terrain-Following Coordinate Models over Steep Slopes  

Science Conference Proceedings (OSTI)

To extend the numerical stability limit over steep slopes, a truly horizontal pressure-gradient discretization based on the ideas formulated by Mahrer in the 1980s has been developed. Conventionally, the pressure gradient is evaluated in the ...

Günther Zängl

2012-11-01T23:59:59.000Z

270

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 approx- imate 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 experi- ments 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.

Ammari, Habib; Garnier, Josselin

2012-01-01T23:59:59.000Z

271

Lessons learned from reactive transport modeling of a low-activity waste glass disposal system  

Science Conference Proceedings (OSTI)

A set of reactive chemical transport calculations were conducted with the Subsurface Transport Over Reactive Multiphases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal ... Keywords: chemical transport, low-level waste, numerical model, unsaturated flow, vadose zone

Diana H. Bacon; B. Peter McGrail

2003-04-01T23:59:59.000Z

272

Numerical Modeling of Cased-hole Instability in High Pressure and High Temperature Wells  

E-Print Network (OSTI)

Down-hole damages such as borehole collapse, circulation loss and rock tensile/compressive cracking in the open-hole system are well understood at drilling and well completion stages. However, less effort has been made to understand the instability of cemented sections in High Pressure High Temperature (HPHT) wells. The existing analysis shows that, in the perforation zones, casing/cement is subject to instability, particularly in the presence of cavities. This dissertation focuses on the instability mechanism of casing/cement in the non-perforated zones. We investigate the transient thermal behavior in the casing-cement-formation system resulting from the movement of wellbore fluid using finite element method. The critical value of down-hole stresses is identified in both wellbore heating and cooling effects. Differently with the heating effect, the strong cooling effect in a cased hole can produce significant tension inside casing/cement. The confining formation has an obvious influence on the stability of casing/cement. The proposed results reveal that the casing/cement system in the non-homogeneous formation behaves differently from that in homogeneous formation. With this in mind, a three-dimensional layered finite element model is developed to illustrate the casing/cement mechanical behavior in the non-homogeneous formation. The radial stress of cement sheath is found to be highly variable and affected by the contrast in Young’s moduli in the different formation layers. The maximum stress is predicted to concentrate in the casing-cement system confined by the sandstone. Casing wear in the cased-hole system causes significant casing strength reduction, possibly resulting in the casing-cement tangential collapse. In this study, an approach for calculating the stress concentration in the worn casing with considering temperature change is developed, based on boundary superposition. The numerical results indicate that the casing-cement system after casing wear will suffer from severe tangential instability due to the elevated compressive hoop stress. Gas migration during the cementing process results from the fluid cement’s inability to balance formation pore pressure. Past experience emphasized the application of chemical additives to reduce or control gas migration during the cementing process. This report presents the thermal and mechanical behaviors in a cased hole caused by created gas channels after gas migration. In conclusion, the size and the number of gas channels are two important factors in determining mechanical instability in a casing-cement system.

Shen, Zheng 1983-

2012-12-01T23:59:59.000Z

273

Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method  

E-Print Network (OSTI)

Better understanding and control of crack growth direction during hydraulic fracturing are essential for enhancing productivity of geothermal and petroleum reservoirs. Structural analysis of fracture propagation and impact on fluid flow is a challenging issue because of the complexity of rock properties and physical aspects of rock failure and fracture growth. Realistic interpretation of the complex interactions between rock deformation, fluid flow, heat transfer, and fracture propagation induced by fluid injection is important for fracture network design. In this work, numerical models are developed to simulate rock failure and hydraulic fracture propagation. The influences of rock deformation, fluid flow, and heat transfer on fracturing processes are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering a stochastic heterogeneity distribution. The constitutive modeling by the energy release rate-based damage evolution allows characterizing brittle rock failure and strength degradation. This approach is then used to simulate the sequential process of heterogeneous rock failures from the initiation of microcracks to the growth of macrocracks. The hydraulic fracturing path, especially for fractures emanating from inclined wellbores and closed natural fractures, often involves mixed mode fracture propagation. Especially, when the fracture is inclined in a 3D stress field, the propagation cannot be modeled using 2D fracture models. Hence, 2D/3D mixed-modes fracture growth from an initially embedded circular crack is studied using the damage mechanics approach implemented in a finite element method. As a practical problem, hydraulic fracturing stimulation often involves fluid pressure change caused by injected fracturing fluid, fluid leakoff, and fracture propagation with brittle rock behavior and stress heterogeneities. In this dissertation, hydraulic fracture propagation is simulated using a coupled fluid flow/diffusion and rock deformation analysis. Later THM analysis is also carried out. The hydraulic forces in extended fractures are solved using a lubrication equation. Using a new moving-boundary element partition methodology (EPM), fracture propagation through heterogeneous media is predicted simply and efficiently. The method allows coupling fluid flow and rock deformation, and fracture propagation using the lubrication equation to solve for the fluid pressure through newly propagating crack paths. Using the proposed model, the 2D/3D hydraulic fracturing simulations are performed to investigate the role of material and rock heterogeneity. Furthermore, in geothermal and petroleum reservoir design, engineers can take advantage of thermal fracturing that occurs when heat transfers between injected flow and the rock matrix to create reservoir permeability. These thermal stresses are calculated using coupled THM analysis and their influence on crack propagation during reservoir stimulation are investigated using damage mechanics and thermal loading algorithms for newly fractured surfaces.

Min, Kyoung

2013-08-01T23:59:59.000Z

274

SECA Core Program - Recent Development of Modeling Activities at PNNL  

DOE Green Energy (OSTI)

This presentation discusses recent modeling activities at the Pacific Northwest National Laboratory.

Khaleel, M.A.; Recknagle, K.P.; Koeppel, B.; Vetrano, J.; Sun, X.; Korolev, V.; Johnson, K.I.; Nguygen, N.; Rector, D.; Singh, P.

2005-01-27T23:59:59.000Z

275

Current Capability of Operational Numerical Models in Predicting Tropical Cyclone Intensity in the Western North Pacific  

Science Conference Proceedings (OSTI)

Forecasts of tropical cyclone (TC) intensity from six operational models (three global models and three regional models) during 2010 and 2011 are assessed to study the current capability of model guidance in the western North Pacific. The ...

Hui Yu; Peiyan Chen; Qingqing Li; Bi Tang

2013-04-01T23:59:59.000Z

276

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

Science Conference Proceedings (OSTI)

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

277

A preliminary evaluation of the performance of wind tunnel and numerical modeling simulations of the wind flow over a wind farm  

SciTech Connect

This report is an analysis of physical and numerical model simulations of the wind flow over complex terrain. The specific area to which these models were applied is a wind farm in the Altamont Pass area of California. The physical model results were obtained from wind tunnel flow simulations, and the numerical model used was the optimizing version of the NOABL model. The goals of this analysis were (1) to evaluate the relative performance of the two models and (2) to uncover any clues that would point toward improvement of the wind tunnel modeling. The performances of the models were gauged by comparing model simulations to wind observations taken over the modeled area.

Barnard, J.C.; Wegley, H.L.

1987-01-01T23:59:59.000Z

278

Tidal Exchange through a Strait: A Numerical Experiment Using a Simple Model Basin  

Science Conference Proceedings (OSTI)

In order to investigate the mechanism of tidal exchange through a strait, we numerically track the Lagrangian movement of water particles over a full cycle of the M2 tide. As a result, it is found that the spatially rapid changes of the amplitude ...

Toshiyuki Awaji; Norihisa Imasato; Hideaki Kunishi

1980-10-01T23:59:59.000Z

279

Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters  

E-Print Network (OSTI)

or measurements made from space [Gregg and Carder, 1990; Mueller et al., 2004]. This energy can be considered as two separate portions: energy with wavelengths less than 700 nm (visible domain, EVIS), and energy values of a and bb as inputs. To reach this goal, we carried out extensive numerical simulations by Hydro

Lee, Zhongping

280

Examination of Numerical Results from Tangent Linear and Adjoint of Discontinuous Nonlinear Models  

Science Conference Proceedings (OSTI)

The forward model solution and its functional (e.g., the cost function in 4DVAR) are discontinuous with respect to the model's control variables if the model contains discontinuous physical processes that occur during the assimilation window. In ...

S. Zhang; X. Zou; Jon E. Ahlquist

2001-11-01T23:59:59.000Z

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

Three-Dimensional Numerical Modeling of Convection Produced by Interacting Thunderstorm Outflows. Part I: Control Simulation and Low-Level Moisture Variations  

Science Conference Proceedings (OSTI)

The Klemp–Wilhelmson three-dimensional numerical cloud model is used to investigate cloud development along intersecting thunderstorm outflow boundaries. The model initial environment is characterized by a temperature and moisture profile ...

Kelvin K. Droegemeier; Robert B. Wilhelmson

1985-11-01T23:59:59.000Z

282

Numerical modeling of the temperature illumination intensity dependent performance of CIS solar cells  

DOE Green Energy (OSTI)

In this paper, the temperature dependence of CIS solar cell illuminated I-V is studied numerically using ADEPT. The effects of having a second junction either at the interface or at the back contact are investigated. These two placements of the second junction result in two distinctive shapes of the I-V at low temperatures. Both of these distinctive shapes have been observed experimentally.

Lee, Y.J.; Gray, J.L. [Purdue Univ., Lafayette, IN (United States). School of Electrical Engineering

1994-12-31T23:59:59.000Z

283

Numerical Modeling Study and Assessment of PWR Fuel Rod and Assembly Distortion  

Science Conference Proceedings (OSTI)

Fuel assembly and rod distortion experienced in pressurized water reactors (PWRs) result in numerous operational challenges to plant operators such as mechanical interference between distorted assembly and control rods, difficulties in unloading and reloading cores during outages, and possibly anomalous fuel performance due to atypical water gaps. Therefore, an improved understanding of the various parameters contributing to distortion is important in order to manage or otherwise eliminate these ...

2012-11-30T23:59:59.000Z

284

Numerical study on transient heat transfer under soil with plastic mulch in agriculture applications using a nonlinear finite element model  

E-Print Network (OSTI)

In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.

De Castro, Carlos Armando

2011-01-01T23:59:59.000Z

285

An improved numerical model for the investigation of thermal hydraulic phenomena with applications to LMR reactor components  

SciTech Connect

A basic limited scope, fast-running computer model is presented for the solution of single phase two-dimensional transients in thermally coupled incompressible fluid flow problems. The governing equations and the two-equation transport model (k-{epsilon}) of turbulence are reduced to a set of linear algebraic equations in an implicit finite difference scheme, based on the control volume approach. These equations are solved iteratively in a line-by-line procedure using the tri-diagonal matrix algorithm. The numerical formulation and general calculational procedure are described in detail. The calculations show good agreement when compared with experimental data and other independent analyses.

Chan, B.C.; Kennett, R.J.; Van Tuyle, G.J.

1992-01-01T23:59:59.000Z

286

An improved numerical model for the investigation of thermal hydraulic phenomena with applications to LMR reactor components  

SciTech Connect

A basic limited scope, fast-running computer model is presented for the solution of single phase two-dimensional transients in thermally coupled incompressible fluid flow problems. The governing equations and the two-equation transport model (k-{epsilon}) of turbulence are reduced to a set of linear algebraic equations in an implicit finite difference scheme, based on the control volume approach. These equations are solved iteratively in a line-by-line procedure using the tri-diagonal matrix algorithm. The numerical formulation and general calculational procedure are described in detail. The calculations show good agreement when compared with experimental data and other independent analyses.

Chan, B.C.; Kennett, R.J.; Van Tuyle, G.J.

1992-08-01T23:59:59.000Z

287

Shape Optimization for Navier-Stokes Equations with Algebraic Turbulence Model: Numerical Analysis and Computation  

SciTech Connect

We study the shape optimization problem for the paper machine headbox which distributes a mixture of water and wood fibers in the paper making process. The aim is to find a shape which a priori ensures the given velocity profile on the outlet part. The mathematical formulation leads to the optimal control problem in which the control variable is the shape of the domain representing the header, the state problem is represented by the generalized Navier-Stokes system with nontrivial boundary conditions. This paper deals with numerical aspects of the problem.

Haslinger, Jaroslav, E-mail: hasling@karlin.mff.cuni.cz [Charles University, Department of Numerical Mathematics, Faculty of Mathematics and Physics (Czech Republic); Stebel, Jan, E-mail: stebel@math.cas.cz [Academy of Sciences of the Czech Republic, Institute of Mathematics (Czech Republic)

2011-04-15T23:59:59.000Z

288

Numerical Model Studies of the Winter-Storm Response of the West Florida Shelf  

Science Conference Proceedings (OSTI)

The wintertime, wind-driven Ocean circulation on the West Florida Continental Shelf is studied within the framework of a linearized storm-surge model. The model bathymetry incorporates a realistic shelf, extending from New Orleans to the southern ...

Ya Hsueh; G. O. Marmorino; Linda L. Vansant

1982-10-01T23:59:59.000Z

289

Ensemble Data Assimilation to Characterize Surface-Layer Errors in Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

Experiments with the single-column implementation of the Weather Research and Forecasting Model provide a basis for deducing land–atmosphere coupling errors in the model. Coupling occurs both through heat and moisture fluxes through the land–...

J. P. Hacker; W. M. Angevine

2013-06-01T23:59:59.000Z

290

Toward a Dynamic-Thermodynamic Assimilation of Satellite Surface Temperature in Numerical Atmospheric Models  

Science Conference Proceedings (OSTI)

An assimilation technique is described in which satellite-observed surface skin temperature tendencies are used in a model surface energy budget so that the predicted rate of temperature change in the model more closely agrees with the satellite ...

Richard T. McNider; Aaron J. Song; Daniel M. Casey; Peter J. Wetzel; William L. Crosson; Robert M. Rabin

1994-12-01T23:59:59.000Z

291

Numerical Prediction of Convectively Driven Mesoscale Pressure Systems. Part II. Mesoscale Model  

Science Conference Proceedings (OSTI)

A 20-level, three-dimensional, primitive equation model with 20 km horizontal resolution is used to predict the development of convectively driven mesoscale pressure systems. Systems produced by the model have life histories and structural ...

J. M. Fritsch; C. F. Chappell

1980-08-01T23:59:59.000Z

292

Numerical Simulation of a Buoyant Thermal Using the k-? Turbulence Model  

Science Conference Proceedings (OSTI)

Possibilities for describing turbulent mixing processes through the use of the two-equation k-? model modified to take into account the effects of streamline curvature and buoyancy are discussed. It is shown that one of the k-? model constants ...

Y. A. Dovgalyuk; M. A. Zatevakhin; E. N. Stankova

1994-09-01T23:59:59.000Z

293

A Numerical Study of Climatic Oscillations Using a Coupled Atmosphere–Ocean Primitive Equation Model  

Science Conference Proceedings (OSTI)

A coupled atmosphere-ocean primitive equation model is developed. It is a free-dimensional general circulation model, with two layers in the atmosphere and two layers in the ocean and includes solar radiation, longwave radiation, sensible heating,...

Xiong-Shan Chen

1984-03-01T23:59:59.000Z

294

Numerical Simulation of ANATEX Tracer Data Using a Turbulence Closure Model for Long-Range Dispersion  

Science Conference Proceedings (OSTI)

A long-range transport model based on turbulence closure concepts is described. The model extends the description of planetary boundary layer turbulent diffusion to the larger scales and uses statistical wind information to predict contaminant ...

R. I. Sykes; S. F. Parker; D. S. Henn; W. S. Lewellen

1993-05-01T23:59:59.000Z

295

3-D numerical modelling of coastal currents and suspended sediment transport  

Science Conference Proceedings (OSTI)

A three dimensional hydrodynamic and suspended sediment transport model (HYDROTAM-3) has been developed and applied to Fethiye Bay. Model can simulate the transport processes due to tidal or nontidal forcing which may be barotropic or baroclinic. The ...

Lale Balas; Alp Küçükosmano?lu; Umut Yegül

2006-05-01T23:59:59.000Z

296

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

Science Conference Proceedings (OSTI)

Computational models based on discrete dynamical equations are a successful way of approaching the problem of predicting or forecasting the future evolution of dynamical systems. For linear and mildly nonlinear models, the solutions of the ...

