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1

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

2

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

3

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

4

Model Validation  

Science Conference Proceedings (OSTI)

...thus establishing appropriate and important benchmarks. Benchmarking can go beyond validation and also measure relative computational speed, accuracy, and breadth for available modeling approaches and implementations, providing valuable information for users to discern the best models and for modelers...

5

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

6

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 ...

7

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;

8

Model Validation Bernie Lesieutre  

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

Model Validation Model Validation Bernie Lesieutre University of Wisconsin lesieutre@wisc.edu 27 June 2013 Washington, DC DOE/OE Transmission Reliability Program 2 Project Objectives To Develop techniques and tools for PMU- and feature-based power system model validation. Background: Our prior proof-of-concept research demonstrated that feature-based sensitivity models can be used to calibrate power system dynamic models. This was applied to the WECC composite load model for oscillatory and FIDVR events. 3 Project Objectives PSLF simulation features features Sensitivity Model (parameters) Measured Data Simulated Data Features Error Adjust Parameters Technical Approach 4 Project Objectives Current Research: Use PMU data to calibrate power plant models. Four Tasks:

9

Groundwater Model Validation  

SciTech Connect

Models have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport models, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on models of subsurface conditions require developing confidence in the models through an iterative process. The definition of model validation is postulated as a confidence building and long-term iterative process (Hassan, 2004a). Model validation should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the validation process of stochastic groundwater models. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using validation data to reduce input parameter uncertainty are presented and applied to two case studies. During the validation process for stochastic models, a question arises as to the sufficiency of the number of acceptable model realizations (in terms of conformity with validation data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for validation (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the model or significantly different from the model results. In both cases it is shown how the two measures would lead to the appropriate decision about the model performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating model realizations. The use of validation data to constrain model input parameters is shown for the second case study using a Bayesian approach known as Markov Chain Monte Carlo. The approach shows a great potential to be helpful in the validation process and in incorporating prior knowledge with new field data to derive posterior distributions for both model input and output.

Ahmed E. Hassan

2006-01-24T23:59:59.000Z

10

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

11

Feature extraction for structural dynamics model validation  

SciTech Connect

This study focuses on defining and comparing response features that can be used for structural dynamics model validation studies. Features extracted from dynamic responses obtained analytically or experimentally, such as basic signal statistics, frequency spectra, and estimated time-series models, can be used to compare characteristics of structural system dynamics. By comparing those response features extracted from experimental data and numerical outputs, validation and uncertainty quantification of numerical model containing uncertain parameters can be realized. In this study, the applicability of some response features to model validation is first discussed using measured data from a simple test-bed structure and the associated numerical simulations of these experiments. issues that must be considered were sensitivity, dimensionality, type of response, and presence or absence of measurement noise in the response. Furthermore, we illustrate a comparison method of multivariate feature vectors for statistical model validation. Results show that the outlier detection technique using the Mahalanobis distance metric can be used as an effective and quantifiable technique for selecting appropriate model parameters. However, in this process, one must not only consider the sensitivity of the features being used, but also correlation of the parameters being compared.

Hemez, Francois [Los Alamos National Laboratory; Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Nishio, Mayuko [UNIV OF TOKYO; Worden, Keith [UNIV OF SHEFFIELD; Takeda, Nobuo [UNIV OF TOKYO

2010-11-08T23:59:59.000Z

12

Solar radiation model validation  

Science Conference Proceedings (OSTI)

Several mathematical models have been developed within the past few years which estimate the solar radiation from other weather variables. Some of these models have been used to generate data bases which are extensively used in the design and analysis of solar system. Three of these solar radiation models have been used in developing the Augmented SOLMET Solar Data Tapes for the 26 SOLMET sites and the 222 ERSATZ Solar Data Tapes. One of the models, a theoretical one, predicts the solar noon radiation for clear sky conditions from the optical air mass, precipitable water vapor and turbidity variables. A second model, an empirical one, predicts the hourly total horizontal radiation from meteorological variables. And, a third model, also an empirical one, predicts the hourly direct normal radiation from the hourly total horizontal radiation. A study of the accuracy of these three solar radiation models is reported here. To assess the accuracy of these models, data were obtained from several US National Weather Service Stations and other sources, used the models to estimate the solar-radiation, and then compared the modeled radiation values with observed radiation values. The results of these comparisons and conclusions regarding the accuracy of the models are presented.

Hall, I.J.; Prairie, R.R.; Anderson, H.E.; Boes, E.C.

1980-10-01T23:59:59.000Z

13

Verification and validation of simulation models  

Science Conference Proceedings (OSTI)

In this paper we discuss verification and validation of simulation models. Four different approaches to deciding model validity are described; two different paradigms that relate verification and validation to the model development process are presented; ...

Robert G. Sargent

2009-12-01T23:59:59.000Z

14

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 ...

15

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

16

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

17

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

18

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

19

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

20

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.

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


21

Numerical 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

22

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

23

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

24

Yankee Rowe simulator core model validation  

Science Conference Proceedings (OSTI)

This paper presents the validation of the Yankee Rowe simulator core model. Link-Miles Simulation Corporation is developing the Yankee Rowe simulator and Yankee Atomic Electric Company is involved in input and benchmark data generation, as well as simulator validation. Core model validation by Yankee comprises three tasks: (1) careful generation of fuel reactivity characteristics (B constants); (2) nonintegrated core model testing; and (3) fully integrated core model testing. Simulator core model validation and verification is a multistage process involving input and benchmark data generation as well as interactive debugging. Core characteristics were brought within acceptable criteria by this process. This process was achieved through constant communication between Link-Miles and Yankee engineers. Based on this validation, the Yankee Rowe simulator core model is found to be acceptable for training purposes.

Napolitano, M.E.

1990-01-01T23:59:59.000Z

25

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

26

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

27

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

28

Validation of the Window Model of the Modelica Buildings Library  

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

Validation of the Window Model of the Modelica Buildings Library Title Validation of the Window Model of the Modelica Buildings Library Publication Type Report LBNL Report Number...

29

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

30

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

31

Numerical and experimental validation of heat and mass transfer during heat treatment of wood  

Science Conference Proceedings (OSTI)

In the current work, the three-dimensional Navier-Stokes equations along with the energy and concentration equations for the fluid coupled with the energy and mass conservation equations for the solid (wood) are solved to study the transient heat and ... Keywords: Luikov's model, conjugate problem, heat and mass transfer, high-temperature wood treatment, mathematical modeling, validation

R. Younsi; D. Kocaefe; S. Poncsak; T. Junjun

2007-05-01T23:59:59.000Z

32

Cross Validation of Satellite Radiation Transfer Models during...  

Open Energy Info (EERE)

Cross Validation of Satellite Radiation Transfer Models during SWERA Project in Brazil (Abstract):  This work describes the cross validation between two different...

33

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

34

Microplane constitutive model M4L for concrete. II: Calibration and validation  

Science Conference Proceedings (OSTI)

This paper, Part II of a two-part study, presents the numerical calibration and validation of the microplane constitutive model M4L for concrete formulated in the preceding part. The model parameters are firstly calibrated through optimum fitting of ... Keywords: Concrete, Finite elements, Fracture and damage, Microplane model, Structural analysis

Jiabin Li, Nguyen V. Tue, Ferhun C. Caner

2013-11-01T23:59:59.000Z

35

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"

36

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

37

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

38

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...

39

Empirical Validation of a Transient Computer Model for ...  

Science Conference Proceedings (OSTI)

Page 1. _— EMPIRICAL VALIDATION OF A lRANSIENT COMPUTER MODEL FOR COMBINED HEAT AND MOISTURE TRANSFER ...

1997-09-03T23:59:59.000Z

40

Boron-10 Lined Proportional Counter Model Validation  

SciTech Connect

The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project “Coincidence Counting With Boron-Based Alternative Neutron Detection Technology” at Pacific Northwest National Laboratory (PNNL) for the development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube-based alternative system in the configuration of a coincidence counter. This report discusses the validation studies performed to establish the degree of accuracy of the computer modeling methods current used to simulate the response of boron-lined tubes. This is the precursor to developing models for the uranium neutron coincidence collar under Task 2 of this project.

Lintereur, Azaree T.; Siciliano, Edward R.; Kouzes, Richard T.

2012-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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 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

42

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

43

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

44

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

45

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

46

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

47

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

48

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

Science Conference Proceedings (OSTI)

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

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

2011-12-31T23:59:59.000Z

49

Validation of HEDR models. Hanford Environmental Dose Reconstruction Project  

Science Conference Proceedings (OSTI)

The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computer models for estimating the possible radiation doses that individuals may have received from past Hanford Site operations. This document describes the validation of these models. In the HEDR Project, the model validation exercise consisted of comparing computational model estimates with limited historical field measurements and experimental measurements that are independent of those used to develop the models. The results of any one test do not mean that a model is valid. Rather, the collection of tests together provide a level of confidence that the HEDR models are valid.

Napier, B.A.; Simpson, J.C.; Eslinger, P.W.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

1994-05-01T23:59:59.000Z

50

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

51

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 ...

52

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; Jørgen B. Jensen

1993-01-01T23:59:59.000Z

53

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

54

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

55

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

56

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

57

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

58

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

59

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

60

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

62

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

63

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

64

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

65

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

66

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...

67

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

68

Validation of Global Weather Forecast and Climate Models Over...  

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

Validation of Global Weather Forecast and Climate Models Over the North Slope of Alaska Xie, Shaocheng Lawrence Livermore National Laboratory Klein, Stephen Lawrence Livermore...

69

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

70

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

71

Techniques and Issues in Agent-Based Modeling Validation  

Science Conference Proceedings (OSTI)

Validation of simulation models is extremely important. It ensures that the right model has been built and lends confidence to the use of that model to inform critical decisions. Agent-based models (ABM) have been widely deployed in different fields for studying the collective behavior of large numbers of interacting agents. However, researchers have only recently started to consider the issues of validation. Compared to other simulation models, ABM has many differences in model development, usage and validation. An ABM is inherently easier to build than a classical simulation, but more difficult to describe formally since they are closer to human cognition. Using multi-agent models to study complex systems has attracted criticisms because of the challenges involved in their validation [1]. In this report, we describe the challenge of ABM validation and present a novel approach we recently developed for an ABM system.

Pullum, Laura L [ORNL; Cui, Xiaohui [New York Institute of Technology (NYIT)

2012-01-01T23:59:59.000Z

72

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

73

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

74

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

75

System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report  

SciTech Connect

The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

Freeman, J.; Whitmore, J.; Kaffine, L.; Blair, N.; Dobos, A. P.

2013-12-01T23:59:59.000Z

76

Systematic approach to verification and validation: High explosive burn models  

SciTech Connect

Most material models used in numerical simulations are based on heuristics and empirically calibrated to experimental data. For a specific model, key questions are determining its domain of applicability and assessing its relative merits compared to other models. Answering these questions should be a part of model verification and validation (V and V). Here, we focus on V and V of high explosive models. Typically, model developers implemented their model in their own hydro code and use different sets of experiments to calibrate model parameters. Rarely can one find in the literature simulation results for different models of the same experiment. Consequently, it is difficult to assess objectively the relative merits of different models. This situation results in part from the fact that experimental data is scattered through the literature (articles in journals and conference proceedings) and that the printed literature does not allow the reader to obtain data from a figure in electronic form needed to make detailed comparisons among experiments and simulations. In addition, it is very time consuming to set up and run simulations to compare different models over sufficiently many experiments to cover the range of phenomena of interest. The first difficulty could be overcome if the research community were to support an online web based database. The second difficulty can be greatly reduced by automating procedures to set up and run simulations of similar types of experiments. Moreover, automated testing would be greatly facilitated if the data files obtained from a database were in a standard format that contained key experimental parameters as meta-data in a header to the data file. To illustrate our approach to V and V, we have developed a high explosive database (HED) at LANL. It now contains a large number of shock initiation experiments. Utilizing the header information in a data file from HED, we have written scripts to generate an input file for a hydro code, run a simulation, and generate a comparison plot showing simulated and experimental velocity gauge data. These scripts are then applied to several series of experiments and to several HE burn models. The same systematic approach is applicable to other types of material models; for example, equations of state models and material strength models.

Menikoff, Ralph [Los Alamos National Laboratory; Scovel, Christina A. [Los Alamos National Laboratory

2012-04-16T23:59:59.000Z

77

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

78

Cross Validation of Satellite Radiation Transfer Models during SWERA  

Open Energy Info (EERE)

Cross Validation of Satellite Radiation Transfer Models during SWERA Cross Validation of Satellite Radiation Transfer Models during SWERA Project in Brazil Dataset Summary Description (Abstract): This work describes the cross validation between two different core radiation transfer models that will be applied during the SWERA (Solar and Wind Energy Assessment): the BRAZIL-SR, and the SUNY-Albany. The model cross validation was performed by using two reference sites in Brazil: at Caicó (06°28'01"S - 037°05'05"W,175.8 m), and Florianópolis (27°34'18"S - 048°31'42"W, 10 m), Satellite data were collected by INPE-CPTEC for GOES-8, that also provides for its quality assessment, sectoring, storing and distribution to the participating teams. In this work we show the first results of this cross-validation along with some discussions on model deviations

79

Development and Validation of an Advanced Stimulation Prediction Model for  

Open Energy Info (EERE)

Validation of an Advanced Stimulation Prediction Model for Validation of an Advanced Stimulation Prediction Model for Enhanced Geothermal Systems Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Development and Validation of an Advanced Stimulation Prediction Model for Enhanced Geothermal Systems Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Stimulation Prediction Models Project Description The proposal is in response to DOE FOA DE-PS36-08GO99018/DE-FOA-0000075, specifically: the Topic Area: Stimulation Prediction Models - "To develop and validate models to predict a reservoir's response to stimulation and/or to quantitatively compare existing stimulation prediction models," and the Target Specification: "Development of stimulation prediction models capable of accurately predicting the location, spacing, orientation, and flow properties of created fractures."

80

Wave Tank Testing and Model Validation … An Integrated Approach  

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

Wave Tank Testing and Model Validation - Lessons Learned Wave Tank Testing and Model Validation - Lessons Learned Mirko Previsic 7-7-12 2 Representing the Full-Scale System P, V qv q T u q Generator Guide vanes Turbine Blades Configuration 3 Appropriate Modeling of Physics Run-time is important to make a model useful as an engineering and/or optimization tool. * Have to be selective about how the physics is represented in the model * Different physical phenomena are important to different WEC devices Subscale modeling allows to help us understand and validate the models physics. * Ideally we can isolate physical phenomena to properly debug theoretical model * Focus is on validating fluid-structure interaction * Scaling of mechanical systems needs to represent the physics of the full- scale system (i.e. mooring, power-take-off, control system).

