Numerical Modeling At Neal Hot Springs Geothermal Area (U.S....
Area Exploration Technique Numerical Modeling Activity Date 2011 - 2011 Usefulness useful DOE-funding Unknown Exploration Basis A numerical reservoir model was created to...
Guerin, Gilles
hydrocarbons by migration of fluids from overpressured shales upwards along the active fault system. The heat field in the Northern Gulf of Mexico (Figure 4.1) has been the focus of an unprecedented
Numerical wind speed simulation model
Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.
1981-09-01
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.
Numerical Model Construction with Closed Observables
Felix Dietrich; Gerta Köster; Hans-Joachim Bungartz
2015-10-18
Performing analysis, optimization and control using simulations of many-particle systems is computationally demanding when no macroscopic model for the dynamics of the variables of interest is available. In case observations on the macroscopic scale can only be produced via legacy simulator code or live experiments, finding a model for these macroscopic variables is challenging. In this paper, we employ time-lagged embedding theory to construct macroscopic numerical models from output data of a black box, such as a simulator or live experiments. Since the state space variables of the constructed, coarse model are dynamically closed and observable by an observation function, we call these variables closed observables. The approach is an online-offline procedure, as model construction from observation data is performed offline and the new model can then be used in an online phase, independent of the original. We illustrate the theoretical findings with numerical models constructed from time series of a two-dimensional ordinary differential equation system, and from the density evolution of a transport-diffusion system. Applicability is demonstrated in a real-world example, where passengers leave a train and the macroscopic model for the density flow onto the platform is constructed with our approach. If only the macroscopic variables are of interest, simulation runtimes with the numerical model are three orders of magnitude lower compared to simulations with the original fine scale model. We conclude with a brief discussion of possibilities of numerical model construction in systematic upscaling, network optimization and uncertainty quantification.
High performance computing and numerical modelling
,
2014-01-01
Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...
Lattice Boltzmann Model for Numerical Relativity
Ilseven, E
2015-01-01
In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for Numerical Relativity. Our model is validated with well-established tests, showing good agreement with analytical solutions. Furthermore, we show that by increasing the relaxation time, we gain stability at the cost of losing accuracy, and by decreasing the lattice spacings while keeping a constant numerical diffusivity, the accuracy and stability of our simulations improves. Finally, in order to show the potential of our approach a linear scaling law for parallelisation with respect to number of CPU cores is demonstrated. Our model represents the first step in using lattice kinetic theory to solve gravitational problems.
Numerical Modeling of Eastern Connecticut's Visual Resources1
Numerical Modeling of Eastern Connecticut's Visual Resources1 Daniel L. Civco 2/ l Submitted Conservation, The University of Connecticut, Storrs, Connecticut. / Abstract: A numerical model capable of accurately predicting the preference for landscape photographs of selected points in eastern Connecticut
NUMERICAL MODELING OF CATHODE CONTACT MATERIAL DENSIFICATION
Koeppel, Brian J.; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.
2011-11-01
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.
INCORPORATION OF GROUNDWATER FLOW INTO NUMERICAL MODELS AND DESIGN MODELS
-coupled, ground-source heat pumps, groundwater, heat pump, heat exchanger, heat transfer, numerical models-loop ground-coupled heat exchangers. Green and Perry (1961) demonstrated that the value of effective thermal on the design and performance of vertical closed-loop ground heat exchangers. Based on the investigation results
Nagurney, Anna
Contributions Motivation Literature Models Synergy Measure Numerical Examples Conclusions Supply Motivation Literature Models Synergy Measure Numerical Examples Conclusions 1 Contributions 2 Motivation 3 University of Massachusetts Amherst #12;Contributions Motivation Literature Models Synergy Measure Numerical
NUMERICAL APPROXIMATION OF A MACROSCOPIC MODEL OF PEDESTRIAN FLOWS
Chalons, Christophe
NUMERICAL APPROXIMATION OF A MACROSCOPIC MODEL OF PEDESTRIAN FLOWS CHRISTOPHE CHALONS Abstract for the description of the flow of pedestrians. Solutions of the associated Riemann problem are known to be possibly in obtaining an efficient numerical scheme. Numerical evidences are proposed. Key words. macroscopic pedestrian
Validation of Eddy-renewal model by numerical simulation
Garbe, Christoph S.
Validation of Eddy-renewal model by numerical simulation Li-Ping Hung1,2 , Christoph S. Garbe1, E-mail: wttsai@ncu.edu.tw Abstract. The eddy-renewal model proposes that the dominant vortical flows as the diffusivity effect in the thin diffusive sublayer beneath surface. Key Words: eddy-renewal model, numerical
A Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal...
A Hydro-Thermo-Mechanical Numerical Model For Hdr Geothermal Reservoir Evaluation Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A...
Numerical Modeling of the Nucleation Conditions of Petal-Centerline...
Numerical Modeling of the Nucleation Conditions of Petal-Centerline Fractures below a Borehole Floor, A Sensitivity Study and Application to the Coso Geothermal Field Jump to:...
Numerical Modeling of PCCI Combustion | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
PCCI Combustion Numerical Modeling of PCCI Combustion 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Lawrence Livermore National LaboratoryUniversity of...
Starting laminar plumes: Comparison of laboratory and numerical modeling
van Keken, Peter
Starting laminar plumes: Comparison of laboratory and numerical modeling Judith Vatteville Institut, France (davaille@fast.u-psud.fr) [1] A detailed comparison of starting laminar plumes in viscous fluids. Davaille (2009), Starting laminar plumes: Comparison of laboratory and numerical modeling, Geochem. Geophys
Evolution of the Bohemian Massif: Insights from numerical modeling
Cerveny, Vlastislav
Evolution of the Bohemian Massif: Insights from numerical modeling Petra Maierová Supervisor: Doc of Geophysics Faculty of Mathematics and Physics Charles University in Prague #12;February 4, 2013Evolution Conclusions Outline #12;February 4, 2013Evolution of the Bohemian Massif: Insights from numerical modeling 3
NUMERICAL MODELING OF LOW FREQUENCY HYDRO-ACOUSTIC WAVES
Kirby, James T.
NUMERICAL MODELING OF LOW FREQUENCY HYDRO-ACOUSTIC WAVES GENERATED BY SUBMARINE TSUNAMIGENIC#al to increase the reliability of the system Â· Can we use precursors of tsunami? Hydro numerical models applicable on an oceanic scale #12;Index Â· Introduc#on on hydro
Numerical models of phosphate esters in the Chattahoochee River
Haffey, Samuel Fraad, 1973-
2004-01-01
A numerical model was constructed to assess the magnitude of organophosphoric acid triester sinks in the Chattahoochee River and to identify concentration patterns downstream of point source discharges. The model was built ...
A numerical model simulation of longshore transport for Galveston Island
Gilbreath, Stephen Alexander
1995-01-01
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...
Category:Numerical Modeling | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,CammackFLIR Jump to: navigation,GroundNear Infrared SurveysNumerical
Data Assimilation for Idealised Mathematical Models of Numerical Weather Prediction
Wirosoetisno, Djoko
Data Assimilation for Idealised Mathematical Models of Numerical Weather Prediction Supervisors). Background: Numerical Weather Prediction (NWP) has seen significant gains in accuracy in recent years due in weather dynamics, e.g., the asymptotic balance seen in high and low pressure systems. Aims of the project
Fully kinetic numerical modeling of a plasma thruster
Szabo, James Joseph, 1969-
2001-01-01
A Hall effect plasma thruster with conductive acceleration channel walls was numerically modeled using 2D3V Particle-in-Cell (PIC) and Monte-Carlo Collision (MCC) methodolo- gies. Electron, ion, and neutral dynamics were ...
Stress and diffusion induced interface motion: Modelling and numerical simulations
Styles, Vanessa
Stress and diffusion induced interface motion: Modelling and numerical simulations Harald Garcke of Mathematics, University of Sussex, Brighton, BN1 9QH, U.K. Abstract We propose a phase field model for stress stress effects. In this paper we will demonstrate that the model can also be used to describe other
Numerical modelling of tsunami mitigation by mangroves Putu Harry Gunawan
Mancini, Simona
Numerical modelling of tsunami mitigation by mangroves Putu Harry Gunawan LAMA (Laboratoire d'Analyse et de Mathmatiques Appliques) UPEM putu-harry.gunawan@univ.paris-est.fr Abstract Figure 1: Mangrove-Tsunami Model. The role of mangroves (coastal forests) in the mitigation of tsunami impacts is a debated topic
Diffusion and Dispersion Characterization of a Numerical Tsunami Model
Tolkova, Elena
Diffusion and Dispersion Characterization of a Numerical Tsunami Model David Burwell, Elena Tolkova and Arun Chawla February 6, 2007 1 Introduction Method Of Splitting Tsunami (MOST) is a depth averaged long wave tsunami inundation model that was originally developed by Titov and Synolakis (1995) for 1D
SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION
Dixon, K.; Knox, A.
2012-02-13
Active capping involves the use of capping materials that react with sediment contaminants to reduce their toxicity or bioavailability. Although several amendments have been proposed for use in active capping systems, little is known about their long-term ability to sequester metals. Recent research has shown that the active amendment apatite has potential application for metals contaminated sediments. The focus of this study was to evaluate the effectiveness of apatite in the sequestration of metal contaminants through the use of short-term laboratory column studies in conjunction with predictive, numerical modeling. A breakthrough column study was conducted using North Carolina apatite as the active amendment. Under saturated conditions, a spike solution containing elemental As, Cd, Co, Se, Pb, Zn, and a non-reactive tracer was injected into the column. A sand column was tested under similar conditions as a control. Effluent water samples were periodically collected from each column for chemical analysis. Relative to the non-reactive tracer, the breakthrough of each metal was substantially delayed by the apatite. Furthermore, breakthrough of each metal was substantially delayed by the apatite compared to the sand column. Finally, a simple 1-D, numerical model was created to qualitatively predict the long-term performance of apatite based on the findings from the column study. The results of the modeling showed that apatite could delay the breakthrough of some metals for hundreds of years under typical groundwater flow velocities.
EXPERIMENTAL CHARACTERIZATION AND NUMERICAL MODELING OF THERMAL AND ELECTROCHEMISTRY EFFECTS IN
Kassegne, Samuel Kinde
EXPERIMENTAL CHARACTERIZATION AND NUMERICAL MODELING OF THERMAL AND ELECTROCHEMISTRY EFFECTS IN 3D and Numerical Modeling of Thermal and Electrochemistry Effects in 3D Bionanoelectronics Platform by Neha
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolarNewsusceptometer under pressureNavyNumerical simulations of current
Small Buoys for Energy Harvesting : Experimental and Numerical Modeling Studies
Grilli, Stéphan T.
Small Buoys for Energy Harvesting : Experimental and Numerical Modeling Studies St´ephan T. Grilli for wave energy harvesting (free-floating or slackly moored), to produce about 1 KW per unit at full scale-contained (water tight) resonating multiple-spar buoy (or Starspar), in which a longer central spar houses the LEG
Thermodynamics cycle analysis and numerical modeling of thermoelastic cooling systems
Rubloff, Gary W.
Thermodynamics cycle analysis and numerical modeling of thermoelastic cooling systems Suxin Qian level. However, a thermoelastic cooling system integrated with heat transfer fluid loops have not been;2012) (a.k.a. elastocaloric cooling). These solid-state cooling systems offer us alternatives to eliminate
Small Buoys for Energy Harvesting : Experimental and Numerical Modeling Studies
Grilli, Stéphan T.
Small Buoys for Energy Harvesting : Experimental and Numerical Modeling Studies St´ephan T. Grilli, Inc., Cranston, RI, USA ABSTRACT We present the development and application of small buoy systems climates, of two new types of buoy systems equipped with an embedded Linear Electric Generator (LEG; made
Numerical Modeling of Periodic Composite Media for Electromagnetic Shielding Application
Koledintseva, Marina Y.
on a conventional mixing theory, have served as the fundamentals for these techniques. In these formulationsNumerical Modeling of Periodic Composite Media for Electromagnetic Shielding Application Dagang Wu-difference time-domain (FDTD) method. The results are compared with conventional mixing theories and 3D Fourier
Direct Numerical Simulations and Modeling of Jets in Crossflow
Mahesh, Krishnan
Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies
Validation of Erosion Modeling: Physical and Numerical Mehrad Kamalzare1
Franklin, W. Randolph
-3590 ABSTRACT The overall intent of this research is to develop numerical models of erosion of levees, dams is necessary for emergency plans for levee or dam breaches. Griffis, 2007 addressed the overall design and hydraulic shear stress. #12;2 Xu and Zhang (2009) found that in addition to soil type, the degree
Numerical simulation of micro-fluidic passive and active mixers
Kumar, Saurabh
2002-01-01
the flow rate. Hence, output channels exhibit predetermined concentration values, which allow concentration dependent chemistry experiments in each output channel. Convective diffusive transport in this micro mixer is studied numerically and theoretically...
Integrating Numerical Computation into the Modeling Instruction Curriculum
Caballero, Marcos D; Aiken, John M; Douglas, Scott S; Scanlon, Erin M; Thoms, Brian; Schatz, Michael F
2012-01-01
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.
On numerical considerations for modeling reactive astrophysical shocks
Papatheodore, Thomas L.; Messer, O. E. Bronson, E-mail: tpapathe@utk.edu, E-mail: bronson@ornl.gov [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)
2014-02-10
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds and associated quantities is to prohibit burning inside the numerically broadened shock. We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in models of Type Ia supernovae, including potential impacts on observables.
Mathiesen, Patrick; Collier, Craig; Kleissl, Jan
2013-01-01
of numerical weather prediction solar irradiance forecasts numerical weather prediction model for solar irradiance weather prediction for intra?day solar forecasting in the
ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS
Chiswell, S.; Buckley, R.
2009-01-15
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.
Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling
Du, Qiang
2014-11-12
The rational design of materials, the development of accurate and efficient material simulation algorithms, and the determination of the response of materials to environments and loads occurring in practice all require an understanding of mechanics at disparate spatial and temporal scales. The project addresses mathematical and numerical analyses for material problems for which relevant scales range from those usually treated by molecular dynamics all the way up to those most often treated by classical elasticity. The prevalent approach towards developing a multiscale material model couples two or more well known models, e.g., molecular dynamics and classical elasticity, each of which is useful at a different scale, creating a multiscale multi-model. However, the challenges behind such a coupling are formidable and largely arise because the atomistic and continuum models employ nonlocal and local models of force, respectively. The project focuses on a multiscale analysis of the peridynamics materials model. Peridynamics can be used as a transition between molecular dynamics and classical elasticity so that the difficulties encountered when directly coupling those two models are mitigated. In addition, in some situations, peridynamics can be used all by itself as a material model that accurately and efficiently captures the behavior of materials over a wide range of spatial and temporal scales. Peridynamics is well suited to these purposes because it employs a nonlocal model of force, analogous to that of molecular dynamics; furthermore, at sufficiently large length scales and assuming smooth deformation, peridynamics can be approximated by classical elasticity. The project will extend the emerging mathematical and numerical analysis of peridynamics. One goal is to develop a peridynamics-enabled multiscale multi-model that potentially provides a new and more extensive mathematical basis for coupling classical elasticity and molecular dynamics, thus enabling next generation atomistic-to-continuum multiscale simulations. In addition, a rigorous studyof nite element discretizations of peridynamics will be considered. Using the fact that peridynamics is spatially derivative free, we will also characterize the space of admissible peridynamic solutions and carry out systematic analyses of the models, in particular rigorously showing how peridynamics encompasses fracture and other failure phenomena. Additional aspects of the project include the mathematical and numerical analysis of peridynamics applied to stochastic peridynamics models. In summary, the project will make feasible mathematically consistent multiscale models for the analysis and design of advanced materials.
Numerical simulation model for vertical flow in geothermal wells
Tachimori, M.
1982-01-01
A numerical simulation model for vertical flow in geothermal wells is presented. The model consists of equations for the conservation of mass, momentum, and energy, for thermodynamic state of water, for friction losses, for slip velocity relations, and of the criteria for various flow regimes. A new set of correlations and criteria is presented for two-phase flow to improve the accuracy of predictions; bubbly flow - Griffith and Wallis correlation, slug flow - Nicklin et al. one, annular-mist flow - Inoue and Aoki and modified by the author. The simulation method was verified by data from actual wells.
Numerical Model for Conduction-Cooled Current Lead Heat Loads
White, M.J.; Wang, X.L.; Brueck, H.D.; /DESY
2011-06-10
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).
Comparison of numerical models of a pyrotechnic device
Pierce, K.G.
1986-01-01
The predictions of two numerical models of a hot-wire initiated pyrotechnic device are compared to each other and to experimental results. Both models employ finite difference approximations to the heat diffusion equation in cylindrical coordinates. The temperature dependence of the thermal properties of the pyrotechnic materials and of the bridgewire are modeled. An Arrhenius' model is used to describe the exothermic reaction in the powder. One model employs a single radial coordinate and predicts the radial temperature distribution in the bridgewire and surrounding powder mass. In addition to the radial coordinate, the other model also employs a longitudinal coordinate to predict the temperature distribution parallel to the axis of the bridgewire. The predictions of the two-dimensional model concerning the energy requirements for ignition and the energy losses from the ends of the bridgewire are presented. A comparison of the predictions of the two models and the development of thermal gradients are employed to define the regime where the assumption, in the one-dimensional model, of negligible heat transfer axial to the bridgewire does not lead to significant error. The general problems associated with predicting ignition from a diffusion model are also discussed.
On Numerical Considerations for Modeling Reactive Astrophysical Shocks
Papatheodore, Thomas L; Messer, Bronson
2014-01-01
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds (and associated quantities) is to prohibit burning inside the numerically broadened shock (Fryxell et al. 1989). We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that, in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. (1989). In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly-resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in Type Ia supernovae.
Constitutive modeling of active polymers
Therkelsen, Scott V. (Scott Vincent), 1980-
2005-01-01
This thesis develops a three-dimensional constitutive model of active polymeric materials, including changes in material volume and properties due to actuation. Active polymers reversibly change shape, volume and/or material ...
Numerical model of Electron Cyclotron Resonance Ion Source
Mironov, V; Bondarchenko, A; Efremov, A; Loginov, V
2015-01-01
Important features of Electron Cyclotron Resonance Ion Source (ECRIS) operation are accurately reproduced with a numerical code. The code uses the particle-in-cell technique to model a dynamics of ions in ECRIS plasma. It is shown that gas dynamical ion confinement mechanism is sufficient to provide the ion production rates in ECRIS close to the experimentally observed values. Extracted ion currents are calculated and compared to the experiment for few sources. Changes in the extracted ion currents are obtained with varying the gas flow into the source chamber and the microwave power. Empirical scaling laws for ECRIS design are studied and the underlying physical effects are discussed.
Numerical Modeling of Submarine Mass-Movement Generated Waves Using RANS Model
Yim, Solomon C.
Numerical Modeling of Submarine Mass-Movement Generated Waves Using RANS Model D. YUK and S. YIM model for predicting waves generated by nearshore submarine mass-movements is described. The model to coastal scientists and engineers for many years. Coastal wave generation due to submarine mass movement
Progress report on LBL's numerical modeling studies on Cerro Prieto
Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.
1989-04-01
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.
Pearce, Fred
2003-01-01
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir
Numeric modeling of fire suppression by organophosphorous inhibitors
Makhviladze, G M; Zykov, A P
2008-01-01
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...
A numerical model of aerosol scavenging: Part 1, Microphysics parameterization
Molenkamp, C.R.; Bradley, M.M.
1991-09-01
We have developed a three-dimensional numerical model (OCTET) to simulate the dynamics and microphysics of clouds and the transport, diffusion and precipitation scavenging of aerosol particles. In this paper we describe the cloud microphysics and scavenging parameterizations. The representation of cloud microphysics is a bulk- water parameterization which includes water vapor and five types of hydrometeors (cloud droplets, rain drops, ice crystals, snow, and graupel). A parallel parameterization represents the scavenging interactions between pollutant particles and hydrometeors including collection of particles because of condensation nucleation, Brownian and phoretic attachment, and inertial capture, resuspension because of evaporation and sublimation; and transfer interactions where particles collected by one type of hydrometeor are transferred to another type of freezing, melting, accretion, riming and autoconversion.
Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory
Zhihao Ge; Ruihua Li
2015-03-08
In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.
NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS
NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS. Special focus is posed on the numerical solution algorithms for the saturation equation, which. The general background for the reservoir ow model is reviewed, and the main features of the numerical
NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS
NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS focus is posed on the numerical solution algorithms for the saturation equation, which is a convectionÂ eral background for the reservoir flow model is reviewed, and the main features of the numerical
Surussavadee, Chinnawat
2007-01-01
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 ...
Numerical study of energy diffusion in King models
Tom Theuns
1995-11-07
The energy diffusion coefficients D_n(E) (n=1,2) for a system of equal mass particles moving self-consistently in an N-body realisation of a King model are computed from the probability per unit time, P(E, Delta E), that a star with initial energy E will undergo an energy change Delta E. In turn, P is computed from the number of times during the simulation that a particle in a state of given energy undergoes a transition to another state. These particle states are defined directly from the time evolution of E by identifying them with the event occuring between two local maxima in the E(t) curve. If one assumes next that energy changes are uncorrelated between different states, one can use diffusion theory to compute D_n(E). The simulations employ N=512, 2048,... , 32768 particles and are performed using an implementation of Aarseth's direct integrator N-body1 on a massively parallel computer. The more than seven million transitions measured in the largest N simulation provide excellent statistics. The numerically determined D(E)'s are compared against their theoretical counterparts which are computed from phase-space averaged rates of energy change due to independent binary encounters. The overall agreement between them is impressive over most of the energy range, notwithstanding the very different type of approximations involved, giving considerable support to the valid usage of these theoretical expressions to simulate dynamical evolution in Fokker-Planck type calculations.
Baudouin, Lucie
A controlled distributed parameter model for a fluid-flexible structure system: numerical consider the problem of active reduction of vibrations in a fluid-flexible structure system and the sloshing of the fuel inside the wing's tank. The control is performed using piezoelectric patches
A regional numerical ocean model of the circulation in the Bay of Biscay
Drijfhout, Sybren
A regional numerical ocean model of the circulation in the Bay of Biscay Y. Friocourt,1,2,3 B Peninsula and in the Bay of Biscay is investigated by means of a regional ocean model. In particular numerical ocean model of the circulation in the Bay of Biscay, J. Geophys. Res., 112, C09008, doi:10
ENINALS Experimental and Numerical Investigations of Nonlinearity in soils using Advanced of Nonlinearity in Soils Using Advanced Laboratory-scaled Models Concluding Workshop Ispra, May 28-30 2013 IFSTTAR-geological constraints - centrifuge modelling - numerical modelling MILESTONES - Experiencing techniques for realising
Huerta, Antonio
NUMERICAL MODELLING OF IMPACT NOISE Cristina Díaz Cereceda | Laboratori de Càlcul Numèric Modelling of Impact Noise. In Congreso de Métodos Numéricos en Ingeniería 2009. [2] J. Hetherington, J. Poblet-Puig, A. Rodríguez-Ferran. Numerical Modelling of Impact Noise in Lightweight Floors: a Modal
Toriumi, Shin; Katsukawa, Yukio
2015-01-01
Light bridges, the bright structure dividing umbrae in sunspot regions, show various activity events. In Paper I, we reported on analysis of multi-wavelength observations of a light bridge in a developing active region (AR) and concluded that the activity events are caused by magnetic reconnection driven by magnetconvective evolution. The aim of this second paper is to investigate the detailed magnetic and velocity structures and the formation mechanism of light bridges. For this purpose, we analyze numerical simulation data from a radiative magnetohydrodynamics model of an emerging AR. We find that a weakly-magnetized plasma upflow in the near-surface layers of the convection zone is entrained between the emerging magnetic bundles that appear as pores at the solar surface. This convective upflow continuously transports horizontal fields to the surface layer and creates a light bridge structure. Due to the magnetic shear between the horizontal fields of the bridge and the vertical fields of the ambient pores,...
Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and
Sites, James R.
Thesis Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and Explanation our supervision by Markus Gloeckler entitled "Numerical Modeling of CIGS Solar Cells: Definition. A three-layer structure, simulating a Cu(InGa)Se2 (CIGS) heterojunction solar cell, was set up using
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE
Sites, James R.
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION Numerical modeling of polycrystalline thin-film solar cells is an important strategy to test the viability
Stutzmann, Eléonore
Detection of microseismic compressional (P) body waves aided by numerical modeling of oceanic noise), Detection of microseismic compressional (P) body waves aided by numerical modeling of oceanic noise sources in seismic noise, body waves present appealing properties but are still challenging to extract. Here we first
CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF
CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF MEMBRANE, Number 1, Pages 1Â18 CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF MEMBRANE DEFORMATIONS QIANG DU AND XIAOQIANG WANG This paper is dedicated to Prof.Max Gunzburger
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters
Lee, Zhongping
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters (2005), Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal; Siegel et al., 1995] have demonstrated that the penetration of EVIS in the upper layer of the ocean plays
Numerical modeling of fluid flow and time-lapse seismics to monitor CO2
Santos, Juan
Numerical modeling of fluid flow and time-lapse seismics to monitor CO2 Sequestration in aquifers J, ITALY). IMAL, 30/5/2014 Numerical modeling of fluid flow and time-lapse seismics to monitor CO2 Sequestration in aquifers Â p. #12;Introduction. I Storage of CO2 in geological formations is a procedure
Modelling and Control of Activated Sludge Processes
Skogestad, Sigurd
Modelling and Control of Activated Sludge Processes Michela Mulas Dottorato di Ricerca of Activated Sludge Processes Michela Mulas Supervisors: Prof. Roberto Baratti Ing. Stefania Tronci Dottorato . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 ASP Models and Simulations 7 2.1 The Activated Sludge Process
Numerical Model of a Tensioner System and Flex Joint
Huang, Han
2013-07-27
D 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...
Bardhan, Jaydeep Porter, 1978-
2006-01-01
This thesis presents a set of numerical techniques that extend and improve computational modeling approaches for biomolecule analysis and design. The presented research focuses on surface formulations of modeling problems ...
Mathematical Models and Numerical Solutions of Liquid-Solid and Solid-Liquid Phase Change
Surana, Karan S.; Joy, Aaron; Quiros, Luis; Reddy, JN
2015-04-01
This paper presents numerical simulations of liquid-solid and solid-liquid phase change processes using mathematical models in Lagrangian and Eulerian descriptions. The mathematical models are derived by assuming a smooth ...
Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling
Xu, Xianfan
Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling (TEG) designed for automotive waste heat recovery systems. This model is capable of computing telluride TEMs. Key words: Thermoelectric generators, waste heat recovery, automotive exhaust, skutterudites
Fractional Calculus in Hydrologic Modeling: A Numerical Perspective
David A. Benson; Mark M. Meerschaert; Jordan Revielle
2012-01-01
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.
Turbulent Supersonic Channel Flow: Direct Numerical Simulation and Modeling
Heinz, Stefan
modeling: the turbulence frequency production mechanism, wall damping effects on turbulence model frequency production mechanisms and wall damping effects may be explained very well on the basis, Chik w = wall viscosity = kinematic viscosity, = T = turbulent kinematic viscosity, Ck d = pressure
Numerical Modeling At Dixie Valley Geothermal Area (Iovenitti...
is needed to preserve the geochemical signature of the reservoir and . Finally, a new stress model is planned to be used for Dixie Valley, the model will utilize a boundary...
Numerically Efficient Water Quality Modeling and Security Applications
Mann, Angelica
2013-02-04
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.4 Summary of contributions . . . . . . . . . . . . . . . . . . . . . . . . 17 2 THE MERLION WATER QUALITY MODEL . . . . . . . . . . . . . . . . 20 2.1 Model development . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.2 Origin... tracking algorithm . . . . . . . . . . . . . . . . . . . . . . . . 24 2.3 Merlion water quality model . . . . . . . . . . . . . . . . . . . . . . . 31 2.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3 EFFICIENT MULTI...
Numerical Simulation of Pulse-Tube Refrigerators: 1D model I.A. Lyulina1
Eindhoven, Technische Universiteit
of a piston, an aftercooler (AC), a regenerator, a cold heat exchanger (CHX), a tube, a hot heat exchanger numerical model has been introduced to study steady oscillatory heat and mass transfer in the tube section, numerical simulation, high resolution scheme 1 Introduction The pulse tube is a relatively new type
Numerical modeling of extreme rogue waves generated by directional energy focusing
Grilli, Stéphan T.
Numerical modeling of extreme rogue waves generated by directional energy focusing Christophe that contributes to the generation of extreme waves, also known as rogue waves, in the ocean. To simulate and analyze this phenomenon, we generate extreme waves in a 3D numerical wave tank (NWT), by specifying
Zhu, Chen
of radioactive waste repositories. A case study of a regional aquifer in northeastern Arizona shows the rechargeEstimate of recharge from radiocarbon dating of groundwater and numerical flow and transport ages using a linked numerical 14 C transport and flow model while hydraulic conductivity values
NUMERICAL MODELING OF COASTAL TSUNAMI DISSIPATION AND Stphan T. Grilli1
Grilli, Stéphan T.
1 NUMERICAL MODELING OF COASTAL TSUNAMI DISSIPATION AND IMPACT Stéphan T. Grilli1 , Jeffrey C Tehranirad2 Recent observations of the coastal impact of large tsunamis (e.g., Indian Ocean 2004; Tohoku 2011) and related numerical and theoretical works have made it increasingly clear that tsunami waves arrive
NUMERICAL MODELING OF COASTAL TSUNAMI IMPACT DISSIPATION Stphan T. Grilli1
Kirby, James T.