Joăo Teixeira; Carolyn A. Reynolds; Kevin Judd

2007-01-01T23:59:59.000Z

297

African Easterly Wave Dynamics in a Mesoscale Numerical Model: The Upscale Role of Convection  

Science Conference Proceedings (OSTI)

To examine the dynamical role of convection in African easterly wave (AEW) life cycles the Weather Research and Forecasting (WRF) model is used to simulate the evolution of a single AEW from September 2004. The model simulations are validated ...

Gareth J. Berry; Chris D. Thorncroft

2012-04-01T23:59:59.000Z

298

Interannual Variability of Meridional Heat Transport in a Numerical Model of the Upper Equatorial Pacific ocean  

Science Conference Proceedings (OSTI)

The interannual heat budget of the Pacific equatorial upwelling zone is studied using a primitive equation, a reduced gravity model of the upper Pacific equatorial ocean. The model is forced with monthly mean FSU winds from 1971 to 1990. A ...

Esther C. Brady

1994-12-01T23:59:59.000Z

299

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

300

Motion and Evolution of Binary Tropical Cyclones in a Coupled Atmosphere–Ocean Numerical Model  

Science Conference Proceedings (OSTI)

The interaction of binary tropical cyclones (TC) is investigated using a coupled TC-ocean movable nested-grid model. The model consists of an eight-layer atmospheric model in the sigma coordinate system and a three-layer primitive equation ocean ...

Alexander I. Falkovich; Alexander P. Khain; Isaac Ginis

1995-05-01T23:59:59.000Z

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.


301

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

E-Print Network (OSTI)

A numerical investigation of laminar forced convective heat transfer was performed in a three-dimensional channel with baffles in which a uniform heat flux was applied to the top and bottom walls, and the side walls were considered adiabatic. The trade-off between heat transfer enhancement and pressure drop produced by the baffles was studied for periodically fully developed flow (PDF). The numerical analysis was performed using a finite volume approach. The computer code was validated against the experimental results of Goldstein and Kreid (1967) and Beavers et. al. (1970) for a three-dimensional laminar flow in a channel without baffles. Parametric runs were made for Reynolds Numbers (Re) of 150, 250, 3 50, and 450, for blockage ratios (H/Dy) of 0. 5, 0.6, 0. 7, 0.8. Heat transfer behavior was studied for Prandtl Numbers (Pr) of 0. 7 and 7. 0, and for wall thermal conductivity to fluid thermal conductivity ratios (K) of 1, 10, 100 and 1000. It was found that three dimensional effects were present for the range of Reynolds number studied. The pressure drop penalty becomes highly important above blockage ratios of 0.7. Higher heat transfer enhancement was found for high Prandtl numbers (Pr--7. 0) than for low Prandtl numbers (Pr--O. 7). The heat transfer enhancement due to an increase in the thermal conductivity ratio of the solid to the fluid regions is greater than the one obtained by increasing the blockage ratio.

Lopez Buso, Jorge Ricardo

1995-01-01T23:59:59.000Z

302

Design and Analysis of Numerical Experiments  

Science Conference Proceedings (OSTI)

Calculations with numerical models are often referred to as numerical experiments, by analogy to classical laboratory experiments. Usually, many numerical experiments are carried out to determine the response of a numerical model to variations of ...

Kenneth P. Bowman; Jerome Sacks; Yue-Fang Chang

1993-05-01T23:59:59.000Z

303

TA Orientation 2004 Activity 4. Rationale for UMN Model  

E-Print Network (OSTI)

TA Orientation 2004 Activity 4. Rationale for UMN Model #12;TA Orientation 2004 Activity 4 (continued) #12;TA Orientation 2004 Activity 4 (continued) Page 45 #12;TA Orientation 2004 Activity 4 (continued) Page 46 #12;TA Orientation 2004 Activity 4 (continued) Page 47 #12;TA Orientation 2004 Activity 4

Minnesota, University of

304

Building reliable activity models using hierarchical shrinkage and mined ontology  

Science Conference Proceedings (OSTI)

Activity inference based on object use has received considerable recent attention. Such inference requires statistical models that map activities to the objects used in performing them. Proposed techniques for constructing these models (hand definition, ...

Emmanuel Munguia Tapia; Tanzeem Choudhury; Matthai Philipose

2006-05-01T23:59:59.000Z

305

Context-Aware Modeling and Recognition of Activities in Video  

Science Conference Proceedings (OSTI)

In this paper, rather than modeling activities in videos individually, we propose a hierarchical framework that jointly models and recognizes related activities using motion and various context features. This is motivated from the observations that the ...

Yingying Zhu, Nandita M. Nayak, Amit K. Roy-Chowdhury

2013-06-01T23:59:59.000Z

306

Proceedings of the workshop on numerical modeling of thermohydrological flow in fractured rock masses  

DOE Green Energy (OSTI)

Nineteen papers were presented at the workshop on modeling thermohydrologic flow in fractured masses. This workshop was a result of the interest currently being given to the isolation of nuclear wastes in geologic formations. Included in these proceedings are eighteen of the presentations, one abstract and summaries of the panel discussions. The papers are listed under the following categories: introduction; overviews; fracture modelings; repository studies; geothermal models; and recent developments. Eighteen of the papers have been abstracted and indexed.

Not Available

1980-09-01T23:59:59.000Z

307

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

E-Print Network (OSTI)

thermal calculations for the WIPP site in southeastern NewWaste Isolation Pilot Plant (WIPP) in bedded salt. The codepersonal communication 1980). WIPP The modeling for WIPP is

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

308

Efficient Schemes for Reducing Numerical Dispersion in Modeling Multiphase Transport through Porous and Fractured Media  

E-Print Network (OSTI)

within a fluid in a multiphase- porous-medium system isand radiation in a multiphase, multicomponent, porous mediumModeling Multiphase Transport through Porous and Fractured

Wu, Yu-Shu; Forsyth, Peter A.

2006-01-01T23:59:59.000Z

309

A physically based numerical approach for modeling fracture-matrix interaction in fractured reservoirs  

E-Print Network (OSTI)

in modeling multiphase flow in porous and fractured media,multiphase tracer transport in heterogeneous fractured porousof multiphase flow through fractured or porous media. 3.

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

310

A physically based numerical approach for modeling fracture-matrix interaction in fractured reservoirs  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow through unsaturated fractured porous media, Proceedings of the Second International Symposium on Dynamics of Fluids

Wu, Yu-Shu; Pruess, Karsten

2004-01-01T23:59:59.000Z

311

Numerical modelling of heat and mass transfer and optimisation of a natural draft wet cooling tower.  

E-Print Network (OSTI)

??The main contribution of this work is to answer several important questions relating to natural draft wet cooling tower (NDWCT) modelling, design and optimisation. Specifically,… (more)

Williamson, Nicholas J

2007-01-01T23:59:59.000Z

312

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

E-Print Network (OSTI)

media and land surface subsidence: Proceedings, 12th AnnualSymnposium on Land Subsidence, Anaheim, California 9A. Witherspoon, 1977a, Modeling subsidence due to geothermal

Wang, J.S.Y.

2013-01-01T23:59:59.000Z

313

Numerical Modeling of Heat Pipe Radiator and Fin Size Optimization for Low and No Gravity Environments.  

E-Print Network (OSTI)

??A heat-pipe radiator element has been designed and modeled to study the efficiency of heat transfer for low and no gravity environments, like in lunar… (more)

Bieger, Virginia Ruth

2013-01-01T23:59:59.000Z

314

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

315

Numerical Modeling of Coupled Variably-Saturated Fluid Flow and Reactive Transport with Fast and Slow Chemical Reactions  

SciTech Connect

The couplings among chemical reaction rates, advective and diffusive transport in fractured media or soils, and changes in hydraulic properties due to precipitation and dissolution within fractures and in rock matrix are important for both nuclear waste disposal and remediation of contaminated sites. This paper describes the development and application of LEHGC2.0, a mechanistically-based numerical model for simulation of coupled fluid flow and reactive chemical transport including both fast and slow reactions invariably saturated media. Theoretical bases and numerical implementations are summarized, and two example problems are demonstrated. The first example deals with the effect of precipitation-dissolution on fluid flow and matrix diffusion in a two-dimensional fractured media. Because of the precipitation and decreased diffusion of solute from the fracture into the matrix, retardation in the fractured medium is not as large as the case wherein interactions between chemical reactions and transport are not considered. The second example focuses on a complicated but realistic advective-dispersive-reactive transport problem. This example exemplifies the need for innovative numerical algorithms to solve problems involving stiff geochemical reactions.

LI, MING-HSU; SIEGEL, MALCOLM D.; YEH, GOUR-TSYH (GEORGE)

1999-09-20T23:59:59.000Z

316

Numerical modeling of electrochemical-mechanical interactions in lithium polymer batteries  

Science Conference Proceedings (OSTI)

This paper presents a multi-scale finite element approach for lithium batteries to study electrochemical-mechanical interaction phenomena at macro- and micro-scales. The battery model consists of a lithium foil anode, a separator, and a porous cathode ... Keywords: Finite element method, Homogenization, Multi-scale modeling, Porous electrode theory

Stephanie Golmon; Kurt Maute; Martin L. Dunn

2009-12-01T23:59:59.000Z

317

A numerical model of hydro-thermo-mechanical coupling in a fractured rock mass  

DOE Green Energy (OSTI)

Coupled hydro-thermo-mechanical codes with the ability to model fractured materials are used for predicting groundwater flow behavior in fractured aquifers containing thermal sources. The potential applications of such a code include the analysis of groundwater behavior within a geothermal reservoir. The capability of modeling hydro-thermo systems with a dual porosity, fracture flow model has been previously developed in the finite element code, FEHM. FEHM has been modified to include stress coupling with the dual porosity feature. FEHM has been further developed to implicitly couple the dependence of fracture hydraulic conductivity on effective stress within two dimensional, saturated aquifers containing fracture systems. The cubic law for flow between parallel plates was used to model fracture permeability. The Bartin-Bandis relationship was used to determine the fracture aperture within the cubic law. The code used a Newton Raphson iteration to implicitly solve for six unknowns at each node. Results from a model of heat flow from a reservoir to the moving fluid in a single fracture compared well with analytic results. Results of a model showing the increase in fracture flow due to a single fracture opening under fluid pressure compared well with analytic results. A hot dry rock, geothermal reservoir was modeled with realistic time steps indicating that the modified FEHM code does successfully model coupled flow problems with no convergence problems.

Bower, K.M.

1996-06-01T23:59:59.000Z

318

FITOVERT: A dynamic numerical model of subsurface vertical flow constructed wetlands  

Science Conference Proceedings (OSTI)

This paper introduces a mathematical model (FITOVERT) specifically developed to simulate the behaviour of vertical subsurface flow constructed wetlands (VSSF-CWs). One of the main goals of the development of FITOVERT was to keep the complexity of the ... Keywords: Constructed wetlands, Hydrodynamics, Modelling, Reactive transport, Unsaturated flow, Vertical subsurface flow

D. Giraldi; M. de Michieli Vitturi; R. Iannelli

2010-05-01T23:59:59.000Z

319

Numerical Extended-Range Prediction: Forecast Skill Using a Low-Resolution Climate Model  

Science Conference Proceedings (OSTI)

A pilot study that evaluates the potential forecast skill of winter 10–30-day time-mean flow from a low-resolution (R15) climate simulation model is presented. The hypothesis tested is that low-resolution climate model forecasts might be as ...

David P. Baumhefner

1996-09-01T23:59:59.000Z

320

Mesoscale Impacts of Explicit Numerical Diffusion in a Convection-Permitting Model  

Science Conference Proceedings (OSTI)

In convection-permitting simulations, the spectrum of resolved motions is truncated near scales where convection is active. An “energy gap” between resolved and unresolved motions does not exist, such that the upscale and downscale fluxes of ...

Wolfgang Langhans; Juerg Schmidli; Christoph Schär

2012-01-01T23:59:59.000Z

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.


321

Internal Tides in the Southwestern Atlantic off Brazil: Observations and Numerical Modeling  

Science Conference Proceedings (OSTI)

Data collected from moored instruments, deployed over the southeastern Brazilian continental shelf during the summer and winter months of 2001, show internal tide activity near the shelf break. To help to elucidate the observations, a fully three-...

Adriene F. Pereira; Belmiro M. Castro

2007-06-01T23:59:59.000Z

322

Thermodynamic Modeling and Numerical Simulation of Single-Shaft Microturbine Performance  

E-Print Network (OSTI)

A combined production system based on microturbine holds the promise of increasing energy utilization efficiency and improving environmental quality due to its many attractive merits as a distributed energy source technology. To analyze and evaluate the energy saving potential and economical benefits of microturbine and its combined production system, a simple mathematical model of microturbine is proposed. Part-load characteristics of main components are also considered for analyzing the unit's performance under off-design situations. The proposed model is validated by operational data of a commercially available micro- turbine from a reference. The result shows that the proposed mathematical model can preferably represent the quasi-static operational features of microturbine.

Hao, X.; Zhang, G.; Zhou, J.; Chen, Y.

2006-01-01T23:59:59.000Z

323

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

Science Conference Proceedings (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

324

A Numerical Modeling Study of the Propagation of Idealized Sea-Breeze Density Currents  

Science Conference Proceedings (OSTI)

Sea breezes are often modeled as a wave response to transient heating in a stratified environment. They occur, however, as density currents with well-defined fronts, the understanding of which rests primarily on experiments and theory that do not ...

F. J. Robinson; M. D. Patterson; S. C. Sherwood

2013-02-01T23:59:59.000Z

325

The Behavior of Gravitational Modes in Numerical Forecasts with the NCAR Community Climate Model  

Science Conference Proceedings (OSTI)

Characteristics of gravitational-wave noise in noninitialized forecasts were investigated with the NCAR Community Climate Model. Forecasts were begun from FGGE analyses. The behavior of individual, gravitational normal modes was examined. In ...

R. M. Errico; D. L. Williamson

1988-09-01T23:59:59.000Z

326

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

327

Quadratic Galerkin Finite Element Schemes for the Vertical Discretization of Numerical Forecast Models  

Science Conference Proceedings (OSTI)

A finite element scheme with second-order basis functions is introduced for vertical discretization using a spectral model for horizontal discretization. The basis functions are required to be continuous, and no assumption is made concerning the ...

J. Steppeler

1987-08-01T23:59:59.000Z

328

Numerical Investigations with a Hybrid Isentropic?Sigma Model. Part II: The Inclusion of Moist Processes  

Science Conference Proceedings (OSTI)

The main goals of this paper are 1) to demonstrate the feasibility of incorporating a prognostic equation for water vapor and diabatic processes in the University of Wisconsin ??? model discussed in Part I, 2) to document methods applied to ...

Tom H. Zapotocny; Fred M. Reames; R. Bradley Pierce; Donald R. Johnson; Bart J. Wolf

1991-09-01T23:59:59.000Z

329

Numerical study of roughness distributions in nonlinear models of interface growth  

E-Print Network (OSTI)

We analyze the shapes of roughness distributions of discrete models in the Kardar, Parisi and Zhang (KPZ) and in the Villain, Lai and Das Sarma (VLDS) classes of interface growth, in one and two dimensions. Three KPZ models in d=2 confirm the expected scaling of the distribution and show a stretched exponential tail approximately as exp[-x^(0.8)], with a significant asymmetry near the maximum. Conserved restricted solid-on-solid models belonging to the VLDS class were simulated in d=1 and d=2. The tail in d=1 has the form exp(-x^2) and, in d=2, has a simple exponential decay, but is quantitatively different from the distribution of the linear fourth-order (Mullins-Herring) theory. It is not possible to fit any of the above distributions to those of 1/f^\\alpha noise interfaces, in contrast with recently studied models with depinning transitions.

Fabio D. A. Aarăo Reis

2005-08-09T23:59:59.000Z

330

Numerical Simulations of Observed Arctic Stratus Clouds Using a Second-Order Turbulence Closure Model  

Science Conference Proceedings (OSTI)

A high-resolution one-dimensional version of a second-order turbulence closure radiative-convective model, developed at Los Alamos National Laboratory, is used to simulate the interactions among turbulence, radiation, and bulk cloud parameters in ...

