An implicit finite-element model for 3D non-hydrostatic mesoscale ocean M.A. Maidana1
Politècnica de Catalunya, Universitat
An implicit finite-element model for 3D non-hydrostatic mesoscale ocean flows M.A. Maidana1 , J-dimensional, non-hydrostatic mesoscale ocean flows. The model considered here incorporates surface wind stress and the idea of using unstructured grids for modelling mesoscale ocean dynamics sounds very attractive given
Mesoscale Modeling Spring Semester 2014
ATS730 Mesoscale Modeling Spring Semester 2014 Meeting Times: T/TH: 9-10:15am Room: ATS 101 is to present the development of the basic equations used in mesoscale models, as well as the various methods than on actual simulations of mesoscale phenomena or the evaluation of specific mesoscale models
4, 54555514, 2004 Mesoscale modeling
Paris-Sud XI, Université de
ACPD 4, 54555514, 2004 Mesoscale modeling of combined aerosol and photo-oxidant processes M Union 2004 Atmospheric Chemistry and Physics Discussions Mesoscale modeling of combined aerosol5514, 2004 Mesoscale modeling of combined aerosol and photo-oxidant processes M. Lazaridis et al. Title Page
Mesoscale ocean dynamics modeling
mHolm, D.; Alber, M.; Bayly, B.; Camassa, R.; Choi, W.; Cockburn, B.; Jones, D.; Lifschitz, A.; Margolin, L.; Marsden, L.; Nadiga, B.; Poje, A.; Smolarkiewicz, P. [Los Alamos National Lab., NM (United States); Levermore, D. [Arizona Univ., Tucson, AZ (United States)
1996-05-01T23:59:59.000Z
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The ocean is a very complex nonlinear system that exhibits turbulence on essentially all scales, multiple equilibria, and significant intrinsic variability. Modeling the ocean`s dynamics at mesoscales is of fundamental importance for long-time-scale climate predictions. A major goal of this project has been to coordinate, strengthen, and focus the efforts of applied mathematicians, computer scientists, computational physicists and engineers (at LANL and a consortium of Universities) in a joint effort addressing the issues in mesoscale ocean dynamics. The project combines expertise in the core competencies of high performance computing and theory of complex systems in a new way that has great potential for improving ocean models now running on the Connection Machines CM-200 and CM-5 and on the Cray T3D.
LMD Martian Mesoscale Model User Manual
Spiga, Aymeric
LMD Martian Mesoscale Model [LMD-MMM] User Manual A. Spiga aymeric.spiga@upmc.fr Laboratoire de;#12;Contents 1 What is the LMD Martian Mesoscale Model? 3 1.1 Dynamical core on mesoscale levels . . . . . . . . . . . . . . . 35 iii #12;iv User Manual for the LMD Martian Mesoscale Model
Sleep Dynamics and Seizure Control in a Mesoscale Cortical Model
Lopour, Beth Ann
2009-01-01T23:59:59.000Z
Contributions . . . . . . . . . 2 Mesoscale Cortical Modelstates in h e from the mesoscale cortical model, here- afterand Seizure Control in a Mesoscale Cortical Model by Beth
Mesoscale Model Development and the Meteorological Community
Mass, Clifford F.
Mesoscale Model Development and the Meteorological Community Cliff Mass University of Washington: Although the U.S. remains a leader in mesoscale model development and application, the community is not fulfilling its potential. The resources of the U.S. mesoscale forecasting community are considerable
MESOSCALE AVERAGING OF NUCLEATION AND GROWTH MODELS
Burger, Martin
MESOSCALE AVERAGING OF NUCLEATION AND GROWTH MODELS MARTIN BURGER , VINCENZO CAPASSO , AND LIVIO-Kolmogorov relations for the degree of crystallinity. By relating the computation of expected values to mesoscale averaging, we obtain a suitable description of the process at the mesoscale. We show how the variance
Analytical mesoscale modeling of aeolian sand transport
Marc Lämmel; Anne Meiwald; Klaus Kroy
2014-05-03T23:59:59.000Z
We analyze the mesoscale structure of aeolian sand transport, based on a recently developed two-species continuum model. The calculated sand flux and important average characteristics of the grain trajectories are found to be in remarkable agreement with field and wind-tunnel data. We conclude that the essential mesoscale physics is insensitive to unresolved details on smaller scales and well captured by the coarse-grained analytical model, thus providing a sound basis for precise and numerically efficient mesoscale modeling of aeolian structure formation.
AN URBAN SURFACE EXCHANGE PARAMETERISATION FOR MESOSCALE MODELS
AN URBAN SURFACE EXCHANGE PARAMETERISATION FOR MESOSCALE MODELS ALBERTO MARTILLI1, , ALAIN CLAPPIER. A scheme to represent the impact of urban buildings on airflow in mesoscale atmospheric models is presented the presence of the buildings. The parameterisation is introduced into a mesoscale model and tested
A Mesoscale Diffusion Model in Population Genetics with
O'Leary, Michael
' & $ % A Mesoscale Diffusion Model in Population Genetics with Dynamic Fitness Mike O'Leary Towson University Judith R. Miller Georgetown University 1 #12;A mesoscale diffusion model in population genetics that dominance and epistasis are absent. April 28, 2005 Mike O'Leary and Judith Miller Slide 2 #12;A mesoscale
Identification of a mesoscale model with multiscale experimental observations
Paris-Sud XI, Université de
Identification of a mesoscale model with multiscale experimental observations M.T. Nguyen, C and at mesoscale within the framework of a heterogeneous microstruc- ture which is modeled by a random elastic measurements of the displacement fields at macroscale and at mesoscale performed with only a single specimen
A study of mesoscale gravity waves over the North Atlantic with satellite observations and a mesoscale model Dong L. Wu Jet Propulsion Laboratory, California Institute of Technology, Pasadena and compare AMSU-A observations to simulations from a mesoscale model (MM5). The simulated gravity waves
Impact of Agricultural Practice on Regional Climate in a Coupled Land Surface Mesoscale Model
Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.
2004-01-01T23:59:59.000Z
winter wheat belt on the mesoscale environment, Monthlygeneration Penn State/NCAR mesoscale model (MM5), NCAR,in a Coupled Land Surface Mesoscale Model H.S. Cooley Energy
Rotational and divergent kinetic energy in the mesoscale model ALADIN
Zagar, Nedjeljka
energy, divergent energy, ALADIN, limited-area modelling 1. Introduction Horizontal divergenceRotational and divergent kinetic energy in the mesoscale model ALADIN By V. BLAZ ICA1 *, N. Z AGAR1 received 7 June 2012; in final form 7 March 2013) ABSTRACT Kinetic energy spectra from the mesoscale
Mesoscale modelling of polyelectrolyte electrophoresis
Kai Grass; Christian Holm
2009-02-11T23:59:59.000Z
The electrophoretic behaviour of flexible polyelectrolyte chains ranging from single monomers up to long fragments of hundred repeat units is studied by a mesoscopic simulation approach. Abstracting from the atomistic details of the polyelectrolyte and the fluid, a coarse-grained molecular dynamics model connected to a mesoscopic fluid described by the Lattice Boltzmann approach is used to investigate free-solution electrophoresis. Our study demonstrates the importance of hydrodynamic interactions for the electrophoretic motion of polyelectrolytes and quantifies the influence of surrounding ions. The length-dependence of the electrophoretic mobility can be understood by evaluating the scaling behavior of the effective charge and the effective friction. The perfect agreement of our results with experimental measurements shows that all chemical details and fluid structure can be safely neglected, and a suitable coarse-grained approach can yield an accurate description of the physics of the problem, provided that electrostatic and hydrodynamic interactions between all entities in the system, i.e., the polyelectrolyte, dissociated counterions, additional salt and the solvent, are properly accounted for. Our model is able to bridge the single molecule regime of a few nm up to macromolecules with contour lengths of more than 100 nm, a length scale that is currently not accessible to atomistic simulations.
Schlick, Tamar
Constructing Irregular Surfaces to Enclose Macromolecular Complexes for Mesoscale Modeling Using proteins. DiSCO is generally applicable to other interesting macromolecular systems for which mesoscale
Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle are derived either at microscale with random distribution of material properties or at a mesoscale
Modeling of passive microwave responses in convective situations using output from mesoscale models
Pardo-Carrión, Juan R.
Modeling of passive microwave responses in convective situations using output from mesoscale models using output from nonhydrostatic mesoscale atmospheric model, Meso-NH, simulations. The radiative for a systematic evaluation of the mesoscale cloud models. An overall good agreement is obtained for both
MPMM: A Massively Parallel Mesoscale Model
Foster, I.; Michalakes, J.
1992-12-31T23:59:59.000Z
Static domain decomposition is a technique that provides a quick path to porting atmospheric models on distributed memory parallel computers. However, parallel inefficiencies in the form of load imbalances and ill-tuned communication are difficult to correct without complicated and explicit recoding. Reconfiguring the code to run on larger or smaller numbers of processors may require recompiling. Modularity and machine independence may also suffer. If full advantage is to be taken of Massively Parallel Processing (MPP) technology, tools and techniques that allow for dynamic performance tuning and reconfiguration are required. Program Composition Notation (PCN) is a language and run-time system for expressing parallel programs developed at Argonne and at the California Institute of Technology. It provides an intermediate layer between the application program and the physical processors of a computer. It allows the model to be statically decomposed over a virtual machine, but this virtual machine can be mapped and remapped dynamically over the physical computer. Programs are portable to as many machines as PCN itself, modularity is easily preserved, and communication tuning for a particular computer is encapsulated within the PCN run-time system. In this paper we report on a project at Argonne National Laboratory to parallelize the Penn State/NCAR Mesoscale Model version 5 using a fine grain decomposition dynamically mapped and managed under PCN.
Daniels, Megan Hanako
2010-01-01T23:59:59.000Z
groundwater, land-surface, and mesoscale atmospheric model-and modification of mesoscale circulations. , Mon. Wea.J. Davis, The effects of mesoscale surface heterogeneity on
Boyer, Edmond
2003-01-01T23:59:59.000Z
Intercomparison of mesoscale meteorological models for precipitation forecasting 799 Hydrology and Earth System Sciences, 7(6), 799811 (2003) © EGU Intercomparison of mesoscale meteorological models
Author's personal copy Mesoscale modeling of electric double layer capacitors with three-dimensional
Pilon, Laurent
Author's personal copy Mesoscale modeling of electric double layer capacitors with three Mesoscale modeling Mesoporous electrodes a b s t r a c t This paper presents general mathematical
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
Schlegel, Nicole-Jeanne
2011-01-01T23:59:59.000Z
ice sheet model with a mesoscale climate model By Nicole-ice sheet model with a mesoscale climate model Copyrightice sheet model with a mesoscale climate model by Nicole-
Modeled biogeochemical responses to mesoscale eddies in the South China Sea
Maine, University of
Modeled biogeochemical responses to mesoscale eddies in the South China Sea Peng Xiu1 and Fei Chai1] Mesoscale eddies are observed each year in the South China Sea (SCS); however, their contributions physicalbiogeochemical model to evaluate the eddy impact. We first track the modeled mesoscale eddies in the SCS
Development of the Flux-Adjusting Surface Data Assimilation System for Mesoscale Models
Niyogi, Dev
Development of the Flux-Adjusting Surface Data Assimilation System for Mesoscale Models KIRAN and temperature and for surface air temperature and water vapor mixing ratio for mesoscale models. In the FASDAS-field variables. The FASDAS is coupled to a land surface submodel in a three-dimensional mesoscale model and tests
Mesoscale Modeling of a Li-Ion Polymer Cell Chia-Wei Wanga,
Sastry, Ann Marie
Mesoscale Modeling of a Li-Ion Polymer Cell Chia-Wei Wanga, * and Ann Marie Sastrya,b,c, *,z, the study reported critical data required for mesoscale numerical simulation, including ionic con- ductivity
Elliott, James
Mesoscale modeling of electrical percolation in fiber-filled systems Sameer S. Rahatekar and Marc online 4 October 2005 The research described in this paper primarily involves mesoscale simulations
A Diagnostic Suite of Models for the Evaluation of Oceanic Mesoscale Eddy Parameterizations
Fox-Kemper, Baylor
A Diagnostic Suite of Models for the Evaluation of Oceanic Mesoscale Eddy Parameterizations by S. D of Oceanic Mesoscale Eddy Parameterizations written by S. D. Bachman has been approved for the Department and Oceanic Sciences) A Diagnostic Suite of Models for the Evaluation of Oceanic Mesoscale Eddy
MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN
Pielke, Roger A.
MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN (ReviewArticle) Y. MAHRER.1. OBSERVATIONALAPPROACHES Evaluations of wind energy based on wind observations (usually surface winds) at well, the resolution of the wind energy pattern throughout an extended area by this methodology requires a large number
Wind resource assessment with a mesoscale non-hydrostatic model
Boyer, Edmond
Wind resource assessment with a mesoscale non- hydrostatic model Vincent Guénard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k
WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO-AND MESOSCALE MODELLING
sets for evaluating the potential wind power output from large electricity-producing wind turbine and accurate wind atlas data sets for evaluating the potential wind power output from large electricityWIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO- AND MESOSCALE MODELLING Niels G. Mortensen1 , Jens
Cai, Wei
1995-01-01T23:59:59.000Z
Atomistic and Mesoscale Modeling of Dislocation Mobility by Wei Cai B.S., Huazhong University by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sow-Hsin Chen Chairman, Department Committee on Graduate Students #12;2 #12;Atomistic and Mesoscale theories and simulations of dislocations in Si and BCC transition metals, with emphasis on the atomistic-mesoscale
DETECTING AND TRACKING OF MESOSCALE OCEANIC FEATURES IN THE MIAMI ISOPYCNIC CIRCULATION OCEAN MODEL
Tandon, Amit
DETECTING AND TRACKING OF MESOSCALE OCEANIC FEATURES IN THE MIAMI ISOPYCNIC CIRCULATION OCEAN MODEL developed to automatically detect, locate and track mesoscale eddies spatially and temporally. Using an invaluable tool to assess mesoscale oceanic features. Key Words Scientific Visualization, Eddy Detection
Mesoscale Modeling of LX-17 Under Isentropic Compression
Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S; Baer, M R
2010-03-06T23:59:59.000Z
Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the lower density TATB adiabatic EOS data demonstrated the least agreement with VISAR velocity data.
Mesoscale modeling of metal-loaded high explosives
Bdzil, John Bohdan [Los Alamos National Laboratory; Lieberthal, Brandon [UNIV OF ILLINOIS; Srewart, Donald S [UNIV OF ILLINOIS
2010-01-01T23:59:59.000Z
We describe a 3D approach to modeling multi-phase blast explosive, which is primarily condensed explosive by volume with inert embedded particles. These embedded particles are uniform in size and placed on the array of a regular lattice. The asymptotic theory of detonation shock dynamics governs the detonation shock propagation in the explosive. Mesoscale hydrodynamic simulations are used to show how the particles are compressed, deformed, and accelerated by the high-speed detonation products flow.
Hogan, Robin
in Evaluating a Mesoscale Model ROBIN J. HOGAN, MARION P. MITTERMAIER,* AND ANTHONY J. ILLINGWORTH Department-GHz radar with the values held in the Met Office mesoscale forecast model, for eight precipitating
Niyogi, Dev
(GEM) for Mesoscale Weather Forecasting Applications DEV NIYOGI Department of Agronomy, and Department form 13 May 2008) ABSTRACT Current land surface schemes used for mesoscale weather forecast models use model (GEM) as a land surface scheme for mesoscale weather forecasting model applications. The GEM
Mesoscale modeling of colloidal suspensions with adsorbing solutes
Rei Tatsumi; Osamu Koike; Yukio Yamaguchi
2015-01-14T23:59:59.000Z
We construct a mesoscale model of colloidal suspensions that contain solutes reversibly adsorbing onto the colloidal particle surfaces. The present model describes the coupled dynamics of the colloidal particles, the host fluid, and the solutes through the Newton-Euler equations of motion, the hydrodynamic equations, and the advection-diffusion equation, respectively. The solute adsorption is modeled through a square-well potential, which represents a short-range attractive interaction between a particle and a solute molecule. The present model is formulated to be solved through direct numerical simulations. Some numerical results are presented to validate the simulations. The present model enables investigations of solute adsorption effects in the presence of a fluid flow and an inhomogeneous solute concentration distribution.