1 NUMERICAL MODELING OF COASTAL TSUNAMI IMPACT DISSIPATION AND IMPACT Stéphan T. Grilli1 , Jeffrey Tehranirad2 Recent observations of the coastal impact of large tsunamis (e.g., Indian Ocean 2004; Tohoku 2011) and related numerical and theoretical works have made it increasingly clear that tsunami waves arrive
Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment
Brown, Michael R.
of Physics. DOI: 10.1063/1.1362294 I. OVERVIEW There are several unresolved mysteries related to solar and astrophysical magnetism. First is the origin of solar and astrophysical magnetic fields: the dynamo problem Alfve´nic outflow jets from a solar flare reconnection site have been observed using a Doppler technique
Numerical model for steel catenary riser on seafloor support
You, Jung Hwan
2007-04-25
of development of a simplified seafloor support model. This model simulates the seafloor-pipe interaction as a flexible pipe supported on a bed of springs. Constants for the soil springs were derived from finite element studies performed in a separate, parallel...
Numerically Estimating Internal Models of Dynamic Virtual Objects
Sekuler, Robert
human subjects to manipulate a computer-animated virtual object. This virtual object (vO) was a high, human cognition, human information processing, ideal performer, internal model, virtual object, virtual, specifically how humans acquire an internal model of a dynamic virtual object. Our methodology minimizes
Mathematical Modelling and Numerical Simulation of Oil Pollution Problems
due to convective and storm energy, and by major currents that include the Loop Current and its associ- ated rings. Shelf processes are also strongly influenced by seasonal river discharge, winds, and storms from active and passive radars, as well as from visible and infrared sensors were used to de- termine
Seismic scattering attributes to estimate reservoir fracture density : a numerical modeling study
Pearce, Frederick D. (Frederick Douglas), 1978-
2003-01-01
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...
NUMERICAL MODELING OF 3D ORGANIC SOLAR CELLS Presented to the
Kassegne, Samuel Kinde
.2 Physical Process in Polymer: Fullerene Build Heterojunction Solar CellsNUMERICAL MODELING OF 3D ORGANIC SOLAR CELLS _______________ A Thesis Presented to the Faculty Solar Cells by Anurag Kaushik Master of Science in Electrical Engineering San Diego State University
Numerical modeling of elastic wave scattering by near-surface heterogeneities
Al Muhaidib, Abdulaziz
2013-01-01
A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...
Numerical Modelling of a Pulse Combustion Burner: Limiting Conditions of Stable
Vuik, Kees
Numerical Modelling of a Pulse Combustion Burner: Limiting Conditions of Stable Operation P.A. van in the burner system. Self-sustained pulse combustion and high-intensity sound waves result if the system
Mass and charge flow in nanopores: numerical simulation via mesoscale models
Cecconi, Fabio
Mass and charge flow in nanopores: numerical simulation via mesoscale models Mauro Chinappi1 at nanoscale is here addressed via a recent developed mesoscale approach. In particular the flow
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests
Paris-Sud XI, Université de
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests P. Lalousis developed for computing the expansion of pellet-produced clouds in the poloidal plane. The expansion
Observational and Numerical Modeling Studies of Turbulence on the Texas-Louisiana Continental Shelf
Zhang, Zheng
2013-05-24
), dissipation rate of temperature variance (?), eddy diffusivity of temperature (?'t), and eddy diffusivity of density (?'p). Numerical models were also applied to test their capability of simulating these turbulence quantities. At site D, TKE, E, and ? were...
Ravago Bastardo, Delmira Cristina
2005-08-29
The main objective of this research is to compare the performance of cyclic steam injection using horizontal wells based on the analytical model developed by Gunadi against that based on numerical simulation. For comparison, a common reservoir...
P. Douillet S. Ouillon E. Cordier A numerical model for ne suspended sediment transport
transport á Numerical model á Deposition á Erosion á New Caledonia Introduction In New Caledonia, where open-cast for cohesive particles (e.g., Nicholson and O'Connor 1986; Teisson 1991; Brenon and Le Hir 1999), around sand
Banerjee, Debjyoti
Numerical modeling and experimental validation of uniform microchamber filling in centrifugal analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro microchambers, such as those needed for nucleic acid amplification or detection. With centrifugal devices
Seismic Scattering Attributes to Estimate Reservoir Fracture Density: A Numerical Modeling Study
Pearce, Frederick Douglas
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...
Numerical modeling of hydraulic fracture initiation and development
2007-05-25
Calculation scheme for modeling a hydraulic fracturing process: horizontal section of a ...... Jr., “Overview of current hydraulic fracturing design and treatment technology. .... A. A. Dobroskok, A. Ghassemi, and A. M. Linkov, “Extended structural ...
NUMERICAL MODELING OF TURBULENT FLOW IN A COMBUSTION TUNNEL
Ghoniem, A.F.
2013-01-01
1VJcDona·ld, H. (1979) Combustion r 1 iodeJ·ing in Two and1979) Practical Turbulent-Combustion Interaction Models forInternation on Combustors. Combustion The 17th Symposium
Ductile fracture modeling : theory, experimental investigation and numerical verification
Xue, Liang, 1973-
2007-01-01
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 ...
Giovanni Noselli; Antonio DeSimone
2014-08-26
We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. 'breathing-like' deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.
Development and validation of a vertically two-dimensional mesoscale numerical model
Walters, Michael Kent
1985-01-01
DEVELOPMENT AND VALIDATION OF A VERTICALLY TWO-DIMENSIONAL MESOSCALE NUMERICAL MODEL A Thesis by MICHAEL KENT WALTERS Submitted to the Graduate College of Texas AsM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1985 Major Subject: Meteorology DEVELOPMENT AND VALIDATION OF A VERTICALLY TWO-DIMENSIONAL MESOSCALE NUMERICAL MODEL A Thesis by MICHAEL KENT WALTERS Approved as to style and content by: Dusan Djuric (Chair of Committee) WP...
Moist processes and the quasi-hydrostatic approximation in a mesoscale numerical model
Kennedy, Charles Joseph
1987-01-01
MOIST PROCESSES AND THE QUASI-HYDROSTATIC APPROXIMATION IN A MESOSCALE NUMERICAL MODEL A Thesis by CHARLES JOSEPH KENNEDY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1987 Major Subject: Meteorology MOIST PROCESSES AND THE QUASI-HYDROSTATIC APPROXIMATION IN A MESOSCALE NUMERICAL MODEL A Thesis by CHARLES JOSEPH KENNEDY Approved as to style and content by: Dusan Djuric (Chair...
Numerical modeling of the wind flow over a transverse dune
Ascânio D. Araújo; Eric J. R. Parteli; Thorsten Poeschel; José S. Andrade Jr.; Hans J. Herrmann
2013-09-30
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.
Numerical modeling of the wind flow over a transverse dune
Araújo, Ascânio D; Poeschel, Thorsten; Andrade, José S; Herrmann, Hans J
2013-01-01
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.
Numerical models of pressure pulse generation by imploding metal liners
Humphries, S. Jr. [Acceleration Associates, Albuquerque, NM (United States)] [Acceleration Associates, Albuquerque, NM (United States); [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical Engineering; Ekdahl, C.A. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)
1996-12-01
The authors describe numerical calculations of pressure pulse generation using imploding liners. Liners are metal cylinders that are magnetically compressed by an intense axial current flow from a high-power pulse generator. The simulations cover the acceleration of the liner, collision with an internal diagnostic target, followed by compression and shock wave heating of the target. With the projected current waveform of the Atlas capacitor bank (in development at Los Alamos National Laboratory), initial results suggest that it may be possible to achieve pressures exceeding 3,000 Gpa (30 Mbar) in a 4 mm diameter sample over an interval of 100--200 ns. The simulations were carried out with Crunch, a new one-dimensional hydrodynamics package for advanced personal computers. The program uses finite-element techniques to solve the coupled problems of hydrodynamics and magnetic diffusion. Crunch fully supports loading and interpolating Sesame equation-of-state tables. The program exhibits excellent stability, even for collisions between material shells and shock convergence on axis. In contrast to previous work, the present studies follow the full process through solid target collision and compression. The work supports the High-Energy Density Physics Program of Los Alamos National Laboratory (LANL), a component of the US Department of Energy Stockpile Stewardship Program. The purpose of this program is maintenance of the nuclear weapons stockpile through improved computational ability and above-ground experiments. Imploding liners driven by conventional capacitor banks constitute a portion of the program to study matter at high pressure.
Numerical approaches to combustion modeling. Progress in Astronautics and Aeronautics. Vol. 135
Oran, E.S.; Boris, J.P. )
1991-01-01
Various papers on numerical approaches to combustion modeling are presented. The topics addressed include; ab initio quantum chemistry for combustion; rate coefficient calculations for combustion modeling; numerical modeling of combustion of complex hydrocarbons; combustion kinetics and sensitivity analysis computations; reduction of chemical reaction models; length scales in laminar and turbulent flames; numerical modeling of laminar diffusion flames; laminar flames in premixed gases; spectral simulations of turbulent reacting flows; vortex simulation of reacting shear flow; combustion modeling using PDF methods. Also considered are: supersonic reacting internal flow fields; studies of detonation initiation, propagation, and quenching; numerical modeling of heterogeneous detonations, deflagration-to-detonation transition to reactive granular materials; toward a microscopic theory of detonations in energetic crystals; overview of spray modeling; liquid drop behavior in dense and dilute clusters; spray combustion in idealized configurations: parallel drop streams; comparisons of deterministic and stochastic computations of drop collisions in dense sprays; ignition and flame spread across solid fuels; numerical study of pulse combustor dynamics; mathematical modeling of enclosure fires; nuclear systems.
Stetiu, C.
1993-07-01
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.
IMPROVED NUMERICAL METHODS FOR MODELING RIVER-AQUIFER INTERACTION.
Tidwell, Vincent C.; Sue Tillery; Phillip King
2008-09-01
A new option for Local Time-Stepping (LTS) was developed to use in conjunction with the multiple-refined-area grid capability of the U.S. Geological Survey's (USGS) groundwater modeling program, MODFLOW-LGR (MF-LGR). The LTS option allows each local, refined-area grid to simulate multiple stress periods within each stress period of a coarser, regional grid. This option is an alternative to the current method of MF-LGR whereby the refined grids are required to have the same stress period and time-step structure as the coarse grid. The MF-LGR method for simulating multiple-refined grids essentially defines each grid as a complete model, then for each coarse grid time-step, iteratively runs each model until the head and flux changes at the interfacing boundaries of the models are less than some specified tolerances. Use of the LTS option is illustrated in two hypothetical test cases consisting of a dual well pumping system and a hydraulically connected stream-aquifer system, and one field application. Each of the hypothetical test cases was simulated with multiple scenarios including an LTS scenario, which combined a monthly stress period for a coarse grid model with a daily stress period for a refined grid model. The other scenarios simulated various combinations of grid spacing and temporal refinement using standard MODFLOW model constructs. The field application simulated an irrigated corridor along the Lower Rio Grande River in New Mexico, with refinement of a small agricultural area in the irrigated corridor.The results from the LTS scenarios for the hypothetical test cases closely replicated the results from the true scenarios in the refined areas of interest. The head errors of the LTS scenarios were much smaller than from the other scenarios in relation to the true solution, and the run times for the LTS models were three to six times faster than the true models for the dual well and stream-aquifer test cases, respectively. The results of the field application show that better estimates of daily stream leakage can be made with the LTS simulation, thereby improving the efficiency of daily operations for an agricultural irrigation system. ACKNOWLEDGEMENTSThe authors appreciatively acknowledge support for Sue Tillery provided by Sandia National Laboratories' through a Campus Executive Laboratory Directed Research and Development (LDRD) research project.Funding for this study was provided by Directed Research and Development (LDRD) research project.
Numerical Solution of a Free-Boundary Problem for Percussive Deep Drilling Modeling by BEM
Mikhailov, Sergey
Numerical Solution of a Free-Boundary Problem for Percussive Deep Drilling Modeling by BEM S to a stationary-periodic quasi-static model of rock percus- sive deep drilling is presented. The rock is modeled. An auxiliary problem of stationary inden- tation of a rigid drill bit is considered first, where it is assumed
Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University
2011-01-01
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.
Acoustics 2000 1 The Two Dimensional Numerical Modeling
-difference methods have often been used. This report terms the wave equations suited to waves in fluids, acoustic, Sven Treitel, and Alford, 1976) but the acoustic wave equations have also been used for geophysical. Key features of the model at present are: (i) The use of acoustic wave equation (ii) Time domain
Numerical modeling of an all vanadium redox flow battery.
Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.
2014-01-01
We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.
Numerical modelling and analysis of a room temperature magnetic
and analysis of a room temperature magnetic refrigeration system Department: Fuel Cells and Solid State 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
A Two Pressure Numerical Model of Two Fluid Mixing \\Lambda
New York at Stoney Brook, State University of
fluid. The model is designed for the study of acceleration driven mixing layers in a chunk mix regime to the description of natural phenomena, as in meteorological temperature inÂ version driven updrafts quantities directly, to close the system of equations. Closure is a physics level identity, independent
NUMERICAL MODELING OF FLUID FLOW AND TIME-LAPSE ...
gabriela
CO2 injection operation at the Sleipner gas field in the North Sea, operated by Statoil ... The simultaneous flow of brine and CO2 is modeled with the Black-Oil formulation for ..... As water saturation is reduced, and the larger pores drained first, ...
Numerical Modeling of Seafloor Interation with Steel Catenary Riser
You, Jung Hwan
2012-10-19
, and moment. Primary outputs from this model include the deflected shape of the riser pipe and bending moments along riser length. The code also provides the location of maximum trench depth and the position where the maximum bending moment occurs and any...
THEACCURACY OF NUMERICAL MODELS FOR CONTINUUM STANLY STEINBERG
Steinberg, Stanly
Water Rain Evaporation Figure 1.1. A Lake These notes are directed towards students who have some modest of water in the lake. Water can enter and leave the lake by various means: rain; evaporation; rivers and how much error is there is solving the mathematical model. #12; 2 Lake Ground Ground Water Ground
Joint physical and numerical modeling of water distribution networks.
Zimmerman, Adam; O'Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei
2009-01-01
This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.
Realistic Numerical Modeling of Solar Magnetoconvection and Oscillations
Kitiashvili, Irina; Kosovichev, Alexander; Wray, Alan; Mansour, Nagi
2009-01-01
We have developed 3D, compressible, non-linear radiative MHD simulations to study the influence of the magnetic field of various strength and geometry on the turbulent convective cells and on the excitation mechanisms of the acoustic oscillations. The results reveal substantial changes of the granulation structure with increased magnetic field, and a frequency-dependent reduction in the oscillation power. These simulation results reproduce the enhanced high-frequency acoustic emission observed at the boundaries of active region ("acoustic halo" phenomenon). In the presence of inclined magnetic field the solar convection develops filamentary structure with flows concentrated along magnetic filaments, and also exhibits behavior of running magnetoconvective waves, resembling recent observations of the sunspot penumbra dynamics from Hinode/SOT.
Approximations to the Distributed Activation Energy Model
Approximations to the Distributed Activation Energy Model for Pyrolysis C.P. Please, 1 M.J. Mc, then resubmitted after minor revisions in September 2002. Abstract The Distributed Activation Energy Model (DAEM effective method for estimating kinetic parameters and the distribution of activation energies. Comparison
ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS
Yang, Zhaoqing; Wang, Taiping; Copping, Andrea
2014-04-18
This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.
Firoozabadi, Abbas
Mathematical formulation and numerical modeling of wax deposition in pipelines from enthalpy in the layer composed of the two-phase wax and oil (that is the gel layer), and (3) use Fick's law to describe to temperature gradient. In this work, a rigorous math- ematical model for the prediction of wax deposition
Intercomparison of Single-Column Numerical Models for the Prediction of Radiation Fog
Intercomparison of Single-Column Numerical Models for the Prediction of Radiation Fog THIERRY-term forecasting of fog is a difficult issue that can have a large societal impact. Radiation fog appears layers of the atmosphere. Current NWP models poorly forecast the life cycle of fog, and improved NWP
Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques
Tentzeris, Manos
Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques N. A Abstract The modeling of MEMS structures using MRTD is presented. Many complex RF structures have been communication systems efficiently and accurately. Specifically, micromachined structures such as MEMS
NUMERICAL COUPLING OF ELECTRIC CIRCUIT EQUATIONS AND ENERGY-TRANSPORT MODELS FOR SEMICONDUCTORS
Jüngel, Ansgar
NUMERICAL COUPLING OF ELECTRIC CIRCUIT EQUATIONS AND ENERGY-TRANSPORT MODELS FOR SEMICONDUCTORS effects is proposed. The charged particle flow in the semiconductor devices is described by the energy-transport equations for the electrons and the drift-diffusion equations for the holes. The electric circuit is modeled
Effects of winds and Caribbean eddies on the frequency of Loop Current eddy shedding: A numerical of Mexico, Caribbean Current, Loop Current, eddy shedding, winds and eddies, numerical ocean model Citation of Loop Current eddy shedding: A numerical model study, J. Geophys. Res., 108(C10), 3324, doi:10
Modeling Temporal Activity Patterns in Dynamic Social Networks
Raghavan, Vasanthan; Galstyan, Aram; Tartakovsky, Alexander G
2013-01-01
The focus of this work is on developing probabilistic models for user activity in social networks by incorporating the social network influence as perceived by the user. For this, we propose a coupled Hidden Markov Model, where each user's activity evolves according to a Markov chain with a hidden state that is influenced by the collective activity of the friends of the user. We develop generalized Baum-Welch and Viterbi algorithms for model parameter learning and state estimation for the proposed framework. We then validate the proposed model using a significant corpus of user activity on Twitter. Our numerical studies show that with sufficient observations to ensure accurate model learning, the proposed framework explains the observed data better than either a renewal process-based model or a conventional uncoupled Hidden Markov Model. We also demonstrate the utility of the proposed approach in predicting the time to the next tweet. Finally, clustering in the model parameter space is shown to result in dist...
Characterization of Texas lignite and numerical modeling of its in-situ gasification
Wang, Yih-Jy
1983-01-01
Modeling Site selection for in-situ gasification projects normally involves application of site screen1ng criteria. Some of these cr1teria were discussed by Russell et al. (1983). Numerical simulation may play an important role in s1te selection...CHARACTERIZATION OF TEXAS LIGNITE AND NUMERICAL MODELING OF ITS IN-SITU GASIFICATION A Thesis by YIH-JY WANG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...
Numerical Investigation of Flapwise-Torsional Vibration Model of a Smart Section Blade with Microtab
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Li, Nailu; Balas, Mark J.; Yang, Hua; Jiang, Wei; Magar, Kaman T.
2015-01-01
This study presents a method to develop an aeroelastic model of a smart section blade equipped with microtab. The model is suitable for potential passive vibration control study of the blade section in classic flutter. Equations of the model are described by the nondimensional flapwise and torsional vibration modes coupled with the aerodynamic model based on the Theodorsen theory and aerodynamic effects of the microtab based on the wind tunnel experimental data. The aeroelastic model is validated using numerical data available in the literature and then utilized to analyze the microtab control capability on flutter instability case and divergence instabilitymore »case. The effectiveness of the microtab is investigated with the scenarios of different output controllers and actuation deployments for both instability cases. The numerical results show that the microtab can effectively suppress both vibration modes with the appropriate choice of the output feedback controller.« less
:,; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ain, A; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Andersen, M; Anderson, R; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauchrowitz, J; Bauer, Th S; Behnke, B; Bejger, M; Beker, M G; Belczynski, C; Bell, A S; Bell, C; Bergmann, G; Bersanetti, D; Bertolini, A; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bloemen, S; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bosi, L; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Buchman, S; Bulik, T; Bulten, H J; Buonanno, A; Burman, R; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Celerier, C; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio, M; Conte, A; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corpuz, A; Corsi, A; Costa, C A; Coughlin, M W; Coughlin, S; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; Debreczeni, G; Degallaix, J; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Donath, A; Donovan, F; Dooley, K L; Doravari, S; Dossa, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H; Ehrens, P; Eichholz, J; Eikenberry, S S; Endr?czi, G; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fehrmann, H; Fejer, M M; Feldbaum, D; Feroz, F; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Gaonkar, S; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Gräf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K; Gustafson, E K; Gustafson, R; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hart, M; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hooper, S; Hopkins, P; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jaranowski, P; Ji, Y; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karlen, J; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawazoe, F; Kéfélian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N; Kim, N G; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I
2014-01-01
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered w...
Numerical model for vibration damping resulting from the first-order phase transformations
Melnik, Roderick
: Martensite transformation; Thermo-mechanical coupling; Vibration damping; GinzburgLandau theory 1Numerical model for vibration damping resulting from the first-order phase transformations L LandauGinzburg theory that couples nonlinear mechanical and thermal fields. The free energy function
Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters
methods of ion exchange is based on passing of source water or partially treated water through a filter-exchange filters results in highly mineralized, acidic and alkaline waste water [9]. With the continuous1 Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters
Numerical modeling of fluid flow and time-lapse seismograms applied to
Santos, Juan
; and CO2 and CO2 are the CO2 mole fraction and the CO2 mass fraction in the brine phase. This conversionNumerical modeling of fluid flow and time-lapse seismograms applied to CO2 storage and monitoring G and time-lapse seismograms applied to CO2 storage and monitoring p. #12;Introduction · Fossil
Numerical analysis of electric field formulations of the eddy current model
RodrÃguez, Rodolfo
Numerical analysis of electric field formulations of the eddy current model Alfredo BermÂ´udez1 methods for the numeri- cal solution of the eddy current problem in a bounded conducting domain crossed): 78M10, 65N30 Key words Low-frequency harmonic Maxwell equations, eddy currents, finite elements
Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model
RodrÃguez, Rodolfo
Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model the theoretically predicted behavior of the method, are reported. Keywords transient eddy current Â· axisymmetric is the accurate computation of power losses in the ferromagnetic components of the core due to hysteresis and eddy-current
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON-LOCAL
RodrÃguez, Rodolfo
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON@ing-mat.udec.cl This paper deals with an axisymmetric transient eddy current problem in conductive nonlinear magnetic media of the proposed scheme. Keywords: transient eddy current problem; electromagnetic losses; nonlinear magnetic
A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness
Nagy, Peter B.
A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation, the path of the eddy current must follow a more tortuous route in the material, which produces a reduction
Wells, Scott A.
792 / JOURNAL OF ENVIRONMENTAL ENGINEERING / SEPTEMBER 1999 NUMERICAL MODEL OF SEDIMENTATION with the ASCE Manager of Journals. The manuscript for this paper was submitted for review and possible publication on July 20, 1998. This paper is part of the Journal of Environmental Engineering, Vol. 125, No. 9
Numerical and analytical modelling of entropy noise in a supersonic nozzle with a shock
Nicoud, Franck
Numerical and analytical modelling of entropy noise in a supersonic nozzle with a shock M. Leyko a these sources, the noise coming from the turbulent flame within the combustor is already identified in a supersonic nozzle with a shock, Journal of Sound and Vibration (2011), doi:10.1016/j.jsv.2011.01.025 #12;Two
DROP-SCALE NUMERICAL MODELING OF CHEMICAL PARTITIOING DURING CLOUD HYDROMETEOR FREEZING
Stuart, Amy L.
DROP-SCALE NUMERICAL MODELING OF CHEMICAL PARTITIOING DURING CLOUD HYDROMETEOR FREEZING A.L. Stuart freezing provide greatly varying estimates of the retention efficiency of volatile solutes (e.g., Lamb understanding of the dependence of partitioning on chemical properties and freezing conditions (Stuart
Turova, Varvara
International Series of Numerical Mathematics, Vol. 160, 521540 Freezing of Living Cells, stresses arising due to non-simultaneous freezing of water in- side and outside of cells are modeled and outside of living cells during freezing is derived by applying an appropriate averaging technique
COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS
Ostromsky, Tzvetan
COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS I. DIMOV , K. GEORGIEVy, TZ. OSTROMSKY , R. J. VAN DER PASz, AND Z. ZLATEVx Abstract. The air pollution, and especially the reduction of the air pollution to some acceptable levels, is an important environmental problem, which
Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting
Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting SAMUEL RE, a need exists for accurate and updated fog and low-cloud forecasts. Couche Brouillard Eau Liquide (COBEL for the very short-term forecast of fog and low clouds. This forecast system assimilates local observations
A faster numerical scheme for a coupled system modelling soil erosion and sediment transport
d'OrlÃ©ans, UniversitÃ©
A faster numerical scheme for a coupled system modelling soil erosion and sediment transport M flow and the bed sediment, are classically described by a well-established system coupling the shallow states and the positivity of both water depth and sediment concentration. Recently, finite volume schemes
Mathematical, physical and numerical principles essential for models of turbulent mixing
Sharp, David Howland [Los Alamos National Laboratory; Lim, Hyunkyung [STONY BROOK UNIV; Yu, Yan [STONY BROOK UNIV; Glimm, James G [STONY BROOK UNIV
2009-01-01
We propose mathematical, physical and numerical principles which are important for the modeling of turbulent mixing, especially the classical and well studied Rayleigh-Taylor and Richtmyer-Meshkov instabilities which involve acceleration driven mixing of a fluid discontinuity layer, by a steady accerleration or an impulsive force.
Modeling and Numerical Simulation of Bioheat Transfer and Biomechanics in Soft Tissue
Zhang, Jun
Modeling and Numerical Simulation of Bioheat Transfer and Biomechanics in Soft Tissue #3; Wensheng techniques are eÆcient. Key words: Bioheat transfer, biomechanics, discretization, iterative solver. 1 do in engineering area by solving constitutive equations. One of the major diÆculties in biomechanics
NUMERICAL MODELLING OF THE DEEP IMPACT MISSION EXPERIMENT K. Wnnemann1 , and H. J. Melosh1
Collins, Gareth
NUMERICAL MODELLING OF THE DEEP IMPACT MISSION EXPERIMENT K. Wünnemann1 , G. S. Collins2 , and H. J@lpl.arizona.edu, 2 Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UK, g.collins@imperial.ac.uk . Introduction: NASA's Deep Impact Mission (launched January 2005) will provide, for the first time ever
Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Boussinesq model
Kirby, James T.
tsunami education or tsunami warning system in the re- gion exaccerbated the number of fatalities, even. Scientists had been warning of the growing exposure of coastal residents to tsunami hazards for yearsNumerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a Boussinesq model Philip
September 25, 2006 Numerical modeling of the effect of carbon dioxide
Paris-Sud XI, Université de
September 25, 2006 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la déformation des calcaires par dissolution sous contrainte: résultats@obs.ujf- grenoble.fr, marielle.collombet@ujf-grenoble.fr, yleguen@lgit.obs.ujf-grenoble.fr. #12;Abstract When carbon
LABORATORY-NUMERICAL MODEL COMPARISONS OF CANYON FLOWS: A PARAMETER STUDY.
LABORATORY-NUMERICAL MODEL COMPARISONS OF CANYON FLOWS: A PARAMETER STUDY. DON L. BOYER Cite Scientifique 59655 - Villeneuve d'Ascq cedex (France) ABSTRACT An integrated set of laboratory surrounding a coastal canyon and, further, to explore the degree to which laboratory experiments can provide
Aubertin, Michel
CONCEPTUAL AND NUMERICAL MODELS OF OXYGEN DIFFUSION, SULPHIDE OXIDATION AND ACID MINE DRAINAGE The generation and transport of acid mine drainage (AMD) through discretely fractured porous media is simulated. RÉSUMÉ La génération et le transport des produits issus du drainage minier acide (DMA) dans un milieu
January 2, 2008 Numerical modeling of the effect of carbon dioxide
Boyer, Edmond
January 2, 2008 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la déformation des calcaires par dissolution sous contrainte: résultats;Abstract When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its
Numerical modelling of the blowing phase in the production of glass containers
Eindhoven, Technische Universiteit
Numerical modelling of the blowing phase in the production of glass containers W. Dijkstraa , R to simulate the blowing of glass containers that are not rotationally symmetric. The contact between glass illustrates the results. Keywords: Boundary element method, blowing phase, glass, Stokes equations 1
MODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI-DATION OF CERAMIC COMPOSITES
Adjerid, Slimane
. INTRODUCTION Oxidation shortens the life of ceramic matrix composites by, e.g., chang- ing the elasticMODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI- DATION OF CERAMIC COMPOSITES S. Adjerid, M. Ai reaction 1-3 . Composite materials are protected by coatings; however, cracks that form as a result
NUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA-HIGH
Boyer, Edmond
in the cementitious matrix can react with carbon dioxide dissolved in the water filling the crack. Autogenous healingNUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA into the crack and leads to a partial recovery of mechanical properties (Young's modulus, tensile strength
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda
Schmeiser, Christian
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda A. Klar y C. Schmeiser z Abstract Radiative heat transfer equations including heat conduction are considÂ ered situations are presented. Keywords. radiative heat transfer, asymptotic analysis, nonlinear diffusion limit
LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY CONVERTERS
Haller, Merrick
1 LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY of wave energy converters (WECs) on water waves through the analysis of extensive laboratory experiments absorption is a reasonable predictor of the effect of WECs on the far field. Keywords: wave- energy; spectral
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2
Kirby, James T.