W. S. Smith; C-Y. J. Kao

1996-01-01T23:59:59.000Z

331

The influence of Microphysics in the Formation of Intense Wake Lows: A Numerical Modeling Study  

Science Conference Proceedings (OSTI)

A two-dimensional cloud model is used to investigate whether microphysical processes alone within the stratiform rain regions of mesoscale convection systems can induce strong descent and intense surface wake lows accompanying such systems. ...

William A. Gallus Jr.

1996-10-01T23:59:59.000Z

332

Numerical Modeling of the Turbulent Fluxes of Chemically Reactive Trace Gases in the Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Turbulent fluxes of chemically reactive trace gases in the neutral atmospheric boundary layer (ABL) were simulated with a one-dimensional, coupled diffusion-chemistry model. The effects of rapid chemical reactions were included with a suite of ...

W. Gao; M. L. Wesely

1994-07-01T23:59:59.000Z

333

A Verification of Numerical Model Forecasts for Sounding-Derived Indices above Udine, Northeast Italy  

Science Conference Proceedings (OSTI)

In this work, 40 different indices derived from real soundings and the corresponding ECMWF model forecasts for the same location (near Udine, northeast Italy) are compared. This comparison is repeated for more than 500 days, from June 2004 to ...

Agostino Manzato

2008-06-01T23:59:59.000Z

334

A Numerical Model Study of Nocturnal Drainage Flows with Strong Wind and Temperature Gradients  

Science Conference Proceedings (OSTI)

A second-moment turbulence-closure model described in Yamada and Bunker is used to simulate nocturnal drainage flows observed during the 1984 ASCOT field expedition in Brush Creek, Colorado. In order to simulate the observed strong wind ...

T. Yamada; S. Bunker

1989-07-01T23:59:59.000Z

335

A Unified Representation of Deep Moist Convection in Numerical Modeling of the Atmosphere. Part I  

Science Conference Proceedings (OSTI)

A generalized framework for cumulus parameterization applicable to any horizontal resolution between those typically used in general circulation and cloud-resolving models is presented. It is pointed out that the key parameter in the ...

Akio Arakawa; Chien-Ming Wu

2013-07-01T23:59:59.000Z

336

Numerical Prediction of an Antarctic Severe Wind Event with the Weather Research and Forecasting (WRF) Model  

Science Conference Proceedings (OSTI)

This study initiates the application of the maturing Weather Research and Forecasting (WRF) model to the polar regions in the context of the real-time Antarctic Mesoscale Prediction System (AMPS). The behavior of the Advanced Research WRF (ARW) ...

Jordan G. Powers

2007-09-01T23:59:59.000Z

337

Numerical Simulations and a Conceptual Model of the Stratocumulus to Trade Cumulus Transition  

Science Conference Proceedings (OSTI)

A two-dimensional eddy-resolving model is used to study the transition from the stratocumulus topped boundary layer to the trade cumulus boundary layer. The 10-day simulations use an idealized Lagrangian trajectory representative of summertime ...

Matthew C. Wyant; Christopher S. Bretherton; Hugh A. Rand; David E. Stevens

1997-01-01T23:59:59.000Z

338

Oblique, Stratified Winds about a Shelter Fence. Part II: Comparison of Measurements with Numerical Models  

Science Conference Proceedings (OSTI)

To evaluate Reynolds-averaged Navier–Stokes (RANS) models of disturbed micrometeorological winds, steady-state computations using a second-order closure are compared with observations (see Part I) in which the surface layer wind was disturbed by ...

John D. Wilson

2004-10-01T23:59:59.000Z

339

Mesoscale Forecasts Generated from Operational Numerical Weather-Prediction Model Output  

Science Conference Proceedings (OSTI)

A technique called Model Output Enhancement (MOE) has been developed for the generation and display of mesoscale weather forecasts. The MOE technique derives mesoscale or high-resolution (order of 1 km) weather forecasts from synoptic-scale ...

John G. W. Kelley; Joseph M. Russo; Toby N. Carlson; J. Ronald Eyton

1988-01-01T23:59:59.000Z

340

The Formation and Fate of a River Plume: A Numerical Model  

Science Conference Proceedings (OSTI)

A mathematical model that describes the formation and dilution of a frontally bounded river plume is presented. Such features were first studied at the mouth of the Connecticut River during periods of high discharge and have subsequently been ...

James O'Donnell

1990-04-01T23:59:59.000Z

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

Sensors and Actuators B 94 (2003) 8198 Numerical modeling of transport and accumulation of DNA on  

E-Print Network (OSTI)

, and entomologists who informed Jake Kosek's ethnographic account of drone aircraft in the hills of Afghanistan and Pakistan, programmed with algorithms modeled on bee behavior to adopt "swarming" tactics (Kosek this issue

Kassegne, Samuel Kinde

342

Numerical Treatment of Cross-Shelf Open Boundaries in a Barotropic Coastal Ocean Model  

Science Conference Proceedings (OSTI)

Using a barotropic coastal ocean model with a straight coastline and uniform cross-shelf bottom slope, seven different cross-shelf open boundary conditions (four of which are applied in either implicit or explicit form) are compared in three ...

David C. Chapman

1985-08-01T23:59:59.000Z

343

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

Science Conference Proceedings (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

344

A real-time emergency response workstation using a 3-D numerical model initialized with sodar  

Science Conference Proceedings (OSTI)

Many emergency response dispersion modeling systems provide simple Gaussian models driven by single meteorological tower inputs to estimate the downwind consequences from accidental spills or stack releases. Complex meteorological or terrain settings demand more sophisticated resolution of the three-dimensional structure of the atmosphere to reliably calculate plume dispersion. Mountain valleys and sea breeze flows are two common examples of such settings. To address these complexities, the authors have implemented the three-dimensional diagnostic MATHEW mass-adjusted wind field and ADPIC particle-in-cell dispersion models on a workstation for use in real-time emergency response modeling. MATHEW/ADPIC have shown their utility in a variety of complex settings over the last 15 years within the Department of Energy`s Atmospheric Release Advisory Capability (ARAC) project. The models are initialized using an array of surface wind measurements from meteorological towers coupled with vertical profiles from an acoustic sounder (sodar). The workstation automatically acquires the meteorological data every 15 minutes. A source term is generated using either defaults or a real-time stack monitor. Model outputs include contoured isopleths displayed on site geography or plume densities shown over 3-D color shaded terrain. The models are automatically updated every 15 minutes to provide the emergency response manager with a continuous display of potentially hazardous ground-level conditions if an actual release were to occur. Model run time is typically less than 2 minutes on 6 megaflop ({approximately}30 MIPS) workstations. Data acquisition, limited by dial-up modem communications, requires 3 to 5 minutes.

Lawver, B.S.; Sullivan, T.J. [Lawrence Livermore National Lab., CA (US); Baskett, R.L. [EG& G Energy Measurements, Inc., Pleasanton, CA (US)

1993-01-28T23:59:59.000Z

345

Final Report: A Model Management System for Numerical Simulations of Subsurface Processes  

SciTech Connect

The DOE and several other Federal agencies have committed significant resources to support the development of a large number of mathematical models for studying subsurface science problems such as groundwater flow, fate of contaminants and carbon sequestration, to mention only a few. This project provides new tools to help decision makers and stakeholders in subsurface science related problems to select an appropriate set of simulation models for a given field application.

Zachmann, David

2013-10-07T23:59:59.000Z

346

A Finite-Element Model of the Atmospheric Boundary Layer Suitable for Use with Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

We give a detailed description of an atmospheric boundary layer model capable of simulating the diurnal cycles of wind, temperature and humidity. The model includes a formulation of various physical processes (radiative effects, variation of soil ...

J. Mailhot; R. Benoit

1982-10-01T23:59:59.000Z

347

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

Science Conference Proceedings (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

348

Numerical model for the vacuum pyrolysis of scrap tires in batch reactors  

Science Conference Proceedings (OSTI)

A quantitative model for scrap tire pyrolysis in a batch scale reactor developed comprises the following basic phenomena: conduction inside tire particles; conduction, convection, and radiation between the feedstock particles or between the fluids and the particles; tire pyrolysis reaction; exothermicity and endothermicity caused by tire decomposition and volatilization; and the variation of the composition and the thermal properties of tire particles. This model was used to predict the transient temperature and density distributions in the bed of particles, the volatile product evolution rate, the mass change, the energy consumption during the pyrolysis process, and the pressure history in a tire pyrolysis reactor with a load of 1 kg. The model predictions agree well with independent experimental data.

Yang, J.; Tanguy, P.A.; Roy, C. [Univ. Laval, Quebec, PQ (Canada). Dept. de Genie Chimique

1995-06-01T23:59:59.000Z

349

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

DOE Green Energy (OSTI)

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

350

Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds  

Science Conference Proceedings (OSTI)

This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

None

2005-07-01T23:59:59.000Z

351

Numerical Modeling of Coupled Groundwater and Surface Water Interactions in an Urban Setting  

Science Conference Proceedings (OSTI)

The Dominguez Channel Watershed (DCW), located in the southern portion of Los Angeles County (Figure A.1), drains about 345 square miles into the Los Angeles Harbor. The cities and jurisdictions in DCW are shown in Figure A.2. The largest of these include the cities of Los Angeles, Carson, and Torrance. This watershed is unique in that 93% of its land area is highly developed (i.e. urbanized). The watershed boundaries are defined by a complex network of storm drains and flood control channels, rather than being defined by natural topography. Table (1) shows a summary of different land uses in the Dominguez Channel Watershed (MEC, 2004). The Dominguez Watershed has the highest impervious area of all watersheds in the Los Angeles region. The more impervious the surface, the more runoff is generated during a storm. Storm water runoff can carry previously accumulated contaminants and transport them into receiving water systems. Point sources such as industrial wastewater and municipal sewage as well as urban runoff from commercial, residential, and industrial areas are all recognized as contributors to water quality degradation at DWC. Section 303(d) of the 1972 Federal Clean Water Act (CWA) requires states to identify and report all waters not meeting water quality standards and to develop action plans to pursue the water quality objectives. These plans specify the maximum amount of a given pollutant that the water body of concern can receive and still meet water quality standards. Such plans are called Total Maximum Daily Loads (TMDLs). TMDLs also specify allocations of pollutant loadings to point and non-point sources taking into account natural background pollutant levels. This demonstrates the importance of utilizing scientific tools, such as flow and transport models, to identify contaminant sources, understand integrated flow paths, and assess the effectiveness of water quality management strategies. Since overland flow is a very important component of the water balance and hydrology of DCW, a parallel, distributed watershed model that treats flow in groundwater and surface water in a dynamically coupled manner will be used to build a flow model of the watershed. This coupled model forms the basis for modeling and understanding the transport of contaminants through the Dominguez Channel Watershed, which can be used in designing and implementing TMDLs to manage the water quality in this basin. In this report, the coupled surface water-groundwater flow model of DCW will be presented. This flow model was calibrated against a storm that occurred in February 21st, 2004. The model and approach are explained further in the following sections.

Rihani, J F; Maxwell, R M

2007-09-26T23:59:59.000Z

352

GATE Air-Sea Interactions II: Numerical-Model Calculation of Regional Sea-Surface Temperature Fields Using the GATE Version III Gridded Global Data Set  

Science Conference Proceedings (OSTI)

The numerical model of air-sea interaction previously described in Brown et al. (1982), Pandolfo and Jacobs (1972) and Pandolfo (1969) is applied over a limited horizontal portion of the GATE III Gridded Global Data set (including continental ...

P. S. Brown Jr.; J. P. Pandolfo; G. D. Robinson

1982-10-01T23:59:59.000Z

353

The Conversion of Total Column Ozone Data to Numerical Weather Prediction Model Initializing Fields, with Simulations of the 24–25 January 2000 East Coast Snowstorm  

Science Conference Proceedings (OSTI)

Satellites are uniquely capable of providing uniform data coverage globally. Motivated by such capability, this study builds on a previously described methodology that generates numerical weather prediction (NWP) model initial conditions (ICs) ...

Dorothy Durnford; John Gyakum; Eyad Atallah

2009-01-01T23:59:59.000Z

354

Use of a Radar Simulator on the Output Fields from a Numerical Mesoscale Model to Analyze X-Band Rain Estimators  

Science Conference Proceedings (OSTI)

A full radar simulator, which works with the 3D output fields from a numerical mesoscale model, has been developed. This simulator uses a T-matrix code to calculate synthetic radar measurements, accounts for both backscattering and propagation ...

E-P. Zahiri; M. Gosset; J-P. Lafore; V. Gouget

2008-03-01T23:59:59.000Z

355

The Use of Satellite Data in the Specification of Convective Heating for Diabatic Initialization and Moisture Adjustment in Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

Although diabatic processes play an important role in the tropical circulation, current analysis schemes and numerical weather prediction models are unable to adequately include diabatic heating information. In this paper, procedures for using ...

Kamal Puri; M. J. Miller

1990-01-01T23:59:59.000Z

356

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 ď‚— Near-field (Vicinity of the Device) ď‚— Flow redirection ď‚— Interaction with marine life ď‚— 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

357

Numerical test of Polyakov loop models in high temperature SU(2)  

E-Print Network (OSTI)

We study the compatibility of effective mean-field models of the Polyakov loop for the deconfined phase of SU(N) pure gauge theories with lattice data obtained for the case of SU(2), in the temperature range T_c - 4.8 T_c.

Roberto Fiore; Pietro Giudice; Alessandro Papa

2004-09-07T23:59:59.000Z

358

Dissipation and Cascades to Small Scales in Numerical Models Using a Shape-Preserving Advection Scheme  

Science Conference Proceedings (OSTI)

A nondivergent barotropic mode1 and a shallow-water model are presented that exploit a high-order shape-preserving scheme for the advection of vorticity or potential vorticity as well as tracers. The dissipation associated with the advection ...

John Thuburn

1995-06-01T23:59:59.000Z

359

Numerical Experiments with a General Circulation Model Concerning the Distribution of Ozone in the Stratosphere  

Science Conference Proceedings (OSTI)

Two experiments were performed with a nine-layer quasi-geostrophic spectral model to simulate the distribution of ozone below 60 km. Experiment I included thermal and orographic forcing of the planetary-scale waves while Experiment II did not ...

R. J. Kurzeja; K. V. Haggard; W. L. Grose

1984-07-01T23:59:59.000Z

360

A Numerical Model for Evaluating the Impact of Noble Metal Chemical Addition in Boiling Water Reactors  

SciTech Connect

The technique of noble metal chemical addition (NMCA), accompanied by a low-level hydrogen water chemistry (HWC), is being employed by several U.S. nuclear power plants for mitigating intergranular stress corrosion cracking in the vessel internals of their boiling water reactors (BWRs). An improved computer model by the name of DEMACE was employed to evaluate the performance of NMCA throughout the primary coolant circuit (PCC) of a commercial BWR. The molar ratios of hydrogen to oxidizing species in the PCC under normal water chemistry and HWC are analyzed. The effectiveness of NMCA is justified by calculated electrochemical corrosion potential (ECP) around the PCC and in a local power range monitoring (LPRM) housing tube, in which practical in-vessel ECP measurements are normally taken.Prior to the modeling work for the BWR, the Mixed Potential Model, which is embedded in DEMACE and responsible for ECP calculation, was calibrated against both laboratory and plant ECP data. After modeling for various HWC conditions, it is found that the effectiveness of NMCA in the PCC of the selected BWR varies from region to region. In particular, the predicted ECP in the LPRM housing tube is notably different from that in the nearby bulk environment under NMCA, indicating that cautions must be given to a possible, undesirable outcome due to a distinct ECP difference between a locally confined area and the actual bulk environment.

Yeh, T.-K. [National Tsing-Hua University, Taiwan (China)

2002-10-15T23:59:59.000Z

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.


361

Cloud-Top Entrainment Instability through Small-Scale Mixing and Its Parameterization in Numerical Models  

Science Conference Proceedings (OSTI)

In a recent paper, Kuo and Schubert demonstrated the lack of observational support for the relevance of the criterion for cloud-top entrainment instability proposed by Randall and by Deardorff. Here we derive a new criterion, based on a model of ...