Strain in the mesoscale kinetic Monte Carlo model for sintering
Bjørk, R; Tikare, V; Olevsky, E; Pryds, N
2014-01-01T23:59:59.000Z
Shrinkage strains measured from microstructural simulations using the mesoscale kinetic Monte Carlo (kMC) model for solid state sintering are discussed. This model represents the microstructure using digitized discrete sites that are either grain or pore sites. The algorithm used to simulate densification by vacancy annihilation removes an isolated pore site at a grain boundary and collapses a column of sites extending from the vacancy to the surface of sintering compact, through the center of mass of the nearest grain. Using this algorithm, the existing published kMC models are shown to produce anisotropic strains for homogeneous powder compacts with aspect ratios different from unity. It is shown that the line direction biases shrinkage strains in proportion the compact dimension aspect ratios. A new algorithm that corrects this bias in strains is proposed; the direction for collapsing the column is determined by choosing a random sample face and subsequently a random point on that face as the end point for...
Niyogi, Dev
and Indian monsoon precipitation -- A mesoscale modeling perspective E.M. Douglas a, , A. Beltrán-Przekurat b convergence, mesoscale convection, and precipitation patterns over the Indian monsoon region. Four experiments pattern and changes in mesoscale precipitation. These agricultural changes, including irrigation modify
Smith, K. Shafer
Mesoscale Eddy Energy Locality in an Idealized Ocean Model IAN GROOMS, LOUIS-PHILIPPE NADEAU, AND K investigates the energy budget of mesoscale eddies in wind-driven two-layer quasigeostrophic simulations of eddy energy are ``nonlocal.'' Many mesoscale parameterizations assume that statistics of the unresolved
Isolating the role of mesoscale eddies in mixing of a passive tracer in an eddy resolving model
Miami, University of
Isolating the role of mesoscale eddies in mixing of a passive tracer in an eddy resolving model February 2008; published 16 May 2008. [1] This study examines the role of mesoscale eddies in distribution was replaced by a down-gradient diffusive parameterization. Our results demonstrate that advection by mesoscale
MESOSCALE DESCRIPTION OF DEFECTED MATERIALS
Vinals, Jorge
MESOSCALE DESCRIPTION OF DEFECTED MATERIALS Jorge Vi~nals School of Physics and Astronomy. Laughlin) Small but finite wavenumber and finite frequency ("mesoscale") response functions and transport;MESOSCALE DESCRIPTION B B B B B B B A B A B A A B B A A A A BB A B Microscopic Mesoscopic Macroscopic vn
Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor
Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.
2002-01-01T23:59:59.000Z
boundary conditions for the mesoscale landfill bioreactor. (and Biodegradation in a Mesoscale Landfill Bioreactor Curtisapplied it to our own mesoscale laboratory aerobic landfill
Meso-scale eects of tropical deforestation in Amazonia: preparatory LBA modelling studies
Paris-Sud XI, UniversitÃ© de
Meso-scale eects of tropical deforestation in Amazonia: preparatory LBA modelling studies A. J forest is good, above deforested areas (pasture) poor. The models' underestimate of the temperature Modelling studies with general circulation models have shown that large-scale deforestation of the Amazon
Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment
Avramov, A.; Harringston, J.Y.; Verlinde, J.
2005-03-18T23:59:59.000Z
Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic (Curry et al. 2000) and through various feedback mechanisms exert a strong influence on the Arctic climate. Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. It has been hypothesized that mixed-phase clouds are maintained through a balance between liquid water condensation resulting from the cloud-top radiative cooling and ice removal by precipitation (Pinto 1998; Harrington et al. 1999). In their modeling study Harrington et al. (1999) found that the maintenance of this balance depends strongly on the ambient concentration of ice forming nucleus (IFN). In a follow-up study, Jiang et al. (2002), using only 30% of IFN concentration predicted by Meyers et al. (1992) IFN parameterization were able to obtain results similar to the observations reported by Pinto (1998). The IFN concentration measurements collected during the Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004 over the North Slope of Alaska and the Beaufort Sea (Verlinde et al. 2005), also showed much lower values then those predicted (Prenne, pers. comm.) by currently accepted ice nucleation parameterizations (e.g. Meyers et al. 1992). The goal of this study is to use the extensive IFN data taken during M-PACE to examine what effects low IFN concentrations have on mesoscale cloud structure and coastal dynamics.
Niyogi, Dev
Assimilation on a Mesoscale Model Simulation of an Indian Monsoon Depression VINODKUMAR AND A. CHANDRASEKAR-generation Pennsylvania State UniversityNCAR Mesoscale Model (MM5) simulation utilized the humidity and temperature
Takada, Shoji
A Simple Water Balance Model for a Mesoscale Catchment Based on Heterogeneous Soil Water Storage Capacity, for the mesoscale catchments of Japan and Thailand. Sensitivity analysis of the model parameters has been conducted
Mesoscale coupled ocean-atmosphere interaction
Seo, Hyodae
2007-01-01T23:59:59.000Z
2000: A Coupled Air-Sea Mesoscale Model: Experiments inWind Stress Curl from a Mesoscale Model. Mon. Wea. Rev. ,2006: Effect of Ocean Mesoscale Variability on the Mean
Mesoscale Coupled Ocean-Atmosphere Interaction
Seo, Hyodae
2007-01-01T23:59:59.000Z
2000: A Coupled Air-Sea Mesoscale Model: Experiments inWind Stress Curl from a Mesoscale Model. Mon. Wea. Rev. ,2006: Effect of Ocean Mesoscale Variability on the Mean
Harting, Jens
Steering in computational science: mesoscale modelling and simulation J. CHIN{, J. HARTING{, S. JHA steering for high performance computing applications. Lattice-Boltzmann mesoscale fluid simulations, there is currently considerable interest in mesoscale models. These models coarse grain most of the atomic
Meng, Zhiyong
Tests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II In Part I of this two-part work, the feasibility of using an ensemble Kalman filter (EnKF) for mesoscale that using an ensemble Kalman filter (EnKF) in the context of a perfect model (i.e., both the truth
Chaboureau, Jean-Pierre
Mesoscale model cloud scheme assessment using satellite observations Jean-Pierre Chaboureau, Jean of the mesoscale nonhydrostatic (Meso-NH) model has been conducted by comparing synthetic METEOSAT brightness combines the output from a bulk explicit cloud scheme routinely used in mesoscale simulations
Mesoscale modelling for an offshore wind farm Jake Badger*, Rebecca Barthelmie, Sten Frandsen for an offshore wind farm in a coastal location. Spatial gradients and vertical profiles between 25 m and 70 m offshore wind farms tend to be placed within the coastal zone, the region within around 50km from
Madeleine, Jean-Baptiste
THE LMD MESOSCALE MODEL. J.-B. Madeleine1 , J. W. Head1 , A. Spiga2 , J. L. Dickson1 and F. Forget2 , 1 formed, using geolog- ical observations [e.g., 1-4] and mesoscale climate simulations [5 provide essential constraints on the mesoscale climate which prevailed during their formation
Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.
2014-06-01T23:59:59.000Z
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.
Burian, S. J. (Steven J.); Brown, M. J. (Michael J.); Ching, J. (Jason); Cheuk, M. L. (Mang Lung); Yuan, M. (May); McKinnon, A. T. (Andrew T.); Han, W. S. (Woo Suk)
2004-01-01T23:59:59.000Z
Accurate predictions of air quality and atmospheric dispersion at high spatial resolution rely on high fidelity predictions of mesoscale meteorological fields that govern transport and turbulence in urban areas. However, mesoscale meteorological models do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in and around buildings and other urban structures that have been shown to modify micro- and mesoscale flow fields (e.g., see review by Bornstein 1987). Mesoscale models therefore have been adapted using numerous approaches to incorporate urban effects into the simulations (e.g., see reviews by Brown 2000 and Bornstein and Craig 2002). One approach is to introduce urban canopy parameterizations to approximate the drag, turbulence production, heating, and radiation attenuation induced by sub-grid scale buildings and urban surface covers (Brown 2000). Preliminary results of mesoscale meteorological and air quality simulations for Houston (Dupont et al. 2004) demonstrated the importance of introducing urban canopy parameterizations to produce results with high spatial resolution that accentuates variability, highlights important differences, and identifies critical areas. Although urban canopy parameterizations may not be applicable to all meteorological and dispersion models, they have been successfully introduced and demonstrated in many of the current operational and research mode mesoscale models, e.g., COAMPS (Holt et al. 2002), HOTMAC (Brown and Williams 1998), MM5 (e.g., Otte and Lacser 2001; Lacser and Otte 2002; Dupont et al. 2004), and RAMS (Rozoff et al. 2003). The primary consequence of implementing an urban parameterization in a mesoscale meteorological model is the need to characterize the urban terrain in greater detail. In general, urban terrain characterization for mesoscale modeling may be described as the process of collecting datasets of urban surface cover physical properties (e.g., albedo, emissivity) and morphology (i.e., ground elevation, building and tree height and geometry characteristics) and then processing the data to compute physical cover and morphological parameters. Many of the surface cover and morphological parameters required for mesoscale meteorological models are also needed by atmospheric dispersion models. Thus, most of the discussion below is relevant to both types of modeling. In this paper, the term urban morphological analysis will be used to define the component of urban terrain characterization concerned with the morphological parameters. Furthermore, the focus will be building morphological parameters; therefore, the term urban morphological analysis will refer exclusively to the task of inventorying, computing or estimating building morphological parameters. Several approaches to perform urban morphological analysis exist; however, all have in common three types of practice issues related to the uncertainty of (1) data, (2) parameter definitions and calculation methods, and (3) extrapolation techniques. The objective of this paper is to describe the state-of-the-practice of urban morphological analysis by reviewing the primary approaches presented in the literature and outlining and commenting on key aspects of the three types of practice issues listed above.
Development and validation of a vertically two-dimensional mesoscale numerical model
Walters, Michael Kent
1985-01-01T23:59:59.000Z
values of model variables for static test and kinetic energy calculations . . . . . . . . . 25 2 Results of kinetic energy budget calculations . . 29 ? 1 -5 Surface heating rate (K s x 10 ) . . . . . . . 32 4 Initial values of variables for nonlinear.... These tests provide an important means of debugging the numerical scheme. The validation tests performed on the mesoscale model consisted of a simple static test, calculation of the mass continuity and the kinet. ic energy budget, and performing non...
MESO-SCALE MODELING OF THE INFLUENCE OF INTERGRANULAR GAS BUBBLES ON EFFECTIVE THERMAL CONDUCTIVITY
Paul C. Millett; Michael Tonks
2011-06-01T23:59:59.000Z
Using a mesoscale modeling approach, we have investigated how intergranular fission gas bubbles, as observed in high-burnup nuclear fuel, modify the effective thermal conductivity in a polycrystalline material. The calculations reveal that intergranular porosity has a significantly higher resistance to heat transfer compared to randomly-distributed porosity. A model is developed to describe this conductivity reduction that considers an effective grain boundary Kapitza resistance as a function of the fractional coverage of grain boundaries by bubbles.
Massively parallel implementation of the Penn State/NCAR Mesoscale Model
Foster, I.; Michalakes, J.
1992-12-01T23:59:59.000Z
Parallel computing promises significant improvements in both the raw speed and cost performance of mesoscale atmospheric models. On distributed-memory massively parallel computers available today, the performance of a mesoscale model will exceed that of conventional supercomputers; on the teraflops machines expected within the next five years, performance will increase by several orders of magnitude. As a result, scientists will be able to consider larger problems, more complex model processes, and finer resolutions. In this paper. we report on a project at Argonne National Laboratory that will allow scientists to take advantage of parallel computing technology. This Massively Parallel Mesoscale Model (MPMM) will be functionally equivalent to the Penn State/NCAR Mesoscale Model (MM). In a prototype study, we produced a parallel version of MM4 using a static (compile-time) coarse-grained ``patch`` decomposition. This code achieves one-third the performance of a one-processor CRAY Y-MP on twelve Intel 1860 microprocessors. The current version of MPMM is based on all MM5 and uses a more fine-grained approach, decomposing the grid as finely as the mesh itself allows so that each horizontal grid cell is a parallel process. This will allow the code to utilize many hundreds of processors. A high-level language for expressing parallel programs is used to implement communication strearns between the processes in a way that permits dynamic remapping to the physical processors of a particular parallel computer. This facilitates load balancing, grid nesting, and coupling with graphical systems and other models.
Massively parallel implementation of the Penn State/NCAR Mesoscale Model
Foster, I.; Michalakes, J.
1992-01-01T23:59:59.000Z
Parallel computing promises significant improvements in both the raw speed and cost performance of mesoscale atmospheric models. On distributed-memory massively parallel computers available today, the performance of a mesoscale model will exceed that of conventional supercomputers; on the teraflops machines expected within the next five years, performance will increase by several orders of magnitude. As a result, scientists will be able to consider larger problems, more complex model processes, and finer resolutions. In this paper. we report on a project at Argonne National Laboratory that will allow scientists to take advantage of parallel computing technology. This Massively Parallel Mesoscale Model (MPMM) will be functionally equivalent to the Penn State/NCAR Mesoscale Model (MM). In a prototype study, we produced a parallel version of MM4 using a static (compile-time) coarse-grained patch'' decomposition. This code achieves one-third the performance of a one-processor CRAY Y-MP on twelve Intel 1860 microprocessors. The current version of MPMM is based on all MM5 and uses a more fine-grained approach, decomposing the grid as finely as the mesh itself allows so that each horizontal grid cell is a parallel process. This will allow the code to utilize many hundreds of processors. A high-level language for expressing parallel programs is used to implement communication strearns between the processes in a way that permits dynamic remapping to the physical processors of a particular parallel computer. This facilitates load balancing, grid nesting, and coupling with graphical systems and other models.
THE APPLICATION OF AN EVOLUTIONARY ALGORITHM TO THE OPTIMIZATION OF A MESOSCALE METEOROLOGICAL MODEL
Werth, D.; O'Steen, L.
2008-02-11T23:59:59.000Z
We show that a simple evolutionary algorithm can optimize a set of mesoscale atmospheric model parameters with respect to agreement between the mesoscale simulation and a limited set of synthetic observations. This is illustrated using the Regional Atmospheric Modeling System (RAMS). A set of 23 RAMS parameters is optimized by minimizing a cost function based on the root mean square (rms) error between the RAMS simulation and synthetic data (observations derived from a separate RAMS simulation). We find that the optimization can be efficient with relatively modest computer resources, thus operational implementation is possible. The optimization efficiency, however, is found to depend strongly on the procedure used to perturb the 'child' parameters relative to their 'parents' within the evolutionary algorithm. In addition, the meteorological variables included in the rms error and their weighting are found to be an important factor with respect to finding the global optimum.
Patrick B. Warren; Andrey Vlasov
2014-02-25T23:59:59.000Z
We extend our previous study [J. Chem. Phys. 138, 204907 (2013)] to quantify the screening properties of four mesoscale smoothed charge models used in dissipative particle dynamics. Using a combination of the hypernetted chain integral equation closure and the random phase approximation, we identify regions where the models exhibit a real-valued screening length, and the extent to which this agrees with the Debye length in the physical system. We find that the second moment of the smoothed charge distribution is a good predictor of this behaviour. We are thus able to recommend a consistent set of parameters for the models.
Moist processes and the quasi-hydrostatic approximation in a mesoscale numerical model
Kennedy, Charles Joseph
1987-01-01T23:59:59.000Z
of Committee) James P. McGuirk (Member) J'ohn M. Klinck (Member) James R. Sco ns (Head of Department) December 1987 ABSTRACT Moist Processes and the Ouasi-Hydrostatic Approximation in a Mesoscale Numerical Model. (December 1987) Charles Joseph...HV)ds' ? gHp s + gHps a dg 1 gt = (gt), s 1 1 (19) the pressure tendency at the model top equation: g f V ~ (pHV)ds' ? VS Vp Q ( el 1 + 0 Yp CpT ? V (H0) ds' )' ? ) (20) Richardson's equation for vertical motion: s f , , f Id d'D &DDVdd ' ? 0 D, 0...
Fridlind, Ann
jcl92c.tex The Importance of Mesoscale Circulations Generated by SubgridScale Landscape Oceanography, Cook Campus, Rutgers University, New Brunswick, NJ 08903, USA. #12; Abstract A mesoscale. These results emphasize the need to parameterize mesoscale processes induced by landscape discontinuities
Calibrated Probabilistic Mesoscale Weather Field Forecasting: The Geostatistical Output Perturbation
Washington at Seattle, University of
Calibrated Probabilistic Mesoscale Weather Field Forecasting: The Geostatistical Output. This is typically not feasible for mesoscale weather prediction carried out locally by organizations without by simulating realizations of the geostatistical model. The method is applied to 48-hour mesoscale forecasts
Mesoscale Eddies in the Gulf of Alaska: Observations and Implications
Rovegno, Peter
2012-01-01T23:59:59.000Z
Chao, Y. 2012. Modeling the mesoscale eddy field in the GulfShriver, J. F. 2001. Mesoscale variability in the boundaryof the Gulf of Alaska mesoscale circulation. Progress in
The lipid bilayer at the mesoscale: a physical continuum model
Phillip L. Wilson; Huaxiong Huang; Shu Takagi
2008-02-26T23:59:59.000Z
We study a continuum model of the lipid bilayer based on minimizing the free energy of a mixture of water and lipid molecules. This paper extends previous work by Blom & Peletier (2004) in the following ways. (a) It formulates a more physical model of the hydrophobic effect to facilitate connections with microscale simulations. (b) It clarifies the meaning of the model parameters. (c) It outlines a method for determining parameter values so that physically-realistic bilayer density profiles can be obtained, for example for use in macroscale simulations. Points (a)-(c) suggest that the model has potential to robustly connect some micro- and macroscale levels of multiscale blood flow simulations. The mathematical modelling in point (a) is based upon a consideration of the underlying physics of inter-molecular forces. The governing equations thus obtained are minimized by gradient flows via a novel numerical approach; this enables point (b). The numerical results are shown to behave physically in terms of the effect of background concentration, in contrast to the earlier model which is shown here to not display the expected behaviour. A "short-tail" approximation of the lipid molecules also gives an analytical tool which yields critical values of some parameters under certain conditions. Point (c) involves the first quantitative comparison of the numerical data with physical experimental results.