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2 , James T of Civil Engineering, University of Roma Tre Low-frequency hydro-acoustic waves are precursors of tsunamis. Detection of hydro-acoustic waves generated due to the water column compression triggered by sudden seabed
Numerical simulation of breaking waves by a multi-scale turbulence model
Zhao, Qun
and diffusion are of the same order at the trough level. Above the trough level, turbulent convection dominates-dimensional MAC type finite difference method. The third-order upwind scheme proposed by Kawamura and KawaharaNumerical simulation of breaking waves by a multi-scale turbulence model Qun Zhaoa,*, Steve
On the application of robust numerical methods to a complete-flow wave-current model
Madden, Niall
-current interaction in the presence of weakly turbulent flow leading to an Orr-Sommerfeld type problem, and a system of two singularly perturbed reaction-diffusion equations from a k- turbulence model. The numerical of modifying the scheme to stabilize it, a mesh tailored to the specific problem is used. In this study we
On the application of robust numerical methods to a complete-flow wave-current model
Madden, Niall
-current interaction in the presence of weakly turbulent flow leading to an Orr-Sommerfeld type problem and a system of two singularly perturbed reaction-diffusion equations from a k- turbulence model. The numerical layers. Instead of modifying the scheme to stabilize it, a mesh tailored to the specific problem is used
On the seismic response of deep-seated rock slope instabilities --Insights from numerical modeling
On the seismic response of deep-seated rock slope instabilities -- Insights from numerical modeling 2015 Accepted 3 April 2015 Available online 15 April 2015 Keywords: Seismic landslide hazard Spectral component of seismic hazard in mountainous regions. While many seismic slope stability analysis methods
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results
Precipitation sensitivity to autoconversion rate in a Numerical Weather Prediction model
Marsham, John
1 Precipitation sensitivity to autoconversion rate in a Numerical Weather Prediction model Céline;2 Summary Aerosols are known to significantly affect cloud and precipitation patterns and intensity. The impact of changing cloud droplet number concentration (CDNC), on cloud and precipitation evolution can
NUMERICAL VERIFICATION OF THE RELAP-7 CORE CHANNEL SINGLE-PHASE MODEL
Haihua Zhao; Ling Zou; Hongbin Zhang; Richard Martineau
2014-06-01
The RELAP-7 code is the next generation of nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). All the physics in RELAP-7 are fully coupled and the errors resulted from the traditional operator-splitting approach are eliminated. By using 2nd order methods in both time and space and eliminating operator-splitting errors, the numerical error of RELAP-7 can be minimized. Numerical verification is the process to verify the orders of numerical methods. It is an important part of modern verification and validation process. The core channel component in RELAP-7 is designed to simulate coolant flow as well as the conjugated heat transfer between coolant flow and the fuel rod. A special treatment at fuel centerline to avoid numerical singularity for the cylindrical heat conduction in the continuous finite element mesh is discussed. One steady state test case and one fast power up transient test case are utilized for the verification of the core channel model with single-phase flow. Analytical solution for the fuel pin temperature and figures of merit such as peak clad temperature and peak fuel temperature are used to define numerical errors. These cases prove that the mass and energy are well conserved and 2nd order convergence rates for both time and space are achieved in the core channel model.
Coclite, A; De Palma, P; Pascazio, G
2015-01-01
The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined ...
Modelling and Numerical Simulation of Gas Migration in a Nuclear Waste Repository
Bourgeat, Alain; Smai, Farid
2010-01-01
We present a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological radioactive waste repository. This model includes capillary effects and the gas diffusivity. The choice of the main variables in this model, Total or Dissolved Hydrogen Mass Concentration and Liquid Pressure, leads to a unique and consistent formulation of the gas phase appearance and disappearance. After introducing this model, we show computational evidences of its adequacy to simulate gas phase appearance and disappearance in different situations typical of underground radioactive waste repository.
A numerical model for the gamma-ray emission of the microquasar LS 5039
V. Bosch-Ramon; J. M. Paredes
2004-07-01
The possible association between the microquasar LS 5039 and the EGRET source 3EG J1824-1514 suggests that microquasars could also be sources of high energy gamma-rays. In this paper, we explore, with a detailed numerical model, if this system can produce the emission detected by EGRET (>100 MeV) through inverse Compton (IC) scattering. Our numerical approach considers a population of relativistic electrons entrained in a cylindrical inhomogeneous jet, interacting with both the radiation and the magnetic fields, taking into account the Thomson and Klein-Nishina regimes of interaction. The computed spectrum reproduces the observed spectral characteristics at very high energy.
Vršnak, B.; Žic, T.; Dumbovi?, M.; Temmer, M.; Möstl, C.; Veronig, A. M.; Taktakishvili, A.; Mays, M. L.; Odstr?il, D. E-mail: tzic@geof.hr E-mail: manuela.temmer@uni-graz.at E-mail: astrid.veronig@uni-graz.at E-mail: m.leila.mays@nasa.gov
2014-08-01
Real-time forecasting of the arrival of coronal mass ejections (CMEs) at Earth, based on remote solar observations, is one of the central issues of space-weather research. In this paper, we compare arrival-time predictions calculated applying the numerical ''WSA-ENLIL+Cone model'' and the analytical ''drag-based model'' (DBM). Both models use coronagraphic observations of CMEs as input data, thus providing an early space-weather forecast two to four days before the arrival of the disturbance at the Earth, depending on the CME speed. It is shown that both methods give very similar results if the drag parameter ? = 0.1 is used in DBM in combination with a background solar-wind speed of w = 400 km s{sup –1}. For this combination, the mean value of the difference between arrival times calculated by ENLIL and DBM is ?-bar =0.09±9.0 hr with an average of the absolute-value differences of |?|-bar =7.1 hr. Comparing the observed arrivals (O) with the calculated ones (C) for ENLIL gives O – C = –0.3 ± 16.9 hr and, analogously, O – C = +1.1 ± 19.1 hr for DBM. Applying ? = 0.2 with w = 450 km s{sup –1} in DBM, one finds O – C = –1.7 ± 18.3 hr, with an average of the absolute-value differences of 14.8 hr, which is similar to that for ENLIL, 14.1 hr. Finally, we demonstrate that the prediction accuracy significantly degrades with increasing solar activity.
2D numerical simulation of the MEP energy-transport model with a finite difference scheme
Romano, V. . E-mail: romano@dmi.unict.it
2007-02-10
A finite difference scheme of Scharfetter-Gummel type is used to simulate a consistent energy-transport model for electron transport in semiconductors devices, free of any fitting parameters, formulated on the basis of the maximum entropy principle. Simulations of silicon n{sup +}-n-n{sup +} diodes, 2D-MESFET and 2D-MOSFET and comparisons with the results obtained by a direct simulation of the Boltzmann transport equation and with other energy-transport models, known in the literature, show the validity of the model and the robustness of the numerical scheme.
Qualification of the ITER CS Quench Detection System using Numerical Modeling
Martovetsky, Nicolai N [ORNL; Radovinsky, Alexey L [ORNL
2013-01-01
Abstract The ITER Central Solenoid (CS) magnet needs to be protected against overheating of the conductor in the event of the occurrence of a normal zone (NZ). Due to a large amount of stored energy and slow NZ propagation, the NZ needs to be detected and the switchyard needs to open the breakers within 2 s after detection of the NZ. The CS will be discharged on a dump resistor with a time constant of 7.5 s. During operation of the CS and its interaction with the poloidal field (PF) coils and plasma current, the CS experiences large inductive voltages from multiple sources, including nonlinear signals from eddy currents in the vacuum vessel and plasma current variation, that make the task of detecting the resistive signal even more difficult. This inductive voltage needs to be cancelled by quench detection (QD) hardware (e.g., bridges, converters, filters, processors) and appropriate processing of the QD signals to reliably detect NZ initiation and propagation. Two redundant schemes are proposed as the baseline for the CS QD System: 1) A scheme with Regular Voltage Taps (RVT) from triads of Double Pancakes (DP) supplemented by Central Difference Averaging (CDA) and by digital suppression of the inductive voltage from all active coils (the CS and PF coils). Voltage taps are taken from helium outlets at the CS outer diameter. 2)A scheme with Cowound Voltage Taps (CVT) taken from cowound wires routed from the helium inlet at the CS inner diameter. Summary of results of the numerical modeling of the performance of both baseline CS QD systems is presented in this paper. Index Terms Quench detection, Central Solenoid, ITER
Numerical upscaling for the eddy-current model with stochastic magnetic materials
Eberhard, Jens P. [Computer Simulation Technology, Bad Nauheimer Strasse, 19, D-64289 Darmstadt (Germany)], E-mail: jens.eberhard@cst.com; Popovic, Dan [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: dan.popovic@stud.uni-heidelberg.de; Wittum, Gabriel [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: wittum@uni-hd.de
2008-04-01
This paper deals with the upscaling of the time-harmonic Maxwell equations for heterogeneous media. We analyze the eddy-current approximation of Maxwell's equations to describe the electric field for heterogeneous, isotropic magnetic materials. The magnetic permeability of the materials is assumed to have random heterogeneities described by a Gaussian random field. We apply the so-called Coarse Graining method to develop a numerical upscaling of the eddy-current model. The upscaling uses filtering and averaging procedures in Fourier space which results in a formulation of the eddy-current model on coarser resolution scales where the influence of sub-scale fluctuations is modeled by effective scale- and space-dependent reluctivity tensors. The effective reluctivity tensors can be obtained by solving local partial differential equations which contain a Laplacian as well as a curl-curl operator. We present a computational method how the equation of the combined operators can be discretized and solved numerically using an extended variational formulation compared to standard discretizations. We compare the results of the numerical upscaling of the eddy-current model with theoretical results of Eberhard [J.P. Eberhard, Upscaling for the time-harmonic Maxwell equations with heterogeneous magnetic materials, Physical Review E 72 (3), (2005)] and obtain a very good agreement.
Numerical study of a slip-link model for polymer melts and nanocomposites
Diego Delbiondo; Elian Masnada; Samy Merabia; Marc Couty; Jean-Louis Barrat
2013-06-10
We present a numerical study of the slip link model introduced by Likhtman for describing the dy- namics of dense polymer melts. After reviewing the technical aspects associated with the implemen- tation of the model, we extend previous work in several directions. The dependence of the relaxation modulus with the slip link density and the slip link stiffness is reported. Then the nonlinear rheolog- ical properties of the model, for a particular set of parameters, are explored. Finally, we introduce excluded volume interactions in a mean field such as manner in order to describe inhomogeneous systems, and we apply this description to a simple nanocomposite model. With this extension, the slip link model appears as a simple and generic model of a polymer melt, that can be used as an alternative to molecular dynamics for coarse grained simulations of complex polymeric systems.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
François, Marianne M.
2015-05-28
A review of recent advances made in numerical methods and algorithms within the volume tracking framework is presented. The volume tracking method, also known as the volume-of-fluid method has become an established numerical approach to model and simulate interfacial flows. Its advantage is its strict mass conservation. However, because the interface is not explicitly tracked but captured via the material volume fraction on a fixed mesh, accurate estimation of the interface position, its geometric properties and modeling of interfacial physics in the volume tracking framework remain difficult. Several improvements have been made over the last decade to address these challenges.more »In this study, the multimaterial interface reconstruction method via power diagram, curvature estimation via heights and mean values and the balanced-force algorithm for surface tension are highlighted.« less
Numerical-Model Investigation of the Hydrothermal Regime of a Straight-Through Shallow Cooling Pond
Sokolov, A. S. [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)] [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)
2013-11-15
A mathematic model based on solution of hydrodynamics and heat-transfer equations by the finite-element method is constructed to predict the hydrothermal regime of a straight-through shallow cooling pond, which provides cooling circulating water to a repository of spent nuclear fuel. Numerical experiments made it possible to evaluate the influence exerted by wind conditions and flow rate of water in the river on the temperature of the circulating water.
Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model
Paris-Sud XI, Université de
or radioactive waste [30], geothermal Corresponding author Email address: benoit.carrier@enpc.fr (Benoit Carrier processes. During the last sixty years, numerous papers [3, 7, 14, 21, 35, 34, 41, 25, 27, 22, 38, 36, 1. In the recent years, a scaling and asymptotic framework was built to determine the influence of the physical
Active Gel Model of Amoeboid Cell Motility
A. C. Callan-Jones; R. Voituriez
2013-02-01
We develop a model of amoeboid cell motility based on active gel theory. Modeling the motile apparatus of a eukaryotic cell as a confined layer of finite length of poroelastic active gel permeated by a solvent, we first show that, due to active stress and gel turnover, an initially static and homogeneous layer can undergo a contractile-type instability to a polarized moving state in which the rear is enriched in gel polymer. This agrees qualitatively with motile cells containing an actomyosin-rich uropod at their rear. We find that the gel layer settles into a steadily moving, inhomogeneous state at long times, sustained by a balance between contractility and filament turnover. In addition, our model predicts an optimal value of the gel-susbstrate adhesion leading to maximum layer speed, in agreement with cell motility assays. The model may be relevant to motility of cells translocating in complex, confining environments that can be mimicked experimentally by cell migration through microchannels.
A Numerical Model of the Temperature Field of the Cast and Solidified Ceramic Material
Kavicka, Frantisek; Sekanina, Bohumil; Stransky, Karel; Stetina, Josef [Brno University of Technology, Brno, Technicka 2 (Czech Republic); Dobrovska, Jana [Technical University of Ostrava, Ostrava, Tr. 17.listopadu 17 (Czech Republic)
2010-06-15
Corundo-baddeleyit material (CBM)--EUCOR--is a heat- and wear-resistant material even at extreme temperatures. This article introduces a numerical model of solidification and cooling of this material in a non-metallic mould. The model is capable of determining the total solidification time of the casting and also the place of the casting which solidifies last. Furthermore, it is possible to calculate the temperature gradient in any point and time, and also determine the local solidification time and the solidification interval of any point. The local solidification time is one of the input parameters for the cooperating model of chemical heterogeneity. This second model and its application on samples of EUCOR prove that the applied method of measurement of chemical heterogeneity provides detailed quantitative information on the material structure and makes it possible to analyse the solidification process. The analysis of this process entails statistical processing of the results of the measurements of the heterogeneity of the components of EUCOR and performs correlation of individual components during solidification. The crystallisation process seems to be very complicated, where the macro- and microscopic segregations differ significantly. The verification of both numerical models was conducted on a real cast 350x200x400 mm block.
Modeling Solar Activity Bayesian Analysis of Stellar Evolution
Wolfe, Patrick J.
Modeling Solar Activity Bayesian Analysis of Stellar Evolution Astrostatistical Analysis in Solar, David Astrostatistical Analysis in Solar and Stellar Physics #12;Modeling Solar Activity Bayesian Analysis of Stellar Evolution Outline 1 Modeling Solar Activity Background Morphological Feature Extraction
gamma-ray emission from microquasars: a numerical model for LSI+61 303
Valenti Bosch-Ramon; Josep M. Paredes
2004-07-01
We explore the possible association between the microquasar LSI+61 303 and the EGRET source 2CG 135+01/3EG J0241$+$6103 by studying, with a detailed numerical model, whether this system can produce the emission and the variability detected by EGRET ($>$100 MeV) through inverse Compton (IC) scattering. Our numerical approach considers a population of relativistic electrons entrained in a cylindrical inhomogeneous jet, interacting with both the radiation and the magnetic fields, taking into account the Thomson and Klein-Nishina regimes of interaction. Our results reproduce the observed spectral characteristics and variability at $\\gamma$-rays, thus strengthening the identification of LSI+61 303 as a high-energy $\\gamma$-ray source.
Connecticut Fuel Cell Activities: Markets, Programs, and Models...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Activities: Markets, Programs, and Models Connecticut Fuel Cell Activities: Markets, Programs, and Models Presented by the Connecticut Center for Advanced Technology, Inc. at the...
Numerical modelling of sandstone uniaxial compression test using a mix-mode cohesive fracture model
Gui, Yilin; Kodikara, Jayantha
2015-01-01
A mix-mode cohesive fracture model considering tension, compression and shear material behaviour is presented, which has wide applications to geotechnical problems. The model considers both elastic and inelastic displacements. Inelastic displacement comprises fracture and plastic displacements. The norm of inelastic displacement is used to control the fracture behaviour. Meantime, a failure function describing the fracture strength is proposed. Using the internal programming FISH, the cohesive fracture model is programmed into a hybrid distinct element algorithm as encoded in Universal Distinct Element Code (UDEC). The model is verified through uniaxial tension and direct shear tests. The developed model is then applied to model the behaviour of a uniaxial compression test on Gosford sandstone. The modelling results indicate that the proposed cohesive fracture model is capable of simulating combined failure behaviour applicable to rock.
The LIGO Scientific Collaboration; the Virgo Collaboration; the NINJA-2 Collaboration; :; J. Aasi; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; K. Ackley; C. Adams; T. Adams; P. Addesso; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; A. Ain; P. Ajith; A. Alemic; B. Allen; A. Allocca; D. Amariutei; M. Andersen; R. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; M. Barbet; B. C. Barish; D. Barker; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. C. Batch; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. Bejger; M. G. Beker; C. Belczynski; A. S. Bell; C. Bell; G. Bergmann; D. Bersanetti; A. Bertolini; J. Betzwieser; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Biscans; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; S. Bloemen; M. Blom; O. Bock; T. P. Bodiya; M. Boer; G. Bogaert; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; Sukanta Bose; L. Bosi; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brückner; S. Buchman; T. Bulik; H. J. Bulten; A. Buonanno; R. Burman; D. Buskulic; C. Buy; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; C. Celerier; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. J. Chamberlin; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; C. Collette; M. Colombini; L. Cominsky; M. Constancio Jr.; A. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corpuz; A. Corsi; C. A. Costa; M. W. Coughlin; S. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; R. Coyne; K. Craig; J. D. E. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; G. Debreczeni; J. Degallaix; S. Deléglise; W. Del Pozzo; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. De Rosa; R. T. DeRosa; R. DeSalvo; S. Dhurandhar; M. Díaz; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; A. Donath; F. Donovan; K. L. Dooley; S. Doravari; S. Dossa; R. Douglas; T. P. Downes; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; S. Dwyer; T. Eberle; T. Edo; M. Edwards; A. Effler; H. Eggenstein; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endr?czi; R. Essick; T. Etzel; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. M. Farr; M. Favata; H. Fehrmann; M. M. Fejer; D. Feldbaum; F. Feroz; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; S. Gaonkar; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; S. Ghosh; J. A. Giaime; K. D. Giardina; A. Giazotto; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Gräf; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. Gushwa; E. K. Gustafson; R. Gustafson; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. Hart; M. T. Hartman; C. -J. Haster; K. Haughian; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; S. Hooper; P. Hopkins; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; P. Jaranowski; Y. Ji; F. Jiménez-Forteza; W. W. Johnson; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; J. Karlen; M. Kasprzack; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; F. Kawazoe; F. Kéfélian; G. M. Keiser; D. Keitel; D. B. Kelley; W. Kells; A. Khalaidovski
2014-01-05
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered with false alarm rates smaller than 1 in a thousand years. Parameter estimation algorithms were run on each of these waveforms to explore the ability to constrain the masses, component angular momenta and sky position of these waveforms. We also perform a large-scale monte-carlo study to assess the ability to recover each of the 60 hybrid waveforms with early Advanced LIGO and Advanced Virgo sensitivity curves. Our results predict that early Advanced LIGO and Advanced Virgo will have a volume-weighted average sensitive distance of 300Mpc (1Gpc) for $10M_{\\odot}+10M_{\\odot}$ ($50M_{\\odot}+50M_{\\odot}$) binary black hole coalescences. We demonstrate that neglecting the component angular momenta in the waveform models used in matched-filtering will result in a reduction in sensitivity for systems with large component angular momenta. [Abstract abridged for ArXiv, full version in PDF
Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri
Rovey, Charles; Gouzie, Douglas; Biagioni, Richard
2013-09-30
The project titled Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri provided training for three graduate students in areas related to carbon capture and storage. Numerical modeling of CO{sub 2} injection into the St. Francois aquifer at the Southwest Power Plant Site in Greene County, Missouri indicates that up to 4.1 x 10{sup 5} metric tons of CO{sub 2} per year could be injected for 30 years without exceeding a 3 MPa differential injection pressure. The injected CO{sub 2} would remain sequestered below the top of the overlying caprock (St. Francois confining unit) for more than 1000 years. Geochemical modeling indicates that portions of the injected CO{sub 2} will react rapidly with trace minerals in the aquifer to form various solid carbonate mineral phases. These minerals would store significant portions of injected CO{sub 2} over geologic time scales. Finally, a GIS data base on the pore-fluid chemistry of the overlying aquifer system in Missouri, the Ozark aquifer, was compiled from many sources. This data base could become useful in monitoring for leakage from future CO{sub 2} sequestration sites.
A phase screen model for simulating numerically the propagation of a laser beam in rain
Lukin, I P; Rychkov, D S; Falits, A V [Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation); Lai, Kin S; Liu, Min R [DSO National Laboratories 20 (Singapore)
2009-09-30
The method based on the generalisation of the phase screen method for a continuous random medium is proposed for simulating numerically the propagation of laser radiation in a turbulent atmosphere with precipitation. In the phase screen model for a discrete component of a heterogeneous 'air-rain droplet' medium, the amplitude screen describing the scattering of an optical field by discrete particles of the medium is replaced by an equivalent phase screen with a spectrum of the correlation function of the effective dielectric constant fluctuations that is similar to the spectrum of a discrete scattering component - water droplets in air. The 'turbulent' phase screen is constructed on the basis of the Kolmogorov model, while the 'rain' screen model utiises the exponential distribution of the number of rain drops with respect to their radii as a function of the rain intensity. Theresults of the numerical simulation are compared with the known theoretical estimates for a large-scale discrete scattering medium. (propagation of laser radiation in matter)
Cirpka, Olaf Arie
Hydrosystemmodellierung Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations 1/16 Modelling April 2008 Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations #12 on Numerical Models for Carbon Dioxide Storage in Geological Formations 2/16 CO2 leakage mitigation using
Stochastic models and numerical algorithms for a class of regulatory gene networks
Thomas Fournier; Jean-Pierre Gabriel; Christian Mazza; Jerome Pasquier; Jose Galbete; Nicolas Mermod
2008-10-01
Regulatory gene networks contain generic modules like those involving feedback loops, which are essential for the regulation of many biological functions. We consider a class of self-regulated genes which are the building blocks of many regulatory gene networks, and study the steady state distributions of the associated Gillespie algorithm by providing efficient numerical algorithms. We also study a regulatory gene network of interest in synthetic biology and in gene therapy, using mean-field models with time delays. Convergence of the related time-nonhomogeneous Markov chain is established for a class of linear catalytic networks with feedback loops
Numerical modeling of the high-temperature geothermal system of Amatitlan, Guatemala
Pham, M.; Menzies, A.J.; Sanyal, S.K. [GeothermEx, Inc., Richmond, CA (United States)] [and others
1996-12-31
Using the conceptual model of the Amatitlin geothermal system as a guide, a 14 by 10 km numerical model was set up with five layers and a total of 1,220 grid blocks. The number of grid blocks varies from layer to layer, with finer resolution in the two production layers. Boundary blocks for conductive heat transfer, heat and mass recharge, shallow discharge and deep regional fluid flow were added to the model as appropriate. With an inflow of hot fluid (336{degrees}C) at a rate of 450 tones per hour, an inflow of cool fluid (50{degrees}C) at a rate of 620 tons per hour and permeabilities varying from 1.5 to 50 md, the initial state temperatures on all five levels were well matched by the numerical model. The initial state results indicate that highest permeability is present to the southeast of the productive wells, suggesting that considerable additional production potential exists in this area. A two-phase region exists in the upper levels of the reservoir and in the outflow plume; the latter is consistent with the presence of fumaroles along the shoreline of Lago de Amatitlan. To further calibrate the numerical model, enthalpy and pressure data collected during tests of wells AMF-1 and -2 were matched, primarily by varying reservoir storage capacity. Good matches to the observed data were obtained for both wells, although sharp transients could not be matched. Modeling proceeded to the prediction stage under two scenarios: production of 12 and 25 MW (gross) for 30 years. 100% injection of separated water and condensate was assumed to take place in the vicinity of well AMF-3 in both cases. The results show an increase in enthalpy caused by expansion of the two-phase zone during the first year of production, followed by an enthalpy decline as reservoir liquid begins to migrate toward the production area. The two existing production wells (AMF-1 and -2) are predicted to be capable of maintaining output in the 12 MW case throughout the 30-year project life.
Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics
Lynett, Patrick
Tsunami inundation modeling in constructed environments: A physical and numerical comparison April 2013 Available online 17 May 2013 Keywords: Tsunami Inundation Macro-roughness Benchmark COULWAVE Friction factor A laboratory benchmark test for tsunami inundation through an urban waterfront including
Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)
2014-01-15
This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice Bhatnagar–Gross–Krook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.
Mücke, Tanja A; Milan, Patrick; Peinke, Joachim
2015-01-01
Based on the Langevin equation it has been proposed to obtain power curves for wind turbines from high frequency data of wind speed measurements u(t) and power output P (t). The two parts of the Langevin approach, power curve and drift field, give a comprehensive description of the conversion dynamic over the whole operating range of the wind turbine. The method deals with high frequent data instead of 10 min means. It is therefore possible to gain a reliable power curve already from a small amount of data per wind speed. Furthermore, the method is able to visualize multiple fixed points, which is e.g. characteristic for the transition from partial to full load or in case the conversion process deviates from the standard procedures. In order to gain a deeper knowledge it is essential that the method works not only for measured data but also for numerical wind turbine models and synthetic wind fields. Here, we characterize the dynamics of a detailed numerical wind turbine model and calculate the Langevin power...
Numerical studies of active current profile control in the reversed-field pinch
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolarNewsusceptometer under pressureNavyNumerical simulations ofstudies of
Numerical modeling of roll structures in mesoscale vortexes over the Black Sea
Iarova, D A
2014-01-01
This paper is a case study of horizontal atmospheric rolls that formed over the Black Sea on 16 August 2007. The rolls were discovered in WRF modeling results for a mesoscale cyclone that originated over the sea on 15 August 2007. The roll formation mechanisms, such as Rayleigh-Benard convective instability, dynamic instability, advection and stretching of vertical velocity field inhomogeneities, are considered. It is shown that indeed convective instability played an important role in the roll formation but dynamic instability did not occur. In order to distinguish other possible mechanisms of the roll formation numerical experiments were performed. In these experiments sea surface temperature in the initial conditions was decreased in order to prevent convective instability. Even though convective instability was suppressed roll-like structures still appeared in the modeling results, although their height and circulation velocity were smaller than in the control run. It was found that these structures were ...
Seth A Veitzer
2008-10-21
Effects of stray electrons are a main factor limiting performance of many accelerators. Because heavy-ion fusion (HIF) accelerators will operate in regimes of higher current and with walls much closer to the beam than accelerators operating today, stray electrons might have a large, detrimental effect on the performance of an HIF accelerator. A primary source of stray electrons is electrons generated when halo ions strike the beam pipe walls. There is some research on these types of secondary electrons for the HIF community to draw upon, but this work is missing one crucial ingredient: the effect of grazing incidence. The overall goal of this project was to develop the numerical tools necessary to accurately model the effect of grazing incidence on the behavior of halo ions in a HIF accelerator, and further, to provide accurate models of heavy ion stopping powers with applications to ICF, WDM, and HEDP experiments.
Two-dimensional numerical model of underground oil-shale retorting
Travis, B.J.; Hommert, P.J.; Tyner, C.E.
1983-01-01
A two-dimensional numerical model of underground oil shale retorting, which fully couples retorting chemistry with fluid and heat flow, has been developed. The model solves the time-dependent, two-dimensional mass, momentum, and energy balance equations for a nine-component fluid (O/sub 2/, N/sub 2/, H/sub 2/, CO/sub 2/, CO, CH/sub 4/, CH/sub x/, H/sub 2/O, and oil). Water and oil can flow in the liquid and/or vapor phases. Retort chemistry includes kerogen pyrolysis, carbonate decomposition, char reactions, and combustion. Also, detailed modeling of heat flow and chemistry inside shale particles allows large rubble sizes as well as small sizes to be considered. The model is compared to one-dimensional experimental data obtained from Lawrence Livermore National Laboratory. The model can be used to examine the effect of two-dimensional variations in shale grade, rubble size, permeability, porosity, geometry, inflow gas composition, etc. on retorting efficiency and process optimization. A sample calculation is presented.
Modeling active electrolocation in weakly electric fish
Habib Ammari; Thomas Boulier; Josselin Garnier
2013-03-06
In this paper, we provide a mathematical model for the electrolocation in weakly electric fishes. We first investigate the forward complex conductivity problem and derive the approximate boundary conditions on the skin of the fish. Then we provide a dipole approximation for small targets away from the fish. Based on this approximation, we obtain a non-iterative location search algorithm using multi-frequency measurements. We present numerical experiments to illustrate the performance and the stability of the proposed multi-frequency location search algorithm. Finally, in the case of disk- and ellipse-shaped targets, we provide a method to reconstruct separately the conductivity, the permittivity, and the size of the targets from multi-frequency measurements.
Anooshehpoor, Rasool; Purvance, Matthew D.; Brune, James N.; Preston, Leiph A.; Anderson, John G.; Smith, Kenneth D.
2006-09-29
This report covers the following projects: Shake table tests of precarious rock methodology, field tests of precarious rocks at Yucca Mountain and comparison of the results with PSHA predictions, study of the coherence of the wave field in the ESF, and a limited survey of precarious rocks south of the proposed repository footprint. A series of shake table experiments have been carried out at the University of Nevada, Reno Large Scale Structures Laboratory. The bulk of the experiments involved scaling acceleration time histories (uniaxial forcing) from 0.1g to the point where the objects on the shake table overturned a specified number of times. The results of these experiments have been compared with numerical overturning predictions. Numerical predictions for toppling of large objects with simple contact conditions (e.g., I-beams with sharp basal edges) agree well with shake-table results. The numerical model slightly underpredicts the overturning of small rectangular blocks. It overpredicts the overturning PGA for asymmetric granite boulders with complex basal contact conditions. In general the results confirm the approximate predictions of previous studies. Field testing of several rocks at Yucca Mountain has approximately confirmed the preliminary results from previous studies, suggesting that he PSHA predictions are too high, possibly because the uncertainty in the mean of the attenuation relations. Study of the coherence of wavefields in the ESF has provided results which will be very important in design of the canisters distribution, in particular a preliminary estimate of the wavelengths at which the wavefields become incoherent. No evidence was found for extreme focusing by lens-like inhomogeneities. A limited survey for precarious rocks confirmed that they extend south of the repository, and one of these has been field tested.