M. K. MacVean; P. J. Mason

1990-04-01T23:59:59.000Z

362

Diabatic Effects on Late-Winter Cold Front Evolution: Conceptual and Numerical Model Evaluations  

Science Conference Proceedings (OSTI)

The impact of diabatic heating on late winter frontogenesis is evaluated both through conceptual scaling and the use of high-resolution Eta Model simulations of a strong but relatively dry cold surface front that occurred during the Storm-scale ...

William A. Gallus Jr.; Moti Segal

1999-07-01T23:59:59.000Z

363

Infrared Cooling in Cloudy Atmospheres: Precision of Grid Point Selection for Numerical Models  

Science Conference Proceedings (OSTI)

The infrared layer temperature change in a cloudy atmosphere normally shows warming at the base of the cloud and intense cooling at the top of the cloud. In a model that uses broad-band radiative transfer to calculate atmospheric temperature ...

L. P. Stearns

1983-07-01T23:59:59.000Z

364

Improved computational schemes for the numerical modeling of hydrothermal resources in Wyoming  

DOE Green Energy (OSTI)

A new method, the Conjugate Gradient Squared (CGS) solution technique, is shown to be extremely effective when applied to the finite-difference solution of conductive and convective heat transfer in geologic systems. The CGS method is compared to the Successive Over/Under Relaxation schemes, a version of the Gaussian elimination method, and the Generalized Minimum Residual (GMRES) approach. The CGS procedure converges at least ten times faster than the nearest competitor. The model is applied to the Thermopolis hydrothermal system, located in northwestern Wyoming. Modeled results are compared with measured temperature-depth profiles and results from other studies. The temperature decrease from 72{degree}C to 54{degrees}C along the crest of the Thermopolis anticline is shown to result from cooling of the geothermal fluid as it moves to the southeast. Modeled results show correct general trends, however, a time-varying three-dimensional model will be needed to fully explain the effects of mixing within the aquifers along the crest of the anticline and thermal affects of surface surface topography. 29 refs., 18 figs., 2 tabs.

Heasler, H.P.; George, J.H.; Allen, M.B.

1990-05-01T23:59:59.000Z

365

The Numerical Modeling for Electrical Behavior of Graphene Nanoribbon in the Present of Optical Detection  

Science Conference Proceedings (OSTI)

A physical model is presented for GNR based photo detector. The photo detector structure is photodiode in which GNR is inserted between two electrodes as a tool for changing pick frequency of absorption. Optical properties of GNR discussed using tight-binding ... Keywords: Graphene Nanoribbon, Optical properties, Optical Detection

Mohammad Hosein Sheikhi; Masoud Berahman; Reza Alaei

2009-12-01T23:59:59.000Z

366

A review of Vlasov-Fokker-Planck numerical modeling of inertial confinement fusion plasma  

Science Conference Proceedings (OSTI)

The interaction of intense lasers with solid matter generates a hot plasma state that is well described by the Vlasov-Fokker-Planck equation. Accurate and efficient modeling of the physics in these scenarios is highly pertinent, because it relates to ... Keywords: Computational, Fast electron transport, Fokker-Planck, Inertial confinement fusion, Laser, Magnetic field, Plasma, Vlasov

A. G. R. Thomas; M. Tzoufras; A. P. L. Robinson; R. J. Kingham; C. P. Ridgers; M. Sherlock; A. R. Bell

2012-02-01T23:59:59.000Z

367

Numerical Simulation of Flow around a Tall Isolated Seamount. Part I: Problem Formulation and Model Accuracy  

Science Conference Proceedings (OSTI)

A sigma coordinate ocean circulation model is employed to study flow trapped to a tall seamount in a periodic f-plane channel. In Part I, errors arising from the pressure gradient formulation in the steep topography/strong stratification limit ...

Aike Beckmann; Dale B. Haidvogel

1993-08-01T23:59:59.000Z

368

Activities and Accomplishments in Model Year 2007  

SciTech Connect

Document summarizes the compliance activity of EPAct-covered state and alternative fuel provider fleets.

Not Available

2008-09-01T23:59:59.000Z

369

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

E-Print Network (OSTI)

Nonlinear coupling problems between the multiple bodies or between the mooring/riser and the offshore platform are incorporated in the CHARM3D-MultiBody, a fully coupled time domain analysis program for multiple bodies with moorings and risers. The nonlinear spring connection module and the three dimensional beam module are added to appropriately solve the structural connection problem. The nonlinear spring connection module includes the hydro-pneumatic tensioner module with the friction & stick/slip implementation, the tendon/mooring disconnection (breakage/unlatch) module with the tendon down-stroke check, and the contact spring with the initial gap with the friction force implemented. The nonlinear coupling may happen in many places for the offshore floating structures, such as hydro-pneumatic tensioner, tendon of TLP down stroke at the bottom joint, stick-slip phenomena at the tie down of the derrick and most of the fender-to-steel or steel-to-steel contact problem with initial gap during the installation. The mooring/tendon broken and unlatch can be a nonlinear connection problem once the transient mode is taken into account. Nonlinearity of the stiffness and friction characteristics of the tensioner combined with stick-slip behavior of riser keel joint is investigated. The relationship between tensions and strokes for hydro-pneumatic tensioner is based on the ideal gas equation where the isotropic gas constant can be varied to achieve an optimum stroke design based on tensioner stiffness. A transient effect of tendon down-stroke and disconnection on global performance of ETLP for harsh environmental condition is also investigated by incorporating the nonlinear boundary condition of the FE tendon model in CHARM3D. The program is made to be capable of modeling the tendon disconnection both at the top and the bottom connection as well as the down stroke behavior for the pinned bottom joint. The performance of the tie-down clamp of derrick is also investigated by using six degrees of freedom 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 or FE beam model. The method reduces too much conservatism when we design the tie-down system by the conventional method, in which all the environmental forces are combined without the phase lag effect between them. The FE beam model is also applied to the connectors between the semisubmersible and the truss for the pre-service and in-place conditions to be verified with the model test results, which shows good agreements.

Yang, Chan K.

2009-05-01T23:59:59.000Z

370

Numerical simulation of self-induced rainout using a dynamic convective cloud model  

Science Conference Proceedings (OSTI)

The hypothesis that self-induced rainout can occur is supported by observations in Hiroshima and Nagasaki, where deposition of weapons debris with precipitation occurred several km downwind of the burst point. This precipitation was initiated either directly by the nuclear weapons or by the ensuing fires. Simulation of the Nagasaki event with a convection cloud precipitation scavenging model, although fraught with many questionable assumptions, agrees surprisingly well with the observations and supports the hypothesis that self-induced rainout can occur.

Molenkamp, C.R.

1980-03-01T23:59:59.000Z

371

Numerical simulations and predictive models of undrained penetration in soft soils  

E-Print Network (OSTI)

There are two aspects in this study: cylinder penetrations and XBP (Expendable Bottom Penetrometer) interpretations. The cylinder studies firstly investigate the relationship between the soil resisting force and penetration depth by a series 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 of rate-dependent plasticity. With all forces acting on the cylinder estimated, penetration depths are predicted from simple equations of motion for a single particle. Comparisons to experimental results show reasonable agreement between model predictions and measurements. The XBP studies follow the same methodology in investigating the soil shearing resistance as a function of penetration depth and velocity by finite element analyses. With the measurements of time decelerations during penetration of the XBP, sediment shear strength profile is inferred from a single particle kinetic model. The predictions compare favorably with experimental measurements by vane shear tests.

Shi, Han

2005-08-01T23:59:59.000Z

372

FOUR-FLUID MODEL AND NUMERICAL SIMULATIONS OF MAGNETIC STRUCTURES IN THE HELIOSHEATH  

Science Conference Proceedings (OSTI)

The first part of this paper extends the three-fluid model of Avinash and Zank for magnetic structures in the heliosheath to a four-fluid model consisting of electrons, pick-up ions (PUIs), solar wind ions (SWIs), and neutral hydrogen. The PUIs are generated by neutrals via charge exchange with SWI. Since the kinetic pressure of PUI is nearly three to four times the pressure of SWI, these are more suited to mediate small-scale structures in the heliosheath such as magnetic holes (MH)/humps etc. The constant energy exchange between these two fluids drives them nonadiabatic. The PUIs are isothermal ({gamma} = 1) while SWIs are nonadiabatic with an index {gamma} {approx} 1.25. The four-fluid model captures these effects via a modified equation of state for PUI and SWI. The phase space of time-independent solutions in terms of the Mach numbers of PUI and SWI is constructed to delineate the parameter space which allows structure formation in the heliosheath. The second part of the paper examines the stability of the time-independent solutions computed in the first part by evolving them via a full system of Hall-MHD equations. The simulation results show that these solutions are not quite stable. As the structure propagates it develops growing oscillations in the wings. Concomitantly, there are changes in the amplitude and width of the structure. This instability could be due to local changes in the velocity of the structure and reflects an exchange between the kinetic and magnetic parts of the total energy. Our results about the presence of growing oscillations in the wings of solitary wave solutions are consistent with the recent analysis of MHs in the heliosheth by Burlaga et al. Their analysis also shows evidence for the presence of oscillations and instabilities in the wings of MHs in the heliosheath.

Avinash, K. [Department of Physics and Astrophysics, University of Delhi, 110007, India. (India); Cox, Sean M.; Shaikh, Dastgeer; Zank, G. P. [Centre for Space Plasma and Aeronomic Research, University of Alabama, Hunstville, AL 35899 (United States)

2009-04-10T23:59:59.000Z

373

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

DOE Green Energy (OSTI)

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

374

Mapping Frost-Sensitive Areas with a Three-Dimensional Local-Scale Numerical Model. Part I. Physical and Numerical Aspects  

Science Conference Proceedings (OSTI)

Radiative frost is one of the most severe weather conditions that affects agricultural activities in many parts of the world. Since various protective methods to reduce frost impact are available, refinements of frost forecasting methodologies ...

R. Avissar; Y. Mahrer

1988-04-01T23:59:59.000Z

375

Numerical modeling of gas migration at a proposed repository for low and intermediate level nuclear wastes at Oberbauenstock, Switzerland  

Science Conference Proceedings (OSTI)

Hydrologic impacts of corrosive gas release from a hypothetical L/ILW nuclear waste repository at Oberbauenstock are explored by means of numerical simulation. A schematic two dimensional vertical section through the mountain is modeled with the simulator TOUGH, which describes two-phase flow of water and gas in porous and fractured media. Two reference cases are considered which represent the formations as a porous and as a fractured-porous (dual permeability) medium, respectively. Both cases predict similar and rather modest pressure increases, from ambient 10 bars to near 25 bars at the repository level. These results are to be considered preliminary because important parameters affecting two-phase flow, such as relative permeabilities of a fractured medium, are not well known at present. 24 refs., 15 figs., 5 tabs.

Pruess, K.

1990-03-01T23:59:59.000Z

376

Understanding, Modeling and Predicting Hidden Solder Joint Shape Using Active Thermography  

E-Print Network (OSTI)

Characterizing hidden solder joint shapes is essential for electronics reliability. Active thermography is a methodology to identify hidden defects inside an object by means of surface abnormal thermal response after applying a heat flux. This research focused on understanding, modeling, and predicting hidden solder joint shapes. An experimental model based on active thermography was used to understand how the solder joint shapes affect the surface thermal response (grand average cooling rate or GACR) of electronic multi cover PCB assemblies. Next, a numerical model simulated the active thermography technique, investigated technique limitations and extended technique applicability to characterize hidden solder joint shapes. Finally, a prediction model determined the optimum active thermography conditions to achieve an adequate hidden solder joint shape characterization. The experimental model determined that solder joint shape plays a higher role for visible than for hidden solder joints in the GACR; however, a MANOVA analysis proved that hidden solder joint shapes are significantly different when describe by the GACR. An artificial neural networks classifier proved that the distances between experimental solder joint shapes GACR must be larger than 0.12 to achieve 85% of accuracy classifying. The numerical model achieved minimum agreements of 95.27% and 86.64%, with the experimental temperatures and GACRs at the center of the PCB assembly top cover, respectively. The parametric analysis proved that solder joint shape discriminability is directly proportional to heat flux, but inversely proportional to covers number and heating time. In addition, the parametric analysis determined that active thermography is limited to five covers to discriminate among hidden solder joint shapes. A prediction model was developed based on the parametric numerical data to determine the appropriate amount of energy to discriminate among solder joint shapes for up to five covers. The degree of agreement between the prediction model and the experimental model was determined to be within a 90.6% for one and two covers. The prediction model is limited to only three solder joints, but these research principles can be applied to generate more realistic prediction models for large scale electronic assemblies like ball grid array assemblies having as much as 600 solder joints.

Giron Palomares, Jose

2012-05-01T23:59:59.000Z

377

GATE Air-Sea Interaction. I: Numerical Model Calculation of Local Sea-Surface Temperatures on Diurnal Time Scales Using the GATE Version III Gridded Global Data Set  

Science Conference Proceedings (OSTI)

The numerical model of air-sea interaction previously described in Jacobs (1978), Pandolfo and Jacobs (1972) and Pandolfo (1969) is inserted at one horizontal grid point in the GATE III Gridded Global Data Set to calculate a model-generated, ...

P. S. Brown Jr.; J. P. Pandolfo; S. J. Thoren

1982-05-01T23:59:59.000Z

378

Improving the Numerical Solution of Soil Moisture–Based Richards Equation for Land Models with a Deep or Shallow Water Table  

Science Conference Proceedings (OSTI)

The soil moisture–based Richards equation is widely used in land models for weather and climate studies, but its numerical solution using the mass-conservative scheme in the Community Land Model is found to be deficient when the water table is ...

Xubin Zeng; Mark Decker

2009-02-01T23:59:59.000Z

379

Fast Track Analysis of Shale Numerical Models A. Kalantari-Dahaghi ,SPE, S. Esmaili, SPE, West Virginia University, S.D. Mohaghegh, SPE, Intelligent Solution  

E-Print Network (OSTI)

SPE 162699 Fast Track Analysis of Shale Numerical Models A. Kalantari-Dahaghi ,SPE, S. Esmaili, SPE of SPE copyright. Abstract Latest advances in shale gas reservoir simulation and modeling have made it possible to optimize and enhance the production from organic rich shale gas reservoirs. Reservoir simulator

Mohaghegh, Shahab

380

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

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

The deposition and burning characteristics during slagging co-firing coal and wood: modeling and numerical simulation  

SciTech Connect

Numerical analysis was used to study the deposition and burning characteristics of combining co-combustion with slagging combustion technologies in this paper. The pyrolysis and burning kinetic models of different fuels were implanted into the WBSF-PCC2 (wall burning and slag flow in pulverized co-combustion) computation code, and then the slagging and co-combustion characteristics (especially the wall burning mechanism of different solid fuels and their effects on the whole burning behavior in the cylindrical combustor at different mixing ratios under the condition of keeping the heat input same) were simulated numerically. The results showed that adding wood powder at 25% mass fraction can increase the temperature at the initial stage of combustion, which is helpful to utilize the front space of the combustor. Adding wood powder at a 25% mass fraction can increase the reaction rate at the initial combustion stage; also, the coal ignitability is improved, and the burnout efficiency is enhanced by about 5% of suspension and deposition particles, which is helpful for coal particles to burn entirely and for combustion devices to minimize their dimensions or sizes. The results also showed that adding wood powder at a proper ratio is helpful to keep the combustion stability, not only because of the enhancement for the burning characteristics, but also because the running slag layer structure can be changed more continuously, which is very important for avoiding the abnormal slag accumulation in the slagging combustor. The theoretic analysis in this paper proves that unification of co-combustion and slagging combustion technologies is feasible, though more comprehensive and rigorous research is needed.