Mesoscale modeling of phase transition dynamics of thermoresponsive polymers
Li, Zhen; Li, Xuejin; Karniadakis, George Em
2015-01-01T23:59:59.000Z
We present a non-isothermal mesoscopic model for investigation of the phase transition dynamics of thermoresponsive polymers. Since this model conserves energy in the simulations, it is able to correctly capture not only the transient behavior of polymer precipitation from solvent, but also the energy variation associated with the phase transition process. Simulations provide dynamic details of the thermally induced phase transition and confirm two different mechanisms dominating the phase transition dynamics. A shift of endothermic peak with concentration is observed and the underlying mechanism is explored.
Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics
Persson, Rasmus A. X.; Chu, Jhih-Wei, E-mail: jwchu@nctu.edu.tw [Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Voulgarakis, Nikolaos K. [Department of Mathematics, Washington State University, Richland, Washington 99372 (United States)
2014-11-07T23:59:59.000Z
Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ? in coupling to the other equations of FHD. The resulting ?-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ?-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ?-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 Å, the ?-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.
Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer Turbulence
Wang, Yao; Manuel, Lance
2013-01-01T23:59:59.000Z
Site-specific flow and turbulence information are needed for various practical applications, ranging from aerodynamic/aeroelastic modeling for wind turbine design to optical diffraction calculations. Even though highly desirable, collecting on-site meteorological measurements can be an expensive, time-consuming, and sometimes a challenging task. In this work, we propose a coupled mesoscale-large-eddy modeling framework to synthetically generate site-specific flow and turbulence data. The workhorses behind our framework are a state-of-the-art, open-source atmospheric model called the Weather Research and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES) model. Using this coupled framework, we simulate a nighttime stable boundary layer (SBL) case from the well-known CASES-99 field campaign. One of the unique aspects of this work is the usage of a diverse range of observations for characterization and validation. The coupled models reproduce certain characteristics of observed low-level jets....
Evans, Jason
-level water consumption were more than doubled relative to simulations that did not incorporate MODIS data to improve the realism of a regional climate model (the fifth-generation Pennsylvania State UniversityNCAR Mesoscale Model) with respect to irrigated agriculture. MODIS data were used to estimate spatially
Padding, J T; Auhl, D; Briels, W J; Bailly, C
2011-01-01T23:59:59.000Z
For optimal application, pressure-sensitive adhesives must have rheological properties in between those of a viscoplastic solid and those of a viscoelastic liquid. Such adhesives can be produced by emulsion polymerisation, resulting in latex particles which are dispersed in water and contain long-chain acrylic polymers. When the emulsion is dried, the latex particles coalesce and an adhesive film is formed. The rheological properties of the dried samples are believed to be dominated by the interface regions between the original latex particles, but the relation between rheology and latex particle properties is poorly understood. In this paper we show that it is possible to describe the bulk rheology of a pressure-sensitive adhesive by means of a mesoscale simulation model. To reach experimental time and length scales, each latex particle is represented by just one simulated particle. The model is subjected to oscillatory shear flow and extensional flow. Simple order of magnitude estimates of the model paramet...
Heinemann, Detlev
the wind energy potential are re- quired. While the European Wind Atlas [3] has been proven to be suitableExperiences with the Application of the Non-Hydrostatic Mesoscale Model GESIMA for assessing Wind.physik.uni-oldenburg.de/ehf *GKSS Research Center Geesthacht, Max-Planck-StraÃ?e 1, D-21494 Geesthacht, Germany To asses wind
Numerical modeling of roll structures in mesoscale vortexes over the Black Sea
Iarova, D A
2014-01-01T23:59:59.000Z
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 ...
Finite Element Modeling of Drilling Using DEFORM
Gardner, Joel D.; Dornfeld, David
2006-01-01T23:59:59.000Z
Vijayaraghavan, A. (2005), “Drilling of Fiber- ReinforcedFINITE ELEMENT MODELING OF DRILLING USING DEFORM J. Gardner,of Comprehensive Drilling Simulation Tool” ABSTRACT DEFORM-
Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations
Boyer, Edmond
Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations Part I: Surface Abstract. A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model current. In order to analyze the eect of mesoscale coupling, three simulations are compared: the ®rst one
TENURE-TRACK FACULTY POSITION Mesoscale Meteorology
Birner, Thomas
TENURE-TRACK FACULTY POSITION Mesoscale Meteorology Colorado State University The Department or associate level faculty position specializing in mesoscale meteorology. Exceptionally qualified candidates in linking models and/or theory with observations for the study of mesoscale processes. The successful
Finite difference model of eccentric labyrinth seals
Davis, Fredrick Michael
1993-01-01T23:59:59.000Z
shaft of a turbomachine, such as a gas turbine engine. To achieve the desired pressure drop between sections, the seal is constructed to convert the pressure energy between sections to kinetic energy in the seal where it is dissipated. When the rotor.... . . . . Finite Difference Method. Generating Eccentric Grids. . . . . . . . . . . . . . . . . . . . . . . . . . Generalizing Finite Difference Relations. . . . Accounting for Rotor Whirl. . . . . . Turbulence Model. . Enthalpy Model. . Boundary Conditions...
Lascaux, Franck; Fini, Luca
2015-01-01T23:59:59.000Z
This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...
Ismael Hernández-Carrasco; Vincent Rossi; Emilio Hernández-García; Veronique Garçon; Cristóbal López
2013-11-05T23:59:59.000Z
Recent studies, both based on remote sensed data and coupled models, showed a reduction of biological productivity due to vigorous horizontal stirring in upwelling areas. In order to better understand this phenomenon, we consider a system of oceanic flow from the Benguela area coupled with a simple biogeochemical model of Nutrient-Phyto-Zooplankton (NPZ) type. For the flow three different surface velocity fields are considered: one derived from satellite altimetry data, and the other two from a regional numerical model at two different spatial resolutions. We compute horizontal particle dispersion in terms of Lyapunov Exponents, and analyzed their correlations with phytoplankton concentrations. Our modelling approach confirms that in the south Benguela there is a reduction of biological activity when stirring is increased. Two-dimensional offshore advection and latitudinal difference in Primary Production, also mediated by the flow, seem to be the dominant processes involved. We estimate that mesoscale processes are responsible for 30 to 50% of the offshore fluxes of biological tracers. In the northern area, other factors not taken into account in our simulation are influencing the ecosystem. We suggest explanations for these results in the context of studies performed in other eastern boundary upwelling areas.
Brown, M.J.; Williams, M.D.
1997-04-01T23:59:59.000Z
Since mesoscale numerical models do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in and around urban structures, urban canopy parameterizations are sometimes used to approximate the drag, heating, and enhanced turbulent kinetic energy (tke) produced by the sub-grid scale urban elements. In this paper, we investigate the effect of the urban canopy parameterizations used in the HOTMAC mesoscale meteorological model by turning the parameterizations on and off. The model simulations were performed in the Paso del Norte region, which includes the cities of El Paso and Ciudad Juarez, the Franklin and Sierra Juarez mountains, and the Rio Grande. The metropolitan area is surrounded by relatively barren scrubland and is intersected by strips of vegetation along the Rio Grande. Results indicate that the urban canopy parameterizations do affect the mesoscale flow field, reducing the magnitude of wind speed and changing the magnitude of the sensible heat flux and tke in the metropolitan area. A nighttime heat island and a daytime cool island exist when urban canopy parameters are turned on, but associated recirculation flows are not readily apparent. Model-computed solar, net, and longwave radiation values look reasonable, agreeing for the most part with published measurements.
Chen, Long-Qing
, neutronics, geomechanics, reac+ve transport, microstructure modeling, computa+onal fluid in verba+m from Schwen, D., E. Mar/nez, and A. Caro, J. Nuclear Mater (cv) in UO2 fuel. Also shown are the switching func+on h, the order
Lisal, Martin
Mesoscale simulation of polymer reaction equilibrium: Combining dissipative particle dynamics a mesoscale simulation technique, called the reaction ensemble dissipative particle dynamics RxDPD method. Coarse-grained, particle- based mesoscale models that retain only the most essential features
Meso-Scale Modeling of Spall in a Heterogeneous Two-Phase Material
Springer, H K
2008-06-26T23:59:59.000Z
The influence of the heterogeneous second-phase particle structure and applied loading conditions on the ductile spall response of a model two-phase material was investigated. Quantitative metallography, three-dimensional (3D) meso-scale simulations (MSS), and small-scale spall experiments provided the foundation for this study. Nodular ductile iron (NDI) was selected as the model two-phase material for this study because it contains a large and readily identifiable second- phase particle population. Second-phase particles serve as the primary void nucleation sites in NDI and are, therefore, central to its ductile spall response. A mathematical model was developed for the NDI second-phase volume fraction that accounted for the non-uniform particle size and spacing distributions within the framework of a length-scale dependent Gaussian probability distribution function (PDF). This model was based on novel multiscale sampling measurements. A methodology was also developed for the computer generation of representative particle structures based on their mathematical description, enabling 3D MSS. MSS were used to investigate the effects of second-phase particle volume fraction and particle size, loading conditions, and physical domain size of simulation on the ductile spall response of a model two-phase material. MSS results reinforce existing model predictions, where the spall strength metric (SSM) logarithmically decreases with increasing particle volume fraction. While SSM predictions are nearly independent of applied load conditions at lower loading rates, which is consistent with previous studies, loading dependencies are observed at higher loading rates. There is also a logarithmic decrease in SSM for increasing (initial) void size, as well. A model was developed to account for the effects of loading rate, particle size, matrix sound-speed, and, in the NDI-specific case, the probabilistic particle volume fraction model. Small-scale spall experiments were designed and executed for the purpose of validating closely-coupled 3D MSS. While the spall strength is nearly independent of specimen thickness, the fragment morphology varies widely. Detailed MSS demonstrate that the interactions between the tensile release waves are altered by specimen thickness and that these interactions are primarily responsible for fragment formation. MSS also provided insights on the regional amplification of damage, which enables the development of predictive void evolution models.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Materials at the Mesoscale 1663 Los Alamos science and technology magazine Latest Issue:January 2015 All Issues submit Materials at the Mesoscale Los Alamos's bold proposal to...
Jochum, Markus
-term in situ measurements. Given the shallow mixed layer, this additional surface heat flux warms the cold of the ocean. The observed relationship between the near-surface winds and mesoscale SSTs generate Ekman pump- ing velocities at the scale of the cold filaments, whose magnitude is the order of 1 m/day in both
Probabilistic finite element analysis of a craniofacial finite element model Michael A. Berthaume a s t r a c t We employed a probabilistic finite element analysis (FEA) method to determine how 2011 Accepted 18 January 2012 Available online 27 January 2012 Keywords: Probabilistic analysis Finite
Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.
2013-10-01T23:59:59.000Z
Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.
Wang, Yuqing
Effect of mesoscale topography over the Tibetan Plateau on summer precipitation in China 2008; accepted 27 August 2008; published 8 October 2008. [1] The effect of mesoscale topography over and topography. In the sensitivity simulation, the mesoscale feature in topography over the TP was smoothed out
Finite Model Finding for Parameterized Verification
Lisitsa, Alexei
2010-01-01T23:59:59.000Z
In this paper we investigate to which extent a very simple and natural "reachability as deducibility" approach, originated in the research in formal methods in security, is applicable to the automated verification of large classes of infinite state and parameterized systems. The approach is based on modeling the reachability between (parameterized) states as deducibility between suitable encodings of states by formulas of first-order predicate logic. The verification of a safety property is reduced to a pure logical problem of finding a countermodel for a first-order formula. The later task is delegated then to the generic automated finite model building procedures. In this paper we first establish the relative completeness of the finite countermodel finding method (FCM) for a class of parameterized linear arrays of finite automata. The method is shown to be at least as powerful as known methods based on monotonic abstraction and symbolic backward reachability. Further, we extend the relative completeness of ...
Modeling Elastic Properties in Finite-Element Analysis: How Much
Modeling Elastic Properties in Finite- Element Analysis: How Much Precision Is Needed to Produce analysis was investigated using a finite-element model of a Macaca fascicularis skull. Four finite-element realistically using the orthotropic elastic properties employed in analysis 4. Results suggest that finite-element
Techniques for Modeling Muscle-Induced Forces in Finite Element
Dumont, Elizabeth R.
program was written to interface with a commercial finite element analysis tool to automatically apply: finite element analysis; muscle force; skull; muscle loading alogorithm, biting Finite element analysisTechniques for Modeling Muscle- Induced Forces in Finite Element Models of Skeletal Structures IAN
Simulation and characterization of the Adriatic Sea mesoscale variability
Cushman-Roisin, Benoit
Simulation and characterization of the Adriatic Sea mesoscale variability Benoit Cushman-Roisin,1 resolve the mesoscale variability because the grid size falls below the first baroclinic deformation in two larger-scale models. The present simulations demonstrate that the DieCAST model allows mesoscale
Report on the use of stability parameters and mesoscale
Report on the use of stability parameters and mesoscale modelling in short-term prediction Jake Nielsen, Henrik Madsen, John Tøfting Title: Report on the use of stability parameters and mesoscale. Mesoscale modelling has been carried out using KAMM at this location. The characteristics of the measured
Flexible finite-element modeling of global geomagnetic depth sounding
Ribaudo, Joseph Thomas
2011-01-01T23:59:59.000Z
OF CALIFORNIA, SAN DIEGO Flexible Finite-Element Modeling ofOF THE DISSERTATION Flexible Finite-Element Modeling ofin Chapter 2. The method is flexible enough to allow for a
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Closing the Mesoscale Gap Los Alamos proposes to fill in the gaps in our fundamental understanding of materials with MaRIE, a facility designed to gain access to the mesoscale....
Coupling the high-complexity land surface model ACASA to the mesoscale model WRF
Pyles, R. D.
In this study, the Weather Research and Forecasting (WRF) model is coupled with the Advanced Canopy–Atmosphere–Soil Algorithm (ACASA), a high-complexity land surface model. Although WRF is a state-of-the-art regional ...
Coupling the High Complexity Land Surface Model ACASA to the Mesoscale Model WRF
Xu, L.
In this study, the Weather Research and Forecasting Model (WRF) is coupled with the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA), a high complexity land surface model. Although WRF is a state-of-the-art regional ...
Modeling Masticatory Muscle Force in Finite Element Analysis
Modeling Masticatory Muscle Force in Finite Element Analysis: Sensitivity Analysis Using Principal: electromyography; muscle force; mastication; primates; principal coordinates analysis; finite element analysis Our Origins, University of Arizona, Tempe, Arizona ABSTRACT Our work on a finite element model of the skull
Meng, Zhiyong
Tests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part I the potential of using the ensemble Kalman filter (EnKF) for mesoscale and regional-scale data assimilation are assimilated. 1. Introduction The ensemble-based data assimilation method [en- semble Kalman filter (En
A Coupling Methodology for Mesoscale-informed Nuclear Fuel Performance Codes
Michael Tonks; Derek Gaston; Cody Permann; Paul Millett; Glen Hansen; Dieter Wolf
2010-10-01T23:59:59.000Z
This study proposes an approach for capturing the effect of microstructural evolution on reactor fuel performance by coupling a mesoscale irradiated microstructure model with a finite element fuel performance code. To achieve this, the macroscale system is solved in a parallel, fully coupled, fully-implicit manner using the preconditioned Jacobian-free Newton Krylov (JFNK) method. Within the JFNK solution algorithm, microstructure-influenced material parameters are calculated by the mesoscale model and passed back to the macroscale calculation. Due to the stochastic nature of the mesoscale model, a dynamic fitting technique is implemented to smooth roughness in the calculated material parameters. The proposed methodology is demonstrated on a simple model of a reactor fuel pellet. In the model, INL’s BISON fuel performance code calculates the steady-state temperature profile in a fuel pellet and the microstructure-influenced thermal conductivity is determined with a phase field model of irradiated microstructures. This simple multiscale model demonstrates good nonlinear convergence and near ideal parallel scalability. By capturing the formation of large mesoscale voids in the pellet interior, the multiscale model predicted the irradiation-induced reduction in the thermal conductivity commonly observed in reactors.