Integration of GIS with Activity-Based Model in ATIS
Kwan, Mei-Po; Golledge, Reginald
1995-01-01
Integration of GIS with Activity-Based Model in ATIS Mei-Poregulation. Integration of GIS with Activity-Based Model inGrant UCTC Grant DTRS92-G-0009: GIS Data Model for DOT "A
A numerical investigation on active and passive scalars in isotropic compressible turbulence
Ni, Qionglin; Chen, Shiyi
2015-01-01
In this paper, we investigated the statistical differences between active and passive scalars in isotropic compressible turbulence. In the inertial range, the kinetic energy and scalar have the Kolmogorov spectra, and the Kolmogorov and Obukhov-Corrsin constants are 2.06 and 0.87, respectively. The local scaling exponents computed from the second-order structure functions exist plateaus for velocity and active scalar, while that for passive scalar takes first a minimum of 0.61 then a maximum of 0.73. The mixed third-order structure function of velocity and passive scalar satisfies the 4/3-law. For the scaling exponent, the one of velocity and passive scalar mixing is between those of velocity and passive scalar, while the one of velocity and active scalar mixing is below those of velocity and active scalar. At large amplitudes, the p.d.f. of active scalar fluctuations is super-Gaussian, whereas that of passive scalar fluctuations is sub-Gaussian. Moreover, the p.d.f.s of the two scalar increments are concave ...
Numerical Modeling of Thermal EOR: Comprehensive Coupling of an AMR-Based Model
Paris-Sud XI, Université de
Flow and Geomechanics N. Guy*, G. Enchéry and G. Renard IFP Energies nouvelles, 1-4 avenue de Bois of Thermal EOR: Comprehensive Coupling of an AMR-Based Model of Thermal Fluid Flow and Geomechanics when both thermal fluid flow and geomechanics are coupled in order to take into account variations
Cheng, C. L.; Gragg, M. J.; Perfect, E.; White, Mark D.; Lemiszki, P. J.; McKay, L. D.
2013-08-24
Numerical simulations are widely used in feasibility studies for geologic carbon sequestration. Accurate estimates of petrophysical parameters are needed as inputs for these simulations. However, relatively few experimental values are available for CO2-brine systems. Hence, a sensitivity analysis was performed using the STOMP numerical code for supercritical CO2 injected into a model confined deep saline aquifer. The intrinsic permeability, porosity, pore compressibility, and capillary pressure-saturation/relative permeability parameters (residual liquid saturation, residual gas saturation, and van Genuchten alpha and m values) were varied independently. Their influence on CO2 injection rates and costs were determined and the parameters were ranked based on normalized coefficients of variation. The simulations resulted in differences of up to tens of millions of dollars over the life of the project (i.e., the time taken to inject 10.8 million metric tons of CO2). The two most influential parameters were the intrinsic permeability and the van Genuchten m value. Two other parameters, the residual gas saturation and the residual liquid saturation, ranked above the porosity. These results highlight the need for accurate estimates of capillary pressure-saturation/relative permeability parameters for geologic carbon sequestration simulations in addition to measurements of porosity and intrinsic permeability.
Colonius, Tim
of Technology, Pasadena, California 91125 ABSTRACT We develop a reduced order model for large-scale unsteadiness mass injection can pinch off vortices with a smaller size; accordingly, their convective velocity
Tidal Downsizing model. I. Numerical methods: saving giant planets from tidal disruptions
Nayakshin, Sergei
2014-01-01
Tidal Downsizing (TD) is a recently developed planet formation theory that supplements the classical Gravitational disc Instability (GI) model with planet migration inward and tidal disruptions of GI fragments in the inner regions of the disc. Numerical methods for a detailed population synthesis of TD planets are presented here. As an example application, the conditions under which GI fragments collapse faster than they migrate into the inner $a\\sim$ few AU disc are considered. It is found that most gas fragments are tidally or thermally disrupted unless (a) their opacity is $\\sim 3$ orders of magnitude less than the interstellar dust opacity at metallicities typical of the observed giant planets, or (b) the opacity is high but the fragments accrete large dust grains (pebbles) from the disc. Case (a) models produce very low mass solid cores ($M_{\\rm core} < 0.1$ Earth masses) and follow a negative correlation of giant planet frequency with host star metallicity. In contrast, case (b) models produce massiv...
Stroud, Jonathan
Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 2006; published 17 February 2007. [1] A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied
Boyer, Edmond
Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model in the coplanar orbit transfer problem M. Cerf1, T. Haberkorn, SADCO 2011, March 2nd M. Cerf, T. Haberkorn, E. Tr´elat Continuation from a flat to a round Earth model
Eckert, Andreas
2013-05-31
In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ?P{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ?P{sub c} magnitudes, especially for the compressional stress regime.
Validation of model based active control of combustion instability
Fleifil, M.; Ghoneim, Z.; Ghoniem, A.F.
1998-07-01
The demand for efficient, company and clean combustion systems have spurred research into the fundamental mechanisms governing their performance and means of interactively changing their performance characteristics. Thermoacoustic instability which is frequently observed in combustion systems with high power density, when burning close to the lean flammability limit, or using exhaust gas recirculation to meet more stringent emissions regulations, etc. Its occurrence and/or means to mitigate them passively lead to performance degradation such as reduced combustion efficiency, high local heat transfer rates, increase in the mixture equivalence ratio or system failure due to structural damage. This paper reports on their study of the origin of thermoacoustic instability, its dependence on system parameters and the means of actively controlling it. The authors have developed an analytical model of thermoacoustic instability in premixed combustors. The model combines a heat release dynamics model constructed using the kinematics of a premixed flame stabilized behind a perforated plate with the linearized conservation equations governing the system acoustics. This formulation allows model based controller design. In order to test the performance of the analytical model, a numerical solution of the partial differential equations governing the system has been carried out using the principle of harmonic separation and focusing on the dominant unstable mode. This leads to a system of ODEs governing the thermofluid variables. Analytical predictions of the frequency and growth ate of the unstable mode are shown to be in good agreement with the numerical simulations as well s with those obtained using experimental identification techniques when applied to a laboratory combustor. The authors use these results to confirm the validity of the assumptions used in formulating the analytical model. A controller based on the minimization of a cost function using the LQR technique has been designed using the analytical model and implemented on a bench top laboratory combustor. The authors show that the controller is capable of suppressing the pressure oscillations in the combustor with a settling time much shorter than what had been attained before and without exciting secondary peaks.
Hans-Dieter Alber
2015-05-20
The accurate simulation of phase interfaces in solids requires small model error and small numerical error. If a phase field model is used and the interface carries low interface energy, then the model error is only small if the interface width in the model is chosen small. Yet, for effective numerical computation the interface width should be large. Choosing the parameters, which determine the width, is therefore an optimality problem. We study this problem for the Allen-Cahn equation coupled to the elasticity equations by constructing an asymptotic solution of second order, which yields an expansion for the kinetic relation of the model. This expansion determines the choice of the parameters, however only if the difference between the expansion and the exact kinetic relation is uniformly small with respect to a second parameter controlling the interface energy. To show this uniformity we determine the asymptotics with respect to this second parameter by scaling of the model equations. Our investigations are formal.
NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES
Okuzumi, Satoshi; Sakagami, Masa-aki [Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501 (Japan); Tanaka, Hidekazu, E-mail: satoshi.okuzumi@ax2.ecs.kyoto-u.ac.j [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan)
2009-12-20
Porosity evolution of dust aggregates is crucial in understanding dust evolution in protoplanetary disks. In this study, we present useful tools to study the coagulation and porosity evolution of dust aggregates. First, we present a new numerical method for simulating dust coagulation and porosity evolution as an extension of the conventional Smoluchowski equation. This method follows the evolution of the mean porosity for each aggregate mass simultaneously with the evolution of the mass distribution function. This method reproduces the results of previous Monte Carlo simulations with much less computational expense. Second, we propose a new collision model for porous dust aggregates on the basis of our N-body experiments on aggregate collisions. As the first step, we focus on 'hit-and-stick' collisions, which involve neither compression nor fragmentation of aggregates. We first obtain empirical data on porosity changes between the classical limits of ballistic cluster-cluster and particle-cluster aggregation. Using the data, we construct a recipe for the porosity change due to general hit-and-stick collisions as well as formulae for the aerodynamical and collisional cross sections. Our collision model is thus more realistic than a previous model of Ormel et al. based on the classical aggregation limits only. Simple coagulation simulations using the extended Smoluchowski method show that our collision model explains the fractal dimensions of porous aggregates observed in a full N-body simulation and a laboratory experiment. By contrast, similar simulations using the collision model of Ormel et al. result in much less porous aggregates, meaning that this model underestimates the porosity increase upon unequal-sized collisions. Besides, we discover that aggregates at the high-mass end of the distribution can have a considerably small aerodynamical cross section per unit mass compared with aggregates of lower masses. This occurs when aggregates drift under uniform acceleration (e.g., gravity) and their collision is induced by the difference in their terminal velocities. We point out an important implication of this discovery for dust growth in protoplanetary disks.
Theory and modeling of active brazing.
van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.
2013-09-01
Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.
Numerical modeling of two-phase behavior in the PEFC gas diffusion layer
Mukherjee, Partha Pa223876 [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rod L [Los Alamos National Laboratory
2009-01-01
A critical performance limitation in the polymer electrolye fuel cell (PEFC) is attributed to the mass transport loss originating from suboptimal liquid water transport and flooding phenomena. Liquid water can block the porous pathways in the fibrous gas diffusion layer (GDL) and the catalyst layer (CL), thus hindering oxygen transport from the flow field to the electrochemically actives sites in the catalyst layer. In this paper, the study of the two phase behavior and the durability implications due to the wetting characteristics in the carbon paper GDL are presented using a pore-scale modeling framework.
Menzies, A.J.; Granados, E.E.; Sanyal, .K.; Merida-I., L.; Caicedo-A, A.
1991-01-01
A significant amount of geoscientific and reservoir engineering data have been collected from the Zunil geothermal field since 1973. The data have been used to define a conceptual model for the field which has formed the basis for the construction of a three dimensional numerical simulation model. The numerical model has successfully matched both the initial state of the reservoir, as indicated by subsurface temperature and pressure distributions within the presently drilled area, and available well test data. The well test data include short and long term discharge tests and a comprehensive pressure interference test. Calibration of the model will continue during 1991 when the results from drilling and testing of three additional deep wells are available. The model will then be used to study various long term production scenarios for the proposed 15 MW power development.
The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and
of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we and the perspectives for future research presented. Key words: tsunami waves, shallow water equations, tsunami
Numerical modeling of alongshore sediment transport and shoreline change along the Galveston coast
Sitanggang, Khairil Irfan
2005-02-17
coast for the period of 2001-2011. The first assessment shows that GENESIS has a numerical error which tends to be large for low energy wave (small breaking wave height) and large breaking wave angle. This numerical inaccuracy cannot be neglected...
Kirby, James T.
Numerical simulation of the 2011 Tohoku tsunami: Comparison with field observations and sensitivity history, created a major tsunami that caused numerous deaths and enormous destruction on the nearby Hon- shu coast. Various tsunami sources were developed for this event, based on inverting seismic or GPS
Huang, Xun
therein. Most recent ap- plications include high-speed flow control using localized arc filament plasma2250 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 37, NO. 11, NOVEMBER 2009 A Numerical Model of Plasma-Actuator Effects in Flow-Induced Noise Control Ed Peers, Xun Huang, and Xinfu Luo Abstract
Harrison, Mark
1988-01-01
IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full are given and then a discrete-time, explicit finite element procedure is defined and analysed, with finite on the existence, uniqueness and finite element approximation of the solution of Biot's equations were given in [15
Occhipinti, Giovanni "Ninto"
LETTER Earth Planets Space, 63, 847851, 2011 Three-dimensional numerical modeling of tsunami, 2011; Accepted June 30, 2011; Online published September 27, 2011) The tremendous tsunami following, to reproduce the tsunami signature observed in the airglow by the imager located in Hawaii and clearly showing
Tandon, Amit
Segmentation and Tracking of Mesoscale Eddies in Numeric Ocean Models Vishal Sood, Bin John suggested that the mesoscale eddies and mesoscale features play a strong role in carrying heat poleward oceanographers an invaluable tool to assess mesoscale eddies and the Lagrangian characteristics of this mesoscale
Numerical study of the mass spectrum in the 2D O(3) sigma model with a theta term
B. Alles; A. Papa
2007-11-12
It has been conjectured that the mass spectrum of the O(3) non-linear sigma model with a theta term in 2 dimensions may possess an excited state, which decays when theta is lowered from pi below a critical value. Since the direct numerical investigation of the model is prevented by a sign problem, we try to infer some information on the mass spectrum at real theta by studying the model at imaginary theta via analytic continuation. A modified Swendsen-Wang cluster algorithm has been introduced to simulate the model with the theta term.
Sim, Yoon Sub; Kim, Eui Kwang; Eoh, Jae Hyuk [Korea Atomic Energy Research Institute (Korea, Republic of)
2005-06-15
To overcome the drawbacks of conventional schemes for a numerical analysis of a steam generator (SG), an efficient numerical model has been developed to analyze the steady state of a once-through-type SG where the feedwater is heated to superheated steam. In the developed model, the temperature and enthalpy are defined at the boundary of a calculation cell, and the exact solutions for the temperature distribution in a calculation cell are utilized. This feature of the developed model frees calculation from the undesirable effects of numerical diffusion, and only a small number of nodes are required. Also, the developed model removes the ambiguity from the parameter values at the inlet and exit of a calculation.The BoSupSG-SS computer code was developed by using the analysis model, and it performed well with only three calculation nodes to analyze a superheated SG. The developed model can be effectively used for the cases where a fast one-dimensional calculation is required such as an SG or system design analysis.
Mathiesen, Patrick; Collier, Craig; Kleissl, Jan
2013-01-01
cycle: The RUC. Monthly Weather Review. 132, 495?518. th Conference on Numerical Weather Prediction. American closure schemes. Monthly Weather Review. 122, 927?945.
Soil Liquefaction–Induced Uplift of Underground Structures: Physical and Numerical Modeling
Chian, Siau Chen; Tokimatsu, Kohji; M.ASCE; Madabhushi, Santana Phani Gopal
2014-07-11
in the liquefiable soil deposit. These consistencies with field observations clearly demonstrate and pave the prospects of applying numerical and/or experimental analyses for geotechnical problems associated with the floatation of underground structures...
Numerical modeling of species transport in turbulent flow and experimental study on aerosol sampling
Vijayaraghavan, Vishnu Karthik
2007-04-25
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 ...
Mohaghegh, Shahab
capability of being able to replicate the pressure and saturation distribution throughout the reservoirSPE 153844 Grid-Based Surrogate Reservoir Modeling (SRM) for Fast Track Analysis of Numerical Reservoir Simulation Models at the Grid block Level Shahab D. Mohaghegh, West Virginia University
Yano, Ryosuke
2015-01-01
We consider a fast and accurate numerical method to calculate the dilute quantum gas. To attain our aim, the Uehing-Uhlenbeck (U-U) model equation is calculated using the direct simulation Monte Carlo (DSMC) method. The proposed algorithm in the DSMC method enables us to obtain the accurate thermalization using a small number of sample particles and calculate the dilute quantum gas dynamics in practical time. Finally, we apply the proposed numerical method to the calculation of the viscosity coefficient on the basis of Green-Kubo expression.
Sensitivity of Optimal Operation of an Activated Sludge Process Model
Skogestad, Sigurd
Sensitivity of Optimal Operation of an Activated Sludge Process Model Antonio Araujo, Simone sensitivity analysis of optimal operation conducted on an activated sludge process model based on the test.[7] applied a systematic procedure for control structure design of an activated sludge process
Modeling the dynamics of a tracer particle in an elastic active gel
E. Ben Isaac; É. Fodor; P. Visco; F. van Wijland; N. S. Gov
2015-07-03
The internal dynamics of active gels, both in artificial (in-vitro) model systems and inside the cytoskeleton of living cells, has been extensively studied by experiments of recent years. These dynamics are probed using tracer particles embedded in the network of biopolymers together with molecular motors, and distinct non-thermal behavior is observed. We present a theoretical model of the dynamics of a trapped active particle, which allows us to quantify the deviations from equilibrium behavior, using both analytic and numerical calculations. We map the different regimes of dynamics in this system, and highlight the different manifestations of activity: breakdown of the virial theorem and equipartition, different elasticity-dependent "effective temperatures" and distinct non-Gaussian distributions. Our results shed light on puzzling observations in active gel experiments, and provide physical interpretation of existing observations, as well as predictions for future studies.
Modeling the dynamics of a tracer particle in an elastic active gel
Isaac, E Ben; Visco, P; van Wijland, F; Gov, N S
2015-01-01
The internal dynamics of active gels, both in artificial (in-vitro) model systems and inside the cytoskeleton of living cells, has been extensively studied by experiments of recent years. These dynamics are probed using tracer particles embedded in the network of biopolymers together with molecular motors, and distinct non-thermal behavior is observed. We present a theoretical model of the dynamics of a trapped active particle, which allows us to quantify the deviations from equilibrium behavior, using both analytic and numerical calculations. We map the different regimes of dynamics in this system, and highlight the different manifestations of activity: breakdown of the virial theorem and equipartition, different elasticity-dependent "effective temperatures" and distinct non-Gaussian distributions. Our results shed light on puzzling observations in active gel experiments, and provide physical interpretation of existing observations, as well as predictions for future studies.
Modeling - Scale-Bridging Simulations Active Materials in Li...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
- Scale-Bridging Simulations Active Materials in Li-ion Batteries, and Validation in BATT Electrodes Modeling - Scale-Bridging Simulations Active Materials in Li-ion Batteries, and...
Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.
2014-06-01
Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.
Imada, Shinsuke; Watanabe, Tetsuya
2015-01-01
We have studied the chromospheric evaporation flow during the impulsive phase of the flare by using the Hinode/EIS observation and 1D hydrodynamic numerical simulation coupled to the time-dependent ionization. The observation clearly shows that the strong redshift can be observed at the base of the flaring loop only during the impulsive phase. We performed two different numerical simulations to reproduce the strong downflows in FeXII and FeXV during the impulsive phase. By changing the thermal conduction coefficient, we carried out the numerical calculation of chromospheric evaporation in the thermal conduction dominant regime (conductivity coefficient kappa0 = classical value) and the enthalpy flux dominant regime (kappa0 = 0.1 x classical value). The chromospheric evaporation calculation in the enthalpy flux dominant regime could reproduce the strong redshift at the base of the flare during the impulsive phase. This result might indicate that the thermal conduction can be strongly suppressed in some cases o...
Modeling Activities in the Department of Energy’s Atmospheric Sciences Program
Fast, Jerome D.; Ghan, Steven J.; Schwartz, Stephen E.
2009-03-01
The Department of Energy's Atmospheric Science Program (ASP) conducts research pertinent to radiative forcing of climate change by atmospheric aerosols. The program consists of approximately 40 highly interactive peer-reviewed research projects that examine aerosol properties and processes and the evolution of aerosols in the atmosphere. Principal components of the program are instrument development, laboratory experiments, field studies, theoretical investigations, and modeling. The objectives of the Program are to 1) improve the understanding of aerosol processes associated with light scattering and absorption properties and interactions with clouds that affect Earth's radiative balance and to 2) develop model-based representations of these processes that enable the effects of aerosols on Earth's climate system to be properly represented in global-scale numerical climate models. Although only a few of the research projects within ASP are explicitly identified as primarily modeling activities, modeling actually comprises a substantial component of a large fraction of ASP research projects. This document describes the modeling activities within the Program as a whole, the objectives and intended outcomes of these activities, and the linkages among the several modeling components and with global-scale modeling activities conducted under the support of the Department of Energy's Climate Sciences Program and other aerosol and climate research programs.
Kenis, Paul J. A.
A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge: Membraneless fuel cell Laminar flow fuel cell Numerical model Convection-diffusion equations Electrode kinetics equations COMSOL a b s t r a c t The operation of a laminar flow fuel cell (LFFC) involves complex interplay
Kusmierczyk, P; Wrobel, M
2012-01-01
The problem of hydraulic fracture for the PKN model is considered within the framework of approach presented recently by Linkov (2011). The modified formulation is further enhanced by employing an improved regularized boundary condition near the crack tip. This increases solution accuracy especially for singular leak-off regimes. A new dependent variable having clear physical sense is introduced. A comprehensive analysis of numerical algorithms based on various dependent variables is provided.
De Castro, Carlos Armando
2011-01-01
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.
Quadratic Inverse Eigenvalue Problems, Active Vibration Control and Model Updating
Datta, Biswa
is an important practical problem that arises in a wide range of applications, including mechanical vibrations control (AVC) and finite element model updating (FEMU) in mechanical vibration. The active vibrationQuadratic Inverse Eigenvalue Problems, Active Vibration Control and Model Updating Biswa N. Datta,1
Nonlinear Modeling and Control Design of Active Helicopter Blades
Patil, Mayuresh
Nonlinear Modeling and Control Design of Active Helicopter Blades Matthias Althoff , Mayuresh J dynamic solution and control design of active helicopter blades. Following are the significant new reduction technique is used to derive a low-order, high fidelity nonlinear blade model for control design
Managing Quality Requirements Using Activity-Based Quality Models
Cengarle, María Victoria
the complexity of software quality. A novel kind of quality mod- els uses the activities performed on and with the software as an explicit dimension. These quality models are a well- suited basis for managing qualityManaging Quality Requirements Using Activity-Based Quality Models Stefan Wagner, Florian
Asymptotic Approximations to the Distributed Activation Energy Model
McGuinness, Mark
Asymptotic Approximations to the Distributed Activation Energy Model M.J.McGuinness1 , E. Donskoi2 by a continuum distribution in activation energy of individual re- actions. An individual reaction is characterised by a pre-exponential coefficient and an activation energy. The distribution, usually Gaussian
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01
disposal of radioactive waste: The Sandia waste isolation flow and transport (SWIFT) model: Sandia Laboratories Report
Summary of FY15 results of benchmark modeling activities
Arguello, J. Guadalupe
2015-08-01
Sandia is participating in the third phase of an is a contributing partner to a U.S.-German "Joint Project" entitled "Comparison of current constitutive models and simulation procedures on the basis of model calculations of the thermo-mechanical behavior and healing of rock salt." The first goal of the project is to check the ability of numerical modeling tools to correctly describe the relevant deformation phenomena in rock salt under various influences. Achieving this goal will lead to increased confidence in the results of numerical simulations related to the secure storage of radioactive wastes in rock salt, thereby enhancing the acceptance of the results. These results may ultimately be used to make various assertions regarding both the stability analysis of an underground repository in salt, during the operating phase, and the long-term integrity of the geological barrier against the release of harmful substances into the biosphere, in the post-operating phase.
Quiros Fonseca, Luis Alonso
2012-12-31
This thesis presents development of mathematical models for liquid-solid and solid-liquid phase change phenomena in Lagrangian and Eulerian descriptions. The mathematical models are derived by assuming a smooth interface ...
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01
improving production by hydraulic fracturing 8 the focus otfor fractures. (d) Hydraulic Fracturing: The model has been
Representation of Dormant and Active Microbial Dynamics for Ecosystem Modeling
Wang, Gangsheng; Mayes, Melanie; Gu, Lianhong; Schadt, Christopher Warren
2014-01-01
Dormancy is an essential strategy for microorganisms to cope with environmental stress. However, global ecosystem models typically ignore microbial dormancy, resulting in notable model uncertainties. To facilitate the consideration of dormancy in these large-scale models, we propose a new microbial physiology component that works for a wide range of substrate availabilities. This new model is based on microbial physiological states and the major parameters are the maximum specific growth and maintenance rates of active microbes and the ratio of dormant to active maintenance rates. A major improvement of our model over extant models is that it can explain the low active microbial fractions commonly observed in undisturbed soils. Our new model shows that the exponentially-increasing respiration from substrate-induced respiration experiments can only be used to determine the maximum specific growth rate and initial active microbial biomass, while the respiration data representing both exponentially-increasing and non-exponentially-increasing phases can robustly determine a range of key parameters including the initial total live biomass, initial active fraction, the maximum specific growth and maintenance rates, and the half-saturation constant. Our new model can be incorporated into existing ecosystem models to account for dormancy in microbially-driven processes and to provide improved estimates of microbial activities.
Atmospheric transmittance model for photosynthetically active radiation
Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana; Pop, Nicolina; Calinoiu, Delia
2013-11-13
A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.
Molenkamp, C.R.; Grossman, A.
1999-12-20
A network of small balloon-borne transponders which gather very high resolution wind and temperature data for use by modern numerical weather predication models has been proposed to improve the reliability of long-range weather forecasts. The global distribution of an array of such transponders is simulated using LLNL's atmospheric parcel transport model (GRANTOUR) with winds supplied by two different general circulation models. An initial study used winds from CCM3 with a horizontal resolution of about 3 degrees in latitude and longitude, and a second study used winds from NOGAPS with a 0.75 degree horizontal resolution. Results from both simulations show that reasonable global coverage can be attained by releasing balloons from an appropriate set of launch sites.
Arima, T.; Sonoda, T.; Shirotori, M.; Tamura, A.; Kikuchi, K.
1999-01-01
The authors have developed a computer simulation code for three-dimensional viscous flow in turbomachinery based on the time-averaged compressible Navier-Stokes equations and a low-Reynolds-number {kappa}-{epsilon} turbulence model. It is described in detail in this paper. The code is used to compute the flow fields for two types of rotor (a transonic fan NASA Rotor 67 and a transonic axial compressor NASA rotor 37), and numerical results are compared to experimental data based on aerodynamic probe and laser anemometer measurements. In the case of Rotor 67, calculated and experimental results are compared under the design speed to validate the code. The calculated results show good agreement with the experimental data, such as the rotor performance map and the spanwise distribution of total pressure, total temperature, and flow angle downstream of the rotor. In the case of Rotor 37, detailed comparisons between the numerical results and the experimental data are made under the design speed condition to assess the overall quality of the numerical solution. Furthermore, comparisons under the part-speed condition are used to investigate a flow field without passage shock. The results are well predicted qualitatively. However, considerable quantitative discrepancies remain in predicting the flow near the tip. In order to assess the predictive capabilities of the developed code, computed flow structures are presented with the experimental data for each rotor and the cause of the discrepancies is discussed.
Grossman, A; Molenkamp, C R
1999-08-25
A proposal has been made to establish a high density global network of atmospheric micro transponders to record time, temperature, and wind data with time resolution of {le} 1 minute, temperature accuracy of {+-} 1 K, spatial resolution no poorer than {approx}3km horizontally and {approx}0.1km vertically, and 2-D speed accuracy of {le} 1m/s. This data will be used in conjunction with advanced numerical weather prediction models to provide increases in the reliability of long range weather forecasts. Major advances in data collection technology will be required to provide the proposed high-resolution data collection network. Systems studies must be undertaken to determine insertion requirements, spacing, and evolution of the transponder ensemble, which will be used to collect the data. Numerical models which provide realistic global weather pattern simulations must be utilized in order to perform these studies. A global circulation model with a 3{sup o} horizontal resolution has been used for initial simulations of the generation and evolution of transponder distributions. These studies indicate that reasonable global coverage of transponders can be achieved by a launch scenario consisting of the sequential launch of transponders at specified heights from a globally distributed set of launch sites.
Mathiesen, Patrick; Collier, Craig; Kleissl, Jan
2013-01-01
of the WRF model solar irradiance forecasts in Andalusia (Beyer, H. , 2009. Irradiance forecasting for the power dependent probabilistic irradiance forecasts for coastal
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01
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
A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras...
a topographic barrier located more than 16 km from the source. Two initial solid volumetric fractions are modeled. For both cases, some of the structures located more distant...
Potyondy, D.O.; Fairhurst, C.E.
1999-07-01
The post-peak load/deformation behavior of cohesive-frictional materials is an integral part of the overall response of a specimen to compressive loading. A more comprehensive understanding of the pre- and post-peak behavior is necessary. Recent developments in numerical modeling that allow study of the overall response of a synthetic material containing discrete heterogeneities and discontinuities both at the micro (particle) scale and at the larger scale of jointed rock masses can greatly aid the interpretation and application of laboratory test results on these materials.
Derouich, M; Barklem, P S
2015-01-01
Interpretation of solar polarization spectra accounting for partial or complete frequency redistribution requires data on various collisional processes. Data for depolarization and polarization transfer are needed but often missing, while data for collisional broadening are usually more readily available. Recent work by Sahal-Br\\'echot and Bommier concluded that despite underlying similarities in the physics of collisional broadening and depolarization processes, relationships between them are not possible to derive purely analytically. We aim to derive accurate numerical relationships between the collisional broadening rates and the collisional depolarization and polarization transfer rates due to hydrogen atom collisions. Such relationships would enable accurate and efficient estimation of collisional data for solar applications. Using earlier results for broadening and depolarization processes based on general (i.e. not specific to a given atom), semi-classical calculations employing interaction potentials...
Katushkina, O A; Alexashov, D B; Schwadron, N A; McComas, D J
2015-01-01
In this paper, we perform numerical modeling of the interstellar hydrogen fluxes measured by IBEX-Lo during orbit 23 (spring 2009) using a state-of-the-art kinetic model of the interstellar neutral hydrogen distribution in the heliosphere. This model takes into account the temporal and heliolatitudinal variations of the solar parameters as well as non-Maxwellian kinetic properties of the hydrogen distribution due to charge exchange in the heliospheric interface. We found that there is a qualitative difference between the IBEX-Lo data and the modeling results obtained with the three-dimensional, time-dependent model. Namely, the model predicts a larger count rate in energy bin~2 (20-41 eV) than in energy bin~1 (11-21 eV), while the data shows the opposite case. We perform study of the model parameter effects on the IBEX-Lo fluxes and the ratio of fluxes in two energy channels. We shown that the most important parameter, which has a major influence on the ratio of the fluxes in the two energy bins, is the solar...
/ free-slip / free-slip Numerical models of slab deformation in the upper mantle
Cerveny, Vlastislav
of the plate. Model: Model domain: Results: Effect of decoupling mechanism 410 km 660 km oceánska doska nadlozná doska Results: Effect of boundary condition Effect of yield stress Plate velocity Kinematic, crust.s 1020 Pa.s 1021 Pa.s Free-slip, crust = 1020 Pas, y = 108 Pa Kinematic, crust = 1020 Pas, y = 109 Pa
NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES
Patel, Harsh Jay
2013-09-27
a node in the fluid to solid (aggregate or the particle) ? b number of discrete velocities 14 In order to stochastically solve the stochastic solute diffusion equation (Eq. 6), initial and boundary conditions are specified before solving...) Model........................................... 1.2.2 The Diffusion Limited Aggregation-Cellular Automata (DLA-CA) Model................................................................................................ 1.2.3 The Reaction-Diffusion...