Wang, X.H.; Zhao, D.Q.; Jiang, L.Q.; Yang, W.B. [Chinese Academy of Sciences, Ghangzhou (China)

2009-07-01T23:59:59.000Z

382

Asymptotic Approximations to the Distributed Activation Energy Model  

E-Print Network (OSTI)

Asymptotic Approximations to the Distributed Activation Energy Model M.J.McGuinness1 , E. Donskoi2 by a continuum distribution in activation energy of individual re- actions. An individual reaction is characterised by a pre-exponential coefficient and an activation energy. The distribution, usually Gaussian

McGuinness, Mark

383

Physics-based activity modelling in phase space  

Science Conference Proceedings (OSTI)

In this paper, we employ ideas grounded in physics to examine activities in video. We build the Multi-Resolution Phase Space (MRPS) descriptor, which is a set of feature descriptors that is able to represent complex activities in multiple domains directly ... Keywords: activity modeling, phase space, physics-based

Ricky J. Sethi; Amit K. Roy-Chowdhury

2010-12-01T23:59:59.000Z

384

Numerical Dispersion of Gravity Waves  

Science Conference Proceedings (OSTI)

When atmospheric gravity waves are simulated in numerical models, they are not only dispersive for physical but also for numerical reasons. Their wave properties (e.g., damping or propagation speed and direction) can depend on grid spacing as ...

Guido Schroeder; K. Heinke Schlünzen

2009-12-01T23:59:59.000Z

385

A QUARTER-CENTURY OF OBSERVATIONS OF COMET 10P/TEMPEL 2 AT LOWELL OBSERVATORY: CONTINUED SPIN-DOWN, COMA MORPHOLOGY, PRODUCTION RATES, AND NUMERICAL MODELING  

Science Conference Proceedings (OSTI)

We report on photometry and imaging of Comet 10P/Tempel 2 obtained at Lowell Observatory from 1983 through 2011. We measured a nucleus rotation period of 8.950 {+-} 0.002 hr from 16 nights of imaging acquired between 2010 September and 2011 January. This rotation period is longer than the period we previously measured in 1999, which was itself longer than the period measured in 1988, and demonstrates that Tempel 2 is continuing to spin down, presumably due to torques caused by asymmetric outgassing. A nearly linear jet was observed which varied little during a rotation cycle in both R and CN images acquired during the 1999 and 2010 apparitions. We measured the projected direction of this jet throughout the two apparitions and, under the assumption that the source region of the jet was near the comet's pole, determined a rotational pole direction of R.A./decl. = 151 Degree-Sign /+59 Degree-Sign from CN measurements and R.A./decl. = 173 Degree-Sign /+57 Degree-Sign from dust measurements (we estimate a circular uncertainty of 3 Degree-Sign for CN and 4 Degree-Sign for dust). Different combinations of effects likely bias both gas and dust solutions and we elected to average these solutions for a final pole direction of R.A./decl. = 162 Degree-Sign {+-} 11 Degree-Sign /+58 Degree-Sign {+-} 1 Degree-Sign . Photoelectric photometry was acquired on 3 nights in 1983, 2 nights in 1988, 19 nights in 1999/2000, and 10 nights in 2010/2011. The activity exhibited a steep 'turn-on' {approx}3 months prior to perihelion (the exact timing of which varies) and a relatively smooth decline after perihelion. The activity during the 1999 and 2010 apparitions was similar; limited data in 1983 and 1988 (along with IUE data from the literature) were systematically higher and the difference cannot be explained entirely by the smaller perihelion distance. We measured a 'typical' composition, in agreement with previous investigators. Monte Carlo numerical modeling with our pole solution best replicated the observed coma morphology for a source region located near a comet latitude of +80 Degree-Sign and having a radius of {approx}10 Degree-Sign . Our model reproduced the seasonal changes in activity, suggesting that the majority of Tempel 2's activity originates from a small active region located near the pole. We also find that a cosine-squared solar angle function gives the best fit as compared to a standard cosine function.

Knight, Matthew M.; Schleicher, David G.; Schwieterman, Edward W.; Christensen, Samantha R. [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Farnham, Tony L., E-mail: knight@lowell.edu [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

2012-11-01T23:59:59.000Z

386

Inner shelf response to cross-shelf wind stress: the importance of the cross-shelf density gradient in an idealized numerical model and field observations  

Science Conference Proceedings (OSTI)

This study investigates the effects of horizontal and vertical density gradients on the inner shelf response to cross-shelf wind stress by using an idealized numerical model and observations from a moored array deployed south of Martha’s Vineyard, ...

Rachel Horwitz; Steven J. Lentz

387

A Numerical Study of a Mesoscale Convective System during TOGA COARE. Part I: Model Description and Verification  

Science Conference Proceedings (OSTI)

A 16-h numerical simulation of the growing and mature stages of the 15 December 1992 Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) mesoscale convective system (MCS) is performed to demonstrate the ...

Badrinath Nagarajan; M. K. Yau; Da-Lin Zhang

2001-10-01T23:59:59.000Z

388

Modeling near-field radiative heat transfer from sharp objects using a general three-dimensional numerical scattering technique  

E-Print Network (OSTI)

We develop a general numerical method to calculate the nonequilibrium radiative heat transfer between a plate and compact objects of arbitrary shapes, making the first accurate theoretical predictions for the total heat ...

McCauley, Alexander Patrick

389

Numerical modeling of self-limiting and self-enhancing caprock alteration induced by CO2 storage in a depleted gas reservoir  

Science Conference Proceedings (OSTI)

This paper presents numerical simulations of reactive transport which may be induced in the caprock of an on-shore depleted gas reservoir by the geological sequestration of carbon dioxide. The objective is to verify that CO{sub 2} geological disposal activities currently being planned for the study area are safe and do not induce any undesired environmental impact. In our model, fluid flow and mineral alteration are induced in the caprock by penetration of high CO{sub 2} concentrations from the underlying reservoir, where it was assumed that large amounts of CO{sub 2} have already been injected at depth. The main focus is on the potential effect of precipitation and dissolution processes on the sealing efficiency of caprock formations. Concerns that some leakage may occur in the investigated system arise because the seal is made up of potentially highly-reactive rocks, consisting of carbonate-rich shales (calcite+dolomite averaging up to more than 30% of solid volume fraction). Batch simulations and multi-dimensional 1D and 2D modeling have been used to investigate multicomponent geochemical processes. Numerical simulations account for fracture-matrix interactions, gas phase participation in multiphase fluid flow and geochemical reactions, and kinetics of fluid-rock interactions. The geochemical processes and parameters to which the occurrence of high CO{sub 2} concentrations are most sensitive are investigated by conceptualizing different mass transport mechanisms (i.e. diffusion and mixed advection+diffusion). The most relevant mineralogical transformations occurring in the caprock are described, and the feedback of these geochemical processes on physical properties such as porosity is examined to evaluate how the sealing capacity of the caprock could evolve in time. The simulations demonstrate that the occurrence of some gas leakage from the reservoir may have a strong influence on the geochemical evolution of the caprock. In fact, when a free CO{sub 2}-dominated phase migrates into the caprock through fractures, or through zones with high initial porosity possibly acting as preferential flow paths for reservoir fluids, low pH values are predicted, accompanied by significant calcite dissolution and porosity enhancement. In contrast, when fluid-rock interactions occur under fully liquid-saturated conditions and a diffusion-controlled regime, pH will be buffered at higher values, and some calcite precipitation is predicted which leads to further sealing of the storage reservoir.

Xu, Tianfu; Gherardi, Fabrizio; Xu, Tianfu; Pruess, Karsten

2007-09-07T23:59:59.000Z

390

Nanoflare statistics in an active region 3D MHD coronal model  

E-Print Network (OSTI)

Context. We investigate the statistics of the spatial and temporal distribution of the coronal heating in a three-dimensional magneto- hydrodynamical (3D MHD) model. The model describes the temporal evolution of the corona above an observed active region. The model is driven by photospheric granular motions which braid the magnetic field lines. This induces currents and their dissipation heats the plasma. We evaluate the transient heating as subsequent heating events and analyze their statistics. The results are then interpreted in the context of observed flare statistics and coronal heating mechanisms. Methods. To conduct the numerical experiment we use a high order finite difference code which solves the partial differential equations for the conservation of mass, the momentum and energy balance, and the induction equation. The energy balance includes the Spitzer heat conduction and the optical thin radiative loss in the corona. Results. The temporal and spatial distribution of the Ohmic heating in the 3D M...

Bingert, Sven

2012-01-01T23:59:59.000Z

391

A Case Study of the 9 August 1988 South Atlantic Storm: Numerical Simulations of the Wave Activity  

Science Conference Proceedings (OSTI)

During 9–11 August 1988, a cyclone developed over Uruguay in the Ice of the Andes Mountains and moved over the South Atlantic Ocean, where it redeveloped into an intense storm. This storm was responsible for unusual wave activity along the ...

Valdir Innocentini; Ernesto Dos Santos Caetano Neto

1996-03-01T23:59:59.000Z

392

Modeling the performance of a two-phase turbine using numerical methods and the results of nozzle, static cascade, and windage experiments  

DOE Green Energy (OSTI)

Performance models for a two-phase turbine were developed to verify the understanding of the loss mechanisms and to extrapolate from the single-nozzle test condition to a full-admission turbine. The numerical models for predicting the performance of the nozzle and the combined nozzle and rotor are described. Results from two-phase, static cascade tests and disk-friction and windage experiments are used to calibrate the performance model(s). Model predictions are compared with single-nozzle prototype-turbine test results, and extrapolations are made to a full-admission design. The modeling also provides predictions of performance for turbines with various blade geometries, inlet conditions, and droplet sizes. Thus the modeling provides insight into design improvements.

Comfort, W.J. III

1978-06-21T23:59:59.000Z

393

Structure of the Atmospheric Boundary Layer in the Vicinity of a Developing Upslope Flow System: A Numerical Model Study  

Science Conference Proceedings (OSTI)

The development of a morning upslope flow is studied by means of idealized numerical simulations. In particular, two cases are examined: a plane slope connecting a lower plain and an elevated plateau and a symmetric mountain in the middle of a ...

Stefano Serafin; Dino Zardi

2010-04-01T23:59:59.000Z

394

Numerical modeling of radiation-dominated and quantum-electrodynamically strong regimes of laser-plasma interaction  

Science Conference Proceedings (OSTI)

Ultra-strong laser pulses can be so intense that an electron in the focused beam loses significant energy due to {gamma}-photon emission while its motion deviates via the radiation back-reaction. Numerical methods and tools designed to simulate radiation-dominated and quantum-electrodynamically strong laser-plasma interactions are summarized here.

Sokolov, Igor V. [Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan 48109 (United States); Naumova, Natalia M. [Laboratoire d'Optique Appliquee, UMR 7639 ENSTA, Ecole Polytechnique, CNRS, 91761 Palaiseau (France); Nees, John A. [Center for Ultrafast Optical Science and FOCUS Center, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-09-15T23:59:59.000Z

395

Numerical Modeling of the Effects of a Thermal Fence on Pollutant Dispersion in the Stable Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Numerical studies were conducted to evaluate the effects of a line of heating-that is, a thermal fence-on the short-range (less than 1 km from the pollutant source) dispersion of pollutants under various stable nighttime conditions. The thermal ...

Youn-Seo Koo; Danny D. Reible

1996-11-01T23:59:59.000Z

396

Double Modelling of the Dynamic of Activities in Rural Municipalities  

E-Print Network (OSTI)

Land use choices and activity prevalence in a selected territory are determined by individual preferences constrained by the characteristic of the analysed zone: population density, soil properties, urbanization level and other similar factors can drive individuals to make different kind of decisions about their occupations. Different approaches can be used to describe land use change, occupation prevalence and their reciprocal inter-relation. In this paper we describe two different kinds of approaches: an agent based model, centred on individual choices and an aggregated model describing the evolution of activity prevalence in terms of coupled differential equation. We use and we compare the two models to analyse the effect of territorial constraints, like the lack of employment in determined sectors, on the possible activity prevalence scenarios.

Ternes, S; Huet, S; Deffuant, G

2009-01-01T23:59:59.000Z

397

Geo topic model: joint modeling of user's activity area and interests for location recommendation  

Science Conference Proceedings (OSTI)

This paper proposes a method that analyzes the location log data of multiple users to recommend locations to be visited. The method uses our new topic model, called Geo Topic Model, that can jointly estimate both the user's interests and activity area ... Keywords: location recommendation, topic model

Takeshi Kurashima; Tomoharu Iwata; Takahide Hoshide; Noriko Takaya; Ko Fujimura

2013-02-01T23:59:59.000Z

398

Numerical Simulations of Air–Sea Interaction under High Wind Conditions Using a Coupled Model: A Study of Hurricane Development  

Science Conference Proceedings (OSTI)

In this study, a coupled atmosphere–ocean wave modeling system is used to simulate air–sea interaction under high wind conditions. This coupled modeling system is made of three well-tested model components: The Pennsylvania State University–...

J-W. Bao; J. M. Wilczak; J-K. Choi; L. H. Kantha

2000-07-01T23:59:59.000Z

399

Numerical Simulation of Dispersal of Inert Seeding Material in Israel Using a Three-Dimensional Mesoscale Model  

Science Conference Proceedings (OSTI)

A mesoscale model RAMS (the Regional Atmospheric Modeling System) was used to investigate the effectiveness of the broadcast static seeding method for dispersing particles into clouds, as it is used in Israel. The model was run using three nested ...

Zev Levin; Shimon O. Krichak; Tamir Reisin

1997-05-01T23:59:59.000Z

400

White Paper on DOE-HEP Accelerator Modeling Science Activities  

E-Print Network (OSTI)

Toward the goal of maximizing the impact of computer modeling on the design of future particle accelerators and the development of new accelerator techniques & technologies, this white paper presents the rationale for: (a) strengthening and expanding programmatic activities in accelerator modeling science within the Department of Energy (DOE) Office of High Energy Physics (HEP) and (b) increasing the community-wide coordination and integration of code development.

Vay, Jean-Luc; Koniges, Alice; Friedman, Alex; Grote, David P; Bruhwiler, David L

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.


401

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

402

Numerical Generation of Entropies  

Science Conference Proceedings (OSTI)

The spurious numerical generation and/or destruction of various types of entropies in models is investigated. It is shown that entropy s? of dry matter tends to be generated if potential temperature is advected by a damping scheme. There is no ...

Joseph Egger

1999-09-01T23:59:59.000Z

403

Downslope Flows on a Low-Angle Slope and Their Interactions with Valley Inversions. Part II: Numerical Modeling  

Science Conference Proceedings (OSTI)

The characteristics of well-developed downslope winds observed by tethered balloon soundings at multiple locations over a low-angle slope in the Salt Lake Valley are studied using the Regional Atmospheric Modeling System (RAMS). The model ...

Shiyuan Zhong; C. David Whiteman

2008-07-01T23:59:59.000Z

404

Revisiting Vacillations in Shallow-Water Models of the Stratosphere Using Potential-Vorticity-Based Numerical Algorithms  

Science Conference Proceedings (OSTI)

Polar vortex vacillations are investigated using long-term simulations of potential-vorticity (PV)-based shallow-water (SW) models for the stratosphere. In the models examined, mechanical forcing is applied through a time-independent topography ...

Seyed Majid MirRokni; Ali R. Mohebalhojeh; David G. Dritschel

2011-05-01T23:59:59.000Z

405

Numerical Simulation Of Gas-Droplet Flow Around A Nozzle In A Cylindrical Chamber Using A Lagrangian Model Based On A Multigrid Navier-Stokes Solver  

E-Print Network (OSTI)

A numerical simulation of an upward directed, 2-- dimensional, turbulent gas--droplet flow around an axisymmetric nozzle in a cylindrical chamber was made. We use a Lagrangian method, where trajectories of many droplets are calculated from the equations of motion along with the continuity and momentum equations of fluid. Strong coupling effects between the two phases are dealt with. Special algorithms were introduced for particle tracking and interpolation of the fluid flow data at the particle location on the numerical grid, which use multigrid structure for improvement of the speed of droplet trajectory calculation. The Lagrangian solver for the calculation of the trajectory and particle momentum source term was parallelised on a workstation cluster using a host--node programming model. The resulting droplet and fluid velocities at different cross sections of the cylindrical chamber are reported and compared with measurements. 2. INTRODUCTION In many engineering flow situations par...

Thomas Frank; Ingvelde Schulze

1994-01-01T23:59:59.000Z

406

High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes  

SciTech Connect

Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.