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


81

A 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

82

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

83

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

84

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

85

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

86

Development of a Two-Fluid Drag Law for Clustered Particles Using Direct Numerical Simulation and Validation through Experiments  

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

Two-Fluid Drag Law Two-Fluid Drag Law for Clustered Particles Using Direct Numerical Simulation and Validation through Experiments Background The Historically Black Colleges and Universities and Other Minority Institutions (HBCU/ OMI) Research and Development (R&D) Program within the U. S. Department of Energy (DOE) Office of Fossil Energy (FE) provides a mechanism for cooperative FE R&D projects between DOE and the HBCU/OMI community. This program encourages

87

Some examples of simulation model validation using hypothesis testing  

Science Conference Proceedings (OSTI)

The use of hypothesis testing with cost-risk analysis is illustrated for simulation model validation by two examples. In the first example, Hotelling's two-sample T2 test with cost-risk analysis is used for illustrating the validation ...

Osman Balci; Robert G. Sargent

1982-12-01T23:59:59.000Z

88

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

89

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

90

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

91

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

92

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

93

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...

94

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

95

Plug-In Hybrid Electric Vehicles - PHEV Modeling - Model Validation  

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

Chevy Equinox, Ford Explorer) have been validated within 1% of fuel economy. Hybrid electric vehicles (e.g., Honda Insight, Toyota Prius, Lexus RX400h) have been validated...

96

An accuracy information annotation model for validated service behavior specifications  

Science Conference Proceedings (OSTI)

Assessing providable service levels based on model-driven prediction approaches requires valid service behavior specifications. Such specifications must be suitable for the requested usage profile and available hardware to make correct predictions and ...

Henning Groenda

2010-10-01T23:59:59.000Z

97

CASL milestone validates reactor model using TVA data | ornl...  

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

Ron Walli Communications 865.576.0226 CASL milestone validates reactor model using TVA data This CASL visualization shows the thermal distribution of neutrons in Watts Bar Unit 1...

98

Validation of security-design models using Z  

Science Conference Proceedings (OSTI)

This paper is aimed at formally specifying and validating security-design models of an information system. It combines graphical languages and formal methods, integrating specification languages such as UML and an extension, SecureUML, with the Z language. ...

Nafees Qamar; Yves Ledru; Akram Idani

2011-10-01T23:59:59.000Z

99

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

100

Maui Electrical System Simulation Model Validation  

E-Print Network (OSTI)

. The results of the production cost model were compared to the 2007 historical operating conditions in the model. · Outages were simulated in MAPS based on 2007 historical outage duration by unit. In future analyses it is likely that the 5-year average outage data, by unit, would be implemented in the model

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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
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101

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

102

Nuclear Systems Modeling, Simulation & Validation | Nuclear Science...  

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

Research Areas Fuel Cycle Science & Technology Fusion Nuclear Science Isotope Development and Production Nuclear Security Science & Technology Nuclear Systems Modeling, Simulation...

103

DEVELOPMENT AND VALIDATION OF A MULTIFIELD MODEL OF CHURN-TURBULENT GAS/LIQUID FLOWS  

DOE Green Energy (OSTI)

The accuracy of numerical predictions for gas/liquid two-phase flows using Computational Multiphase Fluid Dynamics (CMFD) methods strongly depends on the formulation of models governing the interaction between the continuous liquid field and bubbles of different sizes. The purpose of this paper is to develop, test and validate a multifield model of adiabatic gas/liquid flows at intermediate gas concentrations (e.g., churn-turbulent flow regime), in which multiple-size bubbles are divided into a specified number of groups, each representing a prescribed range of sizes. The proposed modeling concept uses transport equations for the continuous liquid field and for each bubble field. The overall model has been implemented in the NPHASE-CMFD computer code. The results of NPHASE-CMFD simulations have been validated against the experimental data from the TOPFLOW test facility. Also, a parametric analysis on the effect of various modeling assumptions has been performed.

Elena A. Tselishcheva; Steven P. Antal; Michael Z. Podowski; Donna Post Guillen

2009-07-01T23:59:59.000Z

104

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

105

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

106

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

107

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

108

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

109

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

110

Experiments for foam model development and validation.  

Science Conference Proceedings (OSTI)

A series of experiments has been performed to allow observation of the foaming process and the collection of temperature, rise rate, and microstructural data. Microfocus video is used in conjunction with particle image velocimetry (PIV) to elucidate the boundary condition at the wall. Rheology, reaction kinetics and density measurements complement the flow visualization. X-ray computed tomography (CT) is used to examine the cured foams to determine density gradients. These data provide input to a continuum level finite element model of the blowing process.

Bourdon, Christopher Jay; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Mahoney, James F. (Honeywell Federal Manufacturing and Technologies, Kansas City Plant, Kansas City, MO); Russick, Edward Mark; Adolf, Douglas Brian; Rao, Rekha Ranjana; Thompson, Kyle Richard; Kraynik, Andrew Michael; Castaneda, Jaime N.; Brotherton, Christopher M.; Mondy, Lisa Ann; Gorby, Allen D.

2008-09-01T23:59:59.000Z

111

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

112

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

113

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

114

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

115

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

116

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

117

Validation of General Circulation Model Radiative Fluxes Using Surface Observations  

Science Conference Proceedings (OSTI)

The surface radiative fluxes of the ECHAM3 General Circulation Model (GCM) with T2 1, T42, and T 106 resolutions have been validated using observations from the Global Energy Balance Archive (GEBA, World Climate Program-Water Project A7). GEBA ...

Martin Wild; Atsumu Ohmura; Hans Gilgen; Erich Roeckner

1995-05-01T23:59:59.000Z

118

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

119

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

120

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

122

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

123

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

124

70 MPa Fast-Fill Modeling and Validation Experiments  

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

0 MPa Fast-Fill Modeling & 0 MPa Fast-Fill Modeling & Validation Experiments Bill Winters Thermal/Fluid Sci. & Eng. Dept. 8365 DOE Tank Safety Workshop April 29, 2010 SAND Number: 2010-2830 P Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Sandia modeling and validation methods can be applied to the 70 MPa Fast Fill Problem * Multi year effort to understand flow and heat transfer in compressed gas storage systems - Vessel Blowdown (supplies) - Vessel Fillup (receivers) - Interconnecting systems of tubes, valves and flow branches * Network flow modeling capability - we have developed dedicated

125

A standardized approach to PV system performance model validation.  

DOE Green Energy (OSTI)

PV performance models are used to predict how much energy a PV system will produce at a given location and subject to prescribed weather conditions. These models are commonly used by project developers to choose between module technologies and array designs (e.g., fixed tilt vs. tracking) for a given site or to choose between different geographic locations, and are used by the financial community to establish project viability. Available models can differ significantly in their underlying mathematical formulations and assumptions and in the options available to the analyst for setting up a simulation. Some models lack complete documentation and transparency, which can result in confusion on how to properly set up, run, and document a simulation. Furthermore, the quality and associated uncertainty of the available data upon which these models rely (e.g., irradiance, module parameters, etc.) is often quite variable and frequently undefined. For these reasons, many project developers and other industry users of these simulation tools have expressed concerns related to the confidence they place in PV performance model results. To address this problem, we propose a standardized method for the validation of PV system-level performance models and a set of guidelines for setting up these models and reporting results. This paper describes the basic elements for a standardized model validation process adapted especially for PV performance models, suggests a framework to implement the process, and presents an example of its application to a number of available PV performance models.

Stein, Joshua S.; Jester, Terry (Hudson Clean Energy Partners); Posbic, Jean (BP Solar); Kimber, Adrianne (First Solar); Cameron, Christopher P.; Bourne, Benjamin (SunPower Corporation)

2010-10-01T23:59:59.000Z

126

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

127

Foundation Heat Exchanger Model and Design Tool Development and Validation  

E-Print Network (OSTI)

. Feasibility of foundation heat exchangers in ground source heat pump systems in the United States. ASHRAE systems, with an estimated 1.7 million installed units with total installed heating capacity on the order Heat Exchangers for Residential Ground Source Heat Pump Systems - Numerical Modeling and Experimental

128

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

129

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

130

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

131

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

132

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

133

Validation of the SUNY Satellite Model in a Meteosat Evironment  

DOE Green Energy (OSTI)

The paper presents a validation of the SUNY satellite-to-irradiance model against four ground-truth stations from the Indian solar radiation network located in and around the province of Rajasthan, India. The SUNY model had initially been developed and tested to process US weather satellite data from the GOES series and has been used as part of the production of the US National Solar Resource Data Base (NSRDB). Here the model is applied to processes data from the European weather satellites Meteosat 5 and 7.

Perez, R.; Schlemmer, J.; Renne, D.; Cowlin, S.; George, R.; Bandyopadhyay, B.

2009-01-01T23:59:59.000Z

134

Validated, unified model for optics and heat transfer in line-axis concentrating solar energy collectors  

SciTech Connect

A rigorous numerical simulation model for the prediction of the combined optical and thermofluid behaviour of line-axis concentrating solar energy collectors combines two-dimensional steady-state finite element analysis of convective heat transfer and ray-trace techniques. The optical analysis considers both direct and diffuse insolation components and is therefore useful for the analysis of compound parabolic concentrating collectors. Experiments using Mach-Zehnder interferometry indicate a parametric range for which such a two-dimensional representation is valid.

Eames, P.C.; Norton, B. (Univ. of Ulster (United Kingdom))

1993-04-01T23:59:59.000Z

135

Beyond validation: alternative uses and associated assessments of goodness for computational social models  

Science Conference Proceedings (OSTI)

This discussion challenges classic notions of validation, suggesting that ‘validity' is not just an attribute of a model. It is a function of the relationship of a particular characteristic of the model (the probability that the model will produce ... Keywords: computational models, social modeling, validation

Jessica Glicken Turnley; Peter A. Chew; Aaron S. Perls

2012-04-01T23:59:59.000Z

136

CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT  

Open Energy Info (EERE)

ISES- 2003 ISES- 2003 CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT IN BRAZIL Enio B. Pereira, Fernando R. Martins 1 Brazilian Institute for Space Research - INPE, São José dos Campos, 12245-970, SP, Brazil Phone + 55 12 39456741, Fax + 55 12 39456810, enio@dge.inpe.br Samuel L. Abreu, Hans Georg Beyer, Sergio Colle, and Solar Energy Laboratory - LABSOLAR - Department of Mechanical Engineering, Federal University of Santa Catarina -UFSC, Florianopolis, 88040-900, (SC), Brazil, Richard Perez The University at Albany (SUNY), ASRC-CESTM, Albany, 12203 (NY), USA Abstract - This work describes the cross validation between two different core radiation transfer models that will be applied during the SWERA (Solar and Wind Energy Assessment): the BRAZIL-SR, and the

137

Modeling Surface Solar Radiation: Model Formulation and Validation  

Science Conference Proceedings (OSTI)

A model for computing global solar radiation at the surface was formulated for use with satellite observations. A compromise in the approach was necessary, whereby the model accuracy and the inherent limitations of satellite observations were ...

R. T. Pinker; J. A. Ewing

1985-05-01T23:59:59.000Z

138

Validation of the WATEQ4 geochemical model for uranium  

SciTech Connect

As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite (UO/sub 2/(OH)/sub 2/ . H/sub 2/O), UO/sub 2/(OH)/sub 2/, and rutherfordine ((UO/sub 2/CO/sub 3/) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions.

Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

1983-09-01T23:59:59.000Z

139

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

140

VALIDATION OF COMPUTER MODELS FOR RADIOACTIVE MATERIAL SHIPPING PACKAGES  

Science Conference Proceedings (OSTI)

Computer models are abstractions of physical reality and are routinely used for solving practical engineering problems. These models are prepared using large complex computer codes that are widely used in the industry. Patran/Thermal is such a finite element computer code that is used for solving complex heat transfer problems in the industry. Finite element models of complex problems involve making assumptions and simplifications that depend upon the complexity of the problem and upon the judgment of the analysts. The assumptions involve mesh size, solution methods, convergence criteria, material properties, boundary conditions, etc. that could vary from analyst to analyst. All of these assumptions are, in fact, candidates for a purposeful and intended effort to systematically vary each in connection with the others to determine there relative importance or expected overall effect on the modeled outcome. These kinds of models derive from the methods of statistical science and are based on the principles of experimental designs. These, as all computer models, must be validated to make sure that the output from such an abstraction represents reality [1,2]. A new nuclear material packaging design, called 9977, which is undergoing a certification design review, is used to assess the capability of the Patran/Thermal computer model to simulate 9977 thermal response. The computer model for the 9977 package is validated by comparing its output with the test data collected from an actual thermal test performed on a full size 9977 package. Inferences are drawn by performing statistical analyses on the residuals (test data--model predictions).

Gupta, N; Gene Shine, G; Cary Tuckfield, C

2007-05-07T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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

Coupled Thermal-Chemical-Mechanical Modeling of Validation Cookoff Experiments  

DOE Green Energy (OSTI)

The cookoff of energetic materials involves the combined effects of several physical and chemical processes. These processes include heat transfer, chemical decomposition, and mechanical response. The interaction and coupling between these processes influence both the time-to-event and the violence of reaction. The prediction of the behavior of explosives during cookoff, particularly with respect to reaction violence, is a challenging task. To this end, a joint DoD/DOE program has been initiated to develop models for cookoff, and to perform experiments to validate those models. In this paper, a series of cookoff analyses are presented and compared with data from a number of experiments for the aluminized, RDX-based, Navy explosive PBXN-109. The traditional thermal-chemical analysis is used to calculate time-to-event and characterize the heat transfer and boundary conditions. A reaction mechanism based on Tarver and McGuire's work on RDX{sup 2} was adjusted to match the spherical one-dimensional time-to-explosion data. The predicted time-to-event using this reaction mechanism compares favorably with the validation tests. Coupled thermal-chemical-mechanical analysis is used to calculate the mechanical response of the confinement and the energetic material state prior to ignition. The predicted state of the material includes the temperature, stress-field, porosity, and extent of reaction. There is little experimental data for comparison to these calculations. The hoop strain in the confining steel tube gives an estimation of the radial stress in the explosive. The inferred pressure from the measured hoop strain and calculated radial stress agree qualitatively. However, validation of the mechanical response model and the chemical reaction mechanism requires more data. A post-ignition burn dynamics model was applied to calculate the confinement dynamics. The burn dynamics calculations suffer from a lack of characterization of the confinement for the flaw-dominated failure mode experienced in the tests. High-pressure burning rates are needed for more detailed post-ignition studies. Sub-models for chemistry, mechanical response and burn dynamics need to be validated against data from less complex experiments. The sub-models can then be used in integrated analysis for comparison with experimental data taken during integrated tests.