Fast, J.D.; O'Steen, B.L.
1992-01-01T23:59:59.000Z
In this study, a four-dimensional data assimilation technique based on Newtonian relaxation is incorporated into Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) and evaluated using data taken from one experiment of the US Department of Energy's (DOE) 1991 Atmospheric Studies in COmplex Terrain (ASCOT) field study along the front range of the Rockies in Colorado. The main objective of this study is to determine the ability of the model to predict small-scale circulations influenced by terrain, such as drainage flows, and assess the impact of data assimilation on the numerical results. In contrast to previous studies in which the smallest horizontal grid spacing was 10 km (Stauffer and Seaman, 1991) and 8 km (Yamada and Hermi, 1991), data assimilation is applied in this study to domains with a horizontal grid spacing as small as 1 km. The prognostic forecasts made by RAMS are evaluated by comparing simulations that employ static initial conditions, with simulations that incorporate continuous data assimilation and data assimilation for fixed period of time (dynamic initialization). This paper will also elaborate on the application and limitation of the Newtonian relaxation technique in limited-area mesoscale models with a relatively small grid spacing.
Fast, J.D.; O`Steen, B.L.
1992-11-01T23:59:59.000Z
In this study, a four-dimensional data assimilation technique based on Newtonian relaxation is incorporated into Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) and evaluated using data taken from one experiment of the US Department of Energy`s (DOE) 1991 Atmospheric Studies in COmplex Terrain (ASCOT) field study along the front range of the Rockies in Colorado. The main objective of this study is to determine the ability of the model to predict small-scale circulations influenced by terrain, such as drainage flows, and assess the impact of data assimilation on the numerical results. In contrast to previous studies in which the smallest horizontal grid spacing was 10 km (Stauffer and Seaman, 1991) and 8 km (Yamada and Hermi, 1991), data assimilation is applied in this study to domains with a horizontal grid spacing as small as 1 km. The prognostic forecasts made by RAMS are evaluated by comparing simulations that employ static initial conditions, with simulations that incorporate continuous data assimilation and data assimilation for fixed period of time (dynamic initialization). This paper will also elaborate on the application and limitation of the Newtonian relaxation technique in limited-area mesoscale models with a relatively small grid spacing.
ATMOSPHERIC DUST AND MESOSCALE/MICROSCALE METEOROLOGY. A. Spiga1 , S.R. Lewis1
Spiga, Aymeric
ATMOSPHERIC DUST AND MESOSCALE/MICROSCALE METEOROLOGY. A. Spiga1 , S.R. Lewis1 , and F. For- get2 to advances in computational resources and modeling techniques. Note also that mesoscale modeling and Large: general circulation models, mesoscale models, microscale models [Large-Eddy Simulations]. Figure 1
From deterministic to stochastic, from mesoscale to macroscopic
Title: From deterministic to stochastic, from mesoscale to macroscopic: multiscale modeling of grain growth Abstract: Many problems in science and engineering ...
Mixed Layer Mesoscales for OGCMs: Model development and assessment with T/P, WOCE and Drifter data
Canuto, V M; Leboissetier, A
2011-01-01T23:59:59.000Z
We present a model for mixed layer (ML) mesoscale (M) fluxes of an arbitrary tracer in terms of the resolved fields (mean tracer and mean velocity). The treatment of an arbitrary tracer, rather than only buoyancy, is necessary since OGCMs time step T, S, CO2, etc and not buoyancy. The particular case of buoyancy is used to assess the model results. The paper contains three parts: derivation of the results, discussion of the results and assessment of the latter using, among others, WOCE, T/P and Drifter data. Derivation. To construct the M fluxes, we first solve the ML M dynamic equations for the velocity and tracer M fields. The goal of the derivation is to emphasize the different treatments of the non-linear terms in the adiabatic vs. diabatic ocean (deep ocean vs. mixed layer). Results. We derive analytic expressions for the following variables: a) vertical and horizontal M fluxes of an arbitrary tracer, b) M diffusivity in terms of the EKE, c) surface value of the EKE in terms of the vertical M buoyancy fl...
Lascaux, Franck; di Arcetri, INAF / Osservatorio Astrofisico; 10.1117/12.925934
2012-01-01T23:59:59.000Z
In the context of the MOSE project, in this contribution we present a detailed analysis of the Meso-NH mesoscale model performances and their dependency on the model and orography horizontal resolutions in proximity of the ground. The investigated sites are Cerro Paranal (site of the ESO Very Large Telescope - VLT) and Cerro Armazones (site of the ESO European Extremely Large Telescope - E-ELT), in Chile. At both sites, data from a rich statistical sample of different nights are available - from AWS (Automated Weather Stations) and masts - giving access to wind speed, wind direction and temperature at different levels near the ground (from 2 m to 30 m above the ground). In this study we discuss the use of a very high horizontal resolution (dX=0.1 km) numerical configuration that overcomes some specific limitations put in evidence with a standard configuration with dX=0.5 km. In both sites results are very promising. The study is co-funded by ESO and INAF.
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Berri, G.J.; Nunez, M.N. (Universidad de Buenos Aires (Argentina) Pabellon II Ciudad Universitaria, Buenos Aires (Argentina))
1993-05-01T23:59:59.000Z
A hydrostatic and incompressible mesoscale model with transformed horizontal coordinates is presented. The model is applied to study the sea-land-breeze circulation over Rio de La Plata. One of the new coordinates is shoreline-following and the other one is locally quasi-perpendicular to the first one. The original set of equations in the Cartesian coordinates is rewritten in the curvilinear coordinates. This transformation is useful provided that the curvilinear coordinates are close to being orthogonal. The horizontal domain covers 250 km [times] 250 km, and the vertical domain is 2 km deep. To predict the sea-land-breeze circulation the model is integrated over 12 h. The forcing of the model is a cyclic perturbation of the surface temperature. The changes in the wind direction during the day are in good agreement with the observations from six weather stations in the region. The same program code is applied to uniform domains of different resolutions in order to test the coordinate transformation. Results show that the predictions based upon the variable-resolution version resemble ones obtained using high uniform resolution but consume only one-fourth the computer time needed by the latter. Comparison of the vertical velocity patterns predicted by the model to the cumulus clouds distribution observed from satellite images show a very good agreement too. The authors believe that all these results justify the use of the coordinate transformation in this type of model, although further verifications are needed in order to draw more definitive conclusions. 28 refs., 11 figs.
Lee, In Young
1993-09-01T23:59:59.000Z
The distribution of atmospheric pollutants is governed by dynamic processes that create the general conditions for transport and mixing, by microphysical processes that control the evolution of aerosol and cloud particles, and by chemical processes that transform chemical species and form aerosols. Pollutants emitted into the air can undergo homogeneous gas reactions to create a suitable environment for the production by heterogeneous nucleation of embryos composed of a few molecules. The physicochemical properties of preexisting aerosols interact with newly produced embryos to evolve by heteromolecular diffusion and coagulation. Hygroscopic particles wig serve as effective cloud condensation nuclei (CCN), while hydrophobic particles will serve as effective ice-forming nuclei. Clouds form initially by condensation of water vapor on CCN and evolve in a vapor-liquid-solid system by deposition, sublimation, freezing, melting, coagulation, and breakup. Gases and aerosols that enter the clouds undergo aqueous chemical processes and may acidity hydrometer particles. Calculations for solar and longwave radiation fluxes depend on how the respective spectra are modified by absorbers such as H{sub 2}O, CO{sub 2}, O{sub 3}, CH{sub 4}, N{sub 2}O, chlorofruorocarbons, and aerosols. However, the flux calculations are more complicated for cloudy skies, because the cloud optical properties are not well defined. In this paper, key processes such as tropospheric chemistry, cloud microphysics parameterizations, and radiation schemes are reviewed in terms of physicochemical processes occurring, and recommendations are made for the development of advanced modules applicable to mesoscale models.
Heavy Duty Diesel Particulate Matter and Fuel Consumption Modeling for Transportation Analysis
Scora, George Alexander
2011-01-01T23:59:59.000Z
measured second-by-second fuel use. Mesoscale Modeling DataSet and Mesoscale ModelCalibration Mesoscale model calibration and validation
Chromatin Ionic Atmosphere Analyzed by a Mesoscale Electrostatic Hin Hark Gan
Schlick, Tamar
Chromatin Ionic Atmosphere Analyzed by a Mesoscale Electrostatic Approach Hin Hark Gan and Tamar an electrostatic model to handle multivalent ions and compute the ionic distribution around a mesoscale chromatin
Taha, H.
2011-01-01T23:59:59.000Z
104. Pielke, R, 1984: Mesoscale Meteorological Modeling . •the CSUMM, as any other mesoscale model, is typically runApplications International Mesoscale Model. SYSAPP- 921069,
New Efficient Sparse SpaceTime Algorithms for Superparameterization on Mesoscales
Xing, Yulong
New Efficient Sparse SpaceTime Algorithms for Superparameterization on Mesoscales YULONG XING-scale and mesoscale processes provided by a cloud-resolving model (CRM) embedded in each column of a large-scale model for limited-area mesoscale ensemble forecasting. 1. Introduction Atmospheric processes of weather and climate
Self-Assembly of Mesoscale Isomers: The Role of Pathways and Degrees of Freedom
Menon, Govind
Self-Assembly of Mesoscale Isomers: The Role of Pathways and Degrees of Freedom Shivendra Pandey1 geometric path sampling and a mesoscale experimental model to investigate the self-assembly of a model. Citation: Pandey S, Johnson D, Kaplan R, Klobusicky J, Menon G, et al. (2014) Self-Assembly of Mesoscale
Lagrangian study of transport and mixing in a mesoscale eddy street
S. V. Prants; M. V. Budyansky; V. I. Ponomarev; M. Yu. Uleysky
2012-02-02T23:59:59.000Z
We use dynamical systems approach and Lagrangian tools to study surface transport and mixing of water masses in a selected coastal region of the Japan Sea with moving mesoscale eddies associated with the Primorskoye Current. Lagrangian trajectories are computed for a large number of particles in an interpolated velocity field generated by a numerical regional multi-layer eddy-resolving circulation model. We compute finite-time Lyapunov exponents for a comparatively long period of time by the method developed and plot the Lyapunov synoptic map quantifying surface transport and mixing in that region. This map uncovers the striking flow structures along the coast with a mesoscale eddy street and repelling material lines. We propose new Lagrangian diagnostic tools --- the time of exit of particles off a selected box, the number of changes of the sign of zonal and meridional velocities --- to study transport and mixing by a pair of strongly interacting eddies often visible at sea-surface temperature satellite images in that region. We develop a technique to track evolution of clusters of particles, streaklines and material lines. The Lagrangian tools used allow us to reveal mesoscale eddies and their structure, to track different phases of the coastal flow, to find inhomogeneous character of transport and mixing on mesoscales and submesoscales and to quantify mixing by the values of exit times and the number of times particles wind around the eddy's center.
A frequency domain finite element model for tidal circulation
Westerink, Joannes J.
1985-01-01T23:59:59.000Z
A highly efficient finite element model has been developed for the numerical prediction of depth average circulation within small scale embayments which are often characterized by irregular boundaries and bottom topography.
Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor
Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.
2002-01-01T23:59:59.000Z
Version 1.0: Landfill bioreactor model for TOUGH2, LawrenceFigures Biodegradation Bioreactor Aerobic CO2 + H2O + heat1. Schematic of bioreactor and T2LBM conceptualizations.
Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor
Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.
2002-01-01T23:59:59.000Z
1179. Popov, V. ; Power, H. Landfill emission of gases intoC.M. T2LBM Version 1.0: Landfill bioreactor model forand recovery from landfills, Ann Arbor Science Publishers,
Hernández-Carrasco, Ismael; Hernández-García, Emilio; Garçon, Veronique; López, Cristóbal
2013-01-01T23:59:59.000Z
Recent studies, both based on remote sensed data and coupled models, showed a reduction of biological productivity due to vigorous horizontal mixing in upwelling systems. In order to better understand this phenomenon, we have considered a system of oceanic flow in the Benguela area coupled with a simple biogeochemical model of Nutrient-Phyto-Zooplankton (NPZ) type. For the flow three different surface velocity fields are considered: one derived from satellite altimetry data, and the other two from a regional numerical model at two different spatial resolutions. We computed horizontal particle dispersion in terms of Lyapunov Exponents, and analyzed their correlations with phytoplankton concentrations. Our modelling approach confirms that in the south Benguela, there is a reduction of biological activity when stirring is increased. Two-dimensional offshore advection seems to be the dominant process involved. In the northern area, other factors not taken into account in our simulation are influencing the ecosyst...
Hu, Shenyang Y.; Li, Yulan; Rosso, Kevin M.; Sushko, Maria L.
2013-01-10T23:59:59.000Z
A phase-field model is developed to investigate the influence of microstructure, thermodynamic and kinetic properties, and charging conditions on charged particle transport in nanocomposite electrodes. Two sets of field variables are used to describe the microstructure. One is comprised of the order parameters describing size, orientation and spatial distributions of nanoparticles, and the other is comprised of the concentrations of mobile species. A porous nanoparticle microstructure filled with electrolyte is taken as a model system to test the phase-field model. Inhomogeneous and anisotropic dielectric constants and mobilities of charged particles, and stresses associated with lattice deformation due to Li-ion insertion/extraction are considered in the model. Iteration methods are used to find the elastic and electric fields in an elastically and electrically inhomogeneous medium. The results demonstrate that the model is capable of predicting charge separation associated with the formation of a double layer at the electrochemical interface between solid and electrolyte, and the effect of microstructure, inhomogeneous and anisotropic thermodynamic and kinetic properties, charge rates, and stresses on voltage versus current density and capacity during charging and discharging.
Silicon Micromachined Dimensional Calibration Artifact for Mesoscale...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 1 Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 2...
Rooker, Jay R.
Distribution and Habitat Associations of Billfish and Swordfish Larvae across Mesoscale Features additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and Swordfish Larvae across Mesoscale Features in the Gulf of Mexico. PLoS ONE 7(4): e34180. doi:10.1371/journal
Mesoscale-resolving simulations of summer and winter bora events in the Adriatic Sea
Cushman-Roisin, Benoit
Mesoscale-resolving simulations of summer and winter bora events in the Adriatic Sea Benoit CushmanCAST model on a 1.2-min grid (about 2-km resolution) and resolve the mesoscale variability because the grid-Roisin, B., and K. A. Korotenko (2007), Mesoscale-resolving simulations of summer and winter bora events
Large-Scale Errors and Mesoscale Predictability in Pacific Northwest Snowstorms DALE R. DURRAN
Large-Scale Errors and Mesoscale Predictability in Pacific Northwest Snowstorms DALE R. DURRAN The development of mesoscale numerical weather prediction (NWP) models over the last two decades has made- search communities. Nevertheless, the predictability of the mesoscale features captured in such forecasts
CONVERGENCE AND STABILITY IN UPSCALING OF FLOW WITH INERTIA FROM PORESCALE TO MESOSCALE
Peszynska, Malgorzata
CONVERGENCE AND STABILITY IN UPSCALING OF FLOW WITH INERTIA FROM PORESCALE TO MESOSCALE MAl with inertia from porescale (microscale) to Darcy scale (lab scale, mesoscale). In particular, we solve Navier-Darcy model with inertia at mesoscale. 1. Introduction. In [1] we presented a proof-of-concept algorithm
MESOSCALE MODELING OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES
Springer, H K; Glascoe, E A; Reaugh, J E; Kercher, J R; Maienschein, J L
2011-08-01T23:59:59.000Z
Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our model explosive. A Prout-Tompkins chemical kinetic model, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength model were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage models and the design of inherently safer explosives.
THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL
Werth, D.; Kurzeja, R.; Parker, M.
2009-04-02T23:59:59.000Z
A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric Modeling System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against the data collected from the site. This model was run at high resolution, and is ideal for calculating the interactions among the various motions within the boundary layer and their influence on the surface. The model reproduces adequately the synoptic situation and the formation and dissolution cycles of the low-level jet, although it suffers from insufficient cloud production and excessive nocturnal cooling. The authors suggest that observed heat flux data may further improve the realism of the simulations both in the cloud formation and in the jet characteristics. In a higher resolution simulation, the NBL experiences motion on a range of timescales as revealed by a wavelet analysis, and these are affected by the presence of the LLJ. The model can therefore be used to provide information on activity throughout the depth of the NBL.