Lackmann, Gary

2013-06-10T23:59:59.000Z

407

Using Analytical and Numerical Modeling to Assess the Utility of Groundwater Monitoring Parameters at Carbon Capture, Utilization, and Storage Sites  

E-Print Network (OSTI)

://www.gettysburg.edu/academics/physics/clea/CLEAhome.html 4) Inner solar system orbital model http://donald.phast

Texas at Austin, University of

408

Numerical Forecasting of Radiation Fog. Part II: A Comparison of Model Simulation with Several Observed Fog Events  

Science Conference Proceedings (OSTI)

A 1D model adapted for forecasting the formation and development of fog, and forced with mesoscale parameters derived from a 3D limited-area model, was used to simulate three fog event observations made during the Lille 88 campaign. The model ...

Daniel Guedalia; Thierry Bergot

1994-06-01T23:59:59.000Z

409

Integration of numerical modeling and Bayesian analysis for setting water quality criteria in Hamilton Harbour, Ontario, Canada  

Science Conference Proceedings (OSTI)

The credibility of the scientific methodology of mathematical models and their adequacy to form the basis of public policy decisions has frequently been challenged. We believe that the development of novel methods for rigorously assessing model uncertainty ... Keywords: Benthic-pelagic coupling, Ecosystem restoration, Eutrophication modeling, Hamilton Harbour, Phosphorus loading, Risk assessment, Top-down control

Maryam Ramin; Serguei Stremilov; Tanya Labencki; Alexey Gudimov; Duncan Boyd; George B. Arhonditsis

2011-04-01T23:59:59.000Z

410

Actin filament segmentation using spatiotemporal active- surface and active-contour models  

Science Conference Proceedings (OSTI)

We introduce a novel algorithm for actin filament segmentation in a 2D TIRFM image sequence. We treat the 2D time-lapse sequence as a 3D image volume and propose an over-grown active surface model to segment the body of a filament on all slices simultaneously. ...

Hongsheng Li; Tian Shen; Dimitrios Vavylonis; Xiaolei Huang

2010-09-01T23:59:59.000Z

411

Goa, India How far does Surface Heave Propagate? A Discussion on Analytical and Numerical Modeling of the Surface Heave Induced by Subsurface Fluid Injection  

E-Print Network (OSTI)

ABSTRACT: Reservoir dilations occur due to variety of subsurface injection operations including waste disposal, waterflooding, steam injection, CO 2 sequestration and aquifer storage recovery. These reservoir dilations propagate to the surrounding formations and extend up to the ground surface resulting in surface heaves. This paper discusses modelling of the surface heave by applying both analytical and numerical methods. Results of the study demonstrate that the lateral extent of a finite element model has a direct impact on the surface heave profile and if the lateral boundaries are too close to the line of symmetry there will be significant errors in the finite element results. This paper proposes a rapid way of estimating a sufficient lateral extent for the finite element model by using a new chart. The chart contains a family of curves which can be used to estimate the surface heave propagation distance under various injection depths, injection periods and soil properties. 1

Asanga S. Nanayakkara; Ron C. K. Wong

2008-01-01T23:59:59.000Z

412

A high-resolution 2-DH numerical scheme for process-based modeling of 3-D turbidite fan stratigraphy  

Science Conference Proceedings (OSTI)

A generic three-dimensional process-based model is presented, aimed at simulation of the construction of turbidite fan stratigraphy by low-density turbidity current events. It combines theoretical formulations on density flow and sediment transport of ... Keywords: MacCormack scheme, Operator splitting, Shock-capturing technique, Stratigraphic modeling, Turbidite reservoirs, Turbidity currents

Remco M. Groenenberg; Kees Sloff; Gert Jan Weltje

2009-08-01T23:59:59.000Z

413

Macroeconomic Activity Module (Mam) 1998 (Kernel Regression), Model Documentation  

Reports and Publications (EIA)

The Macroeconomic Activity Module (MAM) serves two functions within the National Energy Modeling System (NEMS). First, it provides consistent sets of baselines macroeconomic variables (GDP and components, aggregate prices, interest rates, industrial output, housing starts, commercial floorspace, newcar sales, etc.) which are used by the supply, demand and conversion modules in reaching an energy market equilibrium. Second, it is designed to provide a feedback mechanism that alters the baseline variables during the course of an integrated NEMS run.

Ron Earley

1998-10-01T23:59:59.000Z

414

Numerical modeling of gas migration into and through faulted sand reservoirs in Pabst Field (Main Pass East Block 259), northern Gulf of Mexico  

E-Print Network (OSTI)

The further exploration and development of Pabst Gas Field with faulted sand reservoirs require an understanding of the properties and roles of faults, particularly Low Throw near Vertical Faults (LTNVFs), in gas migration and accumulation at a reservoir scale. This study presents numerical modeling of gas migration and accumulation processes in Pabst Field. Based on studies of the reservoirs, structure, faults, and fluid properties of the field, reservoir scale modeling was performed to determine the gas supply style and the fault properties by means of hundreds of iterations in which the fault properties and gas supply pattern were modified to match the gas distribution obtained from modeling with the gas distribution inferred from seismic data constrained by well data and production data. This study finds that in the main three sand reservoirs of Pabst Field the overlying younger sands cut down into the underlying older sands, so that partial connections between the three sands allow gas communication among the sands. Meanwhile, three fault families break up the three sands into numerous compartments. A primary fault and large synthetic and antithetic faults act as gas migration pathways: the synthetic and antithetic faults are inlets for gas flow and the primary fault is an outlet, and LTNVFs act as barriers to gas flow. Modeling requires fault properties in the field to change while the field is formed. The porosity and permeability of the faults in Pabst Field are 10% and 0.1 md, respectively, during gas charging of the sand reservoirs. But when there is no gas charging and large gas columns are maintained, the porosity and permeability of the faults decrease to 6% and 0.001 md, respectively. Pabst Field probably has an impulse gas charge history. Fault opening and closing, gas charge and recharge, and replacement of gas by formation water may occur. A combination of stratigraphy, structure, overpressure and gas charge rate control gas migration style, gas charge history, and gas distribution in the field. The significance of the study is that this improved numerical approach for modeling gas migration into and through specifically faulted sand reservoirs fills the gap between basin modeling and production modeling.

Li, Yuqian

2005-05-01T23:59:59.000Z

415

Physical and Numerical Contributions to the Structure of Kelvin Wave-CISK Modes in a Spectral Transform Model  

Science Conference Proceedings (OSTI)

“Nonlinear Kelvin wave-CISK modes” are critically assessed as a possible mechanism for the Madden–Julian Oscillation (MJO) with a global spectral transform model and a one-dimensional analog. Convection is parameterized using a simple “positive-...

Adrian J. Matthews; Jason Lander

1999-12-01T23:59:59.000Z

416

An Air–Sea Interaction Theory for Tropical Cyclones. Part II: Evolutionary Study Using a Nonhydrostatic Axisymmetric Numerical Model  

Science Conference Proceedings (OSTI)

In Part I of this study an analytical model for a steady-state tropical cyclone is constructed on the assumption that boundary-layer air parcels are conditionally neutral to displacements along the angular momentum surfaces of the hurricane ...

Richard Rotunno; Kerry A. Emanuel

1987-02-01T23:59:59.000Z

417

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

Science Conference Proceedings (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

418

Modeling the Trade-Wind Cumulus Boundary Layer. Part I: Testing the Ensemble Cloud Relations Against Numerical Data  

Science Conference Proceedings (OSTI)

The possibility of studying the cloudy planetary boundary layer through one-dimensional modeling is investigated. The various possible parameterizations of mean liquid water content and correlations, in term of the known statistical properties of ...

Ph Bougeault

1981-11-01T23:59:59.000Z

419

The Effects of Evaporation, Water Load and Wind Shear on Cloud Development in a Three-Dimensional Numerical Model  

Science Conference Proceedings (OSTI)

Steiner's (1973) three-dimensional cloud model has been updated to incorporate the deep anelastic system of equations and the microphysical parameterization scheme of Kessler (1969) for precipitation growth. The interactions between cloud ...

Man Kong Yau

1980-02-01T23:59:59.000Z

420

An Objective Comparison of Model Output Statistics and “Perfect Prog” Systems in Producing Numerical Weather Element Forecasts  

Science Conference Proceedings (OSTI)

The “perfect prog” (PP) and model output statistics (MOS) approaches were used to develop multiple linear regression equations to forecast probabilities of more than a trace of precipitation over 6-h periods, probabilities of precipitation ...

N. Brunet; R. Verret; N. Yacowar

1988-12-01T23:59:59.000Z

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.


421

The Seasonal Cycle of Meridional Heat Transport in a Numerical Model of the Pacific Equatorial Upwelling Zone  

Science Conference Proceedings (OSTI)

The seasonal heat transport mechanisms important in the Pacific equatorial upwelling zone are investigated using the primitive equation, reduced gravity model developed by Gent and Cane. Mechanisms of meridional heat transport are shown and ...

Esther C. Brady; Peter R. Gent

1994-12-01T23:59:59.000Z

422

An Assessment of the Sea Surface Temperature Influence on Surface Wind Stress in Numerical Weather Prediction and Climate Models  

Science Conference Proceedings (OSTI)

The ability of six climate models to capture the observed coupling between SST and surface wind stress in the vicinity of strong midlatitude SST fronts is analyzed. The analysis emphasizes air–sea interactions associated with ocean meanders in ...

Eric D. Maloney; Dudley B. Chelton

2006-06-01T23:59:59.000Z

423

In-vessel activation monitors in JET: Progress in modeling  

SciTech Connect

Activation studies were performed in JET with new in-vessel activation monitors. Though primarily dedicated to R and D in the challenging issue of lost {alpha} diagnostics for ITER, which is being addressed at JET with several techniques, these monitors provide for both neutron and charged particle fluences. A set of samples with different orientation with respect to the magnetic field is transported inside the torus by means of a manipulator arm (in contrast with the conventional JET activation system with pneumatic transport system). In this case, radionuclides with longer half-life were selected and ultralow background gamma-ray measurements were needed. The irradiation was closer to the plasma and this potentially reduces the neutron scattering problem. This approach could also be of interest for ITER, where the calibration methods have yet to be developed. The MCNP neutron transport model for JET was modified to include the activation probe and so provide calculations to help assess the new data. The neutron induced activity on the samples are well reproduced by the calculations.

Bonheure, Georges [Laboratory for Plasma Physics, Association 'Euratom-Belgian State', Avenue de la Renaissance 30, B-1000 Brussels (Belgium); Lengar, I. [Slovenian Fusion Association, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Syme, B.; Popovichev, S. [Euratom/UKAEA Association, Culham Science Centre, Abingdon, OX14 3DB Oxon (United Kingdom); Wieslander, Elisabeth; Hult, Mikael; Gasparro, Joeel; Marissens, Gerd [EC-JRC-IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Arnold, Dirk [Physikalisch-Technische Bundesanstalt, 6.1 Radioactivity, Bundesallee 100, D-38116 Braunschweig (Germany); Laubenstein, Matthias [Laboratori Nazionali del Gran Sasso, S.S, 17/bis, km 18-910, I-67010 Assergi (Italy)

2008-10-15T23:59:59.000Z

424

Numerical evidence for relevance of disorder in a Poland-Scheraga DNA denaturation model with self-avoidance: Scaling behavior of average quantities  

E-Print Network (OSTI)

We study numerically the effect of sequence heterogeneity on the thermodynamic properties of a Poland-Scheraga model for DNA denaturation taking into account self-avoidance, i.e. with exponent c_p=2.15 for the loop length probability distribution. In complement to previous on-lattice Monte Carlo like studies, we consider here off-lattice numerical calculations for large sequence lengths, relying on efficient algorithmic methods. We investigate finite size effects with the definition of an appropriate intrinsic length scale x, depending on the parameters of the model. Based on the occurrence of large enough rare regions, for a given sequence length N, this study provides a qualitative picture for the finite size behavior, suggesting that the effect of disorder could be sensed only with sequence lengths diverging exponentially with x. We further look in detail at average quantities for the particular case x=1.3, ensuring through this parameter choice the correspondence between the off-lattice and the on-lattice studies. Taken together, the various results can be cast in a coherent picture with a crossover between a nearly pure system like behavior for small sizes N = 2/d (=2).

Barbara Coluzzi; Edouard Yeramian

2006-11-28T23:59:59.000Z

425

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

426

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;

427

Modelling regional input markets with numerous processing plants: The case of green maize for biogas production in Germany  

Science Conference Proceedings (OSTI)

The location of first generation processing plants for biogas using bulky inputs is a prominent example of locational decisions of plants that face high per unit transport costs of feedstock and simultaneously depend to a large extent on feedstock availability. ... Keywords: Biogas, Biomass transportation, Competitive facility location, Modelling, Transport costs

Ruth Delzeit; Wolfgang Britz; Karin Holm-Müller

2012-06-01T23:59:59.000Z

428

Numerical Simulation of an Intense Squall Line during 10–11 June 1985 PRE-STORM. Part I: Model Verification  

Science Conference Proceedings (OSTI)

A 24-h nested-grid simulation of an intense squall line during the 1985 PRE-STORM experiment is presented using an improved version of the Pennsylvania State University/National Center for Atmospheric Research three-dimensional mesoscale model. ...

Da-Lin Zhang; Kun Gao; David B. Parsons

1989-05-01T23:59:59.000Z

429

Segmentation and Tracking of Mesoscale Eddies in Numeric Ocean Models Vishal Sood, Bin John, Ramprasad Balasubramanian and Amit Tandon*  

E-Print Network (OSTI)

, Ramprasad Balasubramanian and Amit Tandon* Department of Computer and Information Science. Tandon and V. Shah Visualization methods for heat transport in Miami Isopycnic Circulation Ocean Model (MICOM). IASTED CGIM. Hawaii, USA. 281-286, August 2002. [2] R. Balasubramanian, A. Tandon, B. John and V

Tandon, Amit

430

Numerical Prediction of the 10–11 June 1985 Squall Line with the Canadian Regional Finite-Element Model  

Science Conference Proceedings (OSTI)

In an effort to improve operational forecasts of mesoscale convective systems (MCSs), a mesoscale version of the operational Canadian Regional Finite-Element (RFE) Model with a grid size of 25 km is used to predict an intense MCS that occurred ...

Stéphane Bélair; Da-Lin Zhang; Jocelyn Mailhot

1994-06-01T23:59:59.000Z

431

The Choice of a Vertical Grid for a 2.5D Numerical Model of the Middle Atmosphere  

Science Conference Proceedings (OSTI)

The consequences of choosing an unstaggered grid (UG), Charney-Phillips-type grid (CPG), or Lorenz-type grid (LG) in the vertical for a 2.5D model are examined. Analytical solutions for the linearized and scaled eddy equations in spherical ...

Joseph L. Sabutis

1994-12-01T23:59:59.000Z

432

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)

The hypoxic area in the Gulf of Mexico is the second largest in the world, which has received extensive scientific study and management interest. Previous modeling studies have concluded that the increased hypoxic area in the Gulf of Mexico was caused by the increased anthropogenic nitrogen loading of the Mississippi River; however, the nitrogen-area relationship is complicated by many other factors, such as wind, river discharge, and the ratio of Mississippi to Atchafalaya River flow. These factors are related to large-scale climate variability, and thus will not be affected by regional nitrogen reduction efforts. In the research presented here, both statistical (regression) and numerical models are used to study the influence of anthropogenic and climate factors on the hypoxic area variability in the Gulf of Mexico. The numerical model is a three-dimensional, coupled hydrological-biogeochemical model (ROMS-Fennel). Results include: (1) the west wind duration during the summer explain 55% of the hypoxic area variability since 1993. Combined wind duration and nitrogen loading explain over 70% of the variability, and combined wind duration and river discharge explain over 85% of the variability. (2) The numerical model captures the temporal variability, but overestimates the bottom oxygen concentrations. The model shows that the simulated hypoxic area is in agreement with the observations from the year 1991, as long as hypoxia is defined as oxygen concentrations below 3 mg/L rather than below 2 mg/L. (3) The first three modes from an Empirical Orthogonal Function (EOF) analysis of the numerical model output results explain 62%, 8.1% and 4.9% of the variability of the hypoxic area. The Principle Component time series is cross-correlated with wind, dissolved inorganic nitrogen concentration and river discharge. (4) Scenario experiments with the same nitrogen loading, but different duration of upwelling favorable wind, indicate that the upwelling favorable wind is important for hypoxic area development. However, a long duration of upwelling wind decreases the area. (5) Scenario experiments with the same nitrogen loading, but different discharges, indicate that increasing river discharge by 50% increases the area by 42%. Additionally, scenario experiments with the same river discharge, but different nitrogen concentrations, indicate that reducing the nitrogen concentration by 50% decreases the area by 75%. (6) Scenario experiments with the same nitrogen loading, but different flow diver- sions, indicate that if the Atchafalaya River discharges increased to 66.7%, the total hypoxic area increases the hypoxic area by 30%, and most of the hypoxic area moved from east to west Louisiana shelf. Additionally, if the Atchafalaya River discharge decreased to zero, the total hypoxic area increases by 13%. (7) Scenario experiments with the same nitrogen loading, but different nitrogen forms, indicate that if all the nitrogen was in the inorganic forms, the hypoxic area increases by 15%. These results have multiple implications for understanding the mechanisms that control the oxygen dynamics, reevaluating management strategies, and improving the observational methods.