Simulation of a Polar Low Case in the North Atlantic with different regional numerical models
Zahn, Matthias
by the DWD (German Weather Service) by means of their forecast model HRM (High Resolution Model) and another University Press, Cambridge. (a) CLM (b) REMO (c) HRM, DWD (d) BWK Figure 1: 1(a)- 1(c)10m wind velocity pressure from CLM and REMO simulations and HRM analysis, DWD, respectively, at 15/10/93, 6:00, 1(d) surface
Nick, F. M.; van der Veen, Cornelis J.; Oerlemans, J.
2007-07-11
at the glacier terminus and presented the flotation model. In the flotation model the terminus position is defined as the point where the ice thickness exceeds the flotation thickness by an amount H0. If the glacier thins, the terminus will retreat to a point... where this condition is again satisfied. Vieli et al. [2001] modified the flotation criterion and defined the thickness in excess of flotation H0 as a fraction of the flotation thickness. A recent modeling study by Nick and Oerlemans [2006] compared both...
A simplified numerical model of coronal energy dissipation based on reduced MHD
E. Buchlin; V. Aletti; S. Galtier; M. Velli; G. Einaudi; J. -C. Vial
2003-03-27
A 3D model intermediate between cellular automata (CA) models and the reduced magnetohydrodynamic (RMHD) equations is presented to simulate solar impulsive events generated along a coronal magnetic loop. The model consists of a set of planes distributed along a magnetic loop between which the information propagates through Alfven waves. Statistical properties in terms of power-laws for energies and durations of dissipative events are obtained, and their agreement with X-ray and UV flares observations is discussed. The existence of observational biases is also discussed.
Poisson-Fermi Model of Single Ion Activities
Liu, Jinn-Liang
2015-01-01
A Poisson-Fermi model is proposed for calculating activity coefficients of single ions in strong electrolyte solutions based on the experimental Born radii and hydration shells of ions in aqueous solutions. The steric effect of water molecules and interstitial voids in the first and second hydration shells play an important role in our model. The screening and polarization effects of water are also included in the model that can thus describe spatial variations of dielectric permittivity, water density, void volume, and ionic concentration. The activity coefficients obtained by the Poisson-Fermi model with only one adjustable parameter are shown to agree with experimental data, which vary nonmonotonically with salt concentrations.
Role Model and Activity Volunteers Needed to Help with BEAMS...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Model and Activity Volunteers Needed to Help with BEAMS - Jefferson Lab's Science and Math Outreach Program for Students B.E.A.M.S. BEAMS students learn about energy transfer,...
Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers
Muraya, Norman K.
1994-01-01
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 ...
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
2014-01-01
Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...
Numerical Modeling of Fractured Shale-Gas and Tight-Gas Reservoirs Using Unstructured Grids
Olorode, Olufemi Morounfopefoluwa
2012-02-14
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...
Jia, Dongxing 1984-
2012-11-15
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...
Final Report: A Model Management System for Numerical Simulations of Subsurface Processes
Zachmann, David
2013-10-07
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.
Temperature Modeling in Activated Sludge Systems: A Case Study
Wells, Scott A.
steady-state and dynamic conditions at a full-scale facility, the Rock Creek wastewater treatment plant throughout the year. Water Environ. Res., 77, 000 (2005). KEYWORDS: activated sludge, heat balance, hydraulics, modeling, temperature dynamics, wastewater treatment. Introduction An activated-sludge reactor
Numerical model for the vacuum pyrolysis of scrap tires in batch reactors
Yang, J.; Tanguy, P.A.; Roy, C.
1995-06-01
A quantitative model for scrap tire pyrolysis in a batch scale reactor developed comprises the following basic phenomena: conduction inside tire particles; conduction, convection, and radiation between the feedstock particles or between the fluids and the particles; tire pyrolysis reaction; exothermicity and endothermicity caused by tire decomposition and volatilization; and the variation of the composition and the thermal properties of tire particles. This model was used to predict the transient temperature and density distributions in the bed of particles, the volatile product evolution rate, the mass change, the energy consumption during the pyrolysis process, and the pressure history in a tire pyrolysis reactor with a load of 1 kg. The model predictions agree well with independent experimental data.
Synthesis of Numerical Methods for Modeling Wave Energy Converter-Point Absorbers: Preprint
Li, Y.; Yu, Y. H.
2012-05-01
During the past few decades, wave energy has received significant attention among all ocean energy formats. Industry has proposed hundreds of prototypes such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber as the technology to extract wave energy. Several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. However, no standardized method has been decided. To assist the development of wave energy conversion technologies, this report reviews the methods for modeling the floating-point absorber.
Modeling and numerical techniques for high-speed digital simulation of nuclear power plants
Wulff, W.; Cheng, H.S.; Mallen, A.N.
1987-01-01
Conventional computing methods are contrasted with newly developed high-speed and low-cost computing techniques for simulating normal and accidental transients in nuclear power plants. Six principles are formulated for cost-effective high-fidelity simulation with emphasis on modeling of transient two-phase flow coolant dynamics in nuclear reactors. Available computing architectures are characterized. It is shown that the combination of the newly developed modeling and computing principles with the use of existing special-purpose peripheral processors is capable of achieving low-cost and high-speed simulation with high-fidelity and outstanding user convenience, suitable for detailed reactor plant response analyses.
Kumaran, K.; Babu, V.
2009-04-15
In this numerical study, the influence of chemistry models on the predictions of supersonic combustion in a model combustor is investigated. To this end, 3D, compressible, turbulent, reacting flow calculations with a detailed chemistry model (with 37 reactions and 9 species) and the Spalart-Allmaras turbulence model have been carried out. These results are compared with earlier results obtained using single step chemistry. Hydrogen is used as the fuel and three fuel injection schemes, namely, strut, staged (i.e., strut and wall) and wall injection, are considered to evaluate the impact of the chemistry models on the flow field predictions. Predictions of the mass fractions of major species, minor species, dimensionless stagnation temperature, dimensionless static pressure rise and thrust percentage along the combustor length are presented and discussed. Overall performance metrics such as mixing efficiency and combustion efficiency are used to draw inferences on the nature (whether mixing- or kinetic-controlled) and the completeness of the combustion process. The predicted values of the dimensionless wall static pressure are compared with experimental data reported in the literature. The calculations show that multi step chemistry predicts higher and more wide spread heat release than what is predicted by single step chemistry. In addition, it is also shown that multi step chemistry predicts intricate details of the combustion process such as the ignition distance and induction distance. (author)
Model Validation and Spatial Interpolation by Combining Observations with Outputs from Numerical
Washington at Seattle, University of
""r,c,rn The authors are for hel]JfuI #12;Abstract Constructing maps of pollution levels is vital for air quality concentrations. Key tlJords: air pollution, Ba~yesian inference, change of support, likelihood approaches, Matern Resolutions 2.5 Modeling a Nonstationary Covariance . 3 Estimation 3.1 Algorithm 4 Application: Air Pollution
NUMERICAL MODEL OF PLASMA CONFINEMENT J. C. Sprott and E. J. Strait
Sprott, Julien Clinton
, a fast, simple, time-dependent, zero-dimensional computer model for plasmas confined in cylindrical chamber wall temperature (eV) B = average magnetic field strength (kG) B o = peak magnetic field strength) For the levitated toroidal oetupole, we take the values: T w = .025 eV a = 50 em L = 800 em Q = " 104 o S = 103
Numerical modeling and experiments of creep crack growth under cyclic loading
Brust, F.W.
1995-12-31
This paper presents a summary of some recent studies of creep crack growth under history dependent load conditions. The effect of a proper constitutive law is illustrated. Moreover, the asymptotic fields are reconsidered under cyclic creep conditions. In addition, several experiments are modeled and the behavior of integral parameters is discussed.
A numerical procedure to model and monitor CO2 sequestration in ...
santos
Sep 7, 2012 ... The model of the formation is based on the porosity and clay .... The porosity and dry bulk and shear modulus of the formation were obtained using a pore ... The viscosity, density and bulk modulus of CO2 needed for the flow ...
Aguilar, Guillermo
. The objectives of this paper are: to improve the thermal modeling of skin undergoing CSC-assisted DLS for PWS that incorporate all the complexity of the problem are a valuable and fundamental research tool. Keywords: Spray Engineering, University of California, Riverside, CA 92521 bBeckman Laser Institute Medical Clinic, University
A nanoscale numerical model of calcium silicate hydrate P.C. Fonseca a,
Andrade, Jose
to pre- dict the bulk properties of cement and concrete, such as shrinkage, creep, permeability and the properties of structural concrete are not fully under- stood. Models are becoming increasingly important, and cracking. CSH is responsible for much of the cohesive proper- ties in concrete but the chemical origin
Gracie, Robert
the temperatures and pressures are such that the CO2 exists in a supercritical state. The supercritical CO2 is less method (XFEM) model is presented to analyze the injection and sequestration of carbon dioxide (CO2 method (SUPG-FEM-FDM) to approximate the distribution of CO2 in the aquifer. Near well enrichment
Roberts, Malcolm
analysis, and high-performance computing. I have experience working in the areas of compu- tational fluid mechanics, subgrid models for turbulence, and flows in complex geometries. 1 Introduction Consider, which is the product of the characteristic length and velocity of the flow divided by the kinematic
Modeling and Optimizing Ergonomic Activities in Automobile Product Development
da Silva, Alberto Rodrigues
Modeling and Optimizing Ergonomic Activities in Automobile Product Development João Ferreira Anna.silva@acm.org Abstract We collect ergonomic rules and normative rules considerations for automobile business and modeled as use of past experience. Also we intend to define ergonomic associated templates, which reflect
MODELING DESIGN ACTIVITY IN AUTOMOBILE INDUSTRY Joo Ferreira1
da Silva, Alberto Rodrigues
The Automotive industry is changing drastically. Many companies are re-organizing, reengineering, downsizingMODELING DESIGN ACTIVITY IN AUTOMOBILE INDUSTRY João Ferreira1 , André Carvalho2 , João Pimentel3 and cost. The first step to achieve this goal is the Modeling Business Process using UML (industry standard
Numerical study of three-dimensional PIC for the surface plasmon excitation based on Drude model
Liu, La-Qun; Wang, Hui-Hui; Liu, Da-Gang
2015-01-01
This paper explores the time-domain equations of noble metals, in which Drude model is adopted to describe the dielectric constant, to implement three-dimensional particle-in-cell (PIC) simulations for the surface plasmon excitation with the finite-difference time-domain method (FDTD). A three-dimensional model for an electron bunch movement near the metal film is constructed, and particle-in-cell (PIC) simulations are carried out with various metal films of different thicknesses. The frequency of surface plasmon obtained from PIC simulation is agreed with that from theory. Furthermore, the surface plasmon wave properties of excitation and propagation with the metal film is summarized by PIC results.
Gotika, Priyanka
2012-02-14
: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 73 ix LIST OF FIGURES FIGURE Page 1 Constitutive relation for Bingham-type uid. Force due to dash- pot cannot be written as a function of kinematic variables (that is, velocity of the mass). On the other hand, as shown in the gure, velocity... of constitutive relation between velocity and force due to dash-pot for a dash-pot governed by visco-elastic model. : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 5 A pictorial representation of constitutive relation between velocity...
Karra, Satish
2009-05-15
[35] developed a stability analysis for the ax- isymmetric Rayleigh instability as well as the non-axisymmetric whipping instability in Newtonian fluids. According to them, the Rayleigh instability due to electrical forces is equivalent to the surface... for viscoelasticity between the beads. . . . . . . . 19 7 Typical result for the discrete particle model showing the bending loop in the jet. Top view shows that the envelope of the jet trajectory is a cone. The number of beads for this simulation N = 100 and non...
Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers
Ihab Sraj; Joshua Francois; David W. M. Marr; Charles D. Eggleton
2015-01-15
In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force distribution on the cell surface and the net deformation. Scattering and gradient forces are reported for different nucleus sizes and the effect of nucleus size on the cell deformation is discussed.
Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers
Sraj, Ihab; Marr, David W M; Eggleton, Charles D
2015-01-01
In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force dis...
Dubus, Guillaume; Fromang, Sébastien
2015-01-01
Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to $i\\approx 35^{\\rm o}$. There is a tension between th...
Volker Sick; Dennis N. Assanis
2002-11-27
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.
Prinja, A.K.
1998-09-01
In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton`s method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria {epsilon} is set to be 10{sup {minus}9} based on the fact that lower value of {epsilon} does not alter the solution significantly. Correspondingly, the number of Newton`s iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton`s method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are relatively smooth as a consequence of the less localized recycling, leading to an improved convergence rate of the numerical algorithm. Peak plasma density is lower and the temperature correspondingly higher than those predicted by the standard diffusion model. It is believed that the FFCD model is more accurate. With both the TP continuation and multigrid methods, the author has demonstrated the robustness of these two methods. A mutually beneficial hybridization between the TP method and multigrid methods is clearly an alternative for edge plasma simulation. While the fundamental transport model considered in this work has ignored important physics such as drifts and currents, he has nevertheless demonstrated the versatility and robustness of the numerical scheme to handle such new physics. The application of gaseous-radiative divertor model in this work is just a beginning and up to this point numerically, the future is exciting.
Mathematical and numerical models to achieve high speed with special-purpose parallel processors
Cheng, H.S.; Wulff, W.; Mallen, A.N.
1986-07-01
One simulation facility that has been developed is the BNL Plant Analyzer, currently set up for BWR plant simulations at up to seven times faster than real-time process speeds. The principal hardware components of the BNL Plant Analyzer are two units of special-purpose parallel processors, the AD10 of Applied Dynamics International and a PDP-11/34 host computer. The AD10 is specifically designed for time-critical system simulations, utilizing the modern parallel processing technology with pipeline architecture. The simulator employs advanced modeling techniques and efficient integration techniques in conjunction with the parallel processors to achieve high speed performance.
Numerical modeling of boundary layer flow under shoaling and breaking waves
Pattipawaej, Olga Catherina
1998-01-01
velocities and shear stresses in the bottom boundary layer under breaking waves. The experiment wss conducted in the Precision Wave Tank located in the Ocean Engineering Laboratory at the University of Delaware. The flume was 33 m long, 0. 6 m wide, and 1... modeling of surf zone hydrodynamics. " Rep. No. CACR-95-97, Center for Applied Coastal Research, University Delaware, Newark, Delaware. Cox, D. T. , Kobayashi, N. , and Okayasu, A. (1996). "Bottom shear stress in the surf zone. " J. Geophys. Res. , 101(C...
Numerical modeling of laser tunneling ionization in explicit particle-in-cell codes
Chen, M.; Cormier-Michel, E.; Geddes, C.G.R.; Bruhwiler, D.L.; Yu, L.L.; Esarey, E.; Schroeder, C.B.; Leemans, W.P.
2013-03-01
Methods for the calculation of laser tunneling ionization in explicit particle-in-cell codes used for modeling laser–plasma interactions are compared and validated against theoretical predictions. Improved accuracy is obtained by using the direct current form for the ionization rate. Multi level ionization in a single time step and energy conservation have been considered during the ionization process. The effects of grid resolution and number of macro-particles per cell are examined. Implementation of the ionization algorithm in two different particle-in-cell codes is compared for the case of ionization-based electron injection in a laser–plasma accelerator.
Modelling the polarization dichotomy of Active Galactic Nuclei
Rene W. Goosmann
2007-12-12
I present polarization modelling of Active Galactic Nuclei in the optical/UV range. The modelling is conducted using the Monte-Carlo radiative transfer code Stokes, which self-consistently models the polarization signature of a complex model arrangement for an active nucleus. In this work I include three different scattering regions around the central source: an equatorial electron scattering disk, an equatorial obscuring dusty torus, and polar electron scattering cones. I investigate the resulting dependencies of the V-band polarization for different optical depths of the scattering cones, different dust compositions inside the torus, and various half-opening angles of the torus/polar cones. The observed polarization dichotomy can be successfully reproduced by the model.
Numerical study of a binary Yukawa model in regimes characteristic of globular proteins in solutions
Giacometti, Achille; Gazzillo, Domenico; Pastore, Giorgio; Das, Tushar Kanti [Istituto Nazionale per la Fisica della Materia and Dipartimento di Chimica Fisica, Universita di Venezia, S. Marta DD 2137, I-30123 Venice (Italy); Dipartimento di Fisica Teorica, Universita di Trieste and INFM-DEMOCRITOS, National Simulation Center, Strada Costiera 11, Miramare, I-34100 Trieste (Italy); ICTP, Diploma Course, Strada Costiera 11, Miramare P.O Box 586, I-34100 Trieste (Italy)
2005-03-01
The main goal of this paper is to assess the limits of validity, in the regime of low concentration and strong Coulomb coupling (high molecular charges), of a simple perturbative approximation to the radial distribution functions (RDF's), based upon a low-density expansion of the potential of mean force and proposed to describe protein-protein interactions in a recent small-angle-scattering (SAS) experimental study. A highly simplified Yukawa (screened Coulomb) model of monomers and dimers of a charged globular protein ({beta}-lactoglobulin) in solution is considered. We test the accuracy of the RDF approximation, as a necessary complementary part of the previous experimental investigation, by comparison with the fluid structure predicted by approximate integral equations and exact Monte Carlo (MC) simulations. In the MC calculations, an Ewald construction for Yukawa potentials has been used to take into account the long-range part of the interactions in the weakly screened cases. Our results confirm that the perturbative first-order approximation is valid for this system even at strong Coulomb coupling, provided that the screening is not too weak (i.e., for Debye length smaller than monomer radius). A comparison of the MC results with integral equation calculations shows that both the hypernetted-chain (HNC) and Percus-Yevick closures have a satisfactory behavior under these regimes, with the HNC being superior throughout. The relevance of our findings for interpreting SAS results is also discussed.
Mohaghegh, Shahab
SPE 162699 Fast Track Analysis of Shale Numerical Models A. Kalantari-Dahaghi ,SPE, S. Esmaili, SPE of SPE copyright. Abstract Latest advances in shale gas reservoir simulation and modeling have made it possible to optimize and enhance the production from organic rich shale gas reservoirs. Reservoir simulator
Nagurney, Anna
A Relative Total Cost Index for the Evaluation of Transportation Network Robustness in the Presence Index #12;Motivation Literature Trans. Network Models Relative Total Cost Indices Numerical Examples, Qiang Qiang Relative Total Cost Index #12;Motivation Literature Trans. Network Models Relative Total
Knight, Matthew M.; Schleicher, David G.; Schwieterman, Edward W.; Christensen, Samantha R. [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Farnham, Tony L., E-mail: knight@lowell.edu [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)
2012-11-01
We report on photometry and imaging of Comet 10P/Tempel 2 obtained at Lowell Observatory from 1983 through 2011. We measured a nucleus rotation period of 8.950 {+-} 0.002 hr from 16 nights of imaging acquired between 2010 September and 2011 January. This rotation period is longer than the period we previously measured in 1999, which was itself longer than the period measured in 1988, and demonstrates that Tempel 2 is continuing to spin down, presumably due to torques caused by asymmetric outgassing. A nearly linear jet was observed which varied little during a rotation cycle in both R and CN images acquired during the 1999 and 2010 apparitions. We measured the projected direction of this jet throughout the two apparitions and, under the assumption that the source region of the jet was near the comet's pole, determined a rotational pole direction of R.A./decl. = 151 Degree-Sign /+59 Degree-Sign from CN measurements and R.A./decl. = 173 Degree-Sign /+57 Degree-Sign from dust measurements (we estimate a circular uncertainty of 3 Degree-Sign for CN and 4 Degree-Sign for dust). Different combinations of effects likely bias both gas and dust solutions and we elected to average these solutions for a final pole direction of R.A./decl. = 162 Degree-Sign {+-} 11 Degree-Sign /+58 Degree-Sign {+-} 1 Degree-Sign . Photoelectric photometry was acquired on 3 nights in 1983, 2 nights in 1988, 19 nights in 1999/2000, and 10 nights in 2010/2011. The activity exhibited a steep 'turn-on' {approx}3 months prior to perihelion (the exact timing of which varies) and a relatively smooth decline after perihelion. The activity during the 1999 and 2010 apparitions was similar; limited data in 1983 and 1988 (along with IUE data from the literature) were systematically higher and the difference cannot be explained entirely by the smaller perihelion distance. We measured a 'typical' composition, in agreement with previous investigators. Monte Carlo numerical modeling with our pole solution best replicated the observed coma morphology for a source region located near a comet latitude of +80 Degree-Sign and having a radius of {approx}10 Degree-Sign . Our model reproduced the seasonal changes in activity, suggesting that the majority of Tempel 2's activity originates from a small active region located near the pole. We also find that a cosine-squared solar angle function gives the best fit as compared to a standard cosine function.
Chiswell, S
2009-01-11
Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.
Rockhold, Mark L.; White, Mark D.; Freeman, Eugene J.
2004-10-12
This letter report documents initial numerical analyses conducted by PNNL to provide support for a feasibility study on decommissioning of the canyon buildings at Hanford. The 221-U facility is the first of the major canyon buildings to be decommissioned. The specific objective of this modeling effort was to provide estimates of potential rates of migration of residual contaminants out of the 221-U facility during the first 40 years after decommissioning. If minimal contaminant migration is predicted to occur from the facility during this time period, then the structure may be deemed to provide a level of groundwater protection that is essentially equivalent to the liner and leachate collection systems that are required at conventional landfills. The STOMP code was used to simulate transport of selected radionuclides out of a canyon building, representative of the 221-U facility after decommissioning, for a period of 40 years. Simulation results indicate that none of the selected radionuclides that were modeled migrated beyond the concrete structure of the facility during the 40-year period of interest. Jacques (2001) identified other potential contaminants in the 221-U facility that were not modeled, however, including kerosene, phenol, and various metals. Modeling of these contaminants was beyond the scope of this preliminary effort due to increased complexity. Simulation results indicate that contaminant release from the canyon buildings will be diffusion controlled at early times. Advection is expected to become much more important at later times, after contaminants have diffused out of the facility and into the surrounding soil environment. After contaminants have diffused out of the facility, surface infiltration covers will become very important for mitigating further transport of contaminants in the underlying vadose zone and groundwater.
Non-equilibrium structure and dynamics in a microscopic model of thin film active gels
D. A. Head; W. J. Briels; G. Gompper
2014-02-26
In the presence of ATP, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modelling can help to quantify the relationship between individual motors plus filaments to organisation and dynamics on molecular and supra-molecular length scales. Here we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment and detachment, including a differential detachment rate from filament ends, reveals a range of non-equilibrium behaviour. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles or layers, whose stability depends on motor speed and differential end-detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit super-diffusive mass transport, where filament translocation scales with lag time with non-unique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end-detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modelling in the field of active gels.
Detecting Termination of Active Database Rules Using Symbolic Model Checking
Ray, Indrakshi
Detecting Termination of Active Database Rules Using Symbolic Model Checking Indrakshi Ray is the non-termination of rules. Although algorithms have been proposed to detect non-termination, al- most all provide a conservative estimate; that is, the algorithms detect all the potential cases of non-termination
High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes
Lackmann, Gary
2013-06-10
Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.
Thermally activated breakdown in a simple polymer model
S. Fugmann; I. M. Sokolov
2009-10-28
We consider the thermally activated fragmentation of a homopolymer chain. In our simple model the dynamics of the intact chain is a Rouse one until a bond breaks and bond breakdown is considered as a first passage problem over a barrier to an absorbing boundary. Using the framework of the Wilemski-Fixman approximation we calculate activation times of individual bonds for free and grafted chains. We show that these times crucially depend on the length of the chain and the location of the bond yielding a minimum at the free chain ends. Theoretical findings are qualitatively confirmed by Brownian dynamics simulations.
California at Berkeley, University of
IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. 17, NO. 4, APRIL 1998 305 Numerically Stable Green Function for Modeling and Analysis of Substrate Coupling. Meyer, Fellow, IEEE Abstract-- The Green function over a multilayer substrate is derived by solving
RodrÃguez, Rodolfo
Â´on, Chile. This paper deals with the approximation of the bending of a clamped plate modeled by ReissnerNumerical analysis of a locking-free mixed finite element method for a bending moment formulation the thickness t is small. Here, we propose a new mixed formulation in terms of the bending moments, shear stress
McConnell, Joshua B
2000-01-01
A numerical and analytical model was constructed to determine the resultant stress state imposed on a Rock Melt Drill produced liner. The purpose of this study was to determine if the liner produced would possess the strength required to prevent a...
Whitt, Ward
. Lucantoni a and Ward Whitt b a AT&T Bell Laboratories, Holmdel, NJ 077333030, USA b AT&T Bell Laboratories, Murray Hill, NJ 079740636, USA We describe recently developed algorithms for numerically inverting
Luo, Meng
Advanced High Strength Steels (AHSS) are increasingly used in automotive industry due to their superior strength and substantial weight advantage. However, their compromised ductility gives rise to numerous manufacturing ...
Skogestad, Sigurd
Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no. 1 (BSM1) and the activated sludge model no. 1 (ASM1). The objective is to search for a control
Static and Impulsive Models of Solar Active Regions
S. Patsourakos; J. A. Klimchuk
2008-08-20
The physical modeling of active regions (ARs) and of the global coronal is receiving increasing interest lately. Recent attempts to model ARs using static equilibrium models were quite successful in reproducing AR images of hot soft X-ray (SXR) loops. They however failed to predict the bright EUV warm loops permeating ARs: the synthetic images were dominated by intense footpoint emission. We demonstrate that this failure is due to the very weak dependence of loop temperature on loop length which cannot simultaneously account for both hot and warm loops in the same AR. We then consider time-dependent AR models based on nanoflare heating. We demonstrate that such models can simultaneously reproduce EUV and SXR loops in ARs. Moreover, they predict radial intensity variations consistent with the localized core and extended emissions in SXR and EUV AR observations respectively. We finally show how the AR morphology can be used as a gauge of the properties (duration, energy, spatial dependence, repetition time) of the impulsive heating.
Activity Diagrams for DEVS Models: A Case Study Modeling Health Care Behavior
Ozmen, Ozgur; Nutaro, James J
2015-01-01
Discrete Event Systems Specification (DEVS) is a widely used formalism for modeling and simulation of discrete and continuous systems. While DEVS provides a sound mathematical representation of discrete systems, its practical use can suffer when models become complex. Five main functions, which construct the core of atomic modules in DEVS, can realize the behaviors that modelers want to represent. The integration of these functions is handled by the simulation routine, however modelers can implement each function in various ways. Therefore, there is a need for graphical representations of complex models to simplify their implementation and facilitate their reproduction. In this work, we illustrate the use of activity diagrams for this purpose in the context of a health care behavior model, which is developed with an agent-based modeling paradigm.
Basic, Ivan; Nadramija, Damir; Flajslik, Mario; Amic, Dragan; Lucic, Bono
2007-12-26
Several quantitative structure-activity studies for this data set containing 107 HEPT derivatives have been performed since 1997, using the same set of molecules by (more or less) different classes of molecular descriptors. Multivariate Regression (MR) and Artificial Neural Network (ANN) models were developed and in each study the authors concluded that ANN models are superior to MR ones. We re-calculated multivariate regression models for this set of molecules using the same set of descriptors, and compared our results with the previous ones. Two main reasons for overestimation of the quality of the ANN models in previous studies comparing with MR models are: (1) wrong calculation of leave-one-out (LOO) cross-validated (CV) correlation coefficient for MR models in Luco et al., J. Chem. Inf. Comput. Sci. 37 392-401 (1997), and (2) incorrect estimation/interpretation of leave-one-out (LOO) cross-validated and predictive performance and power of ANN models. More precise and fairer comparison of fit and LOO CV statistical parameters shows that MR models are more stable. In addition, MR models are much simpler than ANN ones. For real testing the predictive performance of both classes of models we need more HEPT derivatives, because all ANN models that presented results for external set of molecules used experimental values in optimization of modeling procedure and model parameters.
Houze, Jr., Robert A.
2013-11-13
We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.
Auletta, C.; Raiconi, G.; De Luca, R.; Pace, S.
1995-05-01
We have performed numerical simulations of a field-cooled dc susceptibility experiment carried out for granular superconductors by modeling these systems with a simple Josephson-junction array proposed by the authors. By this analysis the temperature dependence of the positive field-cooled susceptibility at very low values of the applied magnetic field, observed by Braunisch {ital et} {ital al}. [Phys. Rev. Lett. 68, 1908 (1992)] for some ceramic superonductors, has been reproduced and interpreted.
Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping
2013-03-14
This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluate CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends
Sengupta, Arkaprabha
2010-01-01
Phase transformation in Nitinol polycrystals 3.1 Martensiticvector pairs (m ? , b ? ) for Nitinol . . . . . . . . . . .4 Constitutive model of Nitinol 4.1 Constitutive models for
NONE
1997-02-01
This report documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Macroeconomic Activity Module (MAM) used to develop the Annual Energy Outlook for 1997 (AEO 97). The report catalogues and describes the module assumptions, computations, methodology, parameter estimation techniques, and mainframe source code. This document serves three purposes. First it is a reference document providing a detailed description of the NEMS MAM used for the AEO 1997 production runs for model analysts, users, and the public. Second, this report meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements as future projects.
Boron-10 ABUNCL Prototype Models And Initial Active Testing
Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.
2013-04-23
The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.
Modeling and Control of an Active Magnetic Bearing Spindle System
Cavalier, Grant
2015-01-01
Active Magnetic Bearing SpindleKang. “Control of an Active Magnetic Bearing-Rotor System. ”T.C. Tsao. “Control of Magnetic Bearings with Plug-in Time-
D'Agnese, F.A.; O'Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma
2002-11-22
In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.