Meso-Scale Model for Simulations of Concrete Subjected to Cryogenic Temperatures
Masad, Noor Ahmad
2013-07-17T23:59:59.000Z
temperatures (Marshall, 1982). The air-entrained concrete has the ability to resist freezing-thawing cycles; therefore, it is recommended to be used in applications that need frost resistance. Air entrained concrete has air pores that can handle... and relief the pressure due to ice 13 formulation, however, the ice growth in non-air entrained concrete causes expand in cracks which lead to deterioration of concrete after many freeze-thaw cycles. 2.3 Concrete Plasticity Damage Models Concrete...
Fluid-particle flow modelling and validation using two-way-coupled mesoscale SPH-DEM
Robinson, Martin; Ramaioli, Marco
2013-01-01T23:59:59.000Z
We present a meshless simulation method for multiphase fluid-particle flows coupling Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM). Rather than fully resolving the interstitial fluid, which is often infeasible, the unresolved fluid model is based on the locally averaged Navier Stokes equations, which are coupled with a DEM model for the solid phase. In contrast to similar mesh-based Discrete Particle Methods (DPMs), this is a purely particle-based method and enjoys the flexibility that comes from the lack of a prescribed mesh. It is suitable for problems such as free surface flow or flow around complex, moving and/or intermeshed geometries. It can be used for both one and two-way coupling and is applicable to both dilute and dense particle flows. A comprehensive validation procedure for fluid-particle simulations is presented and applied to the SPH-DEM method, using simulations of single and multiple particle sedimentation in a 3D fluid column and comparison with analytical model...
Experimentally validated finite element model of electrocaloric multilayer ceramic structures
Smith, N. A. S., E-mail: nadia.smith@npl.co.uk, E-mail: maciej.rokosz@npl.co.uk, E-mail: tatiana.correia@npl.co.uk; Correia, T. M., E-mail: nadia.smith@npl.co.uk, E-mail: maciej.rokosz@npl.co.uk, E-mail: tatiana.correia@npl.co.uk [National Physical Laboratory, Hampton Road, TW11 0LW Middlesex (United Kingdom); Rokosz, M. K., E-mail: nadia.smith@npl.co.uk, E-mail: maciej.rokosz@npl.co.uk, E-mail: tatiana.correia@npl.co.uk [National Physical Laboratory, Hampton Road, TW11 0LW Middlesex (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom)
2014-07-28T23:59:59.000Z
A novel finite element model to simulate the electrocaloric response of a multilayer ceramic capacitor (MLCC) under real environment and operational conditions has been developed. The two-dimensional transient conductive heat transfer model presented includes the electrocaloric effect as a source term, as well as accounting for radiative and convective effects. The model has been validated with experimental data obtained from the direct imaging of MLCC transient temperature variation under application of an electric field. The good agreement between simulated and experimental data, suggests that the novel experimental direct measurement methodology and the finite element model could be used to support the design of optimised electrocaloric units and operating conditions.
Singer, M; Mirocha, J; Lundquist, J; Cleve, J
2010-03-03T23:59:59.000Z
Flow dynamics in large wind projects are influenced by the turbines located within. The turbine wakes, regions characterized by lower wind speeds and higher levels of turbulence than the surrounding free stream flow, can extend several rotor diameters downstream, and may meander and widen with increasing distance from the turbine. Turbine wakes can also reduce the power generated by downstream turbines and accelerate fatigue and damage to turbine components. An improved understanding of wake formation and transport within wind parks is essential for maximizing power output and increasing turbine lifespan. Moreover, the influence of wakes from large wind projects on neighboring wind farms, agricultural activities, and local climate are all areas of concern that can likewise be addressed by wake modeling. This work describes the formulation and application of an actuator disk model for studying flow dynamics of both individual turbines and arrays of turbines within wind projects. The actuator disk model is implemented in the Weather Research and Forecasting (WRF) model, which is an open-source atmospheric simulation code applicable to a wide range of scales, from mesoscale to large-eddy simulation. Preliminary results demonstrate the applicability of the actuator disk model within WRF to a moderately high-resolution large-eddy simulation study of a small array of turbines.
Lagrangian study of transport and mixing in a mesoscale eddy street
Prants, S V; Ponomarev, V I; Uleysky, M Yu; 10.1016/j.ocemod.2011.02.008
2012-01-01T23:59:59.000Z
We use dynamical systems approach and Lagrangian tools to study surface transport and mixing of water masses in a selected coastal region of the Japan Sea with moving mesoscale eddies associated with the Primorskoye Current. Lagrangian trajectories are computed for a large number of particles in an interpolated velocity field generated by a numerical regional multi-layer eddy-resolving circulation model. We compute finite-time Lyapunov exponents for a comparatively long period of time by the method developed and plot the Lyapunov synoptic map quantifying surface transport and mixing in that region. This map uncovers the striking flow structures along the coast with a mesoscale eddy street and repelling material lines. We propose new Lagrangian diagnostic tools --- the time of exit of particles off a selected box, the number of changes of the sign of zonal and meridional velocities --- to study transport and mixing by a pair of strongly interacting eddies often visible at sea-surface temperature satellite imag...
Lipid-Based Nanodiscs as Models for Studying Mesoscale Coalescence A Transport Limited Case
Hu, Andrew [University of Connecticut, Storrs; Fan, Tai-Hsi [University of Connecticut, Storrs; Katsaras, John [ORNL; Xia, Yan [University of Connecticut, Storrs; Li, Ming [University of Connecticut, Storrs; Nieh, Mu-Ping [University of Connecticut, Storrs
2014-01-01T23:59:59.000Z
Lipid-based nanodiscs (bicelles) are able to form in mixtures of long- and short-chain lipids. Initially, they are of uniform size but grow upon dilution. Previously, nanodisc growth kinetics have been studied using time-resolved small angle neutron scattering (SANS), a technique which is not well suited for probing their change in size immediately after dilution. To address this, we have used dynamic light scattering (DLS), a technique which permits the collection of useful data in a short span of time after dilution of the system. The DLS data indicate that the negatively charged lipids in nanodiscs play a significant role in disc stability and growth. Specifically, the charged lipids are most likely drawn out from the nanodiscs into solution, thereby reducing interparticle repulsion and enabling the discs to grow. We describe a population balance model, which takes into account Coulombic interactions and adequately predicts the initial growth of nanodiscs with a single parameter i.e., surface potential. The results presented here strongly support the notion that the disc coalescence rate strongly depends on nanoparticle charge density. The present system containing low-polydispersity lipid nanodiscs serves as a good model for understanding how charged discoidal micelles coalesce.
Tomar, Vikas
Analyses of the role of grain boundaries in mesoscale dynamic fracture resistance of SiCSi3N4 with SiC dispersions as well as Si3N4 matrix of mesoscale dimensions ($1 lm) are considered to have, cohesive finite element method (CFEM) based mesoscale dynamic fracture anal- yses of SiCSi3N4
Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model
Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.
2004-07-01T23:59:59.000Z
The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.
Runtime system library for parallel finite difference models with nesting
Michalakes, J.
1997-03-01T23:59:59.000Z
RSL is a parallel run-time system library for implementing regular-grid models with nesting on distributed memory parallel computers. RSL provides support for automatically decomposing multiple model domains and for redistributing work between processors at run time for dynamic load balancing. A unique feature of RSL is that processor subdomains need not be rectangular patches; rather, grid points are independently allocated to processors, allowing more precisely balanced allocation of work to processors. Communication mechanisms are tailored to the application: RSL provides an efficient high-level stencil exchange operation for updating subdomain ghost areas and interdomain communication to support two-way interaction between nest levels. RSL also provides run-time support for local iteration over subdomains, global-local index translation, and distributed I/O from ordinary Fortran record-blocked data sets. The interface to RSL supports Fortran77 and Fortran90. RSL has been used to parallelize the NCAR/Penn State Mesoscale Model (MM5).
Mesoscale Dynamics Spring Semester 2012
Birner, Thomas
ATS 735 Mesoscale Dynamics (3 cr) Spring Semester 2012 Instructor: Richard H. Johnson, Room ATS 305: There are no required texts. The recent book Mesoscale Meteorology in Midlatitudes by Markowski and Richardson covers with mesoscale-related research. A set of notes will be made available for the course, although we will not cover
Mesoscale Dynamics Spring Semester 2014
ATS 735 Mesoscale Dynamics (3 cr) Spring Semester 2014 Instructor: Richard H. Johnson, Room ATS 305: There are no required texts. The recent book Mesoscale Meteorology in Midlatitudes by Markowski and Richardson covers with mesoscale-related research. A set of notes will be made available for the course, although we will not cover
7, 1043910465, 2007 Mesoscale inversion
Boyer, Edmond
ACPD 7, 1043910465, 2007 Mesoscale inversion T. Lauvaux et al. Title Page Abstract Introduction Discussions Mesoscale inversion: first results from the CERES campaign with synthetic data T. Lauvaux 1,2 , M.lauvaux@lsce.ipsl.fr) 10439 #12;ACPD 7, 1043910465, 2007 Mesoscale inversion T. Lauvaux et al. Title Page Abstract
Author's personal copy The effects of modeling simplifications on craniofacial finite element models
a r t i c l e i n f o Article history: Accepted 17 March 2011 Keywords: Finite element analysis Tooth), a biomechanical system commonly studied using finite element analysis (FEA) is that part of the craniofacial in such finite element models (FEMs) depends exten- sively on the objective of the analysis and the performance
Michael Tonks; Derek Gaston; Cody Permann; Paul Millett; Glen Hansen; Chris Newman
2009-08-01T23:59:59.000Z
Reactor fuel performance is sensitive to microstructure changes during irradiation (such as fission gas and pore formation). This study proposes an approach to capture microstructural changes in the fuel by a two-way coupling of a mesoscale phase field irradiation model to an engineering scale, finite element calculation. This work solves the multiphysics equation system at the engineering-scale in a parallel, fully-coupled, fully-implicit manner using a preconditioned Jacobian-free Newton Krylov method (JFNK). A sampling of the temperature at the Gauss points of the coarse scale is passed to a parallel sequence of mesoscale calculations within the JFNK function evaluation phase of the calculation. The mesoscale thermal conductivity is calculated in parallel, and the result is passed back to the engineering-scale calculation. As this algorithm is fully contained within the JFNK function evaluation, the mesoscale calculation is nonlinearly consistent with the engineering-scale calculation. Further, the action of the Jacobian is also consistent, so the composite algorithm provides the strong nonlinear convergence properties of Newton's method. The coupled model using INL's \\bison\\ code demonstrates quadratic nonlinear convergence and good parallel scalability. Initial results predict the formation of large pores in the hotter center of the pellet, but few pores on the outer circumference. Thus, the thermal conductivity is is reduced in the center of the pellet, leading to a higher internal temperature than that in an unirradiated pellet.
Finite element modeling of syntactic foam.
Hobbs, Michael L.
2004-10-01T23:59:59.000Z
A decomposition model has been developed to predict the response of removable syntactic foam (RSF) exposed to fire-like heat fluxes. RSF consists of glass micro-balloons (GMB) in a cured epoxy polymer matrix. A chemistry model is presented based on the chemical structure of the epoxy polymer, mass transport of polymer fragments to the bulk gas, and vapor-liquid equilibrium. Thermophysical properties were estimated from measurements. A bubble nucleation, growth, and coalescence model was used to describe changes in properties with the extent of reaction. Decomposition of a strand of syntactic foam exposed to high temperatures was simulated.
Test of modified BCS model at finite temperature
V. Yu. Ponomarev; A. I. Vdovin
2005-08-24T23:59:59.000Z
A recently suggested modified BCS (MBCS) model has been studied at finite temperature. We show that this approach does not allow the existence of the normal (non-superfluid) phase at any finite temperature. Other MBCS predictions such as a negative pairing gap, pairing induced by heating in closed-shell nuclei, and ``superfluid -- super-superfluid'' phase transition are discussed also. The MBCS model is tested by comparing with exact solutions for the picket fence model. Here, severe violation of the internal symmetry of the problem is detected. The MBCS equations are found to be inconsistent. The limit of the MBCS applicability has been determined to be far below the ``superfluid -- normal'' phase transition of the conventional FT-BCS, where the model performs worse than the FT-BCS.
Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences
2013-11-13T23:59:59.000Z
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.
Boundaries of the Peruvian Oxygen Minimum Zone shaped by coherent mesoscale dynamics
Bettencourt, João H; García, Emilio Hernández; Montes, Ivonne; Sudre, Joël; Dewitte, Boris; Paulmier, Aurélien; Garçon, Véronique
2015-01-01T23:59:59.000Z
Dissolved oxygen in sea water is a major factor affecting marine habitats and biogeochemical cycles. Oceanic zones with oxygen deficits represent significant portions of the area and volume of the oceans and are thought to be expanding. The Peruvian oxygen minimum zone is one of the most pronounced and lies in a region of strong mesoscale activity in the form of vortices and frontal regions, whose effect in the dynamics of the oxygen minimum zone is largely unknown. Here, we study this issue from a modeling approach and a Lagrangian point of view, using a coupled physical-biogeochemical simulation of the Peruvian oxygen minimum zone and finite-size Lyapunov exponent fields to understand the link between mesoscale dynamics and oxygen variations. Our results show that, at depths between 380 and 600 meters, mesoscale structures have a relevant dual role. First, their mean positions and paths delimit and maintain the oxygen minimum zone boundaries. Second, their high frequency fluctuations entrain oxygen across t...
Free Body Analysis, Beam Mechanics, and Finite Element Modeling of the Mandible of Alligator
Free Body Analysis, Beam Mechanics, and Finite Element Modeling of the Mandible of Alligator arm mechanics, 2D and 3D beam mod- els, and three high-resolution finite element models- pared with the beam models, the Alligator finite element models exhibited less spatial variability
Boyer, Edmond
Spatial Intermittency of Surface Layer Wind Fluctuations at Mesoscale Range Rachel Bai¨le* and Jean and to confirm an intermittent nature of mesoscale fluctuations similar to the one observed in fully developed involving a wide range of spatiotemporal scales. The modeling of wind speed behavior in the mesoscale range
Sensitivity of Mesoscale Gravity Waves to the Baroclinicity of Jet-Front Systems SHUGUANG WANG of mesoscale gravity waves to the baroclinicity of the background jet-front systems by simulating different life cycles of baroclinic waves with a high-resolution mesoscale model. Four simulations are made
Mesoscale variability in time series data: Satellite-based estimates for the U.S. JGOFS Bermuda TOPEX/PoseidonERS-1/2) are used to characterize, statistically, the mesoscale variability about the U to better understand the contribution of mesoscale eddies to the time series record and the model- data
An evaluation of finite element models of stiffened plates subjected to impulsive loading
Pedatzur, Omri
2004-01-01T23:59:59.000Z
Different finite element models are evaluated for two very common structures, a cantilever beam and a stiffened plate, subjected to impulsive loading. For the cantilever beam case, the finite element models are one, two ...
Mesoscale hybrid calibration artifact
Tran, Hy D. (Albuquerque, NM); Claudet, Andre A. (Albuquerque, NM); Oliver, Andrew D. (Waltham, MA)
2010-09-07T23:59:59.000Z
A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.
Student Award Competition Finite Element EEG and MEG Simulations for Realistic Head Models
Zhukov, Leonid
than would be possible using linear elements alone. [1] D.S. Burnett. Finite Element Analysis: FromStudent Award Competition Finite Element EEG and MEG Simulations for Realistic Head Models be approximated by a technique such as the finite element method [1]. Most applications of the finite element
Lin, Liwei
Introduction to Finite Element Modeling Engineering analysis of mechanical systems have been of the FEM (don't misuse the FEM - a numerical tool) Finite Element Analysis A typical finite element quantities (e.g., strains and stresses) at selected elements Basic Theory The way finite element analysis
MESOSCALE SIMULATIONS OF POWDER COMPACTION
Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94551 (United States)
2009-12-28T23:59:59.000Z
Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models
Sarkar, Sudeep
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models Leonid V. Tsap finite element models. The method is based on the iterative analysis of the differences betweenÃPhysically-based vision, deformable models, nonrigid motion analysis, biomedical applications, finite element analysis. Ã¦
Energy conserving Anisotropic Anhysteretic Magnetic Modelling for Finite Element Analysis
Jens Krause
2012-12-20T23:59:59.000Z
To model ferromagnetic material in finite element analysis a correct description of the constitutive relationship (BH-law) must be found from measured data. This article proposes to use the energy density function as a centrepiece. Using this function, which turns out to be a convex function of the flux density, guarantees energy conservative modelling. The magnetic field strength can be seen as a derivative with respect to the flux density. Especially for anisotropic materials (from lamination and/or grain orientation) this method has advantages. Strictly speaking this method is only valid for anhysteretic and thermodynamically stable material.