Feng, Yang

2012-05-01T23:59:59.000Z

433

Numerical Simulation of Macrosegregation Formation during ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

434

Numerical Characteriztion of the Fracture Behavior of Solid Oxide Fuel Cell Materials by Means of Modified Boundary Layer Modeling  

Science Conference Proceedings (OSTI)

A modified boundary layer modeling approach is used to predict the fracture toughness and crack resistance behaviors of solid oxide fuel cell (SOFC) materials. In this approach, a pre-existing crack inside a layer or at an interface between two different layers is assumed under plane strain conditions. Fracture is allowed to occur in a small process window situated at the crack tip. The process window is contained in a circular region, which can involve two different materials and their interface. Elastic asymptotic crack-tip fields are prescribed as remote boundary conditions. Special attention focuses on the cracking of the interface between the glass seal and the electrolyte material.

Nguyen, Ba Nghiep; Koeppel, Brian J.; Singh, Prabhakar; Khaleel, Mohammad A.; Ahzi, Said

2004-01-01T23:59:59.000Z

435

An analytical and numerical model to determine stresses in a Rock Melt Drill produced glass liner for potential use on Mars  

E-Print Network (OSTI)

A numerical and analytical model was constructed to determine the resultant stress state imposed on a Rock Melt Drill produced liner. The purpose of this study was to determine if the liner produced would possess the strength required to prevent a failure in the borehole wall. Derivation of energy, mass and momentum conservation equations was performed to aid in the identification of applicable loads acting on the melted material that will form the liner. A finite difference model was coded to produce a temperature profile in the liner thickness. An analytical stress model, using the results of the derived equations and the numerical thermal model, was constructed to determine the magnitude of the stresses the liner is subjected to after operation of the Rock Melt Drill. By using values from the Rock Melt Drill design and formation material properties taken from the literature, from experiment and through calculations, a baseline resultant stress was able to be determined for the liner. Utilizing the thermal and stress model, a parametric analysis of the stresses and temperature profile was conducted over a range of Rock Melt Drill operational parameters and formation material property parameters. This parametric analysis was conducted to determine trends between the above parameters and the resultant temperature and stress profiles. It was determined that the liner would have enough strength to prevent failure by collapse up to the required depths of 5 km, under ideal conditions. Additional loads applied to the liner in the form of an increase pressure gradient or formation fluid load may be enough to cause collapse of the liner. Also, the resultant tensile stress in the liner at shallow depths is great enough to cause crack propagation near the surface. It is a conclusion of this study that the Rock Melt Drill may be a potentially viable drilling system for use on Mars, in terms of preventing borehole collapse. Further study is necessary to determine the state of the liner in more realistic conditions, such as including pressurized fluids in the models, and additional work is needed to optimize the Rock Melt Drill system.

McConnell, Joshua B

2000-01-01T23:59:59.000Z

436

A CRITICAL ASSESSMENT OF NONLINEAR FORCE-FREE FIELD MODELING OF THE SOLAR CORONA FOR ACTIVE REGION 10953  

Science Conference Proceedings (OSTI)

Nonlinear force-free field (NLFFF) models are thought to be viable tools for investigating the structure, dynamics, and evolution of the coronae of solar active regions. In a series of NLFFF modeling studies, we have found that NLFFF models are successful in application to analytic test cases, and relatively successful when applied to numerically constructed Sun-like test cases, but they are less successful in application to real solar data. Different NLFFF models have been found to have markedly different field line configurations and to provide widely varying estimates of the magnetic free energy in the coronal volume, when applied to solar data. NLFFF models require consistent, force-free vector magnetic boundary data. However, vector magnetogram observations sampling the photosphere, which is dynamic and contains significant Lorentz and buoyancy forces, do not satisfy this requirement, thus creating several major problems for force-free coronal modeling efforts. In this paper, we discuss NLFFF modeling of NOAA Active Region 10953 using Hinode/SOT-SP, Hinode/XRT, STEREO/SECCHI-EUVI, and SOHO/MDI observations, and in the process illustrate three such issues we judge to be critical to the success of NLFFF modeling: (1) vector magnetic field data covering larger areas are needed so that more electric currents associated with the full active regions of interest are measured, (2) the modeling algorithms need a way to accommodate the various uncertainties in the boundary data, and (3) a more realistic physical model is needed to approximate the photosphere-to-corona interface in order to better transform the forced photospheric magnetograms into adequate approximations of nearly force-free fields at the base of the corona. We make recommendations for future modeling efforts to overcome these as yet unsolved problems.

DeRosa, Marc L.; Schrijver, Carolus J.; Aschwanden, Markus J.; Cheung, Mark C. M. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover St. B/252, Palo Alto, CA 94304 (United States); Barnes, Graham; Leka, K. D. [North West Research Associates, Colorado Research Associates Division, 3380 Mitchell Ln., Boulder, CO 80301 (United States); Lites, Bruce W. [High Altitude Observatory, National Center for Atmospheric Research , P.O. Box 3000, Boulder, CO 80307 (United States); Amari, Tahar; Canou, Aurelien [CNRS, Centre de Physique Theorique de l'Ecole Polytechnique, 91128 Palaiseau Cedex (France); McTiernan, James M. [Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Regnier, Stephane [Mathematics Institute, University of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); Thalmann, Julia K.; Wiegelmann, Thomas; Inhester, Bernd; Tadesse, Tilaye [Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany); Valori, Gherardo [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam (Germany); Wheatland, Michael S. [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Conlon, Paul A. [Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Fuhrmann, Marcel [Institut fuer Physik, Universitaet Potsdam, Am Neuen Palais 10, 14469 Potsdam (Germany)

2009-05-10T23:59:59.000Z

437

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 density are varied. We further highlight a parameter regime where vortices form exhibiting collective rotation of all filaments, but have a finite life-time before contracting to a semi-aster. Quantifying the distribution of life-times suggests this contraction is a Poisson process. Equivalent systems with fixed volume exhibit persistent vortices with stochastic switching in the direction of rotation, with switching times obeying similar statistics to contraction times in pressurised systems. Furthermore, we show that increasing the detachment rate of motors from filament plus-ends can both destroy vortices and turn some asters into vortices. Based on our findings we argue the need for a deeper understanding of the microscopic activities underpinning macroscopic self-organization in active gels and urge further experiments to help bridge these lengths.

David A. Head; W. J. Briels; Gerhard Gompper

2011-07-22T23:59:59.000Z

438

Modeling spatial variability of 137Cs surface activity in a mountain zone  

Science Conference Proceedings (OSTI)

Based on 137Cs surface activity field studies performed on a workshop zone, we succeeded in identifying the main criterion permitting surface activity modeling to be extended. Geomorphometric data derived from the Digital Elevation Model (slope, ...

J. M. Métivier; L. Pourcelot

2002-01-01T23:59:59.000Z

439

Preliminary numerical modeling for the G-Tunnel welded tuff mining experiment; Yucca Mountain site characterization project  

Science Conference Proceedings (OSTI)

Yucca Mountain, located in Southern Nevada, is to be considered as a potential site for a nuclear waste repository. Located in Rainier Mesa on the Nevada Test Site, G-Tunnel has been the site of a series of experiments, part of whose purpose is to evaluate measurement techniques for rock mechanics before testing in the Exploratory Shaft. Rainier Mesa is composed of welded and nonwelded tuffs that have thermal and mechanical properties and stress states similar to those of tuffs expected to be encountered at Yucca Mountain. A series of finite element calculations were performed to aid in designing instrumentation for the experiments in G-Tunnel and later to correlate with measured data. In this report are presented the results of the preliminary finite element calculations performed in conjunction with experimental measurements of drift convergence, or closure, and rock mass relaxation zones made before, during, and after completing the welded tuff mining experiment in G-Tunnel. Tape extensometer measurements of drift convergences and measurements determined by multiple point borehole extensometers are compared with corresponding calculated values using linear elastic and jointed rock material models. 9 refs., 25 figs., 7 tabs.

Johnson, R.L.; Bauer, S.J.

1991-09-01T23:59:59.000Z

440

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

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

Numerical Simulation of Electro-magnetic Turbulent Inhibitor ...  

Science Conference Proceedings (OSTI)

Numerical Modeling of Centrifugally Cast HSS Rolls · Numerical Simulation of Electro-magnetic Turbulent Inhibitor Technology in a Tundish · Optimizing the ...

442

Thermal Effects of Urban Canyon Structure on the Nocturnal Heat Island: Numerical Experiment Using a Mesoscale Model Coupled with an Urban Canopy Model  

Science Conference Proceedings (OSTI)

A single-layer urban canopy model is incorporated into a simple two-dimensional atmospheric model in order to examine the individual impacts of anthropogenic heating, a large heat capacity, and a small sky-view factor on mesoscale heat island ...

Hiroyuki Kusaka; Fujio Kimura

2004-12-01T23:59:59.000Z

443

-1 -Conservation Activity Conceptual Models June 2008.doc CCF Measures of Conservation Success  

E-Print Network (OSTI)

- 1 -Conservation Activity Conceptual Models June 2008.doc CCF Measures of Conservation Success Conservation Activity Conceptual Models These models are flowchart-style representations of the generic processes by which different types of conservation activity can lead to conservation effects. The components

Foster, William A.

444

Robust 3D Face Tracking on Unknown Users with Dynamical Active Models  

Science Conference Proceedings (OSTI)

The Active Appearance Models [1] and the derived Active Models (AM) [4] allow to robustly track the face of a single user that was previously learnt, but works poorly with multiple or unknown users. Our research aims at improving the tracking robustness ... Keywords: Active Appearance Models, Face Animation, Face Tracking, Virtual Reality

Dianle Zhou; Patrick Horain

2009-01-01T23:59:59.000Z

445

Global and regional aspects of tropical cyclone activity in the CMIP5 models  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) activity is analyzed in 14 Coupled Model Intercomparison Project phase 5 (CMIP5) models. The global TC activity in the historical runs is compared with observations. The simulation of TC activity in the CMIP5 models is not as ...

Suzana J. Camargo

446

Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area  

SciTech Connect

To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.

Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.

2012-03-19T23:59:59.000Z

447

Numerical investigation of the pulsed NF3 + H2 chemical laser using a model which includes rotational relaxation and semi-classical laser equations  

DOE Green Energy (OSTI)

Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF$sub 3$ + H$sub 2$ chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth)

Creighton, J.R.

1975-09-01T23:59:59.000Z

448

Numerical investigation of the pulsed NF3 + H2 chemical laser using a model which includes rotational relaxation and semi-classical laser equations  

SciTech Connect

Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF$sub 3$ + H$sub 2$ chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium is assumed: simultaneous lasing on many transitions, cascade behavior, spikes due to laser relaxation oscillations, non-Boltzmann rotational distributions, and ''hole burning'' in the population distributions. The calculations give insight into the physical phenomena governing the shape and duration of the waveforms. The effect of varying certain parameters, relaxation rates, temperature, pressure, and diluents, is studied. Best fit to experimental waveforms is obtained when the rotational relaxation rate and collisional line broadening rate are approximately equal at about 10 times the hard sphere collision rate. The IXION computer code, developed for these calculations, is described in detail. In addition, an analytic model is presented which accounts for major features of the total (all transitions) output waveform of the laser assuming rotational equilibrium, a steady state laser model, and constant temperature. A second computer code, MINOTAR, was developed as a general purpose chemical kinetics code. It verifies the analytic model and extends the results to adiabatic reactions where the temperature varies, and can yield waveforms using the assumptions of rotational equilibrium and a steady state laser. The MINOTAR code, being general, can also be used for chemical kinetics problems such as air pollution and combustion. (auth)

Creighton, J.R.

1975-09-01T23:59:59.000Z

449

A Comparative Verification of Localized Aviation Model Output Statistics Program (LAMP) and Numerical Weather Prediction (NWP) Model Forecasts of Ceiling Height and Visibility  

Science Conference Proceedings (OSTI)

In an effort to support aviation forecasting, the National Weather Service’s Meteorological Development Laboratory (MDL) has recently redeveloped the Localized Aviation Model Output Statistics (MOS) Program (LAMP) system. LAMP is designed to run ...

David E. Rudack; Judy E. Ghirardelli

2010-08-01T23:59:59.000Z

450

On Intermediate Models for Barotropic Continental Shelf and Slope Flow Fields. Part II: Comparison of Numerical Model Solutions in Doubly Periodic Domains  

Science Conference Proceedings (OSTI)

As part of a program to improve understanding of the dynamics of the complicated, vigorous eddy and jet flow fields recently observed over the continental shelf and slope, we investigate the potential of intermediate models for use in both ...

J. A. Barth; J. S. Allen; P. A. Newberger

1990-07-01T23:59:59.000Z

451

Model Documentation Report: Macroeconomic Activity Module (MAM) of ...  

U.S. Energy Information Administration (EIA)

3. IHS Global Insight’s Industrial Output and Employment by Industry Models Industrial Output Model Overview ...

452

Aerosol–Cloud Interactions in a Mesoscale Model. Part I: Sensitivity to Activation and Collision–Coalescence  

Science Conference Proceedings (OSTI)

High-resolution numerical simulations of the aerosol–cloud feedbacks are performed with a mesoscale model. The multimodal aerosol species, added to the model, and the cloud species were represented by two spectral moments. The aerosol sources ...

Irena T. Ivanova; Henry G. Leighton

2008-02-01T23:59:59.000Z

453

Application of Transilient Turbulence Theory to Mesoscale Numerical Weather Forecasting  

Science Conference Proceedings (OSTI)

In this study we show that a unified turbulence parameterization, when divorced from the smoothing procedures needed for numerical stability of the host model, can be implemented in a numerical weather prediction model. Our host model is the 15-...

William H. Raymond; Roland B. Stull

1990-12-01T23:59:59.000Z

454

A workflow for handling heterogeneous 3D models with the TOUGH2 family of codes: Applications to numerical modeling of CO2 geological storage  

Science Conference Proceedings (OSTI)

This paper is addressed to the TOUGH2 user community. It presents a new tool for handling simulations run with the TOUGH2 code with specific application to CO"2 geological storage. This tool is composed of separate FORTRAN subroutines (or modules) that ... Keywords: 3D visualization, CO2 geological storage, Multiphase flow, Pre and post processing, Reactive transport modeling, TOUGH2

Pascal Audigane; Christophe Chiaberge; Frédéric Mathurin; Julie Lions; Géraldine Picot-Colbeaux

2011-04-01T23:59:59.000Z

455

Numerical overcooling in shocks  

E-Print Network (OSTI)

We present a study of cooling in radiative shocks simulated with smoothed particle hydrodynamics (SPH) and adaptive mesh refinement codes. We obtain a similarity solution for a shock-tube problem in the presence of radiative cooling, and test how well the solution is reproduced in Gadget and Flash. Shock broadening governed by the details of the numerical scheme (artificial viscosity or Riemann solvers) leads to potentially significant overcooling in both codes. We interpret our findings in terms of a resolution criterion, and apply it to realistic simulations of cosmological accretion shocks onto galaxy haloes, cold accretion and thermal feedback from supernovae or active galactic nuclei. To avoid numerical overcooling of accretion shocks onto haloes that should develop a hot corona requires a particle or cell mass resolution of 10^6 M_sun, which is within reach of current state-of-the-art simulations. At this mass resolution, thermal feedback in the interstellar medium of a galaxy requires temperatures of s...