Revisiting the Unified Model of Active Galactic Nuclei
Netzer, Hagai
2015-01-01
This review describes recent developments related to the unified model of active galactic nuclei (AGN). It focuses on new ideas about the origin and properties of the central obscurer (torus), and the connection with its surrounding. The review does not address radio unification. AGN tori must be clumpy but the uncertainties about their properties are still large. Todays most promising models involve disk winds of various types and hydrodynamical simulations that link the large scale galactic disk to the inner accretion flow. IR studies greatly improved the understanding of the spectral energy distribution of AGNs but they are hindered by various selection effects. X-ray samples are more complete. A basic relationship which is still unexplained is the dependence of the torus covering factor on luminosity. There is also much confusion regarding "real type-II AGNs" that do not fit into a simple unification scheme. The most impressive recent results are due to IR interferometry, which is not in accord with most ...
Schuh, Harald
with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum
Dadi, Sireesh Kumar
2011-10-21
: the Neuman model, which assumes instantaneous drainage from the unsaturated zone; the Moench model, which considered gradual drainage from the unsaturated zone using a series of exponential terms in the water table boundary condition; and the Mathias...
Grossman, A.; Errico, R.M.
1999-11-29
The vertical motion of constant density atmospheric balloons has been considered via an equation of motion for the vertical displacement of a balloon, due to vertical air motion, which can be numerically solved for balloon positions. Initial calculations are made for a constant density atmosphere. Various vertical wind models with relatively large amplitudes are applied to the model to determine how tightly the balloons are coupled to the reference level and the time scale for the balloons to change to the wind driven reference altitude. A surface launch of a balloon to a 6 km reference altitude is modeled using a detailed atmospheric pressure-density-temperature profile in the equation of motion. The results show the balloons to be relatively tightly coupled ({approx} 50-100 m) to the reference altitude.
Eindhoven, Technische Universiteit
of a piston, an aftercooler (AC), a regenerator, a cold heat exchanger (CHX), a tube, a hot heat exchanger ( numerical model has been introduced to study steady oscillatory heat and mass transfer in the tube section, numerical simulation, high resolution scheme 1 Introduction The pulse tube is a relatively new type
Bak, Claus Leth
Aalborg Universitet Harmonic Resonances in Wind Power Plants: Modeling, Analysis and Active. (2015). Harmonic Resonances in Wind Power Plants: Modeling, Analysis and Active Mitigation Methods from vbn.aau.dk on: juli 04, 2015 #12;Harmonic Resonances in Wind Power Plants: Modeling, Analysis
A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification
A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification Ilenia of the Activated Sludge Models (ASM) [Henze, M., Gujer, W., Mino, T., van Loosdrecht, M.C.M., 2000. Ac- tivated Sludge Models ASM1, ASM2, ASM2d, and ASM3. IWA Scientific and Technical Report No. 9. IWA Publishing
Rodríguez, Rodolfo
of an induction furnace ALFREDO BERM ´UDEZ Departamento de Matem´atica Aplicada, Universidade de Santiago de problem arising from the modeling of an induction furnace. By taking advantage of the cylindrical symmetry a formulation of the eddy current problem arising from the modeling of an induction furnace, which is based
Shekhar, Ravi
2009-05-15
and amplitude variation with offset (AVO) results for our example model predicts that CO2 is easier to detect than brine in the fractured reservoirs. The effects of geochemical processes on seismics are simulated by time-lapse modeling for t = 1000 years. My...
Current Challenges for Modeling Enzyme Active Sites by Biomimetic Synthetic Diiron Complexes
Friedle, Simone
This tutorial review describes recent progress in modeling the active sites of carboxylate-rich non-heme diiron enzymes that activate dioxygen to carry out several key reactions in Nature. The chemistry of soluble methane ...
Kandelous, Maziar M.; Šim?nek, Ji?í
2010-01-01
and clay (33.5%), and water contents for pressures of -33times, antecedent water contents, and emitter locations, andthe saturated soil water content as one of the model
Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1
Gupta, Prabhat Kumar; Rabehl, Roger
2014-07-01
Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.
Ko, Hanseo
1994-01-01
An analytical model is established to predict an electrostatically charged particle deposition as a function of particle size in fully-developed turbulent pipe flow. The convectivediffusion flux equation is solved for the particle concentration as a...
Pruess, Karsten
2008-01-01
Properties of the Supercritical CO2–Water Pure Interface, J.and pressure conditions, supercritical CO2 (scCO2) has lowerthe overlying free supercritical CO2 phase. This is modeled
Bader, Aaron Craig
2012-01-01
In this thesis we discuss measurements and modeling of minority heated fast-ion distributions in the Ion Cyclotron Range of Frequencies (ICRF) on the Alcator C-Mod tokamak. Analysis of fast-ions >100Te is important for ...
Cartier-Michaud, T; Sarazin, Y; Abiteboul, J; Bufferand, H; Dif-Pradalier, G; Garbet, X; Grandgirard, V; Latu, G; Norscini, C; Passeron, C; Tamain, P
2015-01-01
The Projection on Proper elements (PoPe) is a novel method of code control dedicated to 1) checking the correct implementation of models, 2) determining the convergence of numerical methods and 3) characterizing the residual errors of any given solution at very low cost. The basic idea is to establish a bijection between a simulation and a set of equations that generate it. Recovering equations is direct and relies on a statistical measure of the weight of the various operators. This method can be used in any dimensions and any regime, including chaotic ones. This method also provides a procedure to design reduced models and quantify the ratio costs to benefits. PoPe is applied to a kinetic and a fluid code of plasma turbulence.
Lee, Cheegwan; Schwab, David J.; Beletsky, Dmitry; Stroud, Jonathan; Lesht, B. M.
2007-02-17
A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive+noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically-based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are 1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and 2) the settling velocity of sediment flocs which controls the deposition location.
Lee, C.; Schwab, D. J.; Beletsky, D.; Stroud, J.; Lesht, B.; PNNL; NOAA; Univ. of Michigan; Univ. of Pennsylvania
2007-02-17
A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are (1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and (2) the settling velocity of sediment flocs which controls the deposition location.
Modeling Neural Population Spiking Activity with Gibbs Distributions
Wood, Frank
the neural code and building practical decoding algorithms. No parametric models currently exist for modeling-parametric methods impractical. To address these prob- lems we propose an energy-based model in which the joint a multivariate probability distribution over spike times. Modeling P(s, r) is made challenging by the high
Explorations of iron-iron hydrogenase active site models by experiment and theory
Tye, Jesse Wayne
2009-05-15
This dissertation describes computational and experimental studies of synthetic complexes that model the active site of the iron-iron hydrogenase [FeFe]H2ase enzyme. Simple dinuclear iron dithiolate complexes act as functional models of the ironiron...
US Department of Energy (DOE) National Lab Activities in Marine Hydrokinetics: Scaled Model
Siefert, Chris
US Department of Energy (DOE) National Lab Activities in Marine Hydrokinetics: Scaled Model Testing turbines specifically designed by the US Department of Energy for its Marine and Hydrokinetic Research. Keywords-- current energy conversion, performance testing, reference models, marine hydrokinetic
Modelling and numerical approximation of a 2.5D set of equations for mesoscale atmospheric processes
Kalise, Dante
2011-01-01
The set of 3D inviscid primitive equations for the atmosphere is dimensionally reduced by a Discontinuous Galerkin discretization in one horizontal direction. The resulting model is a 2D system of balance laws where with a source term depending on the layering procedure and the choice of coupling fluxes, which is established in terms of upwind considerations. The "2.5D" system is discretized via a WENO-TVD scheme based in a flux limiter centered approach. We study four tests cases related to atmospheric phenomena to analyze the physical validity of the model.
Mueller, Karl
for the mechanics and kinematics of compressive wedges Phaedra Upton,1,2 Karl Mueller,3 and Yue-Gau Chen4 Received develop three-dimensional mechanical models of a compressive wedge and investigate how the form and kinematics of the outboard wedge are affected by variation in initial topography, material properties
Preprint of the paper "A Numerical Refraction-Diffraction Model in the Ray-front Coordinate System"
Colominas, Ignasi
theory was adapted to water waves3 , allowing engineers and scientists to assess the diffractive effects" (CD-ROM), Parte IV: "Fluid Mechanics", Sección 6: "Shallow Water and Water Waves". S.R. Idelsohn, E, Ray Methods. Abstract. A model for the propagation of water waves is presented, which retrieves
Numerical studies of a one-dimensional three-spin spin-glass model with long-range interactions
Larson, Derek; Katzgraber, Helmut G.; Moore, M. A.; Young, A. P.
2010-01-01
are presented in Sec. V and our conclusions are summarized in Sec. VI. II. THEORETICAL BACKGROUND The field theory associated with p-spin models is a cubic field theory1?3 with the following Ginzburg-Landau-Wilson Hamiltonian: HGLW =? ddr? t2 ??? q??2 ?r...
Zhang, Yongmin
. The model is designed for the study of acceleration driven mixing layers in a chunk mix regime dominated, as in meteorological temperature inversion driven updrafts and the geological evolution of salt dome formations approxi- mately as a function of the averaged flow quantities directly, to close the system of equations
Dynamics of Active Database Rules: Models and Refinements
Zaniolo, Carlo
application areas. In this paper, we introduce a durable change seman- tics for active database rules seman- tics) or as a separate transaction (decoupled seman- tics) [?]. Most systems adopt the coupled seman- tics, inasmuch as this is more effective at enforcing integrity constraints via active rules
NUMERICAL ANALYSIS: This refers to the analysis of mathematical problems by numerical means, es-
Atkinson, Kendall
NUMERICAL ANALYSIS: This refers to the analysis of mathematical problems by numerical means, es- pecially mathematical problems arising from models based on calculus. Effective numerical analysis requires such as rootfinding and numerical integration; but we will also look at the structure of computers and the impli
Pruess, Karsten; Zhang, Keni
2008-11-17
For purposes of geologic storage, CO2 would be injected into saline formations at supercritical temperature and pressure conditions, and would form a separate phase that is immiscible with the aqueous phase (brine). At typical subsurface temperature and pressure conditions, supercritical CO2 (scCO2) has lower density than the aqueous phase and would experience an upward buoyancy force. Accordingly, the CO2 is expected to accumulate beneath the caprock at the top of the permeable interval, and could escape from the storage formation wherever (sub-)vertical pathways are available, such as fractures or faults through the caprock, or improperly abandoned wells. Over time, an increasing fraction of CO2 may dissolve in the aqueous phase, and eventually some of the aqueous CO2 may react with rock minerals to form poorly soluble carbonates. Dissolution into the aqueous phase and eventual sequestration as carbonates are highly desirable processes as they would increase permanence and security of storage. Dissolution of CO2 will establish phase equilibrium locally between the overlying CO2 plume and the aqueous phase beneath. If the aqueous phase were immobile, CO2 dissolution would be limited by the rate at which molecular diffusion can remove dissolved CO2 from the interface between CO2-rich and aqueous phases. This is a slow process. However, dissolution of CO2 is accompanied by a small increase in the density of the aqueous phase, creating a negative buoyancy force that can give rise to downward convection of CO2-rich brine, which in turn can greatly accelerate CO2 dissolution. This study explores the process of dissolution-diffusion-convection (DDC), using high-resolution numerical simulation. We find that geometric features of convection patterns are very sensitive to small changes in problem specifications, reflecting self-enhancing feedbacks and the chaotic nature of the process. Total CO2 dissolution rates on the other hand are found to be quite robust against modest changes in problem parameters, and are essentially constant as long as no dissolved CO2 reaches the lower boundary of the system.
Busschaert, C; Michaut, C; Bonnet-Bidaud, J -M; Mouchet, M
2015-01-01
Magnetic cataclysmic variables are close binary systems containing a strongly magnetized white dwarf that accretes matter coming from an M-dwarf companion. High-energy radiation coming from those objects is emitted from the accretion column close to the white dwarf photosphere at the impact region. Its properties depend on the characteristics of the white dwarf and an accurate accretion column model allows the properties of the binary system to be inferred, such as the white dwarf mass, its magnetic field, and the accretion rate. We study the temporal and spectral behaviour of the accretion region and use the tools we developed to accurately connect the simulation results to the X-ray and optical astronomical observations. The radiation hydrodynamics code Hades was adapted to simulate this specific accretion phenomena. Classical approaches were used to model the radiative losses of the two main radiative processes: bremsstrahlung and cyclotron. The oscillation frequencies and amplitudes in the X-ray and optic...
Keisuke Nishida; Masaki Shimizu; Daikou Shiota; Hiroyuki Takasaki; Tetsuya Magara; Kazunari Shibata
2008-09-04
The plasmoid-induced-reconnection model explaining solar flares based on bursty reconnection produced by an ejecting plasmoid suggests a possible relation between the ejection velocity of a plasmoid and the rate of magnetic reconnection. In this study, we focus on the quantitative description of this relation. We performed magnetohydrodynamic (MHD) simulations of solar flares by changing the values of resistivity and the plasmoid velocity. The plasmoid velocity has been changed by applying an additional force to the plasmoid to see how the plasmoid velocity affects the reconnection rate. An important result is that the reconnection rate has a positive correlation with the plasmoid velocity, which is consistent with the plasmoid-induced-reconnection model for solar flares. We also discuss an observational result supporting this positive correlation.
Masanori Nakamura; Hui Li; Steven Diehl; Shengtai Li
2007-07-10
We argue the behavior of Poynting flux-dominated outflows from AGN in the galactic cluster systems by performing three-dimensional MHD simulations within the framework of the "magnetic tower" model. Of particular interests are the structure of MHD waves, the cylindrical radial force balance, the (de)collimation, and the stability properties of magnetic tower jets. Transition between the jet/lobe and the formation of wiggling jet by growing current-driven instability are discussed.
Switching Between Discrete and Continuous Models To Predict Genetic Activity
Weld, Daniel S.
Molecular biologists use a variety of models when they predict the behavior of genetic systems. A discrete model of the behavior of individual macromolecular elements forms the foundation for their theory of each system. ...
Numerical simulations for low energy nuclear reactions including...
Office of Scientific and Technical Information (OSTI)
Numerical simulations for low energy nuclear reactions including direct channels to validate statistical models Citation Details In-Document Search Title: Numerical simulations for...
Computer Modeling and Simulation of an Active Vision Camera System MingChin Lu
Subbarao, Murali "Rao"
Computer Modeling and Simulation of an Active Vision Camera System MingChin Lu Communications of computer simulation systems. Computer simulation avoids the necessity of building actual camera systems. Based on the proposed model and algorithms, a computer simulation system called Active Vision Simulator
Activity Recognition in Wide Aerial Video Surveillance Using Entity Relationship Models
Southern California, University of
video surveillance us- ing Entity Relationship Models (ERM). In this approach, finding an activity using the ERM framework. We also show how visual tracks can be better interpreted as activities by using Relationship Model (ERM) [3] frame- work (Fig. 1). The ERM is an appropriate framework to capture multiple
Integrated modeling for design of lightweight, active mirrors
Cohan, Lucy E.
Lightweight, active, silicon carbide mirrors have the potential to enable larger primary aperture, space-based optical systems, hence improving the resolution and sensitivity of such systems. However, due to the lack of ...
Radiation interchange modeling for active infrared proximity sensor design
Piper, James Clarice
1999-01-01
. This research focuses on information gathered using active optical proximity sensors in the reflectance sensing mode. The portion of energy reflected to a given sensor in combination with the known location of the source and sensor elements provide the basic...
Characterizing and Modeling User Activity on Smartphones: Summary
Dinda, Peter A.
chipset, and a 1150mAh lithium- ion battery. The Qualcomm MSM7201A chipset contains a 528MHz ARM 11 apps usage behavior, interaction with the battery, power consumption, network activity, frequently
Modeling and characterization of potato quality by active thermography
Sun, Chih-Chen
2009-05-15
This research focuses on characterizing a potato with extra sugar content and identifying the location and depth of the extra sugar content using the active thermography imaging technique. The extra sugar content of the potato is an important...
Pal, Sujay
2015-01-01
In this thesis, we theoretically predict the normal characteristics of Very Low Frequency (3~30 kHz) radio wave propagation through Earth-ionosphere waveguide corresponding to normal behavior of the D-region ionosphere. We took the VLF narrow band data from the receivers of Indian Centre for Space Physics (ICSP) to validate our models. Detection of sudden ionospheric disturbances (SIDs) are common to all the measurements. We apply our theoretical models to infer the D-region characteristics and to reproduce the observed VLF signal behavior corresponding to such SIDs. We develop a code based on ray theory to simulate the diurnal behavior of VLF signals over short propagation paths (2000~3000 km). The diurnal variation from this code are comparable to the variation obtained from a more general Long Wave Propagation Capability (LWPC) code which is based on mode theory approach. We simulate the observational results obtained during the Total Solar Eclipse of July 22, 2009 in India. We also report and simulate a h...
A Model of Household Demand for Activity Participation and Mobility
Golob, Thomas F.
1996-01-01
T.F. R. Kitamura and C. Lula (1994) “Modeling the Effects ofGolob, Kitamura and Lula, 1994) to modify a conventional
Yang, L.H.; Ding, Y.M. [China University of Mining & Technology, Xuzhou (China). College of Resources and Geoscience
2009-07-01
The aim of this article is to discuss the distribution law of the gasification agent concentration in a deep-going way during underground coal gasification and the new method of solving the problem for the convection diffusion of the gas. In this paper, the basic features of convection diffusion for the gas produced in underground coal gasification are studied. On the basis of the model experiment, through the analysis of the distribution and patterns of variation for the fluid concentration field in the process of the combustion and gasification of the coal seams within the gasifier, the 3-D non-linear unstable mathematical models on the convection diffusion for oxygen are established. In order to curb such pseudo-physical effects as numerical oscillation and surfeit which frequently occurred in the solution of the complex mathematical models, the novel finite unit algorithm, the upstream weighted multi-cell balance method is advanced in this article, and its main derivation process is introduced.
Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.
2012-03-19
To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.
Mathiesen, Patrick James
2013-01-01
of numerical weather prediction solar irradiance forecastsof numerical weather prediction solar irradiance forecastsnumerical weather prediction model for solar irradiance
Karlsen, Kenneth Hvistendahl
,Springer,Berlin,2000 NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR for the saturation equation, which is a convection dominated, degenerate convection-diffusion equation. Both theory and applications are discussed. The general background for the reservoir flow model is reviewed, and the main
IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS
Wells, Scott A.
. Wells** *Technical University of Gdansk, Department of Environmental Engineering, ul. Narutowicza 11 the impact of reactor hydraulics and variable oxygen mass transfer on a predicted DO profile along the longitudinal axis of the activated sludge reactor. Many important parameters are influenced by the hydraulic
A RANDOM MODEL OF PUBLICATION ACTIVITY AGNES BACKHAUSZ AND TAMAS F. MORI
Móri, Tamás F.
graphs, martingales, renewal equation. 1. Introduction In this paper we examine a dynamic model inspiredA RANDOM MODEL OF PUBLICATION ACTIVITY ´AGNES BACKHAUSZ AND TAM´AS F. M´ORI Department models. We prove almost sure conver- gence for the weight distribution and show scale-free asymptotic
Modeling of activation data in the BrainMap TM database: Detection of outliers
Nielsen, Finn Ã?rup
Modeling of activation data in the BrainMap TM database: Detection of outliers Finn Å¡ Arup NielsenÂAnalysis, Data Analysis, Estimation Techniques, Probabilistic Models, Neuroanatomy, Databases, Neural Networks and Lars Kai Hansen Informatics and Mathematical Modelling Technical University of Denmark DKÂ2800 Lyngby
Mechanics-Based Modeling of Bending and Torsion in Active Cannulas
transmissions. In this paper, we consider both bending and torsion, describing the total elastic energy storedMechanics-Based Modeling of Bending and Torsion in Active Cannulas D. Caleb Rucker, and Robert J cannula more accurately than previous models, reducing tip error by 72% over a bending-only model, and 35
Active and Accelerated Learning of Cost Models for Optimizing Scientific Applications
Chase, Jeffrey S.
Active and Accelerated Learning of Cost Models for Optimizing Scientific Applications Piyush Shivam of sciences including astrophysics, bioinformatics, systems biology, and climate modeling [15, 31]. This new University chase@cs.duke.edu ABSTRACT We present the NIMO system that automatically learns cost models
Modeling - Scale-Bridging Simulations Active Materials in Li...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Society, v. 154 (10), pp. A978-A986. 3. Wang, C.-W. and Sastry, A.M., 2007, "Mesoscale Modeling of a Li-Ion Poly Cell," Journal of the Electrochemical Society, v. 154...
An Active and Structural Strain Model for Magnetostrictive Transducers \\Lambda
Flatau, Alison B.
by a magnetic bias generated by either the surrounding permanent magnet or an applied DC current to the solenoid consider the modeling of strains generated by magnetostrictive materials in response to applied magnetic magnetic fields and (ii) the application of magnetic fields generates large strains in the material
An Active and Structural Strain Model for Magnetostrictive Transducers
by a magnetic bias generated by either the surrounding permanent magnet or an applied DC current to the solenoid the modeling of strains generated by magnetostrictive materials in response to applied magnetic fields magnetic fields and (ii) the application of magnetic fields generates large strains in the material
An Active and Structural Strain Model for Magnetostrictive Transducers
Flatau, Alison B.
the modeling of strains generated by magnetostrictive materials in response to applied magnetic elds magnetic elds and ii the application of magnetic elds generates large strains in the material. By utilizing magnetostrictive rod, a wound wire solenoid, an enclosing permanent magnet and a prestress mechanism. The rod
MATHEMATICAL MODELING OF NEURAL ACTIVITY Gaute T. Einevoll
Einevoll, Gaute T.
and Technology Norwegian University of Life Sciences, 1432 As, Norway Gaute.Einevoll@umb.no Abstract- nal processing properties of entire neurons [5, 6]. Thus modelers now have a relatively firm starting, for example, magnetoencephalography (MEG), electroencephalography (EEG), positron emission tomography (PET
Bonnefous, Y.C. [Ecole Nationale des Travaux Publics de l`Etat, 69 - Vaulx en Velin (France). Lab. Sciences de l`Habitat]|[Lawrence Berkeley Lab., CA (United States); Gadgil, A.J. [Lawrence Berkeley Lab., CA (United States); Allard, F. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)
1992-04-01
The functioning of an active sub-slab ventilation system (SVS) has been studied successfully with the help of a previously evaluated numerical model. The parameters explored are the permeability of the sub-slab and the gravel placed beneath it, the amplitude of applied pressure at the installation point of the system and the functioning method: depressurization or pressurization. The mechanisms contributing to the success of the two systems are identified. This numerical study shows that the presence of a layer of gravel beneath the sub-slab considerably improves the performance of the SVS. Considered separately from the extremely permeable sub-slabs, the depressurization systems perform better than the pressurization systems. 17 refs. [Francais] Le fonctionnement des Systemes de Ventilation active du Sol (SVS) a ete etudie a l`aide d`un outil numerique precedemment evalue avec succes. Les parametres explores sont les permeabilites du sol et du gravier place sous plancher bas, l`amplitude de la pression appliquee au point d`installation du systeme, et le mode de fonctionnement: Depressurisation ou Pressurisation. Les mecanismes contribuant au succes des deux systemes sont identifies. Cette etude numerique montre que la presence d`une couche de gravier sous plancher bas ameliore de facon considerable les performances des SVS. Mis a part le cas des sols extremement permeables, les systemes de Depressurisation ont de meilleures performances que les systemes de Pressurisation. 17 refs.
Schwantes, Jon M.
2009-06-01
The objective for this work was to demonstrate the utility of mechanistic computer models designed to simulate actinide behavior for use in efficiently and effectively directing advanced laboratory R&D activities associated with developing advanced separations methods.
Numerical Modeling | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII Jump to:Information 3rd|Northfork ElectricName Nueces
Vasquez, Juan Carlos
Aalborg Universitet Modeling, Stability Analysis and Active Stabilization of Multiple DC-Microgrids and Active Stabilization of Multiple DC-Microgrids Clusters. In Proceedings of the 2014 IEEE International of Multiple DC-Microgrid Clusters," in Proc. IEEE International Energy Conference (EnergyCon'14), 2014
Wu, Jianzhong
the separation of hydrogen and carbon dioxide via adsorption in activated carbons. In the simulations, both hydrogen and carbon dioxide molecules are modeled as Lennard-Jones spheres, and the activated carbons essentially no preference over the two gases and the selectivity of carbon dioxide relative to hydrogen falls
Giurgiutiu, Victor
Structural health monitoring with piezoelectric wafer active sensors predictive modeling of the state of the art in structural health monitoring with piezoelectric wafer active sensors and follows with conclusions and suggestions for further work Key Words: structural health monitoring, SHM, nondestructive
Building Evidence for Active Travel: Counting and Modeling Non-motorized Traffic
Bertini, Robert L.
Building Evidence for Active Travel: Counting and Modeling Non-motorized Traffic #12;Scope of Talk & maintenance · Test hypotheses and build theory #12;Multi-use Trails in Indianapolis #12;Min Max Mean Week Days B MN* Active Infrared MM MN* Passive infrared P, MM MN MM MN Pressure Pads P P, B? Pneumatic tubes B
An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions
Juelicher, Frank
Article An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions, sounds that are known as spontaneous otoacoustic emissions. They are a signature of the active amplification mechanism in the cochlea. Emissions occur at frequencies that are unique for an individual
Numerical Simulation of Free Standing Hybrid Risers
Hou, Tiancong
2014-08-13
and offloading (FPSO). The numerical scheme is mainly based on an existing in-house numerical code, known as COUPLE. In using COUPLE, URA is modeled as a rigid body. The URA connects a vertical steel riser and a flexible jumper, both of which are modeled by beam...
High performance computing and numerical Volker Springel
Masci, Frank
High performance computing and numerical modelling Volker Springel Lecture Notes 43rd Saas-mail: volker.springel@h-its.org 1 arXiv:1412.5187v1[astro-ph.GA]16Dec2014 #12;#12;Contents High performance computing and numerical modelling . . . . . . . . . . . . . . . 1 Volker Springel 1 Preamble
Macroeconomic Activity Module of the National Energy Modeling System
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet)DecadeYear Jan Feb Mar Apr 2012 2013(MillionYear5,020CubicCubic(Million::6) MODEL
Souza, Paulo Victor Santos
2015-01-01
Flow of viscous fluids are not usually discussed in detail in general and basic courses of physics. This is due in part to the fact that the Navier-Stokes equation has analytical solution only for a few restricted cases, while more sophisticated problems can only be solved by numerical methods. In this text, we present a computer simulation of wind tunnel, i.e., we present a set of programs to solve the Navier-Stokes equation for an arbitrary object inserted in a wind tunnel. The tunnel enables us to visualize the formation of vortices behind object, the so-called von K\\'arm\\'an vortices, and calculate the drag force on the object. We believe that this numerical wind tunnel can support the teacher and allow a more elaborate discussion of viscous flow. The potential of the tunnel is exemplified by the study of the drag on a simplified model of wing whose angle of attack can be controlled. A link to download the programs that make up the tunnel appears at the end.
Horsfall, F.; Bleck, R.; Hanson, H.P.
1997-11-01
This study addresses the issue of the ocean`s response to the changing climate. The objectives is to determine the effect of variable atmospheric forcing on the ocean on decadal time scales, specifically on the subduction of a passive tracer. In the context of the model used in this study, this tracer is {open_quotes}tagged{close_quotes} water that is subducted into the thermocline and into the deep ocean. The model used in this study is the Miami Isopycnic Coordinate Ocean Model which has a realistic Atlantic domain from 20{degrees}S to 60{degrees}N. There are twelve model layers, the first (top) layer being the thermodynamically active mixed layer and the lower eleven layers all having constant potential density ({sigma}{sub {theta}}). The atmospheric forcing changes vary latitudinally, allowing for a maximum increase in wind at midlatitudes and a maximum increase in temperature at the poles. In these experiments, it was found that wind speed and temperature effects dominate in bringing about changes in mixed-layer depth and in tracer penetration at high latitudes, with wind speed effects having the greater weight. It is apparent from the results that the weakening of the North Atlantic thermohaline circulation is dependent on the atmospheric changes in air temperature and in the wind field. 11 refs., 2 figs.
A fully resolved active musculo-mechanical model for esophageal transport
Wenjun Kou; Amneet Pal Singh Bhalla; Boyce E. Griffith; John E. Pandolfino; Peter J. Kahrilas; Neelesh A. Patankar
2015-01-09
Esophageal transport is a physiological process that mechanically transports an ingested food bolus from the pharynx to the stomach via the esophagus, a multi-layered muscular tube. This process involves interactions between the bolus, the esophagus, and the neurally coordinated activation of the esophageal muscles. In this work, we use an immersed boundary (IB) approach to simulate peristaltic transport in the esophagus. The bolus is treated as a viscous fluid that is actively transported by the muscular esophagus, which is modeled as an actively contracting, fiber-reinforced tube. A simplified version of our model is verified by comparison to an analytic solution to the tube dilation problem. Three different complex models of the multi-layered esophagus, which differ in their activation patterns and the layouts of the mucosal layers, are then extensively tested. To our knowledge, these simulations are the first of their kind to incorporate the bolus, the multi-layered esophagus tube, and muscle activation into an integrated model. Consistent with experimental observations, our simulations capture the pressure peak generated by the muscle activation pulse that travels along the bolus tail. These fully resolved simulations provide new insights into roles of the mucosal layers during bolus transport. In addition, the information on pressure and the kinematics of the esophageal wall due to the coordination of muscle activation is provided, which may help relate clinical data from manometry and ultrasound images to the underlying esophageal motor function.
Segmentation of vessels using weighted local variances and an active contour model
Chung, Albert C. S.