Han, Sang-Ok
1998-01-01T23:59:59.000Z
On 2 June 1995, many supercede thunderstorms were graphics. observed in West Texas between Lubbock and Amarillo under the synoptic and mesoscale environment which was increasingly more supportive of severe convection. Of the storms, those which...
Masciadri, E; 10.1117/12.925924
2012-01-01T23:59:59.000Z
We present very encouraging preliminary results obtained in the context of the MOSE project, an on-going study aiming at investigating the feasibility of the forecast of the optical turbulence and meteorological parameters (in the free atmosphere as well as in the boundary and surface layer) at Cerro Paranal (site of the Very Large Telescope - VLT) and Cerro Armazones (site of the European Extremely Large Telescope - E-ELT), both in Chile. The study employs the Meso-Nh atmospheric mesoscale model and aims at supplying a tool for optical turbulence forecasts to support the scheduling of the scientific programs and the use of AO facilities at the VLT and the E-ELT. In this study we take advantage of the huge amount of measurements performed so far at Paranal and Armazones by ESO and the TMT consortium in the context of the site selection for the E-ELT and the TMT to constraint/validate the model. A detailed analysis of the model performances in reproducing the atmospheric parameters (T, V, p, H, ...) near the g...
Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables
Kumar, Ratnesh
1 Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables for reactive untimed infinite state systems called input- output extended finite automaton (I/O-EFA), which of a finite bisimilar abstraction. The results are illustrated through examples that model reactive software
Finite Element Multi-physics Modeling for Ohmic Contact of Microswitches , D. Leray1, 2
Boyer, Edmond
Finite Element Multi-physics Modeling for Ohmic Contact of Microswitches H.Liu1, 2 , D. Leray1, 2-physics modelling of electrical contact is accomplished with the finite element commercial package ANSYSTM . Two behaviour of electrical contact with rough surface included. Keywords: multi-physics, finite element
METR 4433, Mesoscale Meteorology Spring 2011
Droegemeier, Kelvin K.
METR 4433, Mesoscale Meteorology Spring 2011 Instructor Dr. Kelvin K. Droegemeier Office: Three, 1:00 2:30 pm Required Text Markowski, P. and Y. Richardson: Mesoscale Meteorology in Midlatitudes and physical analysis techniques to mesoscale phenomena. Topics include definition of the term "mesoscale
ATS 641: Mesoscale Meteorology Spring 2014
ATS 641: Mesoscale Meteorology Spring 2014 TR, 1:00-2:50 PM, ATS Room 101 Course Description and Prerequisites This course will cover the theory and application of mesoscale meteorology, and how mesoscale, students will be able to: · Describe the basic theories describing mesoscale weather phenomena · Understand
METR 4433, Mesoscale Meteorology Spring 2013
Droegemeier, Kelvin K.
METR 4433, Mesoscale Meteorology Spring 2013 Instructor Dr. Kelvin K. Droegemeier (kkd Text Markowski, P. and Y. Richardson: Mesoscale Meteorology in Midlatitudes. Wiley-Blackwell, 430pp to mesoscale phenomena. Topics include definition of the term "mesoscale," radar principles and interpretation
Niyogi, Dev
The role of land surface processes on the mesoscale simulation of the July 26, 2005 heavy rain Mesoscale convection Weather research and forecast model Indian summer monsoon Land surface processes
A Finite Element Model for Simulation of Carbon Dioxide Sequestration
Bao, Jie; Xu, Zhijie; Fang, Yilin
2013-11-02T23:59:59.000Z
We present a hydro-mechanical model, followed by stress, deformation, and shear-slip failure analysis for geological sequestration of carbon dioxide (CO2). The model considers the poroelastic effects by taking into account of the two-way coupling between the geomechanical response and the fluid flow process. Analytical solutions for pressure and deformation fields were derived for a typical geological sequestration scenario in our previous work. A finite element approach is introduced here for numerically solving the hydro-mechanical model with arbitrary boundary conditions. The numerical approach was built on an open-source finite element code Elmer, and results were compared to the analytical solutions. The shear-slip failure analysis was presented based on the numerical results, where the potential failure zone is identified. Information is relevant to the prediction of the maximum sustainable injection rate or pressure. The effects of caprock permeability on the fluid pressure, deformation, stress, and the shear-slip failure zone were also quantitatively studied. It was shown that a larger permeability in caprock and base rock leads to a larger uplift but a smaller shear-slip failure zone.
Progress in Developing Finite Element Models Replicating Flexural Graphite Testing
Robert Bratton
2010-06-01T23:59:59.000Z
This report documents the status of flexural strength evaluations from current ASTM procedures and of developing finite element models predicting the probability of failure. This work is covered under QLD REC-00030. Flexural testing procedures of the American Society for Testing and Materials (ASTM) assume a linear elastic material that has the same moduli for tension and compression. Contrary to this assumption, graphite is known to have different moduli for tension and compression. A finite element model was developed and demonstrated that accounts for the difference in moduli tension and compression. Brittle materials such as graphite exhibit significant scatter in tensile strength, so probabilistic design approaches must be used when designing components fabricated from brittle materials. ASTM procedures predicting probability of failure in ceramics were compared to methods from the current version of the ASME graphite core components rules predicting probability of failure. Using the ASTM procedures yields failure curves at lower applied forces than the ASME rules. A journal paper was published in the Journal of Nuclear Engineering and Design exploring the statistical models of fracture in graphite.
Surface photovoltage measurements and finite element modeling of SAW devices.
Donnelly, Christine
2012-03-01T23:59:59.000Z
Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.
Ocean color and atmospheric dimethyl sulfide: On their mesoscale variability
Matrai, Patricia A; Balch, William M; Cooper, David J; Saltzman, Eric S
1993-01-01T23:59:59.000Z
periods of' time, covering mesoscale Campbell, J. W. and W.Dimethyl Sulfide' On Their Mesoscale Variability PATRICIA A.Miami, Miami, Florida The mesoscale variability of dimethyl
Takada, Shoji
Mesoscale Numerical Study over the HEIFE Area Part 1: Three Dimensional Wind Field By Zhong CHEN1),Jiayi, 1996) Abstract In this study the three dimensional mesoscale model, which is based on the Peking University Mesoscale Model, was used to simulate the wind field in the HEIFE experimental region. Simulations
Finite-Volume Spectra of the Lee-Yang Model
Zoltan Bajnok; Omar el Deeb; Paul A. Pearce
2014-12-29T23:59:59.000Z
We consider the non-unitary Lee-Yang minimal model ${\\cal M}(2,5)$ in three different finite geometries: (i) on the interval with integrable boundary conditions labelled by the Kac labels $(r,s)=(1,1),(1,2)$, (ii) on the circle with periodic boundary conditions and (iii) on the periodic circle including an integrable purely transmitting defect. We apply $\\varphi_{1,3}$ integrable perturbations on the boundary and on the defect and describe the flow of the spectrum. Adding a $\\Phi_{1,3}$ integrable perturbation to move off-criticality in the bulk, we determine the finite size spectrum of the massive scattering theory in the three geometries via Thermodynamic Bethe Ansatz (TBA) equations. We derive these integral equations for all excitations by solving, in the continuum scaling limit, the TBA functional equations satisfied by the transfer matrices of the associated $A_{4}$ RSOS lattice model of Forrester and Baxter in Regime III. The excitations are classified in terms of $(m,n)$ systems. The excited state TBA equations agree with the previously conjectured equations in the boundary and periodic cases. In the defect case, new TBA equations confirm previously conjectured transmission factors.
Calibration under uncertainty for finite element models of masonry monuments
Atamturktur, Sezer,; Hemez, Francois,; Unal, Cetin
2010-02-01T23:59:59.000Z
Historical unreinforced masonry buildings often include features such as load bearing unreinforced masonry vaults and their supporting framework of piers, fill, buttresses, and walls. The masonry vaults of such buildings are among the most vulnerable structural components and certainly among the most challenging to analyze. The versatility of finite element (FE) analyses in incorporating various constitutive laws, as well as practically all geometric configurations, has resulted in the widespread use of the FE method for the analysis of complex unreinforced masonry structures over the last three decades. However, an FE model is only as accurate as its input parameters, and there are two fundamental challenges while defining FE model input parameters: (1) material properties and (2) support conditions. The difficulties in defining these two aspects of the FE model arise from the lack of knowledge in the common engineering understanding of masonry behavior. As a result, engineers are unable to define these FE model input parameters with certainty, and, inevitably, uncertainties are introduced to the FE model.
Soft X-ray techniques to study mesoscale magnetism
Kortright, Jeffrey B.
2003-01-01T23:59:59.000Z
X-Ray Techniques to Study Mesoscale Magnetism Jeffrey B.X-Ray Techniques to Study Mesoscale Magnetism Jeffrey B.
Mesoscale Predictability of an Extreme Warm-Season Precipitation Event FUQING ZHANG, ANDREW M Station, Texas (Manuscript received 22 November 2004, in final form 28 August 2005) ABSTRACT A mesoscale model is used to investigate the mesoscale predictability of an extreme precipitation event over central
Structural Analysis of a New Design of a Glenoid Prosthesis by Finite Element Modeling
Downey, John A
1990-01-01T23:59:59.000Z
18 Abstract Prosthesis loosening in total shoulderexcision. Present glenoid prostheses have fixation only inDesign of a Glenoid Prosthesis by Finite Element Modeling By
Sensitivity of mesoscale gravity waves to the baroclinicity of jet-front systems
Wang, Shuguang
2006-04-12T23:59:59.000Z
To investigate the generation of mesoscale gravity waves from upper-tropospheric jet-front systems, five different life cycles of baroclinic waves are simulated with a high-resolution mesoscale model (MM5 with 10-km grid spacing). The baroclinicity...
Sensitivity of mesoscale gravity waves to the baroclinicity of jet-front systems
Wang, Shuguang
2006-04-12T23:59:59.000Z
To investigate the generation of mesoscale gravity waves from upper-tropospheric jet-front systems, five different life cycles of baroclinic waves are simulated with a high-resolution mesoscale model (MM5 with 10-km grid spacing). The baroclinicity...
Mesoscale Simulations of Power Compaction
Lomov, I; Fujino, D; Antoun, T; Liu, B
2009-08-06T23:59:59.000Z
Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.
space/time and modeling formalisms; extensions: Multilevel modeling in CA
Utrecht, Universiteit
expectation (attractors, mesoscale patterns) · Exploration what happens if we assume.... emergent behaviour MESOSCALE ENTITIES: - discovery and description - modeling these entities -'beyond' dynamical systems (IBM models) PREDEFINED MULTIPLE LEVEL - e.g. predefined cells as mesoscale - multiple timescales
FEMA: a Finite Element Model of Material Transport through Aquifers
Yeh, G.T.; Huff, D.D.
1985-01-01T23:59:59.000Z
This report documents the construction, verification, and demonstration of a Finite Element Model of Material Transport through Aquifers (FEMA). The particular features of FEMA are its versatility and flexibility to deal with as many real-world problems as possible. Mechanisms included in FEMA are: carrier fluid advection, hydrodynamic dispersion and molecular diffusion, radioactive decay, sorption, source/sinks, and degradation due to biological, chemical as well as physical processes. Three optional sorption models are embodied in FEMA. These are linear isotherm and Freundlich and Langmuir nonlinear isotherms. Point as well as distributed source/sinks are included to represent artificial injection/withdrawals and natural infiltration of precipitation. All source/sinks can be transient or steady state. Prescribed concentration on the Dirichlet boundary, given gradient on the Neumann boundary segment, and flux at each Cauchy boundary segment can vary independently of each other. The aquifer may consist of as many formations as desired. Either completely confined or completely unconfined or partially confined and partially unconfined aquifers can be dealt with effectively. FEMA also includes transient leakage to or from the aquifer of interest through confining beds from or to aquifers lying below and/or above.
Mesoscale Metallic Pyramids with Nanoscale Tips
Odom, Teri W.
Mesoscale Metallic Pyramids with Nanoscale Tips Joel Henzie, Eun-Soo Kwak, and Teri W. Odom generate free-standing mesoscale metallic pyramids composed of one or more materials and having nanoscale tips (radii of curvature of less than 2 nm). Mesoscale holes (100-300 nm) in a chromium film are used
MESOSCALE CONVECTIVE SYSTEMS Robert A. Houze Jr.
Houze Jr., Robert A.
MESOSCALE CONVECTIVE SYSTEMS Robert A. Houze Jr. Department of Atmospheric Sciences University; published 31 December 2004. [1] Mesoscale convective systems (MCSs) have regions of both convective and stratiform precipitation, and they develop mesoscale circulations as they mature. The upward motion takes
Engineering mesoscale structures with distinct dynamical implications
Engineering mesoscale structures with distinct dynamical implications Anne-Ly Do1 , Johannes H that there are certain mesoscale subgraphs that have precise and distinct consequences for the system-level dynamics. In particular, if mesoscale symmetries are present then eigenvectors of the Jacobian localise on the symmetric
FEWA: a Finite Element model of Water flow through Aquifers
Yeh, G.T.; Huff, D.D.
1983-11-01T23:59:59.000Z
This report documents the implementation and demonstration of a Finite Element model of Water flow through Aquifers (FEWA). The particular features of FEWA are its versatility and flexibility to deal with as many real-world problems as possible. Point as well as distributed sources/sinks are included to represent recharges/pumpings and rainfall infiltrations. All sources/sinks can be transient or steady state. Prescribed hydraulic head on the Dirichlet boundaries and fluxes on Neumann or Cauchy boundaries can be time-dependent or constant. Source/sink strength over each element and node, hydraulic head at each Dirichlet boundary node, and flux at each boundary segment can vary independently of each other. Either completely confined or completely unconfined aquifers, or partially confined and partially unconfined aquifers can be dealt with effectively. Discretization of a compound region with very irregular curved boundaries is made easy by including both quadrilateral and triangular elements in the formulation. Large-field problems can be solved efficiently by including a pointwise iterative solution strategy as an optional alternative to the direct elimination solution method for the matrix equation approximating the partial differential equation of groundwater flow. FEWA also includes transient flow through confining leaky aquifers lying above and/or below the aquifer of interest. The model is verified against three simple cases to which analytical solutions are available. It is then demonstrated by two examples of how the model can be applied to heterogeneous and anisotropic aquifers with transient boundary conditions, time-dependent sources/sinks, and confining aquitards for a confined aquifer of variable thickness and for a free surface problem in an unconfined aquifer, respectively. 20 references, 25 figures, 8 tables.
Modelling and numerical approximation of a 2.5D set of equations for mesoscale atmospheric processes
Kalise, Dante
2011-01-01T23:59:59.000Z
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.
Acoustic Characterization of Mesoscale Objects
Chinn, D; Huber, R; Chambers, D; Cole, G; Balogun, O; Spicer, J; Murray, T
2007-03-13T23:59:59.000Z
This report describes the science and engineering performed to provide state-of-the-art acoustic capabilities for nondestructively characterizing mesoscale (millimeter-sized) objects--allowing micrometer resolution over the objects entire volume. Materials and structures used in mesoscale objects necessitate the use of (1) GHz acoustic frequencies and (2) non-contacting laser generation and detection of acoustic waves. This effort demonstrated that acoustic methods at gigahertz frequencies have the necessary penetration depth and spatial resolution to effectively detect density discontinuities, gaps, and delaminations. A prototype laser-based ultrasonic system was designed and built. The system uses a micro-chip laser for excitation of broadband ultrasonic waves with frequency components reaching 1.0 GHz, and a path-stabilized Michelson interferometer for detection. The proof-of-concept for mesoscale characterization is demonstrated by imaging a micro-fabricated etched pattern in a 70 {micro}m thick silicon wafer.
Radhakrishnan, Balasubramaniam [ORNL; Gorti, Sarma B [ORNL; Stoica, Grigoreta M [ORNL; Muralidharan, Govindarajan [ORNL; Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Specht, Eliot D [ORNL; Kenik, Edward A [ORNL; Muth, Thomas R [ORNL
2012-01-01T23:59:59.000Z
The focus of the present research is to develop an integrated deformation and recrystallization model for magnesium alloys at the microstructural length scale. It is known that in magnesium alloys nucleation of recrystallized grains occurs at various microstructural inhomogeneities such as twins and localized deformation bands. However, there is a need to develop models that can predict the evolution of the grain structure and texture developed during recrystallization and grain growth, especially when the deformation process follows a complicated deformation path such as in asymmetric rolling. The deformation model is based on a crystal plasticity approach implemented at the length scale of the microstructure that includes deformation mechanisms based on dislocation slip and twinning. The recrystallization simulation is based on a Monte Carlo technique that operates on the output of the deformation simulations. The nucleation criterion during recrystallization is based on the local stored energy and the Monte Carlo technique is used to simulate the growth of the nuclei due to local stored energy differences and curvature. The model predictions are compared with experimental data obtained through electron backscatter analysis and neutron diffraction.