ERIKSON,WILLIAM W.; SCHMITT,ROBERT G.; ATWOOD,A.I.; CURRAN,P.D.

2000-11-27T23:59:59.000Z

142

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

143

From model conception to verification and validation, a global approach to multiphase Navier-Stoke models with an emphasis on volcanic explosive phenomenology  

Science Conference Proceedings (OSTI)

Large-scale volcanic eruptions are hazardous events that cannot be described by detailed and accurate in situ measurement: hence, little to no real-time data exists to rigorously validate current computer models of these events. In addition, such phenomenology involves highly complex, nonlinear, and unsteady physical behaviors upon many spatial and time scales. As a result, volcanic explosive phenomenology is poorly understood in terms of its physics, and inadequately constrained in terms of initial, boundary, and inflow conditions. Nevertheless, code verification and validation become even more critical because more and more volcanologists use numerical data for assessment and mitigation of volcanic hazards. In this report, we evaluate the process of model and code development in the context of geophysical multiphase flows. We describe: (1) the conception of a theoretical, multiphase, Navier-Stokes model, (2) its implementation into a numerical code, (3) the verification of the code, and (4) the validation of such a model within the context of turbulent and underexpanded jet physics. Within the validation framework, we suggest focusing on the key physics that control the volcanic clouds—namely, momentum-driven supersonic jet and buoyancy-driven turbulent plume. For instance, we propose to compare numerical results against a set of simple and well-constrained analog experiments, which uniquely and unambiguously represent each of the key-phenomenology. Key

Dartevelle, Sebastian

2007-10-01T23:59:59.000Z

144

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

145

Technical Update -- Wind and Solar PV Modeling and Model Validation  

Science Conference Proceedings (OSTI)

The proliferation of variable generation technologies, particularly wind generation, into the bulk transmission grid in the U.S. and internationally has been significant over the past decade. This trend will most likely continue in light of national (in other countries) and state renewable portfolio standards. Thus, there is at present a need for generic, standard and publicly available models for variable generation technologies for the purpose of power system planning studies. EPRI has ...

2012-11-30T23:59:59.000Z

146

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

147

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

148

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

149

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

150

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

151

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

152

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

153

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

154

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

155

Cross-Validation in Statistical Climate Forecast Models  

Science Conference Proceedings (OSTI)

Cross-validation is a statistical procedure that produces an estimate of forecast skill which is less biased than the usual hindcast skill estimates. The cross-validation method systematically deletes one or more cases in a dataset, derives a ...

Joel Michaelsen

1987-11-01T23:59:59.000Z

156

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

157

An approach to model validation and model-based prediction -- polyurethane foam case study.  

Science Conference Proceedings (OSTI)

Enhanced software methodology and improved computing hardware have advanced the state of simulation technology to a point where large physics-based codes can be a major contributor in many systems analyses. This shift toward the use of computational methods has brought with it new research challenges in a number of areas including characterization of uncertainty, model validation, and the analysis of computer output. It is these challenges that have motivated the work described in this report. Approaches to and methods for model validation and (model-based) prediction have been developed recently in the engineering, mathematics and statistical literatures. In this report we have provided a fairly detailed account of one approach to model validation and prediction applied to an analysis investigating thermal decomposition of polyurethane foam. A model simulates the evolution of the foam in a high temperature environment as it transforms from a solid to a gas phase. The available modeling and experimental results serve as data for a case study focusing our model validation and prediction developmental efforts on this specific thermal application. We discuss several elements of the ''philosophy'' behind the validation and prediction approach: (1) We view the validation process as an activity applying to the use of a specific computational model for a specific application. We do acknowledge, however, that an important part of the overall development of a computational simulation initiative is the feedback provided to model developers and analysts associated with the application. (2) We utilize information obtained for the calibration of model parameters to estimate the parameters and quantify uncertainty in the estimates. We rely, however, on validation data (or data from similar analyses) to measure the variability that contributes to the uncertainty in predictions for specific systems or units (unit-to-unit variability). (3) We perform statistical analyses and hypothesis tests as a part of the validation step to provide feedback to analysts and modelers. Decisions on how to proceed in making model-based predictions are made based on these analyses together with the application requirements. Updating modifying and understanding the boundaries associated with the model are also assisted through this feedback. (4) We include a ''model supplement term'' when model problems are indicated. This term provides a (bias) correction to the model so that it will better match the experimental results and more accurately account for uncertainty. Presumably, as the models continue to develop and are used for future applications, the causes for these apparent biases will be identified and the need for this supplementary modeling will diminish. (5) We use a response-modeling approach for our predictions that allows for general types of prediction and for assessment of prediction uncertainty. This approach is demonstrated through a case study supporting the assessment of a weapons response when subjected to a hydrocarbon fuel fire. The foam decomposition model provides an important element of the response of a weapon system in this abnormal thermal environment. Rigid foam is used to encapsulate critical components in the weapon system providing the needed mechanical support as well as thermal isolation. Because the foam begins to decompose at temperatures above 250 C, modeling the decomposition is critical to assessing a weapons response. In the validation analysis it is indicated that the model tends to ''exaggerate'' the effect of temperature changes when compared to the experimental results. The data, however, are too few and to restricted in terms of experimental design to make confident statements regarding modeling problems. For illustration, we assume these indications are correct and compensate for this apparent bias by constructing a model supplement term for use in the model-based predictions. Several hypothetical prediction problems are created and addressed. Hypothetical problems are used because no guidance was provided concern

Dowding, Kevin J.; Rutherford, Brian Milne

2003-07-01T23:59:59.000Z

158

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

159

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

160

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

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

172

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 .

173

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

174

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

175

Alaska North Slope Tundra Travel Model and Validation Study  

SciTech Connect

The Alaska Department of Natural Resources (DNR), Division of Mining, Land, and Water manages cross-country travel, typically associated with hydrocarbon exploration and development, on Alaska's arctic North Slope. This project is intended to provide natural resource managers with objective, quantitative data to assist decision making regarding opening of the tundra to cross-country travel. DNR designed standardized, controlled field trials, with baseline data, to investigate the relationships present between winter exploration vehicle treatments and the independent variables of ground hardness, snow depth, and snow slab thickness, as they relate to the dependent variables of active layer depth, soil moisture, and photosynthetically active radiation (a proxy for plant disturbance). Changes in the dependent variables were used as indicators of tundra disturbance. Two main tundra community types were studied: Coastal Plain (wet graminoid/moist sedge shrub) and Foothills (tussock). DNR constructed four models to address physical soil properties: two models for each main community type, one predicting change in depth of active layer and a second predicting change in soil moisture. DNR also investigated the limited potential management utility in using soil temperature, the amount of photosynthetically active radiation (PAR) absorbed by plants, and changes in microphotography as tools for the identification of disturbance in the field. DNR operated under the assumption that changes in the abiotic factors of active layer depth and soil moisture drive alteration in tundra vegetation structure and composition. Statistically significant differences in depth of active layer, soil moisture at a 15 cm depth, soil temperature at a 15 cm depth, and the absorption of photosynthetically active radiation were found among treatment cells and among treatment types. The models were unable to thoroughly investigate the interacting role between snow depth and disturbance due to a lack of variability in snow depth cover throughout the period of field experimentation. The amount of change in disturbance indicators was greater in the tundra communities of the Foothills than in those of the Coastal Plain. However the overall level of change in both community types was less than expected. In Coastal Plain communities, ground hardness and snow slab thickness were found to play an important role in change in active layer depth and soil moisture as a result of treatment. In the Foothills communities, snow cover had the most influence on active layer depth and soil moisture as a result of treatment. Once certain minimum thresholds for ground hardness, snow slab thickness, and snow depth were attained, it appeared that little or no additive effect was realized regarding increased resistance to disturbance in the tundra communities studied. DNR used the results of this modeling project to set a standard for maximum permissible disturbance of cross-country tundra travel, with the threshold set below the widely accepted standard of Low Disturbance levels (as determined by the U.S. Fish and Wildlife Service). DNR followed the modeling project with a validation study, which seemed to support the field trial conclusions and indicated that the standard set for maximum permissible disturbance exhibits a conservative bias in favor of environmental protection. Finally DNR established a quick and efficient tool for visual estimations of disturbance to determine when investment in field measurements is warranted. This Visual Assessment System (VAS) seemed to support the plot disturbance measurements taking during the modeling and validation phases of this project.

Harry R. Bader; Jacynthe Guimond

2006-03-01T23:59:59.000Z

176

An independent verification and validation of the Future Theater Level Model conceptual model  

Science Conference Proceedings (OSTI)

This report describes the methodology and results of independent verification and validation performed on a combat model in its design stage. The combat model is the Future Theater Level Model (FTLM), under development by The Joint Staff/J-8. J-8 has undertaken its development to provide an analysis tool that addresses the uncertainties of combat more directly than previous models and yields more rapid study results. The methodology adopted for this verification and validation consisted of document analyses. Included were detailed examination of the FTLM design documents (at all stages of development), the FTLM Mission Needs Statement, and selected documentation for other theater level combat models. These documents were compared to assess the FTLM as to its design stage, its purpose as an analytical combat model, and its capabilities as specified in the Mission Needs Statement. The conceptual design passed those tests. The recommendations included specific modifications as well as a recommendation for continued development. The methodology is significant because independent verification and validation have not been previously reported as being performed on a combat model in its design stage. The results are significant because The Joint Staff/J-8 will be using the recommendations from this study in determining whether to proceed with develop of the model.

Hartley, D.S. III; Kruse, K.L.; Martellaro, A.J.; Packard, S.L.; Thomas, B. Jr.; Turley, V.K.

1994-08-01T23:59:59.000Z

177

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

178

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

179

Validity of the Tangent Linear Approximation in a Moist Convective Cloud Model  

Science Conference Proceedings (OSTI)

The validity of the moist tangent linear model (TLM) derived from a time-dependent 1D Eulerian cloud model is investigated by comparing TLM solutions to differences between results from a nonlinear model identically perturbed. The TLM solutions ...

Seon Ki Park; Kelvin K. Droegemeier

1997-12-01T23:59:59.000Z

180

Modelling and Validation of Three Dimensional Fan Blade 'Twist ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The numerical results obtained from the finite element analysis of the twist and camber forming of a blade are presented. The manufacturing ...

Note: This page contains sample records for the topic "numerical model validation" 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

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

182

Model Validation at the 204-MW New Mexico Wind Energy Center  

DOE Green Energy (OSTI)

Poster for WindPower 2006 held June 4-7, 2006, in Pittsburgh, PA, describing model validation at the 204-MW New Mexico Wind Energy Center.

Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

2006-06-01T23:59:59.000Z

183

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

184

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

185

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

186

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

187

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

188

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

189

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

190

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

191

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

192

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

193

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

194

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

195

Combining Cloud-Resolving Model with Satellite for Cloud Process Model Simulation Validation  

Science Conference Proceedings (OSTI)

Advances in computer power have made it possible to increase the spatial resolution of regional numerical models to a scale encompassing larger convective elements of less than 5 km in size. One goal of high resolution is to begin to resolve ...

Renato G. Negri; Luiz A. T. Machado; Stephen English; Mary Forsythe

196

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

197

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

198

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

199

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

200

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

202

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

203

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

204

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

205

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

206

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

207

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

208

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

209

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

210

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

211

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

212

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

213

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

214

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

215

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

216

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

217

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

218

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

219

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

220

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

222

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

223

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

224

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

225

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

226

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

227

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

228

Development, validation and verification of the Momentum Source Model for discrete rotor blades.  

E-Print Network (OSTI)

??In this research, a novel numerical technique for modeling the unsteady aerodynamics of rotorcraft flows has been developed. The aim of this research is to… (more)

Guntupalli, Kanchan

2011-01-01T23:59:59.000Z

229

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

230

Modeling and experimental validation of unsteady impinging flames  

Science Conference Proceedings (OSTI)

This study reports on a joint experimental and analytical study of premixed laminar flames impinging onto a plate at controlled temperature, with special emphasis on the study of periodically oscillating flames. Six types of flame structures were found, based on parametric variations of nozzle-to-plate distance (H), jet velocity (U), and equivalence ratio (f). They were classified as conical, envelope, disc, cool central core, ring, and side-lifted flames. Of these, the disc, cool central core, and envelope flames were found to oscillate periodically, with frequency and sound pressure levels increasing with Re and decreasing with nozzle-to-plate distance. The unsteady behavior of these flames was modeled using the formulation derived by Durox et al. [D. Durox, T. Schuller, S. Candel, Proc. Combust. Inst. 29 (2002) 69-75] for the cool central core flames where the convergent burner acts as a Helmholtz resonator, driven by an external pressure fluctuation dependent on a velocity fluctuation at the burner mouth after a convective time delay {tau}. Based on this model, the present work shows that {tau} = [Re[2jtanh{sup -1}((2{delta}{omega}+(1+N)j{omega}{sup 2}-j{omega}{sub 0}{sup 2})/ (2{delta}{omega}+(1-N)j{omega}{sup 2}-j{omega}{sub 0}{sup 2}))]+2{pi}K]/{omega}, i.e., there is a relation between oscillation frequency ({omega}), burner acoustic characteristics ({omega}{sub 0},{delta}), and time delay {tau}, not explicitly dependent on N, the flame-flow normalized interaction coefficient [D. Durox, T. Schuller, S. Candel, Proc. Combust. Inst. 29 (2002) 69-75], because {partial_derivative}t/{partial_derivative}N = 0. Based on flame motion and noise analysis, K was found to physically represent the integer number of perturbations on flame surface or number of coherent structures on impinging jet. Additionally, assuming that {tau}={beta}H/U, where H is the nozzle-to-plate distance and U is the mean jet velocity, it is shown that {beta}{sub Disc}=1.8, {beta}{sub CCC}=1.03, and {beta}{sub Env}=1.0. A physical analysis of the proportionality constant {beta} showed that for the disc flames, {tau} corresponds to the ratio between H and the velocity of the coherent structures. In the case of envelope and cool central core flames, {tau} corresponds to the ratio between H and the mean jet velocity. The predicted frequency fits the experimental data, supporting the validity of the mathematical modeling, empirical formulation, and assumptions made. (author)

Fernandes, E.C.; Leandro, R.E. [Center for Innovation, Technology and Policy Research, Mechanical Engineering Department, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa Codex (Portugal)

2006-09-15T23:59:59.000Z

231

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

232

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

233

Guiding the selection of physical experiments supporting validation of electric power system models  

Science Conference Proceedings (OSTI)

As engineering analyses rely more on computer simulation, it is important to develop a methodology that accounts for inaccuracies present in all simulation models. Typically, simulation models are validated against the physical system they try to explain. ... Keywords: physical experiments, power system grounding, quantitative validation

Diomar Infante; James Langston; Lukas Graber; Michael Steurer

2011-06-01T23:59:59.000Z

234

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

235

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

236

Validation and Sensitivity Analysis of a New Atmosphere–Soil–Vegetation Model  

Science Conference Proceedings (OSTI)

This paper describes details, validation, and sensitivity analysis of a new atmosphere–soil–vegetation model. The model consists of one-dimensional multilayer submodels for atmosphere, soil, and vegetation and radiation schemes for the ...