Segmentation of vessels using weighted local variances and an active contour model W. K. Law is a challenging problem. This paper presents a novel approach to segment- ing blood vessels using weighted local variances and an ac- tive contour model. In this work, the vessel boundary orien- tation is estimated
Southern California, University of
recognition system for wide area aerial video surveillance using Entity Relationship Models (ERM and efficiently defined and inferred using the ERM framework. We also show how vi- sual tracks can be better). activities with the Entity Relationship Model (ERM) frame- work [7]. The ERM is an appropriate framework
Modeling and Visualization of Human Activities for Multi-Camera Networks
Sankaranarayanan, Aswin C.
of the scene. These are used to render the scene with virtual 3D human models that mimic the observed instant are then presented to a rendering engine that animates a set of virtual actors synthesizing1 Modeling and Visualization of Human Activities for Multi-Camera Networks Aswin C
Modeling of a Nickel-Hydrogen Cell Phase Reactions in the Nickel Active Material
developed high-energy-density batteries, e.g., the nickel-metal hydride battery and the lithium-ion batteryModeling of a Nickel-Hydrogen Cell Phase Reactions in the Nickel Active Material B. Wu and R. E of South Carolina, Columbia, South Carolina 29208, USA A nonisothermal model of a nickel-hydrogen cell has
Funkhouser, Thomas A.
Matching Volumetric Models of Protein Active Sites Thomas Funkhouser, Roman Laskowski, and Janet Thornton SHORT ABSTRACT: This paper investigates the use of a knowledge-based algorithm to build volumetric similarities in the volumetric models, and a nearest neighbor classifier to predict the type of ligand bound
Technosocial Modeling for Determining the Status and Nature of a State’s Nuclear Activities
Gastelum, Zoe N.; Harvey, Julia B.
2009-09-25
The International Atomic Energy Agency State Evaluation Process: The Role of Information Analysis in Reaching Safeguards Conclusions (Mathews et al. 2008), several examples of nonproliferation models using analytical software were developed that may assist the IAEA with collecting, visualizing, analyzing, and reporting information in support of the State Evaluation Process. This paper focuses on one of the examples a set of models developed in the Proactive Scenario Production, Evidence Collection, and Testing (ProSPECT) software that evaluates the status and nature of a state’s nuclear activities. The models use three distinct subject areas to perform this assessment: the presence of nuclear activities, the consistency of those nuclear activities with national nuclear energy goals, and the geopolitical context in which those nuclear activities are taking place. As a proof-of-concept for the models, a crude case study was performed. The study, which attempted to evaluate the nuclear activities taking place in Syria prior to September 2007, yielded illustrative, yet inconclusive, results. Due to the inconclusive nature of the case study results, changes that may improve the model’s efficiency and accuracy are proposed.
Statistical Models for Solar Flare Interval Distribution in Individual Active Regions
Yuki Kubo
2008-02-01
This article discusses statistical models for solar flare interval distribution in individual active regions. We analyzed solar flare data in 55 active regions that are listed in the GOES soft X-ray flare catalog. We discuss some problems with a conventional procedure to derive probability density functions from any data set and propose a new procedure, which uses the maximum likelihood method and Akaike Information Criterion (AIC) to objectively compare some competing probability density functions. We found that lognormal and inverse Gaussian models are more likely models than the exponential model for solar flare interval distribution in individual active regions. The results suggest that solar flares do not occur randomly in time; rather, solar flare intervals appear to be regulated by solar flare mechanisms. We briefly mention a probabilistic solar flare forecasting method as an application of a solar flare interval distribution analysis.
Active patterning and asymmetric transport in a model actomyosin network
Shenshen Wang; Peter G. Wolynes
2014-12-19
Cytoskeletal networks, which are essentially motor-filament assemblies, play a major role in many developmental processes involving structural remodeling and shape changes. These are achieved by nonequilibrium self-organization processes that generate functional patterns and drive intracellular transport. We construct a minimal physical model that incorporates the coupling between nonlinear elastic responses of individual filaments and force-dependent motor action. By performing stochastic simulations we show that the interplay of motor processes, described as driving anti-correlated motion of the network vertices, and the network connectivity, which determines the percolation character of the structure, can indeed capture the dynamical and structural cooperativity which gives rise to diverse patterns observed experimentally. The buckling instability of individual filaments is found to play a key role in localizing collapse events due to local force imbalance. Motor-driven buckling-induced node aggregation provides a dynamic mechanism that stabilizes the two dimensional patterns below the apparent static percolation limit. Coordinated motor action is also shown to suppress random thermal noise on large time scales, the two dimensional configuration that the system starts with thus remaining planar during the structural development. By carrying out similar simulations on a three dimensional anchored network, we find that the myosin-driven isotropic contraction of a well-connected actin network, when combined with mechanical anchoring that confers directionality to the collective motion, may represent a novel mechanism of intracellular transport, as revealed by chromosome translocation in the starfish oocyte.
Li, Yuqian
2006-08-16
allow gas communication among the sands. Meanwhile, three fault families break up the three sands into numerous compartments. A primary fault and large synthetic and antithetic faults act as gas migration pathways: the synthetic and antithetic faults...
Pelanti, Marica
flows is relevant in numerous areas of engineering, from naval and submarine systems design to aerospace and nuclear power plants technologies. Cavitating fluids are multiphase mixtures that often involve complex
Modeling and production of 240Am by deuteron-induced activation of a 240Pu target
Finn, Erin C.; McNamara, Bruce K.; Greenwood, Lawrence R.; Wittman, Richard S.; Soderquist, Chuck Z.; Woods, Vincent T.; VanDevender, Brent A.; Metz, Lori A.; Friese, Judah I.
2015-02-01
A novel reaction pathway for production of 240Am is reported. Models of reaction cross-sections in EMPIRE II suggests that deuteron-induced activation of a 240Pu target produces maximum yields of 240Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A 240Pu target was activated under the modeled optimum conditions to produce 240Am. The modeled cross-section for the 240Pu(d, 2n)240Am reaction is on the order of 20-30 mbarn, but the experimentally estimated value is 5.3 ± 0.2 mbarn. We discuss reasons for the discrepancy as well as production of other Am isotopes that contaminate the final product.
Activity of the kinesin spindle protein inhibitor ispinesib (SB-715992) in models of breast cancer
Purcell, James W; Davis, Jefferson; Reddy, Mamatha; Martin, Shamra; Samayoa, Kimberly; Vo, Hung; Thomsen, Karen; Bean, Peter; Kuo, Wen Lin; Ziyad, Safiyyah; Billig, Jessica; Feiler, Heidi S; Gray, Joe W; Wood, Kenneth W; Cases, Sylvaine
2009-06-10
Ispinesib (SB-715992) is a potent inhibitor of kinesin spindle protein (KSP), a kinesin motor protein essential for the formation of a bipolar mitotic spindle and cell cycle progression through mitosis. Clinical studies of ispinesib have demonstrated a 9% response rate in patients with locally advanced or metastatic breast cancer, and a favorable safety profile without significant neurotoxicities, gastrointestinal toxicities or hair loss. To better understand the potential of ispinesib in the treatment of breast cancer we explored the activity of ispinesib alone and in combination several therapies approved for the treatment of breast cancer. We measured the ispinesib sensitivity and pharmacodynamic response of breast cancer cell lines representative of various subtypes in vitro and as xenografts in vivo, and tested the ability of ispinesib to enhance the anti-tumor activity of approved therapies. In vitro, ispinesib displayed broad anti-proliferative activity against a panel of 53 breast cell-lines. In vivo, ispinesib produced regressions in each of five breast cancer models, and tumor free survivors in three of these models. The effects of ispinesib treatment on pharmacodynamic markers of mitosis and apoptosis were examined in vitro and in vivo, revealing a greater increase in both mitotic and apoptotic markers in the MDA-MB-468 model than in the less sensitive BT-474 model. In vivo, ispinesib enhanced the anti-tumor activity of trastuzumab, lapatinib, doxorubicin, and capecitabine, and exhibited activity comparable to paclitaxel and ixabepilone. These findings support further clinical exploration of KSP inhibitors for the treatment of breast cancer.
Wu, Weibin; Institutes of Biomedical Science, Fudan University, Shanghai 200032 ; Zhu, Bo; Peng, Xiaomin; Zhou, Meiling; Jia, Dongwei; Gu, Jianxin; Institutes of Biomedical Science, Fudan University, Shanghai 200032
2014-01-03
Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.
Hoffman, Forrest M [ORNL; Randerson, James T [ORNL; Thornton, Peter E [ORNL; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Erickson III, David J [ORNL; Fung, Inez [University of California, Berkeley
2009-12-01
The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Project (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.
A Dynamic Solar Core Model: On the Activity-Related Changes of the Neutrino Fluxes
Attila Grandpierre
1998-10-08
The energy sources of the Sun may actually involve a thermonuclear runaway energy source present in stellar energy producing regions. I consider the conjectures of the derived model for the solar neutrino fluxes in case of a solar core allowed to vary in relation to the surface activity cycle. The observed neutrino flux data suggest a solar core possibly varying in time. In the dynamic solar model the quiet and runaway energy sources together may produce quasi-constant flux in the SuperKamiokande because it is sensitive to neutral currents, axions and anti-neutrinos, too. I calculate the contributions of the runaway source to the individual neutrino detectors. The results of the dynamic solar core model suggest that since the HOMESTAKE detects mostly the high energy electron neutrinos, therefore the HOMESTAKE data may aniticorrelate with the activity cycle. Activity correlated changes are expected to be present only marginally in the GALLEX and GNO data. The gallium detectors are sensitive mostly to the pp neutrinos, and the changes of the pp neutrinos arising from the SSM-like core is mostly compensated by the high-energy electron neutrinos produced by the hot bubbles of the dynamic energy source. The results suggest that the GALLEX data may show an anti-correlation, while the SuperKamiokande data may show a correlation with the activity cycle. Predictions of the dynamic solar model are presented for the SNO and Borexino experiments which can distinguish between the effects of the MSW mechanism and the consequences of the dynamic solar model. The results of the dynamic solar model are consistent with the present heioseismic measurements and can be checked with future heioseismic measurements as well. Keywords: solar neutrino problems - solar activity - thermonuclear runaways
CONTROL OF AN IDEAL ACTIVATED SLUDGE PROCESS IN WASTEWATER TREATMENT VIA AN ODE-PDE MODEL
Diehl, Stefan
CONTROL OF AN IDEAL ACTIVATED SLUDGE PROCESS IN WASTEWATER TREATMENT VIA AN ODE-PDE MODEL STEFAN treatment plants, consists basically of a biological reactor followed by a sedi- mentation tank, which has. 1. Introduction The need for efficient wastewater treatment plants in terms of low effluent con
Huang, Xiaolei
AUTOMATED ACTIN FILAMENT SEGMENTATION, TRACKING AND TIP ELONGATION MEASUREMENTS BASED ON OPEN use a novel open active contour model for filament segmentation and tracking, which is fast and robust against noise; and (ii) different strategies are proposed to solve the filament intersection problem
Implicit Active Shape Models for 3D Segmentation in MR Imaging
Paragios, Nikos
Implicit Active Shape Models for 3D Segmentation in MR Imaging Mika¨el Rousson1 , Nikos Paragios2 , and Rachid Deriche1 1 I.N.R.I.A. Sophia Antipolis, France E-mail: {Mikael of various form and complexity. Promising results on the extraction of brain ventricles in MR images
Static and Dynamic Modeling of a Solar Active Region. I: Soft X-Ray Emission
Harry P. Warren; Amy R. Winebarger
2006-09-01
Recent simulations of solar active regions have shown that it is possible to reproduce both the total intensity and the general morphology of the high temperature emission observed at soft X-ray wavelengths using static heating models. There is ample observational evidence, however, that the solar corona is highly variable, indicating a significant role for dynamical processes in coronal heating. Because they are computationally demanding, full hydrodynamic simulations of solar active regions have not been considered previously. In this paper we make first application of an impulsive heating model to the simulation of an entire active region, AR8156 observed on 1998 February 16. We model this region by coupling potential field extrapolations to full solutions of the time-dependent hydrodynamic loop equations. To make the problem more tractable we begin with a static heating model that reproduces the emission observed in 4 different \\textit{Yohkoh} Soft X-Ray Telescope (SXT) filters and consider dynamical heating scenarios that yield time-averaged SXT intensities that are consistent with the static case. We find that it is possible to reproduce the total observed soft X-ray emission in all of the SXT filters with a dynamical heating model, indicating that nanoflare heating is consistent with the observational properties of the high temperature solar corona.
PREDICTING WATER ACTIVITY IN ELECTROLYTE SOLUTIONS WITH THE CISTERNAS-LAM MODEL
REYNOLDS JG; GREER DA; DISSELKAMP RL
2011-03-01
Water activity is an important parameter needed to predict the solubility of hydrated salts in Hanford nuclear waste supernatants. A number of models available in the scientific literature predict water activity from electrolyte solution composition. The Cisternas-Lam model is one of those models and has several advantages for nuclear waste application. One advantage is that it has a single electrolyte specific parameter that is temperature independent. Thus, this parameter can be determined from very limited data and extrapolated widely. The Cisternas-Lam model has five coefficients that are used for all aqueous electrolytes. The present study aims to determine if there is a substantial improvement in making all six coefficients electrolyte specific. The Cisternas-Lam model was fit to data for six major electrolytes in Hanford nuclear waste supernatants. The model was first fit to all data to determine the five global coefficients, when they were held constant for all electrolytes it yielded a substantially better fit. Subsequently, the model was fit to each electrolyte dataset separately, where all six coefficients were allowed to be electrolyte specific. Treating all six coefficients as electrolyte specific did not make sufficient difference, given the complexity of applying the electrolyte specific parameters to multi-solute systems. Revised water specific parameters, optimized to the electrolytes relevant to Hanford waste, are also reported.
Shankaran, Harish; Zhang, Yi; Chrisler, William B.; Ewald, Jonathan A.; Wiley, H. S.; Resat, Haluk
2012-10-02
The epidermal growth factor receptor (EGFR) belongs to the ErbB family of receptor tyrosine kinases, and controls a diverse set of cellular responses relevant to development and tumorigenesis. ErbB activation is a complex process involving receptor-ligand binding, receptor dimerization, phosphorylation, and trafficking (internalization, recycling and degradation), which together dictate the spatio-temporal distribution of active receptors within the cell. The ability to predict this distribution, and elucidation of the factors regulating it, would help to establish a mechanistic link between ErbB expression levels and the cellular response. Towards this end, we constructed mathematical models for deconvolving the contributions of receptor dimerization and phosphorylation to EGFR activation, and to examine the dependence of these processes on sub-cellular location. We collected experimental datasets for EGFR activation dynamics in human mammary epithelial cells, with the specific goal of model parameterization, and used the data to estimate parameters for several alternate models. Model-based analysis indicated that: 1) signal termination via receptor dephosphorylation in late endosomes, prior to degradation, is an important component of the response, 2) less than 40% of the receptors in the cell are phosphorylated at any given time, even at saturating ligand doses, and 3) receptor dephosphorylation rates at the cell surface and early endosomes are comparable. We validated the last finding by measuring EGFR dephosphorylation rates at various times following ligand addition both in whole cells, and in endosomes using ELISAs and fluorescent imaging. Overall, our results provide important information on how EGFR phosphorylation levels are regulated within cells. Further, the mathematical model described here can be extended to determine receptor dimer abundances in cells co-expressing various levels of ErbB receptors. This study demonstrates that an iterative cycle of experiments and modeling can be used to gain mechanistic insight regarding complex cell signaling networks.
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry
Bell, John B.
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence: 47.40.Fw, 82.40.Py Submitted to: Combust. Theory Modelling #12;Numerical Simulation of Laminar
Yu, Z.; Peldszus, S.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). NSERC Chair in Water Treatment
2009-03-01
The adsorption of two representative pharmaceutically active compounds (PhACs) naproxen and carbamazepine and one endocrine disrupting compound (EDC) nonylphenol was studied in pilot-scale granular activated carbon (GAC) adsorbers using post-sedimentation (PS) water from a full-scale drinking water treatment plant. The GAC adsorbents were coal-based Calgon Filtrasorb 400 and coconut shell-based PICA CTIF TE. Acidic naproxen broke through fastest while nonylphenol was removed best, which was consistent with the degree to which fouling affected compound removals. Model predictions and experimental data were generally in good agreement for all three compounds, which demonstrated the effectiveness and robustness of the pore and surface diffusion model (PSDM) used in combination with the time-variable parameter approach for predicting removals at environmentally relevant concentrations (i.e., ng/L range). Sensitivity analyses suggested that accurate determination of film diffusion coefficients was critical for predicting breakthrough for naproxen and carbamazepine, in particular when high removals are targeted. Model simulations demonstrated that GAC carbon usage rates (CURs) for naproxen were substantially influenced by the empty bed contact time (EBCT) at the investigated conditions. Model-based comparisons between GAC CURs and minimum CURs for powdered activated carbon (PAC) applications suggested that PAC would be most appropriate for achieving 90% removal of naproxen, whereas GAC would be more suitable for nonylphenol. 25 refs., 4 figs., 1 tab.
SOLAR MAGNETIC ACTIVITY CYCLES, CORONAL POTENTIAL FIELD MODELS AND ERUPTION RATES
Petrie, G. J. D.
2013-05-10
We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National Solar Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with active fields over most of the period studied, except between 2003 and 2006 when the active fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The tilt of the solar dipole is therefore almost entirely due to active-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, Solar Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.
Lateral boundary errors in regional numerical weather
?umer, Slobodan
Lateral boundary errors in regional numerical weather prediction models Author: Ana Car Advisor, they describe evolution of atmospher - weather forecast. Every NWP model solves the same system of equations (1: assoc. prof. dr. Nedjeljka Zagar January 5, 2015 Abstract Regional models are used in many national
Meng, Da; Zheng, Bin; Lin, Guang; Sushko, Maria L.
2014-08-29
We have developed efficient numerical algorithms for the solution of 3D steady-state Poisson-Nernst-Planck equations (PNP) with excess chemical potentials described by the classical density functional theory (cDFT). The coupled PNP equations are discretized by finite difference scheme and solved iteratively by Gummel method with relaxation. The Nernst-Planck equations are transformed into Laplace equations through the Slotboom transformation. Algebraic multigrid method is then applied to efficiently solve the Poisson equation and the transformed Nernst-Planck equations. A novel strategy for calculating excess chemical potentials through fast Fourier transforms is proposed which reduces computational complexity from O(N2) to O(NlogN) where N is the number of grid points. Integrals involving Dirac delta function are evaluated directly by coordinate transformation which yields more accurate result compared to applying numerical quadrature to an approximated delta function. Numerical results for ion and electron transport in solid electrolyte for Li ion batteries are shown to be in good agreement with the experimental data and the results from previous studies.
Model Documentation Report: Macroeconomic Activity Module of the National Energy Modeling System
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet)DecadeYear Jan Feb Mar Apr 2012DecadeTotal19FuelYear JanFeet)August4) MODEL
Model Documentation Report: Macroeconomic Activity Module of the National Energy Modeling System
Gasoline and Diesel Fuel Update (EIA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet)DecadeYear Jan Feb Mar Apr 2012DecadeTotal19FuelYear JanFeet)August4) MODEL5)
Particle dynamics in a non-flaring solar active region model
Threlfall, J; Neukirch, T; Parnell, C E
2015-01-01
The aim of this work is to investigate and characterise particle behaviour in a (observationally-driven) 3D MHD model of the solar atmosphere above a slowly evolving, non-flaring active region. We use a relativistic guiding-centre particle code to investigate particle acceleration in a single snapshot of the 3D MHD simulation. Despite the lack of flare-like behaviour in the active region, direct acceleration of electrons and protons to non-thermal energies ($\\lesssim420$MeV) was found, yielding spectra with high-energy tails which conform to a power law. Examples of particle dynamics, including particle trapping caused by local electric rather than magnetic field effects, are observed and discussed, together with implications for future experiments which simulate non-flaring active region heating and reconnection.
Simulation 4, 239-250, 2003 Traffic Flow CA Model in Which Only the Cars Following the Trail of the Ahead Car from the NS model in that only the cars following the trail of the ahead car can be delayed. In other words, a car with spacing ahead longer than the car velocity limit M can not be delayed in the new model
Selection of a Model of Cerebral Activity for fMRI Group Data Analysis
Keller, Merlin; Lavielle, Marc
2010-01-01
This thesis is dedicated to the statistical analysis of multi-sub ject fMRI data, with the purpose of identifying bain structures involved in certain cognitive or sensori-motor tasks, in a reproducible way across sub jects. To overcome certain limitations of standard voxel-based testing methods, as implemented in the Statistical Parametric Mapping (SPM) software, we introduce a Bayesian model selection approach to this problem, meaning that the most probable model of cerebral activity given the data is selected from a pre-defined collection of possible models. Based on a parcellation of the brain volume into functionally homogeneous regions, each model corresponds to a partition of the regions into those involved in the task under study and those inactive. This allows to incorporate prior information, and avoids the dependence of the SPM-like approach on an arbitrary threshold, called the cluster- forming threshold, to define active regions. By controlling a Bayesian risk, our approach balances false positive...
Multigrid methods for improving the variational data assimilation in numerical weather prediction
Kwak, Do Young
Multigrid methods for improving the variational data assimilation in numerical weather prediction conditions are needed to solve numerical weather prediction models: initial condition and boundary condition: numerical weather prediction, variational data assimilation, minimization procedure, multigrid methods, cell
Witherspoon, P.A.
2010-01-01
n The variable is the hydraulic head Energy T r a n s p o rhydraulic fractur ing process requires the modeling of the energy
Disruptive Innovation in Numerical Hydrodynamics
Waltz, Jacob I.
2012-09-06
We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.
Bell, John B.
and Dufour effects, and radiative heat transfer, and assume a mixture-averaged model for differential species methods, low Mach number flows Turbulent premixed combustion is a major active research topic without introducing models for turbulence or turbulence chemistry interaction. We outline the numerical
Introduction to exact numerical computation
Escardó, Martín
Introduction to exact numerical computation Notes 2 Floating-point computation 4 3 Exact numerical (called the operational semantics) for computing a syntactical representative of the mathematical entity
Threedimensional numerical simulation for various geometries
Herbin, Raphaèle
modelling and numerical simulation of natural gasfed solid oxide cells (Solid Oxide Fuel Cell, SOFC) at a stationary regime. The principle of a Solid Oxide Fuel Cell (SOFC) is based on the conversion of the chemical is taken into account in the present model. The SOFC systems seem to be of great interest for use
Thermal Activation Rates in the Chirally Asymmetric Gross-Neveu Model
D. Boyanovsky; David E. Brahm; R. Holman; Da-Shin Lee
1995-11-14
We address the problem of how to incorporate quantum effects into the calculation of finite-temperature decay rates for a metastable state of a quantum field theory. To do this, we consider the Gross-Neveu model with an explicit chiral symmetry breaking term, which allows for a metastable state. This theory can be shown to have a "critical bubble" which is a solution to the *exact* equations of motions (i.e. to all orders in perturbation theory, including all higher derivative, quantum and thermal corrections). This configuration mediates the thermal activation of the metastable vacuum to the true ground state, with a decay rate $\\Gamma \\propto \\exp(-F_c/T)$, where $F_c$ is the free energy of the critical bubble. We then compare this exact calculation to various approximations that have been used in previous work. We find that these approximations all *overestimate* the activation rate. Furthermore, we study the effect of finite baryon number upon the bubble profile and the activation barriers. We find that beyond a critical baryon number the activation barriers disappear altogether.
Pohlmann Karl,Ye Ming
2012-03-01
Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.
Structure and mechanics of active colloids
M. Cristina Marchetti; Yaouen Fily; Silke Henkes; Adam Patch; David Yllanes
2015-10-01
Minimal models of active Brownian colloids consisting of self-propelled spherical particles with purely repulsive interactions have recently been identified as excellent quantitative testing grounds for theories of active matter and have been the subject of extensive numerical and analytical investigation. These systems do not exhibit aligned or flocking states, but do have a rich phase diagram, forming active gases, liquids and solids with novel mechanical properties. This article reviews recent advances in the understanding of such models, including the description of the active gas and its swim pressure, the motility-induced phase separation and the high-density crystalline and glassy behavior.
Chow, Jason C.
2011-01-01
Urine Protease Activity: Gelatin Zymography………………………. 31Plasma Protease Activity: Gelatin Zymography……..………. 19Plasma Protease Activity: Gelatin Zymography (Low M.W. )….
Li, Yang
A novel triptycene-based ligand with a preorganized framework was designed to model carboxylate-bridged diiron active sites in bacterial multicomponent monooxygenase (BMM) hydroxylase enzymes. The synthesis of the ...
Oxidation of substrates tethered to N-donor ligands for modeling non-heme diiron enzyme active sites
Carson, Emily Carrig, 1978-
2005-01-01
Chapter 1. Modeling Carboxylate-Rich Diiron Sites of Dioxygen-Dependent Non-Heme Enzymes Carboxylate-bridged diiron centers are employed in a variety of biological systems to activate dioxygen for substrate oxidation, and ...
Mechanical diode: Comparing numerical and experimental characterizations
Sagartz, M.J.; Segalman, D.; Simmermacher, T.
1998-02-01
In this introductory work, joint compliance is studied in both a numerical and experimental setting. A simple bolted interface is used as the test article and compliance is measured for the joint in both compression and in tension. This simple interface is shown to exhibit a strong non-linearity near the transition from compression to tension (or vice-versa). Modeling issues pertaining to numerically solving for the compliance are addressed. It is shown that the model predictions, in spite of convergence being very sensitive to numerical artifacts of the interface model, are in good agreement with experimentally measured strains and joint compliances. The joint behavior is a mechanical analogy to a diode, i.e., in compression, the joint is very stiff, acting almost as a rigid link, while in tension the joint is relatively soft, acting as a spring.
Payan, Yohan
, was exploited to study the activation of the tongue and mouth floor muscles during the production of French cardinal vowels. The selection of the motor commands to control the tongue and the mouth floor musclesA biomechanical model of cardinal vowel production: Muscle activations and the impact of gravity
Prowell, I.; Robertson, A.; Jonkman, J.; Stewart, G. M.; Goupee, A. J.
2013-01-01
Realizing the critical importance the role physical experimental tests play in understanding the dynamics of floating offshore wind turbines, the DeepCwind consortium conducted a one-fiftieth-scale model test program where several floating wind platforms were subjected to a variety of wind and wave loading condition at the Maritime Research Institute Netherlands wave basin. This paper describes the observed behavior of a tension-leg platform, one of three platforms tested, and the systematic effort to predict the measured response with the FAST simulation tool using a model primarily based on consensus geometric and mass properties of the test specimen.
A nanoflare model for active region radiance: application of artificial neural networks
M. Bazarghan; H. Safari; D. E. Innes; E. Karami; S. K. Solanki
2008-12-20
Context. Nanoflares are small impulsive bursts of energy that blend with and possibly make up much of the solar background emission. Determining their frequency and energy input is central to understanding the heating of the solar corona. One method is to extrapolate the energy frequency distribution of larger individually observed flares to lower energies. Only if the power law exponent is greater than 2, is it considered possible that nanoflares contribute significantly to the energy input. Aims. Time sequences of ultraviolet line radiances observed in the corona of an active region are modelled with the aim of determining the power law exponent of the nanoflare energy distribution. Methods. A simple nanoflare model based on three key parameters (the flare rate, the flare duration time, and the power law exponent of the flare energy frequency distribution) is used to simulate emission line radiances from the ions Fe XIX, Ca XIII, and Si iii, observed by SUMER in the corona of an active region as it rotates around the east limb of the Sun. Light curve pattern recognition by an Artificial Neural Network (ANN) scheme is used to determine the values. Results. The power law exponents, alpha 2.8, 2.8, and 2.6 for Fe XIX, Ca XIII, and Si iii respectively. Conclusions. The light curve simulations imply a power law exponent greater than the critical value of 2 for all ion species. This implies that if the energy of flare-like events is extrapolated to low energies, nanoflares could provide a significant contribution to the heating of active region coronae.
Activated Aging Dynamics and Negative Fluctuation-Dissipation Ratios Peter Mayer,1,2
Berthier, Ludovic
Activated Aging Dynamics and Negative Fluctuation-Dissipation Ratios Peter Mayer,1,2 Se´bastien Le 2006) In glassy materials, aging proceeds at large times via thermal activation. We show that this can theoretical and numerical results for the activated aging regime of simple kinetically constrained models
Eric M. Leonard; Mitchell A. Plummer; Paul E. Carrara
2014-04-01
Well-preserved moraines from the penultimate, or Bull Lake, glaciation of Snowmass Creek Valley in the Elk Range of Colorado present an opportunity to examine the character of the high-altitude climate in the Rocky Mountains during Marine Oxygen Isotope Stage 6. This study employs a 2-D coupled mass/energy balance and flow model to assess the magnitudes of temperature and precipitation change that could have sustained the glacier in mass-balance equilibrium at its maximum extent during the Bull Lake glaciation. Variable substrate effects on glacier flow and ice thickness make the modeling somewhat more complex than in geologically simpler settings. Model results indicate that a temperature depression of about 6.7°C compared with the present (1971–2000 AD) would have been necessary to sustain the Snowmass Creek glacier in mass-balance equilibrium during the Bull Lake glaciation, assuming no change in precipitation amount or seasonality. A 50% increase or decrease from modern precipitation would have been coupled with 5.2°C and 9.1°C Bull Lake temperature depressions respectively. Uncertainty in these modeled temperature depressions is about 1°C.
Dimov, Ivan
investigations related to air pollution in Bulgaria ([6, 7]), Denmark ([8-11]), England ([12]), Europe ([2, 4 been used in some inter-comparisons of European large-scale air pollution models ([20, 21]). Recently Publishers CHAPTER 4 Part C: Sensitivity of European Pollution Levels to Changes of Human-Made Emissions
Hanna, S.R.; Chang, J.C.