Ariza Moreno, Pilar
SEMINARIOS INTERUNIVERSITARIOS MECÁNICA Y MATERIALES STRUCTURAL MODELING OF BIOSOLIDS UNDER FINITE the detailed structure of a biosolid in a material model. We focus on the micro- structure of arterial walls
On a tensor-based finite element model for the analysis of shell structures
Arciniega Aleman, Roman Augusto
2006-04-12T23:59:59.000Z
In the present study, we propose a computational model for the linear and nonlinear analysis of shell structures. We consider a tensor-based finite element formulation which describes the mathematical shell model in a ...
Review of structure representation and reconstruction on mesoscale and microscale
Li, Dongsheng
2014-05-01T23:59:59.000Z
Structure representation and reconstruction on mesoscale and microscale is critical in material design, advanced manufacturing and multiscale modeling. Microstructure reconstruction has been applied in different areas of materials science and technology, structural materials, energy materials, geology, hydrology, etc. This review summarizes the microstructure descriptors and formulations used to represent and algorithms to reconstruct structures at microscale and mesoscale. In the stochastic methods using correlation function, different optimization approaches have been adapted for objective function minimization. A variety of reconstruction approaches are compared in efficiency and accuracy.
Harrison, Mark
1988-01-01T23:59:59.000Z
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
Mesoscale predictability of an extreme warm-season precipitation event
Odins, Andrew Michael
2005-02-17T23:59:59.000Z
. The Penn State University/NCAR Mesoscale Model version 5 (MM5) was used to conduct predictability experiments, which follow closely to the research conducted by Zhang et al. A control simulation initialized at 00Z 1 July is established over a 30-km grid...
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING
Paris-Sud XI, Université de
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING element exploits the advantages of wavelets for the spatial discretization of the displacement field : Wavelet-based Finite Element, Transient Response. 1 INTRODUCTION The dynamic transient response and wave
Model formalisms, continued; CA, ODE, Boolean networks
Utrecht, Universiteit
Mesoscale patterns Zoo QUESTIONS? TODAY · CA as modeling tool: common generalisations · alternative
TEA - a linear frequency domain finite element model for tidal embayment analysis
Westerink, Joannes J.
1984-01-01T23:59:59.000Z
A frequency domain (harmonic) finite element model is developed for the numerical prediction of depth average circulation within small embayments. Such embayments are often characterized by irregular boundaries and bottom ...
Finite element decomposition and grid generation for brain modeling and visualization
Batte, David Allan
1997-01-01T23:59:59.000Z
Numerical grid generation is used to provide a framework for brain and neuron visualization. Smoothing spline surfaces are fit to contour data to generate 3D solid model reconstruction of brain tissues. Finite element methods are then used...
A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model
DÃaz, JesÃºs Ildefonso
A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model R. BERMEJO,1 J. This model belongs to the category of energy balance models introduced independently by the climatologists M climate. The energy balance model we are dealing with consists of a two-dimensional nonlinear parabolic
Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method
Wang, G.; Liu, M.
2005-01-01T23:59:59.000Z
Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method Gang Wang Research Associate University of Nebraska – Lincoln Mingsheng Liu Professor University of Nebraska – Lincoln David E. Claridge Professor Texas A... be decoupled using a constant sensible heat ratio (SHR) and the saturation humidity ratio vs. temperature curve can be treated as linear in a small area corresponding to a finite element of the coil. This paper presents the decoupled cooling coil model...
Dynamic Filtering and Mining Triggers in Mesoscale Meteorology Forecasting
Plale, Beth
Dynamic Filtering and Mining Triggers in Mesoscale Meteorology Forecasting Nithya N. Vijayakumar {rramachandran, xli}@itsc.uah.edu Abstract-- Mesoscale meteorology forecasting as a data driven application Triggers, Data Mining, Stream Processing, Meteorology Forecasting I. INTRODUCTION Mesoscale meteorologists
MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY
Sethna, James P.
MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY A Dissertation Presented RIGHTS RESERVED #12;MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY Surachate Limkumnerd, continuum explanation for the evolution of dislocations into sharp walls. We present here a mesoscale theory
Mesoscale & Microscale Meteorological Division / NCAR WRF Nature Run
Michalakes, John
Mesoscale & Microscale Meteorological Division / NCAR WRF Nature Run John Michalakes Josh Hacker overview and petascale issues Nature run methodology Results and conclusion #12;Mesoscale & Microscale's atmosphere #12;Mesoscale & Microscale Meteorological Division / NCAR Description of Science · Kinetic energy
Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems
Putrasahan, Dian Ariyani
2012-01-01T23:59:59.000Z
Isolating Mesoscale Coupled Ocean-Atmosphere in the KuroshioSST coupler . . . . Chapter 3 Mesoscale Ocean-Atmosphere4.2 Impact of Mesoscale SST on Precipitation Chapter 4 vi
Hoofard, Michael Eugene
1986-01-01T23:59:59.000Z
MESOSCALE CONVECTIVE CCMPLLX VS. NON-MESOSCALE CONVECTIVE COMPLEX THUNDERSTORMS: A COMPARISON OF SELECTED METEOROLOGICAL VARIABLES A Thesis MICHAkL EUGENE JJOOFARD Submitted to the Graduate College of Texas AJkM University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1986 Major Subj ect: Meteorology MESOSCALE CONVECTIVE COMPLEX VS. NON-MESOSCALE CONVECTIVE COMPLEX THUNDERSTORMS: A COMPARISON OF SELECTED METEOROLOGICAL VARIABLES A Thesis...
P h y s i c a l O c e a n o g r a p h y D i v i s i o n Role of Mesoscale Eddies on Decadal representation of mesoscale eddies in the ocean. Therefore, the impact of mesoscale eddies on climate variability the mesoscale eddies are properly parameterized in CMIP5 models. Our overall goal is to explore the impact
Cheng, Hao
2006-10-30T23:59:59.000Z
sensitivity computation of the streamline models with the versatility of finite-difference simulation was developed. Use of finite-difference simulation can account for complex physics. Finally, we developed an approach to history matching three-phase flow...
Ecospace: Prediction of Mesoscale Spatial Patterns in Trophic
Pauly, Daniel
Ecospace: Prediction of Mesoscale Spatial Patterns in Trophic Relationships of Exploited Ecosystems Springer-Verlag 539 Walters, C., D. Pauly and V. Christensen. 1999. Ecospace: Prediction of mesoscale
New Mesoscale Multimodal Imaging of Cellular Communication Between...
Office of Science (SC) Website
New Mesoscale Multimodal Imaging Bioimaging Technology Bioimaging Technology Home About Research Small Worlds New Mesoscale Multimodal Imaging Adaptive Biosystems Imaging Systems...
FINITE VOLUME METHODS APPLIED TO THE COMPUTATIONAL MODELLING OF WELDING PHENOMENA
Taylor, Gary
1 FINITE VOLUME METHODS APPLIED TO THE COMPUTATIONAL MODELLING OF WELDING PHENOMENA Gareth A.Taylor@brunel.ac.uk ABSTRACT This paper presents the computational modelling of welding phenomena within a versatile numerical) and Computational Solid Mechanics (CSM). With regard to the CFD modelling of the weld pool fluid dynamics, heat
Styles, Vanessa
Finite element analysis of a current density - electric #12;eld formulation of Bean's model a current density-electric #12;eld formulation of Bean's model for the experimental set-up of a in#12;nitely. As observed by Bossavit, [4], Bean's critical state model can be formulated as a degenerate Stefan problem
A FINITE ELEMENT APPROXIMATION OF A VARIATIONAL INEQUALITY FORMULATION OF BEAN'S MODEL FOR
Elliott, Charles
A FINITE ELEMENT APPROXIMATION OF A VARIATIONAL INEQUALITY FORMULATION OF BEAN'S MODEL of a variational formulation of Bean's model for the physical configuration of an infinitely long cylindrical's axis, for x R2 . The well-known Bean critical state model can be formulated as an evolutionary
Buscaglia, Gustavo C.
Conservative one-dimensional finite volume discretization of a new cavitation model for piston Cavitation ElrodÂAdams model PistonÂrings a b s t r a c t This paper presents a conservative numerical implementation of a new cavitation model that is well suited for lubrication problems with cavitated regions
Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert; Gao, Fei; Sun, Xin; Tonks, Michael; Biner, Bullent; Millet, Paul; Tikare, Veena; Radhakrishnan, Balasubramaniam; Andersson , David
2012-04-11T23:59:59.000Z
A study was conducted to evaluate the capabilities of different numerical methods used to represent microstructure behavior at the mesoscale for irradiated material using an idealized benchmark problem. The purpose of the mesoscale benchmark problem was to provide a common basis to assess several mesoscale methods with the objective of identifying the strengths and areas of improvement in the predictive modeling of microstructure evolution. In this work, mesoscale models (phase-field, Potts, and kinetic Monte Carlo) developed by PNNL, INL, SNL, and ORNL were used to calculate the evolution kinetics of intra-granular fission gas bubbles in UO2 fuel under post-irradiation thermal annealing conditions. The benchmark problem was constructed to include important microstructural evolution mechanisms on the kinetics of intra-granular fission gas bubble behavior such as the atomic diffusion of Xe atoms, U vacancies, and O vacancies, the effect of vacancy capture and emission from defects, and the elastic interaction of non-equilibrium gas bubbles. An idealized set of assumptions was imposed on the benchmark problem to simplify the mechanisms considered. The capability and numerical efficiency of different models are compared against selected experimental and simulation results. These comparisons find that the phase-field methods, by the nature of the free energy formulation, are able to represent a larger subset of the mechanisms influencing the intra-granular bubble growth and coarsening mechanisms in the idealized benchmark problem as compared to the Potts and kinetic Monte Carlo methods. It is recognized that the mesoscale benchmark problem as formulated does not specifically highlight the strengths of the discrete particle modeling used in the Potts and kinetic Monte Carlo methods. Future efforts are recommended to construct increasingly more complex mesoscale benchmark problems to further verify and validate the predictive capabilities of the mesoscale modeling methods used in this study.
Guglielmi, Y.
2008-01-01T23:59:59.000Z
Mesoscale Characterization of Coupled Hydromechanicalinstrumented for mesoscale hydraulic and mechanicalwords: Fracture; Rock slope; Mesoscale; In situ poroelastic
Isothermal model of ICF burn with finite alpha range treatment
Galloway, Conner Daniel (Conner Daniel Cross)
2009-01-01T23:59:59.000Z
A simple model for simulating deuterium tritium burn in inertial confinement fusion capsules is developed. The model, called the Isothermal Rarefaction Model, is zero dimensional (represented as ordinary differential ...
Nuclear mass systematics by complementing the Finite Range Droplet Model with neural networks
S. Athanassopoulos; E. Mavrommatis; K. A. Gernoth; J. W. Clark
2005-11-30T23:59:59.000Z
A neural-network model is developed to reproduce the differences between experimental nuclear mass-excess values and the theoretical values given by the Finite Range Droplet Model. The results point to the existence of subtle regularities of nuclear structure not yet contained in the best microscopic/phenomenological models of atomic masses. Combining the FRDM and the neural-network model, we create a hybrid model with improved predictive performance on nuclear-mass systematics and related quantities.
RodrÃguez, Rodolfo
Numerical analysis of a finite element method for the axisymmetric eddy current model, 27002, Lugo, Spain The aim of this paper is to analyze a finite element method to solve an eddy current of the method are reported. Keywords: low-frequency harmonic Maxwell equations, eddy current problems, finite
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE EDDY CURRENT MODEL WITH CIRCUIT/FIELD COUPLINGS
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE EDDY CURRENT MODEL WITH CIRCUIT/FIELD COUPLINGS JUNQING for solving the eddy current model with voltage excitations for complicated three dimensional structures of the proposed method. Key words. Eddy current, circuit/field coupling, adaptivity, a posteriori error analysis
Modeling the Effect of Finite-Rate Hydrogen Diffusion on Porosity Formation in Aluminum Alloys
Beckermann, Christoph
Modeling the Effect of Finite-Rate Hydrogen Diffusion on Porosity Formation in Aluminum Alloys KENT of hydrogen in the melt is developed to predict pore formation during the solidification of aluminum alloys by Lee et al.[3] Recent examples of porosity models for aluminum alloy castings, including the effect
A Finite-Element Model for Simulation of Carbon Dioxide Sequestration
Bao, Jie; Xu, Zhijie; Fang, Yilin
2014-09-01T23:59:59.000Z
Herein, we present a coupled thermal-hydro-mechanical model for geological sequestration of carbon dioxide followed by the stress, deformation, and shear-slip failure analysis. This fully coupled model considers the geomechanical response, fluid flow, and thermal transport relevant to geological sequestration. Both analytical solutions and numerical approach via finite element model are introduced for solving the thermal-hydro-mechanical model. Analytical solutions for pressure, temperature, deformation, and stress field were obtained for a simplified typical geological sequestration scenario. The finite element model is more general and can be used for arbitrary geometry. It was built on an open-source finite element code, Elmer, and was designed to simulate the entire period of CO2 injection (up to decades) both stably and accurately—even for large time steps. The shear-slip failure analysis was implemented based on the numerical results from the finite element model. The analysis reveals the potential failure zone caused by the fluid injection and thermal effect. From the simulation results, the thermal effect is shown to enhance well injectivity, especially at the early time of the injection. However, it also causes some side effects, such as the appearance of a small failure zone in the caprock. The coupled thermal-hydro-mechanical model improves prediction of displacement, stress distribution, and potential failure zone compared to the model that neglects non-isothermal effects, especially in an area with high geothermal gradient.
A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors
Pietra, Paola
A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors Stefan Holst #12;tting mixed #12;nite-element method is used to discretize the stationary energy. Energy-transport models describe the ow of electrons through a semi- conductor device, in uenced by di
Finite-element discretization of a linearized 2 -D model for lubricated oil transportation
Frey, Pascal
Finite-element discretization of a linearized 2 - D model for lubricated oil transportation V acts as a lubricant by coating the wall of the pipeline, thus preventing the oil from adhering is devoted to the numerical simulation of a linearized model for the lubricated trans- portation of heavy
Bürger, Raimund
in models of sedimentation Raimund B¨urgera , Sarvesh Kumarb , Ricardo Ruiz-Baierc aCI2MA and Departamento The sedimentation-consolidation and flow processes of a mixture of small particles dispersed in a vis- cous fluid discontinuous finite volume element (DFVE) discretization for this model is pro- posed. The numerical method
Modeling Respiratory Lung Motion a Biophysical Approach using Finite Element Methods
Lübeck, Universität zu
Modeling Respiratory Lung Motion a Biophysical Approach using Finite Element Methods Rene Wernera motion gains in importance. In this paper a biophysical approach for modeling lung motion is described. Main aspects of the process of lung ventilation are identified and outlined as the starting point
Penetrative turbulence associated with mesoscale surface heat flux variations
Alam, Jahrul M
2015-01-01T23:59:59.000Z
This article investigates penetrative turbulence in the atmospheric boundary layer. Using a large eddy simulation approach, we study characteristics of the mixed layer with respect to surface heat flux variations in the range from 231.48 W/m$^2$ to 925.92 W/m$^2$, and observe that the surface heterogeneity on a spatial scale of $20$ km leads to downscale turbulent kinetic energy cascade. Coherent fluctuations of mesoscale horizontal wind is observed at 100m above the ground. Such a surface induced temporal oscillations in the horizontal wind suggest a rapid jump in mesocale wind forecasts, which is difficult to parameterize using traditional one-dimensional ensemble-mean models. Although the present work is idealized at a typical scale (20km) of surface heterogeneity, the results help develop effective subgrid scale parameterization schemes for classical weather forecasting mesoscale models.
Molecule-Mimetic Chemistry and Mesoscale Self-Assembly
Prentiss, Mara
Molecule-Mimetic Chemistry and Mesoscale Self-Assembly NED B. BOWDEN, MARCUS WECK, INSUNG S. CHOI, and possible uses for these processes and assemblies.6-22 Mesoscale Self-Assembly (MESA) Mesoscale Self technically, and especially in physics, a mesoscale object is one whose dimensions are comparable to the scale
Transport and dispersion of pollutants in surface impoundments: a finite element model
Yeh, G.T.
1980-07-01T23:59:59.000Z
A surface impoundment model in finite element (SIMFE) is presented to enable the simulation of flow circulations and pollutant transport and dispersion in natural or artificial lakes, reservoirs or ponds with any number of islands. This surface impoundment model consists of two sub-models: hydrodynamic and pollutant transport models. Both submodels are simulated by the finite element method. While the hydrodynamic model is solved by the standard Galerkin finite element scheme, the pollutant transport model can be solved by any of the twelve optional finite element schemes built in the program. Theoretical approximations and the numerical algorithm of SIMFE are described. Detail instruction of the application are given and listing of FORTRAN IV source program are provided. Two sample problems are given. One is for an idealized system with a known solution to show the accuracy and partial validation of the models. The other is applied to Prairie Island for a set of hypothetical input data, typifying a class of problems to which SIMFE may be applied.