Haruyasu Nagai

2002-02-01T23:59:59.000Z

237

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

238

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

239

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

240

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

Note: This page contains sample records for the topic "numerical model validation" 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

Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report  

Open Energy Info (EERE)

Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report Dataset Summary Description (Abstract): This partial report describes the results obtained by two of the core radiative transfer models adopted in the SWERA Project for global horizontal solar irradiation during the cross-validation step. They are BRASIL-SR and SUNY-ALBANY models (Martins, 2001; Stuhlmann et al. 1990; Perez et al., 2002). The results from other two other core models, NREL and DLR, are not yet available. The HELIOSAT was included as a reference model at this stage. The HELIOSAT model is widely employed for solar energy assessment in Europe and is well know by the solar energy community worldwide (Beyer et al., 1996; Cano et al., 1986). (Purpose): SWERA solar cross-validation study

242

Validating Z specifications using the PROB animator and model checker  

Science Conference Proceedings (OSTI)

We present the architecture and implementation of the proz tool to validate high-level Z specifications. The tool was integrated into prob, by providing a translation of Z into B and by extending the kernel of prob to accommodate some new syntax and ...

Daniel Plagge; Michael Leuschel

2007-07-01T23:59:59.000Z

243

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

244

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

245

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

246

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

247

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

248

Gulf Stream and Ring Feature Analyses for Forecast Model Validation*  

Science Conference Proceedings (OSTI)

A series of Gulf Stream forecast model test cases were developed for the Data Assimilation and Model Evaluation Experiment (DAMEE). The model initialization and verification procedure relies heavily on a series of accurate synoptic snapshots of ...

Scott M. Glenn; Michael F. Crowley

1997-12-01T23:59:59.000Z

249

Verification & validation by docking: a case study of agent-based models of Anopheles gambiae  

Science Conference Proceedings (OSTI)

In this paper, using the technique of docking, we perform verification & validation (V&V) of agent-based simulation models that simulate the life cycle of Anopheles gambiae, the primary vector for malaria transmission. Working with one ... Keywords: Anopheles gambiae, docking, malaria epidemiology, verification & validation

S. M. Niaz Arifin; Gregory J. Davis; Ying Zhou

2010-07-01T23:59:59.000Z

250

The motivations-attributes-skills-knowledge competency cluster validation model an empirical study  

E-Print Network (OSTI)

This empirical research study had two main purposes with regard to competency cluster validation. First, this empirical research study was focused upon finding the gaps in the literature that existed pertaining to the Motivations-Attributes-Skills-Knowledge Inverted Funnel Validation (MIFV) competency cluster model. The second purpose of this empirical research study was to introduce a new competency cluster validation model (MIFV). This model, if properly developed, should serve as a strong workforce development and performance measurement tool as well as a communication tool and a blueprint for success for employees. The MIFV is a sequentially upward funneling competency cluster validation model. The MIFV will provide an opportunity for the study participants to measure their efforts. In summary, the MIFV is a quantifiable model focused on workforce development and efficiencies.

Stevens, Jeffery Allen

2003-08-01T23:59:59.000Z

251

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

252

An Improved Snow Scheme for the ECMWF Land Surface Model: Description and Offline Validation  

Science Conference Proceedings (OSTI)

A new snow scheme for the European Centre for Medium-Range Weather Forecasts (ECMWF) land surface model has been tested and validated. The scheme includes a new parameterization of snow density, incorporating a liquid water reservoir, and revised ...

Emanuel Dutra; Gianpaolo Balsamo; Pedro Viterbo; Pedro M. A. Miranda; Anton Beljaars; Christoph Schär; Kelly Elder

2010-08-01T23:59:59.000Z

253

Estimation and Model Validation of Surface Solar Radiation and Cloud Radiative Forcing Using TOGA COARE Measurements  

Science Conference Proceedings (OSTI)

The Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) radiation measurements in the western Pacific warm pool are used to estimate surface solar radiation budgets and to validate radiation model ...

Ming-Dah Chou; Wenzhong Zhao

1997-04-01T23:59:59.000Z

254

Climatically Diverse Data Set for Flat-Plate PV Module Model Validations (Presentation)  

SciTech Connect

Photovoltaic (PV) module I-V curves were measured at Florida, Colorado, and Oregon locations to provide data for the validation and development of models used for predicting the performance of PV modules.

Marion, B.

2013-05-01T23:59:59.000Z

255

Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications  

Science Conference Proceedings (OSTI)

This report documents the verification and validation (VV) of five selected fire models commonly used in support of risk-informed and performance-based (RI/PB) fire protection at nuclear power plants (NPPs).

2007-05-30T23:59:59.000Z

256

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

257

Data & model conditioning for multivariate systematic uncertainty in model calibration, validation, and extrapolation.  

Science Conference Proceedings (OSTI)

This paper discusses implications and appropriate treatment of systematic uncertainty in experiments and modeling. Systematic uncertainty exists when experimental conditions, and/or measurement bias errors, and/or bias contributed by post-processing the data, are constant over the set of experiments but the particular values of the conditions and/or biases are unknown to within some specified uncertainty. Systematic uncertainties in experiments do not automatically show up in the output data, unlike random uncertainty which is revealed when multiple experiments are performed. Therefore, the output data must be properly 'conditioned' to reflect important sources of systematic uncertainty in the experiments. In industrial scale experiments the systematic uncertainty in experimental conditions (especially boundary conditions) is often large enough that the inference error on how the experimental system maps inputs to outputs is often quite substantial. Any such inference error and uncertainty thereof also has implications in model validation and calibration/conditioning; ignoring systematic uncertainty in experiments can lead to 'Type X' error in these procedures. Apart from any considerations of modeling and simulation, reporting of uncertainty associated with experimental results should include the effects of any significant systematic uncertainties in the experiments. This paper describes and illustrates the treatment of multivariate systematic uncertainties of interval and/or probabilistic natures, and combined cases. The paper also outlines a practical and versatile 'real-space' framework and methodology within which experimental and modeling uncertainties (correlated and uncorrelated, systematic and random, aleatory and epistemic) are treated to mitigate risk in model validation, calibration/conditioning, hierarchical modeling, and extrapolative prediction.

Romero, Vicente Jose

2010-03-01T23:59:59.000Z

258

Short-Term Forecast Validation of Six Models  

Science Conference Proceedings (OSTI)

The short-term forecast accuracy of six different forecast models over the western United States is described for January, February, and March 1996. Four of the models are operational products from the National Centers for Environmental ...

Bryan G. White; Jan Paegle; W. James Steenburgh; John D. Horel; Robert T. Swanson; Louis K. Cook; Daryl J. Onton; John G. Miles

1999-02-01T23:59:59.000Z

259

Atmospheric Dispersion Model Validation in Low Wind Conditions  

DOE Green Energy (OSTI)

and SCIPUFF models and under-prediction bias by the ALOHA model. The experiment parameters were for near field dispersion (less than 100 meters) in low wind speed conditions (less than 2 meters per second).

Patrick Sawyer

2007-11-01T23:59:59.000Z

260

Argonne hosting Modeling, Experimentation and Validation (MeV...  

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

Nuclear Safety Materials Disposition Decontamination & Decommissioning Nuclear Criticality Safety Nuclear Data Program Nuclear Waste Form Modeling Departments Engineering...

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


261

Effective Establishment and Validation of Models and Databases for ...  

Science Conference Proceedings (OSTI)

Materials Genomics Past & Future: From CALPHAD to Flight · Modelling the Properties of Multi-Component Commercial Alloys · Molecular Dynamics ...

262

O`ahu Grid Study: Validation of Grid Models  

E-Print Network (OSTI)

not historically occur in the same time frame. The model uses five-year average heat rates and forced outage rates . The results of the production cost model were compared to the 2007 historical operating conditions, the production cost model provides the unit-by-unit production output (MW) on an hourly basis for an entire year

263

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

264

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

265

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

266

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

267

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

268

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

269

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

270

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

271

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

272

The Use of GPS to Validate NWP Systems: The HIRLAM Model  

Science Conference Proceedings (OSTI)

A meteorological synoptic situation using Global Positioning System (GPS) observations and a numerical weather prediction (NWP) model in the vicinity of the Madrid Sierra, Spain, between 2 and 15 December 1996 has been studied. The experiment was ...

L. Cucurull; B. Navascues; G. Ruffini; P. Elósegui; A. Rius; J. Vilà

2000-06-01T23:59:59.000Z

273

Web-page on UrQMD Model Validation  

E-Print Network (OSTI)

A WEB-page containing materials of comparing experimental data and UrQMD model calculations has been designed. The page provides its user with a variety of tasks solved with the help of the model, accuracy and/or quality of experimental data description, and so on. The page can be useful for new experimental data analysis, or new experimental research planning. The UrQMD model is cited in more than 272 publications. Only 44 of them present original calculations. Their main results on the model are presented on the page.

A. Galoyan; J. Ritman; V. Uzhinsky

2006-05-18T23:59:59.000Z

274

Validation of Models and Simulations of Nuclear Fuels  

Science Conference Proceedings (OSTI)

Symposium, Characterization of Nuclear Reactor Materials and Components with ... Multi-scale theoretical models and computer simulations are often used to ...

275

Validation of the RRTM Shortwave Radiation Model and Comparison...  

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

use at European Center for Medium-Range Weather Forecasts (ECMWF) in their weather forecast model (Morcrette et al. 2001). The absorption coefficients required for RRTM are...

276

Experimental Validation of a Numerical Controller Using Convex Optimization with Linear Matrix Inequalities on a Quarter-Car Suspension System  

E-Print Network (OSTI)

Numerical methods of designing control systems are currently an active area of research. Convex optimization with linear matrix inequalities (LMIs) is one such method. Control objectives like minimizing the H_2, H_infinity norms, limiting the actuating effort to avoid saturation, pole-placement constraints etc., are cast as LMIs and an optimal feedback controller is found by making use of efficient interior-point algorithms. A full-state feedback controller is designed and implemented in this thesis using this method which then forms the basis for designing a static output feedback (SOF) controller. A profile was generated that relates the change in the SOF control gain matrix required to keep the same value of the generalized H_2 norm of the transfer function from the road disturbance to the actuating effort with the change in the sprung mass of the quarter-car system. The quarter-car system makes use of a linear brushless permanent magnet motor (LBPMM) as an actuator, a linear variable differential transformer (LVDT) and two accelerometers as sensors for feedback control and forms a platform to test these control methodologies. For the full-state feedback controller a performance measure (H_2 norm of the transfer function from road disturbance to sprung mass acceleration) of 2.166*10^3 m/s^2 was achieved ensuring that actuator saturation did not occur and that all poles had a minimum damping ratio of 0.2. The SOF controller achieved a performance measure of 1.707*10^3 m/s^2 ensuring that actuator saturation does not occur. Experimental and simulation results are provided which demonstrate the effectiveness of the SOF controller for various values of the sprung mass. A reduction in the peak-to-peak velocity by 73 percent, 72 percent, and 71 percent was achieved for a sprung mass of 2.4 kg, 2.8 kg, and 3.4 kg, respectively. For the same values of the sprung mass, a modified lead-lag compensator achieved a reduction of 79 percent, 77 percent and, 69 percent, respectively. A reduction of 76 percent and 54 percent in the peak-to-peak velocity was achieved for a sprung mass of 6.0 kg in simulation by the SOF controller and the modified lead-lag compensator, respectively. The gain of the modified lead-lag compensator needs to be recomputed in order to achieve a similar attenuation as that of the SOF controller when the value of the sprung mass is changed. For a sprung mass of 3.4 kg and a suspension spring stiffness of 1640 N/m the peak-to-peak velocity of the sprung mass was attenuated by 42 percent.

Chintala, Rohit

2011-08-01T23:59:59.000Z

277

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

278

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

279

Spatial Statistical Procedures to Validate Input Data in Energy Models  

DOE Green Energy (OSTI)

Energy modeling and analysis often relies on data collected for other purposes such as census counts, atmospheric and air quality observations, economic trends, and other primarily non-energy-related uses. Systematic collection of empirical data solely for regional, national, and global energy modeling has not been established as in the above-mentioned fields. Empirical and modeled data relevant to energy modeling is reported and available at various spatial and temporal scales that might or might not be those needed and used by the energy modeling community. The incorrect representation of spatial and temporal components of these data sets can result in energy models producing misleading conclusions, especially in cases of newly evolving technologies with spatial and temporal operating characteristics different from the dominant fossil and nuclear technologies that powered the energy economy over the last two hundred years. Increased private and government research and development and public interest in alternative technologies that have a benign effect on the climate and the environment have spurred interest in wind, solar, hydrogen, and other alternative energy sources and energy carriers. Many of these technologies require much finer spatial and temporal detail to determine optimal engineering designs, resource availability, and market potential. This paper presents exploratory and modeling techniques in spatial statistics that can improve the usefulness of empirical and modeled data sets that do not initially meet the spatial and/or temporal requirements of energy models. In particular, we focus on (1) aggregation and disaggregation of spatial data, (2) predicting missing data, and (3) merging spatial data sets. In addition, we introduce relevant statistical software models commonly used in the field for various sizes and types of data sets.