Creasey, Peter; Bower, Richard G; Lacey, Cedric G

2011-01-01T23:59:59.000Z

456

Computational modeling and design of actively-cooled microvascular materials Soheil Soghrati a,b  

E-Print Network (OSTI)

were used for the calibration and validation of the 2D IGFEM model. Water was used as the coolantComputational modeling and design of actively-cooled microvascular materials Soheil Soghrati a a c t The computational modeling and design of an actively-cooled microvascular fin specimen

Braun, Paul

457

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

458

Modeling Seasonal Tropical Cyclone Activity in the Fiji Region as a Binary Classification Problem  

Science Conference Proceedings (OSTI)

This study presents a binary classification model for the prediction of tropical cyclone (TC) activity in the Fiji, Samoa, and Tonga regions (the FST region) using the accumulated cyclone energy (ACE) as a proxy of TC activity. A probit regression ...

Savin S. Chand; Kevin J. E. Walsh

2012-07-01T23:59:59.000Z

459

Statistical Significance Testing in Numerical Weather Prediction  

Science Conference Proceedings (OSTI)

Experiments are often performed with numerical forecast models to determine the response to a changed model formulation, initial conditions or boundary conditions. Such experiments are inherently subject to sampling error and it is not always ...

Roger Daley; Robert M. Chervin

1985-05-01T23:59:59.000Z

460

Java and Numerical Computing  

Science Conference Proceedings (OSTI)

Java represents both a challenge and an opportunity to practitioners of numerical computing. This article analyzes the current state of Java in numerical computing and identifies some directions for the realization of its full potential.

Ronald F. Boisvert; José Moreira; Michael Philippsen; Roldan Pozo

2001-01-01T23:59:59.000Z

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.


461

Unsupervised Activity Perception in Crowded and Complicated Scenes Using Hierarchical Bayesian Models  

E-Print Network (OSTI)

We propose a novel unsupervised learning framework to model activities and interactions in crowded and complicated scenes. Hierarchical Bayesian models are used to connect three elements in visual surveillance: low-level ...

Wang, Xiaogang

462

Storm-Track Activity in IPCC AR4/CMIP3 Model Simulations  

Science Conference Proceedings (OSTI)

The climatological storm-track activity simulated by 17 Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4)/phase 3 of the Coupled Model Intercomparison Project (CMIP3) models is compared to that in the interim ECMWF Re-...

Edmund K. M. Chang; Yanjuan Guo; Xiaoming Xia; Minghua Zheng

2013-01-01T23:59:59.000Z

463

Modeling the electrical field created by mass neural activity  

Science Conference Proceedings (OSTI)

Gamma oscillations of large scale electrical activity are used in electrophysiological studies as markers for neural activity and functional processes in the cortex, yet the nature of this mass neural phenomenon and its relation to the evoked response ... Keywords: ECoG, ERD, Gamma oscillations, Simulation

Eran Privman; Rafael Malach; Yehezkel Yeshurun

2013-04-01T23:59:59.000Z

464

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

Science Conference Proceedings (OSTI)

Mobile Doppler radar data, along with observations from a nearby Weather Surveillance Radar-1988 Doppler (WSR-88D), are assimilated with an ensemble Kalman filter (EnKF) technique into a nonhydrostatic, compressible numerical weather prediction ...

Robin L. Tanamachi; Louis J. Wicker; David C. Dowell; Howard B. Bluestein; Daniel T. Dawson II; Ming Xue

2013-02-01T23:59:59.000Z

465

Evaluation of the Soil Model of the Hydro–Thermodynamic Soil–Vegetation Scheme by Observations and a Theoretically Advanced Numerical Scheme  

Science Conference Proceedings (OSTI)

The soil module of the Hydro–Thermodynamic Soil–Vegetation Scheme is evaluated by soil temperature observations and independent theoretical numerical results. To gain the latter, a Galerkin weak finite-element (GWFE) scheme is implemented for ...

Balachandrudu Narapusetty; Nicole Mölders

2006-10-01T23:59:59.000Z

466

Using the Learning Design Language to model activities supported by services  

Science Conference Proceedings (OSTI)

The main objective of the field of Learning Design (LD) is to provide teachers and instructional designers with the conceptual and technological means to create and manage e-learning activities. This paper addresses a paradox in existing ... Keywords: CSCL, LDL, MDE, computer-supported collaborative learning, e-learning, educational technologies, electronic learning, learning activities modelling, learning design language, learning technology, model driven architecture, model driven engineering, online learning, services modelling

Christian Martel; Laurence Vignollet

2008-07-01T23:59:59.000Z

467

Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation  

Science Conference Proceedings (OSTI)

Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub 2} are sequestered by ankerite, dawsonite, and lesser siderite. The CO{sub 2} mineral-trapping capacity of the formation can attain 40-50 kg/m{sup 3} medium for the selected arkose. In contrast, secondary sulfates precipitate at lower pH (pH simulations.

Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

2004-09-07T23:59:59.000Z

468

Model Documentation Report: Macroeconomic Activity Module (MAM) of ...  

U.S. Energy Information Administration (EIA)

facilitates continuity in model development by providing documentation from which energy analysts can ... Business spending includes nine fixed investment categories for

469

IAEA Activities on Modelling and Accelerated Irradiation Testing of ...  

Science Conference Proceedings (OSTI)

... Materials Evaluation for Nuclear Application Utilizing Test Reactors, Ion Beam ... and a CRP on accelerator simulation and theoretical modelling of radiation ...

470

Final Report: Performance Modeling Activities in PERC2  

Science Conference Proceedings (OSTI)

Progress in Performance Modeling for PERC2 resulted in: • Automated modeling tools that are robust, able to characterize large applications running at scale while simultaneously simulating the memory hierarchies of mul-tiple machines in parallel. • Porting of the requisite tracer tools to multiple platforms. • Improved performance models by using higher resolution memory models that ever before. • Adding control-flow and data dependency analysis to the tracers used in perform-ance tools. • Exploring and developing several new modeling methodologies. • Using modeling tools to develop performance models for strategic codes. • Application of modeling methodology to make a large number of “blind” per-formance predictions on certain mission partner applications, targeting most cur-rently available system architectures. • Error analysis to correct some systematic biases encountered as part of the large-scale blind prediction exercises. • Addition of instrumentation capabilities for communication libraries other than MPI. • Dissemination the tools and modeling methods to several mission partners, in-cluding DoD HPCMO and two DARPA HPCS vendors (Cray and IBM), as well as to the wider HPC community via a series of tutorials.

Allan Snavely

2007-02-25T23:59:59.000Z

471

Modeling effects of microstructure for electrically active materials  

E-Print Network (OSTI)

A theoretical framework is proposed for the description of multifunctional material properties. The focus of this theory is on deriving equilibrium and kinetic equations for electrically active materials, particularly for ...

García Muńoz, Ramiro Edwin, 1972-

2003-01-01T23:59:59.000Z

472

Computational aspects in numerical simulation of skin tissues  

Science Conference Proceedings (OSTI)

The aim of this paper is to present some computational aspects in numerical simulation of the human skin tissue. A multi-layered model is considered for the skin tissue with emphasis on the mathematical modelling and numerical models in space 2D and ... Keywords: biothermomechanics, coupled problems, finite element method, numerical methods, skin tissue, thermal systems

Iulia Maria Cârstea; Ion Cârstea

2010-04-01T23:59:59.000Z

473

A Distributed Active Information Model Enabling Distributed Autonomics in Complex Electronic Enviornments  

Science Conference Proceedings (OSTI)

Information modeling plays a central role in managing complexity of the distributed electronic systems. This paper proposes a nature-inspired distributed active information model (DAIM) to enable the local decision-making process, that will fundamentally ... Keywords: Distributed Information Model, Object-oriented, XML

Robin Braun; Frank Chiang

2008-11-01T23:59:59.000Z

474

A High-Resolution Modeling Study of the 24 May 2002 Dryline Case during IHOP. Part I: Numerical Simulation and General Evolution of the Dryline and Convection  

Science Conference Proceedings (OSTI)

Results from a high-resolution numerical simulation of the 24 May 2002 dryline convective initiation (CI) case are presented. The simulation uses a 400 km × 700 km domain with a 1-km horizontal resolution grid nested inside a 3-km domain and ...

Ming Xue; William J. Martin

2006-01-01T23:59:59.000Z

475

A Summertime Antarctic Mesocyclone Event over the Southern Pacific during FROST SOP-3: A Mesoscale Analysis Using AVHRR, SSM/I, ERS, and Numerical Model Data  

Science Conference Proceedings (OSTI)

The development of three summertime mesoscale cyclones (MCs) over the northern Amundsen and Bellingshausen Seas from 10 to 12 January 1995 (during FROST SOP-3) is studied by means of AVHRR data, ERS and SSM/I retrievals, and mesoscale numerical ...

Michael Lieder; Günther Heinemann

1999-12-01T23:59:59.000Z

476

The Numerical Simulation of Clouds, Rains and Airflow over the Vosges and Black Forest Mountains: A Meso-? Model with Parameterized Microphysics  

Science Conference Proceedings (OSTI)

A three-dimensional meso-? model with parameterized microphysics is presented. The model is capable of simulating orographically forced clouds, rain, and airflow. Tests using a two-dimensional version confirm the ability of the model to replicate ...

Everett C. Nickerson; Evelyne Richard; Robert Rosset; David R. Smith

1986-02-01T23:59:59.000Z

477

Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation  

SciTech Connect

Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub 2} are sequestered by ankerite, dawsonite, and lesser siderite. The CO{sub 2} mineral-trapping capacity of the formation can attain 40-50 kg/m{sup 3} medium for the selected arkose. In contrast, secondary sulfates precipitate at lower pH (pH < 5) within the acidified zone. Most of the injected SO{sub 2} is transformed and immobilized through alunite precipitation with lesser amounts of anhydrite and minor quantities of pyrite. The dissolved CO{sub 2} increases with time (enhanced solubility trapping). The mineral alteration induced by injection of CO{sub 2} with either SO{sub 2} or H{sub 2}S leads to corresponding changes in porosity. Significant increases in porosity occur in the acidified zones where mineral dissolution dominates. With co-injection of SO{sub 2}, the porosity increases from an initial 0.3 to 0.43 after 100 years. However, within the CO{sub 2} mineral-trapping zone, the porosity decreases to about 0.28 for both cases, because of the addition of CO{sub 2} mass as secondary carbonates to the rock matrix. Precipitation of sulfates at the acidification front causes porosity to decrease to 0.23. The limited information currently available on the mineralogy of naturally occurring high-pressure CO{sub 2} reservoirs is generally consistent with our simulations.

Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

2004-09-07T23:59:59.000Z

478

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

479

Numerical Simulations of Hurricane-Generated Currents  

Science Conference Proceedings (OSTI)

The work described here involves the application of a three-dimensional numerical circulation model to the hindcasting of currents generated during two storms—Tropical Storm Delia and Hurricane Anita. Reasonably high-quality current and other ...

Cortis Cooper; Bryan Pearce

1982-10-01T23:59:59.000Z

480

Numerical Simulation of Sudden Stratospheric Warmings  

Science Conference Proceedings (OSTI)

A mechanistic, quasi-geostrophic, semi-spectral model with a self-consistent calculation of the mean zonal flow fields is used to numerically simulate sudden stratospheric warmings generated by a single zonal harmonic (m) planetary wave. The ...

Mark R. Schoeberl; Darrell F. Strobel

1980-01-01T23:59:59.000Z

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

Numerical Transform Inversion Using Gaussian Quadrature  

Science Conference Proceedings (OSTI)

Numerical inversion of Laplace transforms is a powerful tool in computational probability. It greatly enhances the applicability of stochastic models in many fields. In this article we present a simple Laplace transform inversion algorithm that can compute ...

Peter Den Iseger

2006-01-01T23:59:59.000Z

482

Thunderstorm Electrification—A Numerical Study  

Science Conference Proceedings (OSTI)

The results of a numerical model of thunderstorm electrification that includes riming electrification compare favorably with many cloud observations. A strong electric charge accumulates through two major stages in the cloud: Stage 1 occurs near ...

Tsutomu Takahashi

1984-09-01T23:59:59.000Z

483

Distributed Numerical Weather Prediction via Satellite  

Science Conference Proceedings (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

484

UTILITY OF MECHANISTIC MODELS FOR DIRECTING ADVANCED SEPARATIONS RESEARCH & DEVELOPMENT ACTIVITIES: Electrochemically Modulated Separation Example  

SciTech Connect

The objective for this work was to demonstrate the utility of mechanistic computer models designed to simulate actinide behavior for use in efficiently and effectively directing advanced laboratory R&D activities associated with developing advanced separations methods.

Schwantes, Jon M.

2009-06-01T23:59:59.000Z

485

Numerical Analysis of Electromagnetic Field in an Electroslag ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

486

Numerical Analysis of the Influence of Melting and Application of ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

487

Boron diffusion and activation in polysilicon multilayer films for P+ MOS structure: Characterization and modeling  

Science Conference Proceedings (OSTI)

This work deals with in situ boron diffusion and activation in multilayer films: polysilicon (Poly1)/amorphous silicon (Poly2). These films are deposited by LPCVD technique. However, several heat treatments were carried in order to determine the optimal ... Keywords: Activation, Diffusion, Model, Polysilicon, SIMS profile

R. Mahamdi; L. Saci; F. Mansour; P. Temple-Boyer; E. Scheid; L. Jalabert

2009-01-01T23:59:59.000Z

488

Arentze, Rasouli and Timmermans 1 Integrating a Multi-Agent Model of Land Development and an Activity-Based Model of  

E-Print Network (OSTI)

on Integrated Travel Demand and Network Supply Modeling, Tampa, USA. Theo Arentze, Soora Rasouli and Harry and an Activity-Based Model of Transport Demand: Progress and Developments1 Theo Arentze, Soora Rasouli and Harry aimed at integrating activity-based models of transport demand and models of land development

Kemner, Ken

489

Numerical Simulation of the Evolution of a Three-Dimensional Field of Cumulus Clouds. Part I: Model Description, Comparison with Observations and Sensitivity Studies  

Science Conference Proceedings (OSTI)

A surface boundary layer model was developed which utilizes the single-level surface mesonet data and the results of a surface energy and moisture budget calculation. The heat and moisture fluxes calculated using this model were employed in the ...

Piotr K. Smolarkiewicz; Terry L. Clark

1985-03-01T23:59:59.000Z

490

Extending Simulation Modeling to Activity-Based Costing for Clinical Procedures  

Science Conference Proceedings (OSTI)

A simulation model was developed to measure costs in an Emergency Department setting for patients presenting with possible cervical-spine injury who needed radiological imaging. Simulation, a tool widely used to account for process variability but typically ... Keywords: activity-based costing, animated simulation modeling

Noah D. Glick; C. Craig Blackmore; William N. Zelman

2000-04-01T23:59:59.000Z

491

Incorporating Anthropogenic Water Regulation Modules into a Land Surface Model  

Science Conference Proceedings (OSTI)

Anthropogenic activities have been significantly perturbing global freshwater flows and groundwater reserves. Despite numerous advances in the development of land surface models (LSMs) and global terrestrial hydrological models (GHMs), relatively ...

Yadu Pokhrel; Naota Hanasaki; Sujan Koirala; Jaeil Cho; Pat J.-F. Yeh; Hyungjun Kim; Shinjiro Kanae; Taikan Oki

2012-02-01T23:59:59.000Z

492

A Numerical Evaluation Of Electromagnetic Methods In Geothermal...  

Open Energy Info (EERE)

GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Evaluation Of Electromagnetic Methods In Geothermal Exploration Details Activities (0) Areas (0) Regions (0) Abstract:...