1997-01-01
The HGSYSTEM/UF{sub 6} model was developed for use in preparing Safety Analysis Reports (SARs) by estimating the consequences of possible accidental releases of UF{sub 6} to the atmosphere at the gaseous diffusion plants (GDPs) located in Portsmouth, Ohio, and Paducah, Kentucky. Although the latter report carries a 1996 date, the work that is described was completed in late 1994. When that report was written, the primary release scenarios of interest were thought to be gas pipeline and liquid tank ruptures over open terrain away from the influence of buildings. However, upon further analysis of possible release scenarios, the developers of the SARs decided it was necessary to also consider accidental releases within buildings. Consequently, during the fall and winter of 1995-96, modules were added to HGSYSTEM/UF{sub 6} to account for flow and dispersion around buildings. The original HGSYSTEM/UF{sub 6} model also contained a preliminary method for accounting for the possible lift-off of ground-based buoyant plumes. An improved model and a new set of wind tunnel data for buoyant plumes trapped in building recirculation cavities have become available that appear to be useful for revising the lift-off algorithm and modifying it for use in recirculation cavities. This improved lift-off model has been incorporated in the updated modules for dispersion around buildings.
Pan, Ning
5(1) 5-8, 2004 Thermo-electro-hydrodynamic model for electrospinning process Yu-Qin Wana , Qian Guob-fine polymer fibers, obtained by electrospinning, have a wide range of potential applications such as fluid behind electrospinning. When electrical force is dominant over the other forces, Bratu equation
Laible, Allyson Marie
2009-05-15
that fluorescence increases up to 24 hours after an initial delay of approximately four hours. The fluorescence data was also used to develop a model describing significant events leading to NF-?B activation and GFP expression. In addition, a model describing...
NUMERICAL SIMULATIONS OF TRANSVERSE COMPRESSION AND DENSIFICATION IN WOOD
Nairn, John A.
NUMERICAL SIMULATIONS OF TRANSVERSE COMPRESSION AND DENSIFICATION IN WOOD John A. Nairn1 Professor- terials is a useful tool for stress analysis and for failure modeling. Although FEA of wood as an anisotropic continuum is used, numerical modeling of realistic wood structures, including details of wood
Experimental and numerical analysis of a deepwater mini-TLP
Guichard, Aurelien
2001-01-01
As the quest for oil and gas resources drives the industry to ever deeper waters, model testing still represents an essential step after numerical modeling when designing offshore platforms in these hostile environments. ...
Numerical Weather Forecasting at the Savannah River Site
Buckley, R.L. [Westinghouse Savannah River Company, AIKEN, SC (United States)
1998-08-01
This paper discusses the use of an advanced three-dimensional prognostic numerical model to provide space and time-dependent meteorological data for use in the WIND System dispersion models.
Ribeiro-Filho, Jaime; Calheiros, Andrea Surrage; Vieira-de-Abreu, Adriana; Moraes de Carvalho, Katharinne Ingrid; Silva Mendes, Diego da; Melo, Christianne Bandeira; Martins, Marco Aurélio; Silva Dias, Celidarque da; Piuvezam, Márcia Regina; and others
2013-11-15
Allergic asthma is a chronic inflammatory airway disease with increasing prevalence around the world. Current asthma therapy includes drugs that usually cause significant side effects, justifying the search for new anti-asthmatic drugs. Curine is a bisbenzylisoquinoline alkaloid that modulates calcium influx in many cell types; however, its anti-allergic and putative toxic effects remain to be elucidated. Our aim was to investigate the effects of curine on eosinophil activation and airway hyper-responsiveness (AHR) and to characterize its potential toxic effects. We used a mouse model of allergic asthma induced by sensitization and challenge with ovalbumin (OVA) to evaluate the anti-allergic effects of oral treatment with curine. The oral administration of curine significantly inhibited eosinophilic inflammation, eosinophil lipid body formation and AHR in animals challenged with OVA compared with animals in the untreated group. The curine treatment also reduced eotaxin and IL-13 production triggered by OVA. Verapamil, a calcium channel antagonist, had similar anti-allergic properties, and curine pre-treatment inhibited the calcium-induced tracheal contractile response ex-vivo, suggesting that the mechanism by which curine exerts its effects is through the inhibition of a calcium-dependent response. A toxicological evaluation showed that orally administered curine did not significantly alter the biochemical, hematological, behavioral and physical parameters measured in the experimental animals compared with saline-treated animals. In conclusion, curine showed anti-allergic activity through mechanisms that involve inhibition of IL-13 and eotaxin and of Ca{sup ++} influx, without inducing evident toxicity and as such, has the potential for the development of anti-asthmatic drugs. - Highlights: • Curine is a bisbenzylisoquinoline alkaloid from Chondrodendron platyphyllum. • Curine inhibits eosinophil influx and activation and airway hyper-responsiveness. • Curine mechanisms involve inhibition of Ca{sup 2+} influx, and IL-13 and eotaxin secretion. • No significant toxicity was observed in mice orally treated with curine for 7 days. • Curine has the potential for the development of anti-asthmatic drugs.
Observational and Numerical of the Adriatic Bora
Gohm, Alexander
and radiosoundings) 2. Mesoscale numerical model RAMS: · 5 or 6 nested grids · Horizontal mesh size as low as 800 m RAMS domain 5 #12;The event 28 March 2002: · Deep bora: deep NE flow, no critical level field: · The bora flow weakens and separates during daytime. RAMS vertical transects across Vratnik Pass
MODELING SUPER-FAST MAGNETOSONIC WAVES OBSERVED BY SDO IN ACTIVE REGION FUNNELS
Ofman, L.; Liu, W.; Title, A.; Aschwanden, M.
2011-10-20
Recently, quasi-periodic, rapidly propagating waves have been observed in extreme ultraviolet by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) instrument in about 10 flare/coronal mass ejection (CME) events thus far. A typical example is the 2010 August 1 C3.2 flare/CME event that exhibited arc-shaped wave trains propagating in an active region (AR) magnetic funnel with {approx}5% intensity variations at speeds in the range of 1000-2000 km s{sup -1}. The fast temporal cadence and high sensitivity of AIA enabled the detection of these waves. We identify them as fast magnetosonic waves driven quasi-periodically at the base of the flaring region and develop a three-dimensional MHD model of the event. For the initial state we utilize the dipole magnetic field to model the AR and include gravitationally stratified density at coronal temperature. At the coronal base of the AR, we excite the fast magnetosonic wave by periodic velocity pulsations in the photospheric plane confined to a funnel of magnetic field lines. The excited fast magnetosonic waves have similar amplitude, wavelength, and propagation speeds as the observed wave trains. Based on the simulation results, we discuss the possible excitation mechanism of the waves, their dynamical properties, and the use of the observations for coronal MHD seismology.
Numerical simulation of an electroweak oscillon
Graham, N. [Department of Physics, Middlebury College, Middlebury, Vermont 05753 (United States)
2007-10-15
Numerical simulations of the bosonic sector of the SU(2)xU(1) electroweak standard model in 3+1 dimensions have demonstrated the existence of an oscillon--an extremely long-lived, localized, oscillatory solution to the equations of motion--when the Higgs mass is equal to twice the W{sup {+-}} boson mass. It contains total energy roughly 30 TeV localized in a region of radius 0.05 fm. A detailed description of these numerical results is presented.
Engagement with Australia Active Partnership Agreements
Behmer, Spencer T.
Geomechanics on numerical modeling of suction caisson, pile, and skirt foundations in various offshore oil
Casado, J M
2015-01-01
Rhythms in electrical activity in the membrane of cells in the suprachiasmatic nucleus (SCN) are crucial for the function of the circadian timing system, which is characterized by the expression of the so-called clock genes. Intracellular Ca$^{2+}$ ions seem to connect, at least in part, the electrical activity of SCN neurons with the expression of clock genes. In this paper, we introduce a simple mathematical model describing the linking of membrane activity to the transcription of one gene by means of a feedback mechanism based on the dynamics of intracellular calcium ions.
Numerical simulations of strong incompressible magnetohydrodynamic turbulence
Mason, J.; Cattaneo, F.; Perez, J. C.; Boldyrev, S.
2012-05-15
Magnetised plasma turbulence pervades the universe and is likely to play an important role in a variety of astrophysical settings. Magnetohydrodynamics (MHD) provides the simplest theoretical framework in which phenomenological models for the turbulent dynamics can be built. Numerical simulations of MHD turbulence are widely used to guide and test the theoretical predictions; however, simulating MHD turbulence and accurately measuring its scaling properties is far from straightforward. Computational power limits the calculations to moderate Reynolds numbers and often simplifying assumptions are made in order that a wider range of scales can be accessed. After describing the theoretical predictions and the numerical approaches that are often employed in studying strong incompressible MHD turbulence, we present the findings of a series of high-resolution direct numerical simulations. We discuss the effects that insufficiencies in the computational approach can have on the solution and its physical interpretation.
Status of NINJA: the Numerical INJection Analysis project
Benjamin Aylott; John G. Baker; William D. Boggs; Michael Boyle; Patrick R. Brady; Duncan A. Brown; Bernd Brügmann; Luisa T. Buchman; Alessandra Buonanno; Laura Cadonati; Jordan Camp; Manuela Campanelli; Joan Centrella; Shourov Chatterjis; Nelson Christensen; Tony Chu; Peter Diener; Nils Dorband; Zachariah B. Etienne; Joshua Faber; Stephen Fairhurst; Benjamin Farr; Sebastian Fischetti; Gianluca Guidi; Lisa M. Goggin; Mark Hannam; Frank Herrmann; Ian Hinder; Sascha Husa; Vicky Kalogera; Drew Keppel; Lawrence E. Kidder; Bernard J. Kelly; Badri Krishnan; Pablo Laguna; Carlos O. Lousto; Ilya Mandel; Pedro Marronetti; Richard Matzner; Sean T. McWilliams; Keith D. Matthews; R. Adam Mercer; Satyanarayan R. P. Mohapatra; Abdul H. Mroué; Hiroyuki Nakano; Evan Ochsner; Yi Pan; Larne Pekowsky; Harald P. Pfeiffer; Denis Pollney; Frans Pretorius; Vivien Raymond; Christian Reisswig; Luciano Rezzolla; Oliver Rinne; Craig Robinson; Christian Röver; Lucía Santamaría; Bangalore Sathyaprakash; Mark A. Scheel; Erik Schnetter; Jennifer Seiler; Stuart L. Shapiro; Deirdre Shoemaker; Ulrich Sperhake; Alexander Stroeer; Riccardo Sturani; Wolfgang Tichy; Yuk Tung Liu; Marc van der Sluys; James R. van Meter; Ruslan Vaulin; Alberto Vecchio; John Veitch; Andrea Viceré; John T. Whelan; Yosef Zlochower
2009-05-26
The 2008 NRDA conference introduced the Numerical INJection Analysis project (NINJA), a new collaborative effort between the numerical relativity community and the data analysis community. NINJA focuses on modeling and searching for gravitational wave signatures from the coalescence of binary system of compact objects. We review the scope of this collaboration and the components of the first NINJA project, where numerical relativity groups shared waveforms and data analysis teams applied various techniques to detect them when embedded in colored Gaussian noise.
Modeling hot gas flow in the low-luminosity active galactic nucleus of NGC 3115
Shcherbakov, Roman V.; Reynolds, Christopher S.; Wong, Ka-Wah; Irwin, Jimmy A.
2014-02-20
Based on the dynamical black hole (BH) mass estimates, NGC 3115 hosts the closest billion solar mass BH. Deep studies of the center revealed a very underluminous active galactic nucleus (AGN) immersed in an old massive nuclear star cluster. Recent 1 Ms Chandra X-ray visionary project observations of the NGC 3115 nucleus resolved hot tenuous gas, which fuels the AGN. In this paper we connect the processes in the nuclear star cluster with the feeding of the supermassive BH. We model the hot gas flow sustained by the injection of matter and energy from the stars and supernova explosions. We incorporate electron heat conduction as the small-scale feedback mechanism, the gravitational pull of the stellar mass, cooling, and Coulomb collisions. Fitting simulated X-ray emission to the spatially and spectrally resolved observed data, we find the best-fitting solutions with ?{sup 2}/dof = 1.00 for dof = 236 both with and without conduction. The radial modeling favors a low BH mass <1.3 × 10{sup 9} M {sub ?}. The best-fitting supernova rate and the best-fitting mass injection rate are consistent with their expected values. The stagnation point is at r {sub st} ? 1'', so that most of the gas, including the gas at a Bondi radius r{sub B} = 2''-4'', outflows from the region. We put an upper limit on the accretion rate at 2 × 10{sup –3} M {sub ?} yr{sup –1}. We find a shallow density profile n?r {sup –?} with ? ? 1 over a large dynamic range. This density profile is determined in the feeding region 0.''5-10'' as an interplay of four processes and effects: (1) the radius-dependent mass injection, (2) the effect of the galactic gravitational potential, (3) the accretion flow onset at r ? 1'', and (4) the outflow at r ? 1''. The gas temperature is close to the virial temperature T{sub v} at any radius.
Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.
Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk
2013-08-22
The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.
Design of Predictive Control Strategies for Active BITIES Systems Using Frequency Domain Models
Chen, Y.; Athienitis, A. K.; Gala, K. E.
2013-01-01
Active building-integrated thermal energy storage (BITES) systems, such as ventilated concrete slabs, are able to effectively store and release abundant of thermal energy to assist space conditioning. Since active BITES systems are strongly thermal...
Modeling and Experimental Studies of Densification Rates in Current Activated Densification
Dupuy, Alexander Davis
2011-01-01
yttria stabilized zirconia with varying colors,” Scriptaof Nanostructured Zirconia by Current Activation,” Journaltetragonal and cubic zirconia,” Scripta Materialia, vol. 48,
Blumberg, Bruce
1 Oxidation of Ethidium Using TAML Activators: A Model for High 2 School Research Performed Bruce Blumberg,§ Terrence J. Collins, and Steven G. Sogo*, 6 Laguna Beach High School, Laguna Beach ABSTRACT: A chemical research program at a public high school has been 12 developed. The full-year Advanced
Astrophysical jets: Observations, numerical simulations, and laboratory experiments
Bellan, Paul M.
Astrophysical jets: Observations, numerical simulations, and laboratory experiments P. M. Bellan,1; published online 22 April 2009 This paper provides summaries of ten talks on astrophysical jets given of observation, numerical modeling, and laboratory experiment. One essential feature of jets, namely
MULTISCALE NUMERICAL STUDY OF TURBULENT FLOW AND BUBBLE ENTRAINMENT
Kirby, James T.
MULTISCALE NUMERICAL STUDY OF TURBULENT FLOW AND BUBBLE ENTRAINMENT IN THE SURF ZONE BY GANGFENG MA . . . . . . . . . . . . . . . . . . . . . 3 1.1.2 Numerical Investigations . . . . . . . . . . . . . . . . . . . . . 5 1.2 Bubble Entrainment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4 Bubble Entrainment Model . . . . . . . . . . . . . . . . . . . . . . . 18 2.5 Bubble Breakup
Gnie mcanique Numerical Modeling of Water Splitting
Psaltis, Demetri
reaction takes place.. Laboratory of Renewable Energy Science and Engineering Parametric Study Annual & Tom Bosserez from KU Leuven , Mikaël Dumortier from EPFL Motivation & Objectives It has become accepted in wide ranges of societies that alternative sources of energy need to be developped. Using
Numerical and experimental modelling of microwave applicators
Dibben, David
1995-10-24
This thesis presents a time domain finite element method for the solution of microwave heating problems. This is the first time that this particular technique has been applied to microwave heating. It is found that the standard frequency domain...
numerical modeling | OpenEI Community
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OpenEI Community - numerical modeling
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII JumpQuarterly Smart Grid Data available for download onst,/0Thoughts
Persistence of activity in noisy motor-filament assemblies
Chelakkot, Raghunath; Mahadevan, L
2015-01-01
Long, elastic filaments cross-linked and deformed by active molecular motors occur in various natural settings. The overall macroscopic mechanical response of such a composite network depends on the coupling between the active and the passive properties of the underlying constituents and nonlocal interactions between different parts of the composite. In a simple one dimensional system, using a mean field model, it has been shown that the combination of motor activity and finite filament extensibility yields a persistence length scale over which strain decays. Here we study a similar system, in the complementary limit of strong noise and moderate extensibility, using Brownian multi-particle collision dynamics-based numerical simulations that includes the coupling between motor kinetics and local filament extensibility. While the numerical model shows deviations from the mean field predictions due to the presence of strong active noise caused by the variations in individual motor activity, several qualitative f...
Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b
Maruyama, Shigeo
Numerical study of high heat ¯ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings
Geotextiles and Geomembranes 11 (1992) 115-131 Numerical Investigation of Controlled Yielding of
Horvath, John S.
1992-01-01
Geotextiles and Geomembranes 11 (1992) 115-131 Numerical Investigation of Controlled Yielding- constructed to active conditions is dependent on the cohesion and 115 Geotextiles and Geomembranes 0266
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry
Bell, John B.
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence Simulation of Laminar Reacting Flows 2 1. Introduction Detailed modelling of time-dependent reacting ows
An investigation of the numerical treatment of condensation
Sasson, Joseph
The simulation of complete condensation continues to challenge the numerical methods currently used for multi-phase flow modeling; especially at low pressures, the change of phase process from a two-phase mixture to liquid ...
NUMERICAL APPROXIMATIONS OF ALLEN-CAHN AND CAHN ...
2010-03-18
schemes that satisfy a corresponding discrete energy law, or in other words, energy ... Our first objective is to design stabilized semi-implicit schemes that satisfy an energy ...... Numerical analysis of a continuum model of phase transition.
Mathiesen, Patrick; Kleissl, Jan
2011-01-01
transport and numerical weather modeling. J. Applied cross correlations. Weather and Forecasting, 8:4, 401?of radiation for numerical weather prediction and climate
Suckale, Jenny
This is the second paper of two that examine numerical simulations of buoyancy-driven flow in the presence of large viscosity contrasts. In the first paper, we demonstrated that a combination of three numerical tools, an ...
Switching Between Discrete and Continuous Process Models to Predict Molecular Genetic Activity
Weld, Daniel Sabey
1984-05-01
Two kinds of process models have been used in programs that reason about change: Discrete and continuous models. We describe the design and implementation of a qualitative simulator, PEPTIDE, which uses both kinds of ...
Modeling and Field Test Planning Activities in Support of Disposal of Heat-Generating Waste in Salt
Rutqvist, Jonny; Blanco Martin, Laura; Mukhopadhyay, Sumit; Houseworth, Jim; Birkholzer, Jens
2014-09-26
The modeling efforts in support of the field test planning conducted at LBNL leverage on recent developments of tools for modeling coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. This work includes development related to, and implementation of, essential capabilities, as well as testing the model against relevant information and published experimental data related to the fate and transport of water. These are modeling capabilities that will be suitable for assisting in the design of field experiment, especially related to multiphase flow processes coupled with mechanical deformations, at high temperature. In this report, we first examine previous generic repository modeling results, focusing on the first 20 years to investigate the expected evolution of the different processes that could be monitored in a full-scale heater experiment, and then present new results from ongoing modeling of the Thermal Simulation for Drift Emplacement (TSDE) experiment, a heater experiment on the in-drift emplacement concept at the Asse Mine, Germany, and provide an update on the ongoing model developments for modeling brine migration. LBNL also supported field test planning activities via contributions to and technical review of framework documents and test plans, as well as participation in workshops associated with field test planning.
Understanding, Modeling and Predicting Hidden Solder Joint Shape Using Active Thermography
Giron Palomares, Jose
2012-07-16
Characterizing hidden solder joint shapes is essential for electronics reliability. Active thermography is a methodology to identify hidden defects inside an object by means of surface abnormal thermal response after applying a heat flux...
Cohan, Lucy Elizabeth
2010-01-01
Lightweight, active mirrors are an enabling technology for large aperture, space-based optical systems. These mirrors have the potential to improve the optical resolution and sensitivity beyond what is currently possible. ...
The Potential for Integrating GIS in Activity-Based Forecasting Models
McNally, Michael G.
1997-01-01
3" (ENTERTAINMENT) Figure 4. A GIS-based Microsimulation ofDestinations Figure 5. A GIS-based Microsimulation ofPotential for Integrating GIS in Activity Based Forecasting
Thorn, Catherine A. (Catherine Ann), 1980-
2010-01-01
Parallel cortico-basal ganglia loops are thought to give rise to a diverse set of limbic, associative and motor functions, but little is known about how these loops operate and how their neural activities evolve during ...
A numerical study of pseudoscalar inflation
Cheng, Shu-Lin; Ng, Kin-Wang
2015-01-01
A numerical study of a pseudoscalar inflation having an axion-photon-like coupling is performed by solving numerically the coupled differential equations of motion for inflaton and photon mode functions from the onset of inflation to the end of reheating. The backreaction due to particle production is also included self-consistently. We find that this particular inflation model realizes the idea of a warm inflation in which a steady thermal bath is established by the particle production. In most cases this thermal bath exceeds the amount of radiation released in the reheating process. In the strong coupling regime, the transition from the inflationary to the radiation-dominated phase does not involve either a preheating or reheating process. In addition, energy density peaks produced near the end of inflation may lead to the formation of primordial black holes.
A numerical study of pseudoscalar inflation
Shu-Lin Cheng; Wolung Lee; Kin-Wang Ng
2015-08-02
A numerical study of a pseudoscalar inflation having an axion-photon-like coupling is performed by solving numerically the coupled differential equations of motion for inflaton and photon mode functions from the onset of inflation to the end of reheating. The backreaction due to particle production is also included self-consistently. We find that this particular inflation model realizes the idea of a warm inflation in which a steady thermal bath is established by the particle production. In most cases this thermal bath exceeds the amount of radiation released in the reheating process. In the strong coupling regime, the transition from the inflationary to the radiation-dominated phase does not involve either a preheating or reheating process. In addition, energy density peaks produced near the end of inflation may lead to the formation of primordial black holes.
LINKING MICROBES TO CLIMATE: INCORPORATING MICROBIAL ACTIVITY INTO CLIMATE MODELS COLLOQUIUM
DeLong, Edward; Harwood, Caroline; Reid, Ann
2011-01-01
This report explains the connection between microbes and climate, discusses in general terms what modeling is and how it applied to climate, and discusses the need for knowledge in microbial physiology, evolution, and ecology to contribute to the determination of fluxes and rates in climate models. It recommends with a multi-pronged approach to address the gaps.
MODELING AND EXPERIMENTS OF THE HYSTERETIC RESPONSE OF AN ACTIVE HYDROFOIL ACTUATED BY SMA
A&M University College Station, Texas 77843-3141 1. Introduction All movable control surfaces on Shape Memory Alloy (SMA) actuated control surfaces also indicated that large increases in the lift while getting the equivalent lift as a traditional appendage. The use of active materials to effect
Learning Setting-Generalized Activity Models for Smart Spaces Diane J. Cook
Cook, Diane J.
found in smart homes offer unprecedented opportunities for providing context-aware services, including the recognition of activities is an important step toward monitoring the functional health of a smart home datasets from the CASAS Smart Home project [2]. #12;Figure 1. Sensor layout for the seven CASAS smart
Exploring the activity of a novel Au/TiC(001) model catalyst towards CO and CO2 hydrogenation
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Asara, Gian Giacomo; Ricart, Josep M.; Rodriguez, Jose A.; Illas, Francesc
2015-02-02
Small metallic nanoparticles supported on transition metal carbides exhibit an unexpected high activity towards a series of chemical reactions. In particular, the Au/TiC system has proven to be an excellent catalyst for SO2 decomposition, thiophene hydrodesulfurization, O2 and H2 dissociation and the water gas shift reaction. Recent studies have shown that Au/TiC is a very good catalyst for the reverse water–gas shift (CO2 + H2 ? CO + H2O) and CO2 hydrogenation to methanol. The present work further expands the range of applicability of this novel type of systems by exploring the catalytic activity of Au/TiC towards the hydrogenation ofmore »CO or CO2 with periodic density functional theory (DFT) calculations on model systems. Hydrogen dissociates easily on Au/TiC but direct hydrogenation of CO to methanol is hindered by very high activation barriers implying that, on this model catalyst, methanol production from CO2 involves the hydrogenation of a HOCO-like intermediate. Thus, when dealing with mixtures of syngas (CO/CO2/H2/H2O), CO could be transformed into CO2 through the water gas shift reaction with subsequent hydrogenation of CO2 to methanol.« less
Heydari, Payam
Abstract - A new analytical model for high-frequency noise in RF active CMOS mixers such as single. The analytical model predicts that the output noise and NF are both a strong function of the LO frequency models for the mixer noise proposed in [1] and [2] are, therefore, incapable of accurately predicting
Virtanen, Tuomas
MODEL Mikko Myllym¨aki and Tuomas Virtanen Department of Signal Processing, Tampere University of Technology Korkeakoulunkatu 1, 33720, Tampere, Finland email: mikko.v.myllymaki@tut.fi, tuomas
Stojmenovic, Ivan
Reality Technology and Systems, Beihang University, Beijing 100191, China Guangdong Petrochemical Equipment Fault Diagnosis Key Laboratory Guangdong University of Petrochemical Technology, Guangdong 525000 models to study the diffusion process. The authors in [7] analyzed the behavior diffusion using an event
Research recommendations to the EPA in support of earth system modeling activities
Ambrosiano, J.J.; Dannevik, W.P.; Kercher, J.; Miller, N.L.; Penner, J.E.; Rotman, D.
1994-05-06
A theme which emerges from our simple considerations is that some well-planned early parametric and sensitivity studies, using current-generation coupled Earth system model components, along with simplistic proxy models of terrestrial biospheric and biogeochemical processes, could furnish valuable information to help guide the development of a longer-term plan for research supporting ESM development. This theme is rooted in the premise that the importance of various ESM component processes can be fully assessed only from the perspective of a complete coupling of that process into the ESM context. That is, the question, ``How well must a given process be modelled``? Cannot be answered in isolation, but rather requires a careful blend of process research and coupled model studies.
Model reduction for active control design using multiple-point Arnoldi methods
Lassaux, G.
A multiple-point Arnoldi method is derived for model reduction of computational fluid dynamic systems. By choosing the number of frequency interpolation points and the number of Arnoldi vectors at each frequency point, the ...
Real-time detection of malicious network activity using stochastic models
Jung, Jaeyeon, Ph. D. Massachusetts Institute of Technology
2006-01-01
This dissertation develops approaches to rapidly detect malicious network traffic including packets sent by portscanners and network worms. The main hypothesis is that stochastic models capturing a host's particular ...
Lattice-gas model for active vesicle transport by molecular motors with opposite polarities
Sudipto Muhuri; Ignacio Pagonabarraga
2010-09-09
We introduce a multi-species lattice gas model for motor protein driven collective cargo transport on cellular filaments. We use this model to describe and analyze the collective motion of interacting vesicle cargoes being carried by oppositely directed molecular motors, moving on a single biofilament. Building on a totally asymmetric exclusion process (TASEP) to characterize the motion of the interacting cargoes, we allow for mass exchange with the environment, input and output at filament boundaries and focus on the role of interconversion rates and how they affect the directionality of the net cargo transport. We quantify the effect of the various different competing processes in terms of non-equilibrium phase diagrams. The interplay of interconversion rates, which allow for flux reversal and evaporation/deposition processes introduce qualitatively new features in the phase diagrams. We observe regimes of three-phase coexistence, the possibility of phase re-entrance and a significant flexibility in how the different phase boundaries shift in response to changes in control parameters. The moving steady state solutions of this model allows for different possibilities for the spatial distribution of cargo vesicles, ranging from homogeneous distribution of vesicles to polarized distributions, characterized by inhomogeneities or {\\it shocks}. Current reversals due to internal regulation emerge naturally within the framework of this model. We believe this minimal model will clarify the understanding of many features of collective vesicle transport, apart from serving as the basis for building more exact quantitative models for vesicle transport relevant to various {\\it in-vivo} situations.
An Interactive Course in Numerical Methods for the Earth Susan E. Allen
Stockie, John
are typically in physics, mathematics, chemistry, biology or geography, and exposure to numerical computing science are becoming more and more dependent on numerical simulation, modelling, and computationally courses in numerical methods using MatlabTM as the programming language, or a graduate-level mathematics
A mathematical model for countercurrent moving-bed activated carbon adsorption
Anderson, Douglas Harold
1976-01-01
effluent from a wastewater treatment plant. CHAPTER II LITERATURE REVIEW Activated carbon removes substances from water by adsorption, which is the physical attachment of a mole- cule to a surface. The attractive forces are van der Waal's forces... treatment. Among these are: 1. Capable of removing organic contamination to minimal concentration; 2. No additional disposal or pollutional problems are created; 3. Excess capacity in the carbon beds can effec- tively process unexpected impurity...
Using GIS and Spatial Modeling to Examine Active Travel Potential in a University Town
Rybarczyk, Greg
2014-11-19
retention ? Universities are microcosms of society Greg Rybarczyk, Ph.D. 3 ?Universities and Active Transportation ? Benefits of increasing walking, bicycling, and mass transit utilization among a university population ? Reduce environmental externalities... ? Bicycle facilities ? Traffic Calming ? Programming ? City-wide partnerships ? Reducing parking demand ? Courses Greg Rybarczyk, Ph.D. 5 6Greg Rybarczyk, Ph.D. ?What about spatial and aspatial factors at the trip- origin? ? Neighborhood conditions ? Family...
RELAP-7 Numerical Stabilization: Entropy Viscosity Method
R. A. Berry; M. O. Delchini; J. Ragusa
2014-06-01
The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL's modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5's capability and extends the analysis capability for all reactor system simulation scenarios. RELAP-7 utilizes a single phase and a novel seven-equation two-phase flow models as described in the RELAP-7 Theory Manual (INL/EXT-14-31366). The basic equation systems are hyperbolic, which generally require some type of stabilization (or artificial viscosity) to capture nonlinear discontinuities and to suppress advection-caused oscillations. This report documents one of the available options for this stabilization in RELAP-7 -- a new and novel approach known as the entropy viscosity method. Because the code is an ongoing development effort in which the physical sub models, numerics, and coding are evolving, so too must the specific details of the entropy viscosity stabilization method. Here the fundamentals of the method in their current state are presented.