Lawrence Livermore National Laboratory

2006-01-27T23:59:59.000Z

280

Spatial Statistical Procedures to Validate Input Data in Energy Models  

DOE Green Energy (OSTI)

Energy modeling and analysis often relies on data collected for other purposes such as census counts, atmospheric and air quality observations, economic trends, and other primarily non-energy related uses. Systematic collection of empirical data solely for regional, national, and global energy modeling has not been established as in the abovementioned fields. Empirical and modeled data relevant to energy modeling is reported and available at various spatial and temporal scales that might or might not be those needed and used by the energy modeling community. The incorrect representation of spatial and temporal components of these data sets can result in energy models producing misleading conclusions, especially in cases of newly evolving technologies with spatial and temporal operating characteristics different from the dominant fossil and nuclear technologies that powered the energy economy over the last two hundred years. Increased private and government research and development and public interest in alternative technologies that have a benign effect on the climate and the environment have spurred interest in wind, solar, hydrogen, and other alternative energy sources and energy carriers. Many of these technologies require much finer spatial and temporal detail to determine optimal engineering designs, resource availability, and market potential. This paper presents exploratory and modeling techniques in spatial statistics that can improve the usefulness of empirical and modeled data sets that do not initially meet the spatial and/or temporal requirements of energy models. In particular, we focus on (1) aggregation and disaggregation of spatial data, (2) predicting missing data, and (3) merging spatial data sets. In addition, we introduce relevant statistical software models commonly used in the field for various sizes and types of data sets.

Johannesson, G.; Stewart, J.; Barr, C.; Brady Sabeff, L.; George, R.; Heimiller, D.; Milbrandt, A.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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

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

282

J-Integral modeling and validation for GTS reservoirs.  

DOE Green Energy (OSTI)

Non-destructive detection methods can reliably certify that gas transfer system (GTS) reservoirs do not have cracks larger than 5%-10% of the wall thickness. To determine the acceptability of a reservoir design, analysis must show that short cracks will not adversely affect the reservoir behavior. This is commonly done via calculation of the J-Integral, which represents the energetic driving force acting to propagate an existing crack in a continuous medium. J is then compared against a material's fracture toughness (J{sub c}) to determine whether crack propagation will occur. While the quantification of the J-Integral is well established for long cracks, its validity for short cracks is uncertain. This report presents the results from a Sandia National Laboratories project to evaluate a methodology for performing J-Integral evaluations in conjunction with its finite element analysis capabilities. Simulations were performed to verify the operation of a post-processing code (J3D) and to assess the accuracy of this code and our analysis tools against companion fracture experiments for 2- and 3-dimensional geometry specimens. Evaluation is done for specimens composed of 21-6-9 stainless steel, some of which were exposed to a hydrogen environment, for both long and short cracks.

Martinez-Canales, Monica L.; Nibur, Kevin A.; Lindblad, Alex J.; Brown, Arthur A.; Ohashi, Yuki; Zimmerman, Jonathan A.; Huestis, Edwin; Hong, Soonsung; Connelly, Kevin; Margolis, Stephen B.; Somerday, Brian P.; Antoun, Bonnie R.

2009-01-01T23:59:59.000Z

283

Model validation for the August 10, 1996 WSCC system outage  

SciTech Connect

A major power outage occurred in western North America on August 10, 1996. In this paper the authors describe simulation of the disturbance using a transient stability program. Initially, the sequence of events was simulated using the standard WSCC dynamic data base, and the simulations did not agree with the disturbance recordings. Several model additions and data modifications were made before the simulations approximated the disturbance recordings. These model changes are discussed in the paper.

Kosterev, D.N.; Taylor, C.W.; Mittelstadt, W.A. [Bonneville Power Administration, Portland, OR (United States). Transmission Operations and Planning

1999-08-01T23:59:59.000Z

284

Experimental validation of different modeling approaches for solid particle receivers.  

Science Conference Proceedings (OSTI)

Solid particle receivers have the potential to provide high-temperature heat for advanced power cycles, thermochemical processes, and thermal storage via direct particle absorption of concentrated solar energy. This paper presents two different models to evaluate the performance of these systems. One model is a detailed computational fluid dynamics model using FLUENT that includes irradiation from the concentrated solar flux, two-band re-radiation and emission within the cavity, discrete-phase particle transport and heat transfer, gas-phase convection, wall conduction, and radiative and convective heat losses. The second model is an easy-to-use and fast simulation code using Matlab that includes solar and thermal radiation exchange between the particle curtain, cavity walls, and aperture, but neglects convection. Both models were compared to unheated particle flow tests and to on-sun heating tests. Comparisons between measured and simulated particle velocities, opacity, particle volume fractions, particle temperatures, and thermal efficiencies were found to be in good agreement. Sensitivity studies were also performed with the models to identify parameters and modifications to improve the performance of the solid particle receiver.

Khalsa, Siri Sahib S.; Amsbeck, Lars (German Aerospace Center (DLR), Spain and Stuttgart, Germany); Roger, Marc (German Aerospace Center (DLR), Spain and Stuttgart, Germany); Siegel, Nathan Phillip; Kolb, Gregory J.; Buck, Reiner (German Aerospace Center (DLR), Spain and Stuttgart, Germany); Ho, Clifford Kuofei

2009-07-01T23:59:59.000Z

285

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

286

Verification and validation benchmarks.  

SciTech Connect

Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of achievement in V&V activities, how closely related the V&V benchmarks are to the actual application of interest, and the quantification of uncertainties related to the application of interest.

Oberkampf, William Louis; Trucano, Timothy Guy

2007-02-01T23:59:59.000Z

287

Validation of the FLAGSOL parabolic trough solar power plant performance model  

DOE Green Energy (OSTI)

This paper describes the results of a validation of the FLAGSOL parabolic trough solar power plant performance model. The validation was accomplished by simulating an operating solar electric generating system (SEGS) parabolic trough solar thermal power plant and comparing the model output results with actual plant operating data. This comparison includes instantaneous, daily, and annual total solar thermal electric output, gross solar electric generation, and solar mode parasitic electric consumption. The results indicate that the FLAGSOL model adequately predicts the gross solar electric output of an operating plant, both on a daily and an annual basis.

Price, H.W. [National Renewable Energy Lab., Golden, CO (United States); Svoboda, P. [Flachglas-Solartechnik GmbH, Koeln (Germany); Kearney, D. [Kearney and Associates, Del Mar, CA (United States)

1994-10-01T23:59:59.000Z

288

Modeling HCCI using CFD and Detailed Chemistry with Experimental Validation and a Focus on CO Emissions  

DOE Green Energy (OSTI)

Multi-zone CFD simulations with detailed kinetics were used to model engine experiments performed on a diesel engine that was converted for single cylinder, HCCI operation, here using iso-octane as the fuel. The modeling goals were to validate the method (multi-zone combustion modeling) and the reaction mechanism (LLNL 857 species iso-octane), both of which performed very well. The purpose of this paper is to document the validation findings and to set the ground work for further analysis of the results by first looking at CO emissions characteristics with varying equivalence ratio.

Hessel, R; Foster, D; Aceves, S; Flowers, D; Pitz, B; Dec, J; Sjoberg, M; Babajimopoulos, A

2007-04-23T23:59:59.000Z

289

Validation of Embedded Systems Behavioral Models on a Component-Based Ericsson Nikola Tesla Demonstrator  

Science Conference Proceedings (OSTI)

Embedded systems are challenging to design, due to the implementation platform constraints that have to be considered, preferably from early stages of design, next-by system functionality. Hence, embedded system models need to be timing and resource-aware, ... Keywords: embedded systems, behavioral models, extra-funcational verification, validation, priced timed automata

Aneta Vulgarakis; Cristina Seceleanu; Paul Pettersson; Ivan Skuliber; Darko Huljenic

2011-07-01T23:59:59.000Z

290

Preliminary Validation Using in vivo Measures of a Macroscopic Electrical Model of the Heart  

E-Print Network (OSTI)

Preliminary Validation Using in vivo Measures of a Macroscopic Electrical Model of the Heart Maxime Antipolis, France 2 National Institutes of Health, National Heart Lung and Blood Institute, Laboratory of the cardiac electrical activity in a canine heart coupled with simulations done using macroscopic models

Coudière, Yves

291

Modeling and Validation of a Fuel Cell Hybrid Vehicle  

E-Print Network (OSTI)

This paper describes the design and construction of a fuel cell hybrid electric vehicle based on the conversion of a five passenger production sedan. The vehicle uses a relatively small fuel cell stack to provide average power demands, and a battery pack to provide peak power demands for varied driving conditions. A model of this vehicle was developed using ADVISOR, an A__dvanced Vehicle Simulator that tracks energy flow and fuel usage within the vehicle drivetrain and energy conversion components.

Michael J. Ogburn; Douglas J. Nelson; Keith Wipke; Tony Markel

2000-01-01T23:59:59.000Z

292

Vibration Model Validation for Linear Collider Detector Platforms  

SciTech Connect

The ILC and CLIC reference designs incorporate reinforced-concrete platforms underneath the detectors so that the two detectors can each be moved onto and off of the beamline in a Push-Pull configuration. These platforms could potentially amplify ground vibrations, which would reduce luminosity. In this paper we compare vibration models to experimental data on reinforced concrete structures, estimate the impact on luminosity, and summarize implications for the design of a reinforced concrete platform for the ILC or CLIC detectors.

Bertsche, Kirk; Amann, J.W.; Markiewicz, T.W.; Oriunno, M.; Weidemann, A.; White, G.; /SLAC

2012-05-16T23:59:59.000Z

293

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

294

Validation and Application of the Room Model of the Modelica Buildings  

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

Validation and Application of the Room Model of the Modelica Buildings Validation and Application of the Room Model of the Modelica Buildings Library Title Validation and Application of the Room Model of the Modelica Buildings Library Publication Type Conference Proceedings LBNL Report Number LBNL-5932E Year of Publication 2012 Authors Nouidui, Thierry Stephane, Kaustubh Phalak, Wangda Zuo, and Michael Wetter Conference Name Proc. of the 9th International Modelica Conference Date Published 09/2012 Conference Location Munich, Germany Abstract The Modelica Buildings library contains a package with a model for a thermal zone that computes heat transfer through the building envelope and within a room. It considers various heat transfer phenomena of a room, including conduction, convection, short-wave and long-wave radiation. The first part of this paper describes the physical phenomena considered in the room model. The second part validates the room model by using a standard test suite provided by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). The third part focuses on an application where the room model is used for simulation-based controls of a window shading device to reduce building energy consumption.

295

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

296

Verification and Validation of EnergyPlus Phase Change Material Model for Opaque Wall Assemblies  

Science Conference Proceedings (OSTI)

Phase change materials (PCMs) represent a technology that may reduce peak loads and HVAC energy consumption in buildings. A few building energy simulation programs have the capability to simulate PCMs, but their accuracy has not been completely tested. This study shows the procedure used to verify and validate the PCM model in EnergyPlus using a similar approach as dictated by ASHRAE Standard 140, which consists of analytical verification, comparative testing, and empirical validation. This process was valuable, as two bugs were identified and fixed in the PCM model, and version 7.1 of EnergyPlus will have a validated PCM model. Preliminary results using whole-building energy analysis show that careful analysis should be done when designing PCMs in homes, as their thermal performance depends on several variables such as PCM properties and location in the building envelope.

Tabares-Velasco, P. C.; Christensen, C.; Bianchi, M.

2012-08-01T23:59:59.000Z

297

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

298

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

299

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

300

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

Note: This page contains sample records for the topic "numerical model validation" 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 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

302

Model Reduction, Validation, and Calibration of Wind Power Plants for Dynamic Studies  

SciTech Connect

Accurate representation of wind power plants (WPP) in both offline and online power system stability studies has gained importance because of the rapid increase in installation of wind generation around the world. On the other hand, reduced WPP representation is preferred due to computational efficiency. To improve the accuracy, other authors have proposed changes in structure of the reduced model for large WPPs. The use of model validation and calibration is an alternative to improve the accuracy of the reduced WPP model. In this paper, we compare accuracy improvements brought by changes in model structure with accuracy improvements brought by validation and calibration of the reduced WPP model with minimal changes in structure. We illustrate our findings using a 168-machine WPP connected to the IEEE-39-bus test system. The parameters of the reduced WPP model are either calculated with current equivalencing techniques or validated and calibrated against a more accurate model. The changes in structure of the reduced model are 1-machine or 2-machine reduced models connected with a 1-line or 2-line collector equivalents. We show that the most accurate response is obtained by calibrating the parameters of the reduced model with minimum changes in structure.

Elizondo, Marcelo A.; Lu, Shuai; Zhou, Ning; Samaan, Nader A.

2011-10-10T23:59:59.000Z

303

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

304

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

305

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

306

Validation of a Hot Water Distribution Model Using Laboratory and Field Data  

SciTech Connect

Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the ARBI team validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. In addition to completing validation activities, this project looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. Based on these datasets, we conclude that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws. This has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

Backman, C.; Hoeschele, M.

2013-07-01T23:59:59.000Z

307

Specification verification and validation of wireless sensor network model for environment monitoring  

Science Conference Proceedings (OSTI)

In this paper we propose methodology for modeling and development of wireless sensor network (WSN) application for monitoring, quantifying, verifying and validating organization GHG information. We have discussed preliminary activities and challenges ... Keywords: fault tolerance, formal methods, wireless sensor network (WSN)

R Jaichandran; A. Anthony Irudhayaraj

2011-12-01T23:59:59.000Z

308

Dynamic Model Validation of PV Inverters under Short-Circuit Conditions  

Science Conference Proceedings (OSTI)

Photovoltaic (PV) modules have dramatically decreased in price in the past few years, spurring the expansion of PV deployment. Residential and commercial rooftop installations are connected to the distribution network, large-scale installation PV power ... Keywords: photovoltaic, PV, dynamic model, validation, solar PV inverter, renewables

E. Muljadi, M. Singh, R. Bravo, V. Gevorgian

2013-04-01T23:59:59.000Z

309

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation  

E-Print Network (OSTI)

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation Shan to regulate the speed of a permanent magnet synchronous motor where the design is based on a linearized state rejection, constraints, quadratic programming. 1. Introduction Permanent Magnet Synchronous Motors (PMSMs

310

Model Validation at the 204 MW New Mexico Wind Energy Center: Preprint  

DOE Green Energy (OSTI)

In this paper, we describe methods to derive and validate equivalent models for a large wind farm. FPL Energy's 204-MW New Mexico Wind Energy Center, which is interconnected to the Public Service Company of New Mexico (PNM) transmission system, was used as a case study. The methods described are applicable to any large wind power plant.

Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

2006-06-01T23:59:59.000Z

311

Model Validation at the 204 MW New Mexico Wind Energy Center: Preprint  

SciTech Connect

In this paper, we describe methods to derive and validate equivalent models for a large wind farm. FPL Energy's 204-MW New Mexico Wind Energy Center, which is interconnected to the Public Service Company of New Mexico (PNM) transmission system, was used as a case study. The methods described are applicable to any large wind power plant.

Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hochheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

2006-06-01T23:59:59.000Z

312

Field validation of the DNDC model for greenhouse gas emissions in East Asian cropping systems  

E-Print Network (OSTI)

Field validation of the DNDC model for greenhouse gas emissions in East Asian cropping systems annual variations of greenhouse gas emissions from cropping systems and effects of land management a powerful tool for estimating greenhouse gas emissions from terrestrial ecosystems. INDEX TERMS: 1610 Global

313

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

314

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

315

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

316

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

317

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

318

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

319

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

320

Validation of Precipitable Water Vapor within the NCEP/DOE Reanalysis Using Global GPS Observations from One Decade  

Science Conference Proceedings (OSTI)

In contrast to previous studies validating numerical weather prediction (NWP) models using observations from the global positioning system (GPS), this paper focuses on the validation of seasonal and interannual variations in the water vapor. The ...

Sibylle Vey; Reinhard Dietrich; Axel Rülke; Mathias Fritsche; Peter Steigenberger; Markus Rothacher

2010-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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

Black liquor combustion validated recovery boiler modeling: Final year report. Volume 5 (Appendix V)  

DOE Green Energy (OSTI)

This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 5 contains model validation simulations and comparison with data.

Grace, T.M.; Frederick, W.J.; Salcudean, M.; Wessel, R.A.

1998-08-01T23:59:59.000Z

322

Validated modeling of distributed energy resources at distribution voltages : LDRD project 38672.  

SciTech Connect

A significant barrier to the deployment of distributed energy resources (DER) onto the power grid is uncertainty on the part of utility engineers regarding impacts of DER on their distribution systems. Because of the many possible combinations of DER and local power system characteristics, these impacts can most effectively be studied by computer simulation. The goal of this LDRD project was to develop and experimentally validate models of transient and steady state source behavior for incorporation into utility distribution analysis tools. Development of these models had not been prioritized either by the distributed-generation industry or by the inverter industry. A functioning model of a selected inverter-based DER was developed in collaboration with both the manufacturer and industrial power systems analysts. The model was written in the PSCAD simulation language, a variant of the ElectroMagnetic Transients Program (EMTP), a code that is widely used and accepted by utilities. A stakeholder team was formed and a methodology was established to address the problem. A list of detailed DER/utility interaction concerns was developed and prioritized. The list indicated that the scope of the problem significantly exceeded resources available for this LDRD project. As this work progresses under separate funding, the model will be refined and experimentally validated. It will then be incorporated in utility distribution analysis tools and used to study a variety of DER issues. The key next step will be design of the validation experiments.

Ralph, Mark E.; Ginn, Jerry W.

2004-03-01T23:59:59.000Z

323

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

324

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

325

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

326

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

327

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

328

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

329

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

330

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

331

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

332

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

333

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

334

Model Validation and Testing: The Methodological Foundation of ASHRAE Standard 140; Preprint  

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

Model Validation and Testing: Model Validation and Testing: The Methodological Foundation of ASHRAE Standard 140 Preprint R. Judkoff National Renewable Energy Laboratory J. Neymark J. Neymark & Associates Presented at the ASHRAE 2006 Annual Meeting Quebec City, Canada June 24-29, 2006 Conference Paper NREL/CP-550-40360 July 2006 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

335

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

336

Development and validation of a combustion model for a fuel cell off-gas burner  

E-Print Network (OSTI)

and environmentally clean power generation has never been so important. The increasing cost of fossil fuels and more stringent regulations on emissions (particularly CO2 and NOx), together with increasing demand for electricity, make the provision of cost... Development and Validation of a Combustion Model for a Fuel Cell Off-Gas Burner W. Tristan Collins Magdalene College University of Cambridge A dissertation submitted to the University of Cambridge for the degree of Doctor of Philosophy June 2008...

Collins, William Tristan

2008-10-14T23:59:59.000Z

337

A Model for Flow and Dispersion Around Buildings and Its Validation Using Laboratory Measurements  

DOE Green Energy (OSTI)

Numerical modeling of airflow and pollutant dispersion around buildings is a challenging task due to the geometrical variations of buildings and the extremely complex flow created by such surface-mounted obstacles. The airflow around buildings inevitably involves impingement and separation regions, a multiple vortex system with building wakes, and jetting effects in street canyons. The interference from adjacent buildings further complicates the flow and dispersion patterns. Thus accurate simulations of such flow and pollutant transport require not only appropriate physics submodels but also accurate numerics and significant computing resources. We have developed an efficient, high resolution CFD model for such purposes, with a primary goal to support incident response and preparedness in emergency response planning, vulnerability analysis, and the development of mitigation techniques.

Chan, S.T.; Stevens, D.; Lee, R.

2000-05-17T23:59:59.000Z

338

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

339

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

340

Validation and Calibration of Nuclear Thermal Hydraulics Multiscale Multiphysics Models - Subcooled Flow Boiling Study  

SciTech Connect

In addition to validation data plan, development of advanced techniques for calibration and validation of complex multiscale, multiphysics nuclear reactor simulation codes are a main objective of the CASL VUQ plan. Advanced modeling of LWR systems normally involves a range of physico-chemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which occur over a wide range of spatial and temporal scales. To a large extent, the accuracy of (and uncertainty in) overall model predictions is determined by the correctness of various sub-models, which are not conservation-laws based, but empirically derived from measurement data. Such sub-models normally require extensive calibration before the models can be applied to analysis of real reactor problems. This work demonstrates a case study of calibration of a common model of subcooled flow boiling, which is an important multiscale, multiphysics phenomenon in LWR thermal hydraulics. The calibration process is based on a new strategy of model-data integration, in which, all sub-models are simultaneously analyzed and calibrated using multiple sets of data of different types. Specifically, both data on large-scale distributions of void fraction and fluid temperature and data on small-scale physics of wall evaporation were simultaneously used in this work’s calibration. In a departure from traditional (or common-sense) practice of tuning/calibrating complex models, a modern calibration technique based on statistical modeling and Bayesian inference was employed, which allowed simultaneous calibration of multiple sub-models (and related parameters) using different datasets. Quality of data (relevancy, scalability, and uncertainty) could be taken into consideration in the calibration process. This work presents a step forward in the development and realization of the “CIPS Validation Data Plan” at the Consortium for Advanced Simulation of LWRs to enable quantitative assessment of the CASL modeling of Crud-Induced Power Shift (CIPS) phenomenon, in particular, and the CASL advanced predictive capabilities, in general. This report is prepared for the Department of Energy’s Consortium for Advanced Simulation of LWRs program’s VUQ Focus Area.

Anh Bui; Nam Dinh; Brian Williams

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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

Validation of New Process Models for Large Injection-Molded Long-Fiber Thermoplastic Composite Structures  

Science Conference Proceedings (OSTI)

This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.

Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Kunc, Vlastimil; Tucker III, Charles L.

2012-02-23T23:59:59.000Z

342

Black liquor combustion validated recovery boiler modeling: Final year report. Volume 1 (Main text and Appendix I, sections 1--4)  

DOE Green Energy (OSTI)

This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 1 contains the main body of the report and the first 4 sections of Appendix 1: Modeling of black liquor recovery boilers -- summary report; Flow and heat transfer modeling in the upper furnace of a kraft recovery boiler; Numerical simulation of black liquor combustion; and Investigation of turbulence models and prediction of swirling flows for kraft recovery furnaces.

Grace, T.M.; Frederick, W.J.; Salcudean, M.; Wessel, R.A.

1998-08-01T23:59:59.000Z

343

Coupling an Advanced Land Surface–Hydrology Model with the Penn State–NCAR MM5 Modeling System. Part II: Preliminary Model Validation  

Science Conference Proceedings (OSTI)

A number of short-term numerical experiments conducted by the Penn State–NCAR fifth-generation Mesoscale Model (MM5) coupled with an advanced land surface model, alongside the simulations coupled with a simple slab model, are verified with ...

Fei Chen; Jimy Dudhia

2001-04-01T23:59:59.000Z

344

Wind Turbine Generator Model Validation Software Tool (WTGMV) Version 1.0  

Science Conference Proceedings (OSTI)

This software tool allows the user to validate the model for a wind turbine generator (WTG) using measured disturbance data from either a digital fault recorder (DFR) or a phaor measurement unit (PMU) located at the turbine - factor measured data from type testing of the turbine may also be used. The tool also performs parameter optimization on a some of the model parameters such as a few of the controller gains. The tool is a first step in the ultimate plan to enhance the tool to allow for ...

2012-08-30T23:59:59.000Z

345

Validity of pair truncation of the nuclear shell model in {sup 46}Ca  

SciTech Connect

We study the validity of pair truncation of the nuclear shell model by using the semimagic nucleus {sup 46}Ca. We present low-lying states and their E2 transition rates based on both nucleon pair approximation (NPA) and exact shell-model (SM) calculations. We also calculate overlaps between wave functions of low-lying states calculated by using the NPA and those calculated by using the SM. Our calculated results show a remarkable agreement between the NPA results and the SM results, although the NPA is a drastic truncation of the SM.

Lei, Y.; Xu, Z. Y. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhao, Y. M. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); CCAST, World Laboratory, Post Office Box 8730, Beijing 100080 (China); Arima, A. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Science Museum, Japan Science Foundation, 2-1 Kitanomaru-koen, Chiyoda-ku, Tokyo 102-0091 (Japan)

2009-12-15T23:59:59.000Z

346

Experimental Validation of Stochastic Wireless Urban Channel Model: Estimation and Prediction  

SciTech Connect

Stochastic differential equations (SDE) can be used to describe the time-varying nature of wireless channels. This paper validates a long-term fading channel model for estimation and prediction from solely using measured received signal strength measurements. Such channel models can be used for optimizing wireless networks deployed for industrial automation, public access, and communication. This paper uses two different sets of received signal measurement data to estimate an predict the signal strength based on past measurements. The realworld performance of the estimation and prediction algorithm is demonstrated.

Kuruganti, Phani Teja [ORNL; Ma, Xiao [ORNL; Djouadi, Seddik M [ORNL

2012-01-01T23:59:59.000Z

347

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

348

Importance of Second-Order Difference-Frequency Wave-Diffraction Forces in the Validation of a Fast Semi-Submersible Floating Wind Turbine Model: Preprint  

DOE Green Energy (OSTI)

To better access the abundant offshore wind resource, efforts across the world are being undertaken to develop and improve floating offshore wind turbine technologies. A critical aspect of creating reliable, mature floating wind turbine technology is the development, verification, and validation of efficient computer-aided-engineering (CAE) tools that can be relied upon in the design process. The National Renewable Energy Laboratory (NREL) has created a comprehensive, coupled analysis CAE tool for floating wind turbines, FAST, which has been verified and utilized in numerous floating wind turbine studies. Several efforts are currently underway that leverage the extensive 1/50th-scale DeepCwind wind/wave basin model test dataset, obtained at the Maritime Research Institute Netherlands (MARIN) in 2011, to validate the floating platform functionality of FAST to complement its already validated aerodynamic and structural simulation capabilities. In this paper, further work is undertaken to continue this validation. In particular, the ability of FAST to replicate global response behaviors associated with dynamic wind forces, second-order difference-frequency wave-diffraction forces and their interaction with one another are investigated.

Couling, A. J.; Goupee, A. J.; Robertson, A. N.; Jonkman, J. M.

2013-06-01T23:59:59.000Z

349

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

350

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

351

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

352

Formulation, Implementation and Validation of a Two-Fluid model in a Fuel Cell CFD Code  

SciTech Connect

Water management is one of the main challenges in PEM Fuel Cells. While water is essential for membrane electrical conductivity, excess liquid water leads to ooding of catalyst layers. Despite the fact that accurate prediction of two-phase transport is key for optimal water management, understanding of the two-phase transport in fuel cells is relatively poor. Wang et. al. [1], [2] have studied the two-phase transport in the channel and diffusion layer separately using a multiphase mixture model. The model fails to accurately predict saturation values for high humidity inlet streams. Nguyen et. al. [3] developed a two-dimensional, two-phase, isothermal, isobaric, steady state model of the catalyst and gas diffusion layers. The model neglects any liquid in the channel. Djilali et. al. [4] developed a three-dimensional two-phase multicomponent model. The model is an improvement over previous models, but neglects drag between the liquid and the gas phases in the channel. In this work, we present a comprehensive two- fluid model relevant to fuel cells. Models for two-phase transport through Channel, Gas Diffusion Layer (GDL) and Channel-GDL interface, are discussed. In the channel, the gas and liquid pressures are assumed to be same. The surface tension effects in the channel are incorporated using the continuum surface force (CSF) model. The force at the surface is expressed as a volumetric body force and added as a source to the momentum equation. In the GDL, the gas and liquid are assumed to be at different pressures. The difference in the pressures (capillary pressure) is calculated using an empirical correlations. At the Channel-GDL interface, the wall adhesion affects need to be taken into account. SIMPLE-type methods recast the continuity equation into a pressure-correction equation, the solution of which then provides corrections for velocities and pressures. However, in the two-fluid model, the presence of two phasic continuity equations gives more freedom and more complications. A general approach would be to form a mixture continuity equation by linearly combining the phasic continuity equations using appropriate weighting factors. Analogous to mixture equation for pressure correction, a difference equation is used for the volume/phase fraction by taking the difference between the phasic continuity equations. The relative advantages of the above mentioned algorithmic variants for computing pressure correction and volume fractions are discussed and quantitatively assessed. Preliminary model validation is done for each component of the fuel cell. The two-phase transport in the channel is validated using empirical correlations. Transport in the GDL is validated against results obtained from LBM and VOF simulation techniques. The Channel-GDL interface transport will be validated against experiment and empirical correlation of droplet detachment at the interface. References [1] Y. Wang S. Basu and C.Y. Wang. Modeling two-phase flow in pem fuel cell channels. J. Power Sources, 179:603{617, 2008. [2] P. K. Sinha and C. Y. Wang. Liquid water transport in a mixed-wet gas diffusion layer of a polymer electrolyte fuel cell. Chem. Eng. Sci., 63:1081-1091, 2008. [3] Guangyu Lin and Trung Van Nguyen. A two-dimensional two-phase model of a pem fuel cell. J. Electrochem. Soc., 153(2):A372{A382, 2006. [4] T. Berning and N. Djilali. A 3d, multiphase, multicomponent model of the cathode and anode of a pem fuel cell. J. Electrochem. Soc., 150(12):A1589{A1598, 2003.

Kunal Jain, Vernon Cole, Sanjiv Kumar and N. Vaidya

2008-11-01T23:59:59.000Z

353

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

354

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

355

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

356

Black liquor combustion validated recovery boiler modeling: Final year report. Volume 4 (Appendix IV)  

DOE Green Energy (OSTI)

This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 4 contains the following appendix sections: Radiative heat transfer properties for black liquor combustion -- Facilities and techniques and Spectral absorbance and emittance data; and Radiate heat transfer determination of the optical constants of ash samples from kraft recovery boilers -- Calculation procedure; Computation program; Density determination; Particle diameter determination; Optical constant data; and Uncertainty analysis.

Grace, T.M.; Frederick, W.J.; Salcudean, M.; Wessel, R.A.

1998-08-01T23:59:59.000Z

357

Determining Wind Turbine Gearbox Model Complexity Using Measurement Validation and Cost Comparison: Preprint  

DOE Green Energy (OSTI)

The Gearbox Reliability Collaborative (GRC) has conducted extensive field and dynamometer test campaigns on two heavily instrumented wind turbine gearboxes. In this paper, data from the planetary stage is used to evaluate the accuracy and computation time of numerical models of the gearbox. First, planet-bearing load and motion data is analyzed to characterize planetary stage behavior in different environments and to derive requirements for gearbox models and life calculations. Second, a set of models are constructed that represent different levels of fidelity. Simulations of the test conditions are compared to the test data and the computational cost of the models are compared. The test data suggests that the planet-bearing life calculations should be made separately for each bearing on a row due to unequal load distribution. It also shows that tilting of the gear axes is related to planet load share. The modeling study concluded that fully flexible models were needed to predict planet-bearing loading in some cases, although less complex models were able to achieve good correlation in the field-loading case. Significant differences in planet load share were found in simulation and were dependent on the scope of the model and the bearing stiffness model used.

LaCava, W.; Xing, Y.; Guo, Y.; Moan, T.

2012-04-01T23:59:59.000Z

358

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

359

Characterization of the Thermal Structure inside an Urban Canyon: Field Measurements and Validation of a Simple Model  

Science Conference Proceedings (OSTI)

The results of measurement campaigns are analyzed to investigate the thermal structure in an urban canyon and to validate a simplified model simulating the air and surface temperatures from surface energy budgets. Starting from measurements at ...

Lorenzo Giovannini; Dino Zardi; Massimiliano de Franceschi

2013-01-01T23:59:59.000Z

360

Dynamic Model Validation of PV Inverters Under Short-Circuit Conditions: Preprint  

SciTech Connect

Photovoltaic (PV) modules have dramatically decreased in price in the past few years, spurring the expansion of photovoltaic deployment. Residential and commercial rooftop installations are connected to the distribution network; large-scale installation PV power plants (PVPs) have benefited from tax incentives and the low cost of PV modules. As the level penetration of PV generation increases, the impact on power system reliability will also be greater. Utility power system planners must consider the role of PV generation in power systems more realistically by representing PV generation in dynamic stability analyses. Dynamic models of PV inverters have been developed in the positive sequence representation. NREL has developed a PV inverter dynamic model in PSCAD/EMTDC. This paper validates the dynamic model with an actual hardware bench test conducted by Southern California Edison's Distributed Energy Resources laboratory. All the fault combinations -- symmetrical and unsymmetrical -- were performed in the laboratory. We compare the simulation results with the bench test results.

Muljadi, E.; Singh, M.; Bravo, R.; Gevorgian, V.

2013-03-01T23:59:59.000Z

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361

A NEW OPERATIONAL MODEL FOR SATELLITE-DERIVED IRRADIANCES DESCRIPTION AND VALIDATION  

Open Energy Info (EERE)

Published in Solar Energy - Vol. 73, 5, pp. 307-317, (2002) Published in Solar Energy - Vol. 73, 5, pp. 307-317, (2002) 1 of 23 A NEW OPERATIONAL MODEL FOR SATELLITE-DERIVED IRRADIANCES DESCRIPTION AND VALIDATION Richard Perez * Pierre Ineichen ** Kathy Moore * Marek Kmiecik * Cyril Chain *** Ray George **** Frank Vignola ***** * ASRC - The University at Albany, Albany, NY, USA ** CUEPE - University of Geneva, Geneva, Switzerland *** Vaulx-en-Velin, France **** NREL, Golden, CO, USA ***** University of Oregon, Eugene, OR, USA Published in Solar Energy - Vol. 73, 5, pp. 307-317, (2002) 2 of 23 ABSTRACT We present a new simple model capable of exploiting geostationary satellite visible images for the production of site/time specific global and direct irradiances The new model features new clear sky global and direct irradiance functions, a new

362

Model Validation and Testing: The Methodological Foundation of ASHRAE Standard 140  

SciTech Connect

Ideally, whole-building energy simulation programs model all aspects of a building that influence energy use and thermal and visual comfort for the occupants. An essential component of the development of such computer simulation models is a rigorous program of validation and testing. This paper describes a methodology to evaluate the accuracy of whole-building energy simulation programs. The methodology is also used to identify and diagnose differences in simulation predictions that may be caused by algorithmic differences, modeling limitations, coding errors, or input errors. The methodology has been adopted by ANSI/ASHRAE Standard 140, Method of Test for the Evaluation of Building Energy Analysis Computer Programs (ASHRAE 2001a, 2004). A summary of the method is included in the 2005 ASHRAE Handbook--Fundamentals (ASHRAE 2005). This paper describes the ASHRAE Standard 140 method of test and its methodological basis. Also discussed are possible future enhancements to ASHRAE Standard 140 and related research recommendations.

Judkoff, R.; Neymark, J.

2006-01-01T23:59:59.000Z

363

Model Validation and Testing: The Methodological Foundation of ASHRAE Standard 140; Preprint  

Science Conference Proceedings (OSTI)

Ideally, whole-building energy simulation programs model all aspects of a building that influence energy use and thermal and visual comfort for the occupants. An essential component of the development of such computer simulation models is a rigorous program of validation and testing. This paper describes a methodology to evaluate the accuracy of whole-building energy simulation programs. The methodology is also used to identify and diagnose differences in simulation predictions that may be caused by algorithmic differences, modeling limitations, coding errors, or input errors. The methodology has been adopted by ANSI/ASHRAE Standard 140 (ANSI/ASHRAE 2001, 2004), Method of Test for the Evaluation of Building Energy Analysis Computer Programs. A summary of the method is included in the ASHRAE Handbook of Fundamentals (ASHRAE 2005). This paper describes the ANSI/ASHRAE Standard 140 method of test and its methodological basis. Also discussed are possible future enhancements to Standard 140 and related research recommendations.

Judkoff, R.; Neymark, J.

2006-07-01T23:59:59.000Z

364

Dynamic Model Validation of PV Inverters Under Short-Circuit Conditions: Preprint  

SciTech Connect

Photovoltaic (PV) modules have dramatically decreased in price in the past few years, spurring the expansion of photovoltaic deployment. Residential and commercial rooftop installations are connected to the distribution network; large-scale installation PV power plants (PVPs) have benefited from tax incentives and the low cost of PV modules. As the level penetration of PV generation increases, the impact on power system reliability will also be greater. Utility power system planners must consider the role of PV generation in power systems more realistically by representing PV generation in dynamic stability analyses. Dynamic models of PV inverters have been developed in the positive sequence representation. NREL has developed a PV inverter dynamic model in PSCAD/EMTDC. This paper validates the dynamic model with an actual hardware bench test conducted by Southern California Edison's Distributed Energy Resources laboratory. All the fault combinations -- symmetrical and unsymmetrical -- were performed in the laboratory. We compare the simulation results with the bench test results.

Muljadi, E.; Singh, M.; Bravo, R.; Gevorgian, V.

2013-03-01T23:59:59.000Z

365

Assessment of the Value, Impact, and Validity of the Jobs and Economic Development Impacts (JEDI) Suite of Models  

SciTech Connect

The Jobs and Economic Development Impacts (JEDI) models, developed by the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), use input-output methodology to estimate gross (not net) jobs and economic impacts of building and operating selected types of renewable electricity generation and fuel plants. This analysis provides the DOE with an assessment of the value, impact, and validity of the JEDI suite of models. While the models produce estimates of jobs, earnings, and economic output, this analysis focuses only on jobs estimates. This validation report includes an introduction to JEDI models, an analysis of the value and impact of the JEDI models, and an analysis of the validity of job estimates generated by JEDI model through comparison to other modeled estimates and comparison to empirical, observed jobs data as reported or estimated for a commercial project, a state, or a region.

Billman, L.; Keyser, D.

2013-08-01T23:59:59.000Z

366

Development and Validation of an Aeroelastic Model of a Small Furling Wind Turbine: Preprint  

DOE Green Energy (OSTI)

Small wind turbines often use some form of furling (yawing and/or tilting out of the wind) to protect against excessive power generation and rotor speeds in high winds.The verification study demonstrated the correct implementation of FAST's furling dynamics. During validation, the model tends to predict mean rotor speeds higher than measured in spite of the fact that the mean furl motion and rotor thrust are predicted quite accurately. This work has culminated with an enhanced version of FAST that should prove to be a valuable asset to designers of small wind turbines.

Jonkman, J. M.; Hansen, A. C.

2004-12-01T23:59:59.000Z

367

Validation of Building Energy Modeling Tools Under Idealized and Realistic Conditions  

Science Conference Proceedings (OSTI)

Building energy models provide valuable insight into the energy use of commercial and residential buildings based on the building architecture, materials and thermal loads. They are used in the design of new buildings and the retrofitting to increase the efficiency of older buildings. The accuracy of these models is crucial to reducing the energy use of the United States and building a sustainable energy future. In addition to the architecture and thermal loads of a building, building energy models also must account for the effects of the building's occupants on the energy use of the building. Traditionally simple schedule based methods have been used to account for the effects of the occupants. However, newer research has shown that these methods often result in large differences between the modeled and actual energy use of buildings. In this paper we discuss building energy models and their accuracy in predicting building energy use. In particular we focus on the different types of validation methods which have been used to investigate the accuracy of building energy models and how they account for (or do not account for) the effects of occupants. We also review some of the newer work on stochastic methods for estimating the effects of occupants on building energy use and discuss the improvements necessary to increase the accuracy of building energy models.

Ryan, Emily M.; Sanquist, Thomas F.

2012-04-02T23:59:59.000Z

368

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

369

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

370

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

371

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

372

CASL milestone validates reactor model using TVA data | ornl.gov  

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

Ron Walli Ron Walli Communications 865.576.0226 CASL milestone validates reactor model using TVA data This CASL visualization shows the thermal distribution of neutrons in Watts Bar Unit 1 Cycle 1 reactor core at initial criticality, as calculated by the VERA program. Image courtesy of Oak Ridge National Laboratory. This CASL visualization shows the thermal distribution of neutrons in Watts Bar Unit 1 Cycle 1 reactor core at initial criticality, as calculated by the VERA program. Image courtesy of Oak Ridge National Laboratory. (hi-res image) OAK RIDGE, Tenn., July 10, 2013 -Today, the Consortium for Advanced Simulation of Light Water Reactors announced that its scientists have successfully completed their first full-scale simulation of an operating nuclear reactor. CASL is modeling nuclear reactors on supercomputers to

373

Seasonal thermal energy storage in unsaturated soils: Model development and field validation  

DOE Green Energy (OSTI)

This report summarizes ten years of activity carried out at the Earth Sciences Division of the Lawrence Berkeley Laboratory (LBI) in the subject of seasonal storage of thermal energy in unsaturated soils. The objectives of the work were to make a conceptual study of this type of storage, to offer guidelines for planning and evaluation of the method, to produce models and simulation for an actual field experiment, to participate in an on-line data analysis of experimental results. and to evaluate the results in terms of the validation of the concept, models and the experimental techniques. The actual field experiments were performed in Beer-Sheva, Israel. Details of engineering and field operations are not included in this report.

Doughty, C.; Nir, Aharon, Tsang, Chin-Fu

1991-06-01T23:59:59.000Z

374

Traders' collective portfolio optimization with transaction costs: towards microscopic validation of agent-based models  

E-Print Network (OSTI)

Despite the availability of very detailed data on financial market, agent-based modeling is hindered by the lack of information about real-trader behavior. This makes it impossible to validate agent-based models, which are thus reverse-engineering attempts. This work is a contribution to the building of a set of stylized facts about the traders themselves. Using the client database of Swissquote Bank SA, we find that the transaction cost structure determines on average to a large extend the relationship between the mean turnover per transaction of an investor and his mean wealth. A simple extension of CAPM that includes variable transaction costs is able to reproduce qualitatively the observed behaviors. We argue that this shows the collective ability of a population to construct a mean-variance portfolio that takes into account transaction costs.

de Lachapelle, David Morton

2010-01-01T23:59:59.000Z

375

Validation of the Poisson Stochastic Radiative Transfer Model Against Cloud Cascade Models  

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

Poisson Stochastic Radiative Transfer Poisson Stochastic Radiative Transfer Model Against Cloud Cascade Models T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia A. Marshak National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland Background Starting from a very simple stochastic cloud model by Mullamaa et al. (1972), several different stochastic models have been developed to describe radiative transfer regime in single-layer broken clouds (Kargin 1984; Titov 1990; Malvagi and Pomraning 1992; Barker et al. 1992; Malvagi et al. 1993; Kargin and Prigarin 1994; Prigarin and Titov 1996; Marshak et al. 1998; Prigarin et al. 1998, 2001; Evans et al. 1999, 2001). Recently Kassianov (2003a) generalized the Titov's (1990) stochastic model

376

Validation testing a contaminant transport and natural attenuation simulation model using field data. Master`s thesis  

Science Conference Proceedings (OSTI)

This research extends the work begun by Enyeart (1994) which evaluated the process of intrinsic bioremediation, and which developed a model for predicting the velocity of an aerobic degradation front, as it traverses the length of a JP-4 contaminant plume. In the present work, Enyeart`s model was validity tested by comparing its output prediction with field measured values. A methodology was developed to compare the model output with field measured data. The results were analyzed, and the results of this first stage of validity testing show a reasonable basis for accepting the model.

Flier, S.J.

1995-12-01T23:59:59.000Z

377

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

378

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

379

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

380

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

382

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

383

Model calibration and validation for OFMSW and sewage sludge co-digestion reactors  

SciTech Connect

Highlights: > Disintegration is the limiting step of the anaerobic co-digestion process. > Disintegration kinetic constant does not depend on the waste particle size. > Disintegration kinetic constant depends only on the waste nature and composition. > The model calibration can be performed on organic waste of any particle size. - Abstract: A mathematical model has recently been proposed by the authors to simulate the biochemical processes that prevail in a co-digestion reactor fed with sewage sludge and the organic fraction of municipal solid waste. This model is based on the Anaerobic Digestion Model no. 1 of the International Water Association, which has been extended to include the co-digestion processes, using surface-based kinetics to model the organic waste disintegration and conversion to carbohydrates, proteins and lipids. When organic waste solids are present in the reactor influent, the disintegration process is the rate-limiting step of the overall co-digestion process. The main advantage of the proposed modeling approach is that the kinetic constant of such a process does not depend on the waste particle size distribution (PSD) and rather depends only on the nature and composition of the waste particles. The model calibration aimed to assess the kinetic constant of the disintegration process can therefore be conducted using organic waste samples of any PSD, and the resulting value will be suitable for all the organic wastes of the same nature as the investigated samples, independently of their PSD. This assumption was proven in this study by biomethane potential experiments that were conducted on organic waste samples with different particle sizes. The results of these experiments were used to calibrate and validate the mathematical model, resulting in a good agreement between the simulated and observed data for any investigated particle size of the solid waste. This study confirms the strength of the proposed model and calibration procedure, which can thus be used to assess the treatment efficiency and predict the methane production of full-scale digesters.

Esposito, G., E-mail: giovanni.esposito@unicas.it [Department of Mechanics, Structures and Environmental Engineering, University of Cassino, via Di Biasio 43, 03043 Cassino (Italy); Frunzo, L., E-mail: luigi.frunzo@unina.it [Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, via Cintia, Monte S. Angelo, I-80126 Naples (Italy); Panico, A., E-mail: anpanico@unina.it [Department of Hydraulic, Geotechnical and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples (Italy); Pirozzi, F., E-mail: francesco.pirozzi@unina.it [Department of Hydraulic, Geotechnical and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples (Italy)

2011-12-15T23:59:59.000Z

384

A General Strategy for Physics-Based Model Validation Illustrated with Earthquake Phenomenology, Atmospheric Radiative Transfer, and Computational Fluid Dynamics  

E-Print Network (OSTI)

Validation is often defined as the process of determining the degree to which a model is an accurate representation of the real world from the perspective of its intended uses. Validation is crucial as industries and governments depend increasingly on predictions by computer models to justify their decisions. In this article, we survey the model validation literature and propose to formulate validation as an iterative construction process that mimics the process occurring implicitly in the minds of scientists. We thus offer a formal representation of the progressive build-up of trust in the model, and thereby replace incapacitating claims on the impossibility of validating a given model by an adaptive process of constructive approximation. This approach is better adapted to the fuzzy, coarse-grained nature of validation. Our procedure factors in the degree of redundancy versus novelty of the experiments used for validation as well as the degree to which the model predicts the observations. We illustrate the new methodology first with the maturation of Quantum Mechanics as the arguably best established physics theory and then with several concrete examples drawn from some of our primary scientific interests: a cellular automaton model for earthquakes, an anomalous diffusion model for solar radiation transport in the cloudy atmosphere, and a computational fluid dynamics code for the Richtmyer-Meshkov instability. This article is an augmented version of Sornette et al. [2007] that appeared in Proceedings of the National Academy of Sciences in 2007 (doi: 10.1073/pnas.0611677104), with an electronic supplement at URL http://www.pnas.org/cgi/content/full/0611677104/DC1. Sornette et al. [2007] is also available in preprint form at physics/0511219.

Didier Sornette; Anthony B. Davis; James R. Kamm; Kayo Ide

2007-10-01T23:59:59.000Z

385

Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool  

Science Conference Proceedings (OSTI)

Geothermal heat pumps, sometimes called ground-source heat pumps (GSHPs), have been proven capable of significantly reducing energy use and peak demand in buildings. Conventional equipment for controlling the temperature and humidity of a building, or supplying hot water and fresh outdoor air, must exchange energy (or heat) with the building's outdoor environment. Equipment using the ground as a heat source and heat sink consumes less non-renewable energy (electricity and fossil fuels) because the earth is cooler than outdoor air in summer and warmer in winter. The most important barrier to rapid growth of the GSHP industry is high first cost of GSHP systems to consumers. The most common GSHP system utilizes a closed-loop ground heat exchanger. This type of GSHP system can be used almost anywhere. There is reason to believe that reducing the cost of closed-loop systems is the strategy that would achieve the greatest energy savings with GSHP technology. The cost premium of closed-loop GSHP systems over conventional space conditioning and water heating systems is primarily associated with drilling boreholes or excavating trenches, installing vertical or horizontal ground heat exchangers, and backfilling the excavations. This project investigates reducing the cost of horizontal closed-loop ground heat exchangers by installing them in the construction excavations, augmented when necessary with additional trenches. This approach applies only to new construction of residential and light commercial buildings or additions to such buildings. In the business-as-usual scenario, construction excavations are not used for the horizontal ground heat exchanger (HGHX); instead the HGHX is installed entirely in trenches dug specifically for that purpose. The potential cost savings comes from using the construction excavations for the installation of ground heat exchangers, thereby minimizing the need and expense of digging additional trenches. The term foundation heat exchanger (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of excavation, 50% of which was construction excavation. There are six pipes in all excavations (three par

Hughes, Patrick [ORNL; Im, Piljae [ORNL

2012-01-01T23:59:59.000Z

386

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

387

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

388

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

389

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

390

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

391

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

392

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

393

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

394

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

395

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

396

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

397

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

398

A 3-D Canopy Radiative Transfer Model for Global Climate Modeling: Description, Validation and Application  

Science Conference Proceedings (OSTI)

The process of solar radiative transfer at the land surface is important to energy, water and carbon balance, especially for vegetated areas. Currently the most commonly used two-stream model considers the Plant Functional Types (PFTs) within a ...

Hua Yuan; Robert E. Dickinson; Yongjiu Dai; Muhammad J. Shaikh; Liming Zhou; Wei Shangguan; Duoying Ji

399

Implementation and Validation of the BHR Turbulence Model in the FLAG Hydrocode  

SciTech Connect

The BHR-2 turbulence model, developed at Los Alamos National Laboratory for variable density and compressible flows, is implemented in an Arbitrary Lagrangian-Eulerian hydrocode, FLAG. The BHR-2 formulation is discussed, with emphasis on its connection to multi-component flow formulations that underlie FLAG's treatment of multi-species flow. One-dimensional and two-dimensional validation tests are performed and compared to experiment and Eulerian simulations. Turbulence is an often studied and ubiquitous phenomenon in nature, and modeling its effects is essential in many practical applications. Specifically the behavior of turbulence in the presence of strong density gradients and compressibility is of fundamental importance in applications ranging from Inertial Confinement Fusion (ICF) [1], supernovae [2], and atmospheric flows. The BHR closure approach [3] seeks to model the physical processes at work in variable density turbulence including Kelvin-Helmholtz (KH) [4], Rayleigh-Taylor (RT) [5], and Richtmyer-Meshkov (RM) [6], driven turbulence. The effectiveness of the BHR-2 implementation has been demonstrated for variable density mixing in the KH, RT, and RM cases in an Eulerian framework [7]. The primary motivation of the present work is to implement the BHR-2 turbulence model in the Arbitrary Lagrangian-Eulerian (ALE) hydrodynamics code FLAG. The goal is not only to demonstrate results in agreement with previous Eulerian calculations, but also document behavior that arises from the underlying differences in code philosophy.

Denissen, Nicholas A. [Los Alamos National Laboratory; Fung, Jimmy [Los Alamos National Laboratory; Reisner, Jon M. [Los Alamos National Laboratory; Andrews, Malcolm J. [Los Alamos National Laboratory

2012-08-29T23:59:59.000Z

400

Validation of a Thermodynamic Retrieval Technique by Application to a Simulated Squall Line with Trailing Stratiform Precipitation  

Science Conference Proceedings (OSTI)

A thermodynamic retrieval technique, which uses the equation of motion in conjunction with the thermodynamic equation, is validated in a two-dimensional numerical model simulation of a squall line with a trailing stratiform region. Model wind and ...

J. Sun; R. A. Houze Jr.

1992-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "numerical model validation" 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

Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system  

SciTech Connect

NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

Teng, Zhenke [ORNL; Zhang, F [CompuTherm LLC, Madison, WI; Miller, Michael K [ORNL; Liu, Chain T [Hong Kong Polytechnic University; Huang, Shenyan [ORNL; Chou, Y.T. [Multi-Phase Services Inc., Knoxville; Tien, R [Multi-Phase Services Inc., Knoxville; Chang, Y A [ORNL; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2012-01-01T23:59:59.000Z

402

Generic Models and Model Validation for Wind and Solar PV Generation: Technical Update  

Science Conference Proceedings (OSTI)

The influx of variable generation technologies, particularly wind generation, into the bulk transmission grid in the U.S. and internationally has been significant over the past decade. This trend will most likely continue in light of national (in other countries) and state renewable portfolio standards. Thus, there is at present a need for generic, standard and publicly available models for variable generation technologies for the purpose of power system planning studies. EPRI has been a key participant ...

2011-12-20T23:59:59.000Z

403

Modeling and Model Validation for Variable Generation Technologies: Focus on Wind Generation  

Science Conference Proceedings (OSTI)

The influx of variable-generation technologies, particularly wind generation, into the bulk transmission grid has been tremendous over the past decade. This trend will likely continue, in light of national and state renewable portfolio standards. Thus, there is a need for generic, standard, and publicly available models for variable-generation technologies for power system planning studies. The Electric Power Research Institute (EPRI), in collaboration with the Western Electricity Coordinating Council (...

2010-12-14T23:59:59.000Z

404

Validation of a numerical model for the analysis of thermal-fluid behavior in a solar concentrator vessel  

E-Print Network (OSTI)

The need for innovation in the renewable energy sector is an ever-growing concern. With national-level disasters in the Gulf of Mexico, the necessity to begin the drive to develop effective and practical alternative energy ...

Rodríguez Alvarado, Juan Fernando

2010-01-01T23:59:59.000Z

405

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

406

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

407

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

408

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

409

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

410

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

411

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

412

Validation of the RVACS (Reactor Vessel Auxiliary Cooling System)/RACS (Reactor Air Cooling System) model in SASSYS-1  

SciTech Connect

The SASSYS-1 LMR systems analysis code contains a model for transient analysis of heat removal by a RVACS (Reactor Vessel Auxiliary Cooling System) or a RACS (Reactor Air Cooling System) in an LMR (Liquid Metal Reactor). This model has been validated by comparisons of model predictions with experimental data from a large scale RVACS/RACS simulation experiment performed at Argonne National Laboratory. 4 refs., 1 fig.

Dunn, F.E.

1987-01-01T23:59:59.000Z

413

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

414

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

415

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

416

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

417

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

418

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

419

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

420

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

Note: This page contains sample records for the topic "numerical model validation" 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

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

422

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

423

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

424

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

425

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

426

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

427

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

428

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

429

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 ...

João Teixeira; Carolyn A. Reynolds; Kevin Judd

2007-01-01T23:59:59.000Z

430

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

431

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

432

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

433

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

434

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

435

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

436

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

437

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

438

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

439

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

440

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

Note: This page contains sample records for the topic "numerical model validation" 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 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

442

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

443

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

444

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

445

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

446

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

447

Composing, analyzing and validating software models to assess the performability of competing design candidates  

Science Conference Proceedings (OSTI)

In a perfect world, verification and validation of a software design specification would be possible before any code was generated. Indeed, in a perfect world we would know that the implementation was correct because we could trust the class ...

Frederick T. Sheldon; Stefan Greiner

1999-08-01T23:59:59.000Z

448

Validating Model Clouds and Their Optical Properties Using Geostationary Satellite Imagery  

Science Conference Proceedings (OSTI)

A real-time validation scheme for diagnosing radiatively active clouds has been in operation for a number of years at the Australian Bureau of Meteorology. It compares IR channel imagery from four geostationary satellites and equivalent forward ...

Zhian Sun; Lawrie Rikus

2004-08-01T23:59:59.000Z

449

Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings  

DOE Green Energy (OSTI)

The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.

Bharathan, D.; Parsons, B.K.; Althof, J.A.

1988-10-01T23:59:59.000Z

450

A Step-Mountain Coordinate General Circulation Model: Description and Validation of Medium-Range Forecasts  

Science Conference Proceedings (OSTI)

The step-mountain or eta vertical coordinate has been a proposed solution for eliminating the numerical errors encountered when calculating the pressure gradient force along sloping surfaces. The main objectives of this paper are to describe the ...

B. L. Wyman

1996-01-01T23:59:59.000Z

451

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

452

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

453

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

454

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

455

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

456

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

457

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. Aarão Reis

2005-08-09T23:59:59.000Z

458

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

459

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

460

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

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461

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

462

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

463

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

464

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

465

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

466

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

467

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

468

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

469

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

470

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

471

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

472

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

473

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

474

Validation of the Surface Energy Balance over the Antarctic Ice Sheets in the U.K. Meteorological Office Unified Climate Model  

Science Conference Proceedings (OSTI)

Surface radiation measurements and other climatological data were used to validate the representation of the surface energy balance over the East Antarctic Ice Sheet in the U.K. Meteorological Office Unified Climate Model. Model calculations of ...

J. C. King; W. M. Connolley

1997-06-01T23:59:59.000Z

475

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

476