João H. Bettencourt; Cristóbal López; Emilio Hernández-García
2012-07-09T23:59:59.000Z
We study three dimensional oceanic Lagrangian Coherent Structures (LCSs) in the Benguela region, as obtained from an output of the ROMS model. To do that we first compute Finite-Size Lyapunov exponent (FSLE) fields in the region volume, characterizing mesoscale stirring and mixing. Average FSLE values show a general decreasing trend with depth, but there is a local maximum at about 100 m depth. LCSs are extracted as ridges of the calculated FSLE fields. They present a "curtain-like" geometry in which the strongest attracting and repelling structures appear as quasivertical surfaces. LCSs around a particular cyclonic eddy, pinched off from the upwelling front are also calculated. The LCSs are confirmed to provide pathways and barriers to transport in and out of the eddy.
Parallel finite element modeling of earthquake ground response and liquefaction
Lu, Jinchi
2006-01-01T23:59:59.000Z
T. (1999). Computational Geomechanics with Special ReferenceDynamic Problems in Geomechanics," PhD Thesis, Universityon Numerical Models in Geomechanics, G. N. Pande, Van Impe,
Parallel finite element modeling of earthquake ground response and liquefaction
Lu, Jinchi
2006-01-01T23:59:59.000Z
Failure of Sand Slope in Centrifuge Test." Proceedings ofStephen E. (2001b). "Centrifuge Modeling of Pile-Supportedof Site Liquefaction Using Centrifuge Tests." Proceedings of
One dimensional electroseismic modeling using the finite element ...
2013-01-30T23:59:59.000Z
Section is devoted to a description of the Earth model and electromagnetic source ...... wave phenomena in fluid-saturated sediments”, J. Geophys. Res. .... [
Schlegel, Nicole-Jeanne
2011-01-01T23:59:59.000Z
in running RCM’s over Greenland to produce high-qualityoutlet glaciers. For Greenland, this detail is specificallyCurrently, no coupled Greenland Ice Sheet model experiment
Mapping mesoscale heterogeneity in the plastic deformation of a copper single crystal
Magid, K. R.
2009-01-01T23:59:59.000Z
619. page 18 Mapping mesoscale heterogeneity in a deformedthese planes. page 36 Mapping mesoscale heterogeneity in aJanuary 2009, 77–107 Mapping mesoscale heterogeneity in the
Effect of ocean mesoscale variability on the mean state of tropical Atlantic climate
Seo, H; Jochum, M; Murtugudde, R; Miller, A J
2006-01-01T23:59:59.000Z
Effect of Ocean Mesoscale Variability on the Mean State ofthe effect of oceanic mesoscale features on the mean climatemodel, resolving oceanic mesoscale variability leads to a
Integrating Tactile and Force Feedback with Finite Element Models
, impedances of robot arms, and the computational model. We also describe an implementation of a compliance rendering system combining a low-impedance robot arm for large workspace kinesthetic force feedback, a high on a low-impedance robot arm, used here as a force feedback device. A real-time FEM model accepts user
Moldovan, D.; Wolf, D.; Phillpot, S. R.; Materials Science Division; Louisiana State Univ.
2003-11-01T23:59:59.000Z
Using grain growth in nanocrystalline palladium as a simple case study, we demonstrate how a novel mesoscale approach for simulating microstructural evolution in polycrystalline materials can be validated directly against atomic-level simulations of the same system. We first describe molecular dynamics simulations of grain growth in a columnar model microstructure. The atomic-level insights into the grain-growth mechanism gained from these simulations, particularly in the role of grain rotations, are captured theoretically for incorporation into the mesoscale approach, in which the objects evolving in space and time are the grain boundaries and grain junctions rather than the atoms. With all the input parameters to the mesoscale being physically well defined and obtained directly from the atomic-level simulations, the mesoscale simulations are fully prescribed. We find that the morphology of the mesoscale system evolves in an almost identical manner with that of the molecular dynamics simulation, demonstrating that the length- and time-scale linking has been performed correctly. When applied to systems containing large numbers of grains, the now validated mesoscale simulation approach allows the growth topology and long-time growth kinetics to be determined. As an outlook, we describe how the effects of applied stress can be incorporated.
Development of a finite element model of decompressive craniectomy
Fletcher, Tim L.; Kolias, Angelos G.; Hutchinson, Peter J. A.; Sutcliffe, Michael P. F.
2014-07-15T23:59:59.000Z
would be lost. One aspect that needs to be considered carefully is the type of material model required. In decompressive craniectomy there is a hybrid of confined and unconfined loading, which means that conclusions drawn on appropriate material models... Neurology 9(7): 405–15. 10. Elkin BS, Morrison B (2007) Region-specific tolerance criteria for the living brain. Stapp Car Crash Journal 51: 127–38. 11. Miller K, Wittek A, Joldes G, Horton A, Dutta-Roy T, et al. (2010) Modelling brain deformations...
Heat Transport in Groundwater Systems--Finite Element Model
Grubaugh, E. K.; Reddell, D. L.
into groundwater aquifers for long term energy storage. Analytical solutions are available that predict water temperatures as hot water is injected into a groundwater aquifer, but little field and laboratory data are available to verify these models. The objectives...
Heat Transport in Groundwater Systems--Finite Element Model
Grubaugh, E. K.; Reddell, D. L.
1980-01-01T23:59:59.000Z
into groundwater aquifers for long term energy storage. Analytical solutions are available that predict water temperatures as hot water is injected into a groundwater aquifer, but little field and laboratory data are available to verify these models. The objectives...
Finite-element harmonic experiments to model fractured induced ...
santos
Mar 10, 2014 ... Krzikalla and Müller [7] combined the two previous models to obtain ... Among other works employing numerical simulations to analyze dispersion, ...... layered fluid and gas saturated sediments, Geophysics 62 (1997) ...
Finite element modeling of SHTE and PSVTM electroseismics
Fabio I. Zyserman
2010-10-07T23:59:59.000Z
algorithm to model diffusive electric fields induced by SH waves;. Garambois and Dietrich (2002) ... Santos and Sheen (2007); and the corresponding dispersion analysis was presented in ...... in fluid-saturated sediments. J. Geophys. Res. 111
James, Stephen M.
2011-08-08T23:59:59.000Z
The subject of this thesis is an extension of a two-dimensional, axisymmetric, Timoshenko-beam finite-element rotordynamic code to include a three-dimensional non-axisymmetric solid-element casing model. Axisymmetric beams are sufficient to model...
Finite-temperature order-disorder phase transition in a cluster model of decagonal tilings
Gähler, Franz
phase,2 because its phason degrees of freedom are frozen (locked). The high-temperature state is accordingly called unlocked phase. Here, the thermal energy is suffi- ciently high to excite the phasonFinite-temperature order-disorder phase transition in a cluster model of decagonal tilings Michael
Finite-element modeling of subglacial cavities and related friction law
Gagliardini, Olivier
Finite-element modeling of subglacial cavities and related friction law O. Gagliardini,1 D. Cohen,2, the friction law, can be easily extended from linear to nonlinear ice rheology and is bounded even for bedrocks with locally infinite slopes. Combining our results with earlier works by others, a phenomenological friction
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER
Paris-Sud XI, Université de
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER). To design a Structural Health Monitoring (SHM) system, it is important to understand phenomenologically Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France Copyright © Inria (2014
Adaptive mesh, finite volume modeling of marine ice sheets Stephen L. Cornforda
Adaptive mesh, finite volume modeling of marine ice sheets Stephen L. Cornforda , Daniel F. Martinb Abstract Continental scale marine ice sheets such as the present day West Antarctic Ice Sheet are strongly phenomenon of this kind is the migration of the grounding line -- the division between ice in contact
Modelling CO2 diffusion and assimilation in a leaf with axisymmetric finite volumes
Herbin, RaphaÃ¨le
Modelling CO2 diffusion and assimilation in a leaf with axisymmetric finite volumes Emily GallouÃ«t. This paper deals with the numerical simulation of the diffusion and assimilation by photosynthesis of CO2 medium, from experimental measurements of the pointwise value of internal CO2 concentration, giving some
A mixed finite-element scheme of a semiconductor energy-transport model
Hanke-Bourgeois, Martin
A mixed finite-element scheme of a semiconductor energy-transport model using dual entropy which are able to deal with physical effects such as carrier heating and velocity overshoot. The energy that the Joule heating term vanishes if the dual entropy variables w1 = (Âµ - V )/T and w2 = -1/T are employed
Modeling of board-level package by Finite Element Analysis and laser interferometer measurements
Cao, Wenwu
and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai be simulated by an equivalent Finite Element Analysis (FEA) model of the board-level package, in which detailed layer structure of the Print Circuit Board (PCB), signal wires and through-holes were ignored
S5 S5 S5 lacks the finite model property Dept. of Computer Science
Kurucz, Agi
S5 × S5 × S5 lacks the finite model property A. Kurucz Dept. of Computer Science King's College London Abstract It follows from algebraic results of Maddux that every multi-modal logic L such that [S5, S5, . . . , S5] L S5n is undecidable, whenever n 3. This implies that the product logic S5×S5×S5
Frey, Pascal
2008-01-01T23:59:59.000Z
for glaciers$ A.H. Jarosch Institute of Earth Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik Detailed studies of glacier flow and deformation of ice require high-resolution numerical modeling.40.Cy; 92.40.Sn; 92.40.Vq Keywords: Glacier; Finite element method; Full Stokes; Ice 1. Introduction
Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials
Paris-Sud XI, Université de
Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials A. Karrech a,, A. Seibi thrust is the introduc- tion of the "Chicago" law in a continuum approach to account for the ratcheting or jointly with the ratcheting effect. Non-associated plasticity is adopted since the paper mainly targets
Mortar finite element discretization of a model coupling Darcy and Stokes equations
Boyer, Edmond
Mortar finite element discretization of a model coupling Darcy and Stokes equations by C. Bernardi1 flowing on a homogeneous porous ground, we consider a system where the Darcy and Stokes equations´erons un syst`eme o`u les ´equations de Darcy et de Stokes sont coupl´ees par des conditions de raccord
Finite-Volume-Particle Methods for Models of Transport of Pollutant in Shallow Water
Kurganov, Alexander
Finite-Volume-Particle Methods for Models of Transport of Pollutant in Shallow Water Alina Chertock of shallow water equations and the pollutant propagation is described by a transport equation. The idea and the pollution computations: the shallow water equations are numerically integrated using a #12;nite- volume
A finite difference model for predicting sediment oxygen demand in streams
Charbonnet, Danielle Andrea
2003-01-01T23:59:59.000Z
in the representative river system using benthic chambers. A finite difference model was developed based on Fick's Law of Diffusion. Mass transfer principles are used to perform a mass balance on the oxygen concentrations in the sediment in order to determine SOD...
Suciu, Nicolae
A mixed finite element discretization scheme for a concrete carbonation model with concentration/unsaturated porous media. The special features of our problem are twofold: the reaction produces water and therefore for the case of concrete carbonation Â one of the most important physico-chemical processes affecting
TRAVELING WAVES IN A FINITE CONDENSATION RATE MODEL FOR STEAM INJECTION
Eindhoven, Technische Universiteit
TRAVELING WAVES IN A FINITE CONDENSATION RATE MODEL FOR STEAM INJECTION J. BRUINING AND C.J. VAN DUIJN Abstract. Steam drive recovery of oil is an economical way of producing oil even in times of low oil prices and is used world wide. This paper focuses on the one-dimensional setting, where steam
Analysis of a finite element formulation for modelling phase separation
Wells, G N; Garikipati, Krishna
2007-01-01T23:59:59.000Z
The Cahn-Hilliard equation is of importance in materials science and a range of other fields. It represents a diffuse interface model for simulating the evolution of phase separation in solids and fluids, and is a nonlinear fourth-order parabolic...
Thermodynamics and fluctuations of conserved charges in Hadron Resonance Gas model in finite volume
Bhattacharyya, Abhijit; Samanta, Subhasis; Sur, Subrata
2015-01-01T23:59:59.000Z
The thermodynamics of hot and dense matter created in heavy-ion collision experiments are usually studied as a system of infinite volume. Here we report on possible effects for considering a finite system size for such matter in the framework of the Hadron Resonance Gas model. The bulk thermodynamic variables as well as the fluctuations of conserved charges are considered. We find that the finite size effects are insignificant once the observables are scaled with the respective volumes. The only substantial effect is found in the fluctuations of electric charge which may therefore be used to extract information about the volume of fireball created in heavy-ion collision experiments.
Thermodynamics and fluctuations of conserved charges in Hadron Resonance Gas model in finite volume
Abhijit Bhattacharyya; Rajarshi Ray; Subhasis Samanta; Subrata Sur
2015-02-03T23:59:59.000Z
The thermodynamics of hot and dense matter created in heavy-ion collision experiments are usually studied as a system of infinite volume. Here we report on possible effects for considering a finite system size for such matter in the framework of the Hadron Resonance Gas model. The bulk thermodynamic variables as well as the fluctuations of conserved charges are considered. We find that the finite size effects are insignificant once the observables are scaled with the respective volumes. The only substantial effect is found in the fluctuations of electric charge which may therefore be used to extract information about the volume of fireball created in heavy-ion collision experiments.
Constructing warm inflationary model in finite temperature BIon
M. R. Setare; A. Sepehri
2014-10-07T23:59:59.000Z
We study warm inflationary universe model on the BIon in thermal background. The BIon is a configuration in flat space of a D-brane and a parallel anti-D-brane connected by a wormhole with F-string charge. When the branes and antibranes are well separated and the brane's spike is far from the antibrane's spike, wormhole isn't formed however when two branes are close to each other, they can be connected by a wormhole. In this condition, there exists many channels for flowing energy from extra dimensions into our universe and inflation may naturally occur in a warm region. We present a model that allows all cosmological parameters like the scale factor $a$, the Hubble parameter $H$ and universe energy density depend on the shape function and temperature of wormhole in transverse dimension between two branes. In our model, the expansion of 4D universe is controlled by the thermal wormhole between branes and ends up in Big-Rip singularity. We show that at this singularity, universe would be destroyed and one black F-string formed. Finally, we test our model against WMAP, Planck and BICEP2 data and obtain the ripping time. According to experimental data, $N\\simeq 50$ case leads to $n_{s}\\simeq 0.96$, where \\emph{N} and $n_{s}$ are the number e-folds and the spectral index respectively. This standard case may be found in $0.01 data and $t_{rip}=27.5(Gyr)$ for BICEP2 data. Comparing this time with the time of Big Rip in brane-antibrane, we find that the wormhole in BIonic system accelerates the destruction of the universe.
Boyer, Edmond
identification method - associating a direct finite element model of Gleeble tests and an optimization module1 Inverse Finite Element Modelling and Identification of Constitutive Parameters of UHS Steel Based-2 ) hc heat transfer coefficient at interface between specimen and grips (W m-2 K) hth_eff effective
Postulated Mesoscale Quantum of Internal Friction Hysteresis
Randall D. Peters
2004-05-27T23:59:59.000Z
Evidence is provided, from yet another experiment, for the existence of a mesoscale quantum of internal friction hysteresis, having the value of the electron rest energy divided by the fine structure constant.
Winding Transitions at Finite Energy and Temperature: An O(3) Model
Salman Habib; Emil Mottola; Peter Tinyakov
1996-08-14T23:59:59.000Z
Winding number transitions in the two dimensional softly broken O(3) nonlinear sigma model are studied at finite energy and temperature. New periodic instanton solutions which dominate the semiclassical transition amplitudes are found analytically at low energies, and numerically for all energies up to the sphaleron scale. The Euclidean period beta of these finite energy instantons increases with energy, contrary to the behavior found in the abelian Higgs model or simple one dimensional systems. This results in a sharp crossover from instanton dominated tunneling to sphaleron dominated thermal activation at a certain critical temperature. Since this behavior is traceable to the soft breaking of conformal invariance by the mass term in the sigma model, semiclassical winding number transition amplitudes in the electroweak theory in 3+1 dimensions should exhibit a similar sharp crossover. We argue that this is indeed the case in the standard model for M_H < 4 M_W.
Structure of finite-RSB asymptotic Gibbs measures in the diluted spin glass models
Dmitry Panchenko
2015-02-25T23:59:59.000Z
We suggest a possible approach to proving the M\\'ezard-Parisi formula for the free energy in the diluted spin glass models, such as diluted K-spin or random K-sat model at any positive temperature. In the main contribution of the paper, we show that a certain small modification of the Hamiltonian in any of these models forces all finite-RSB asymptotic Gibbs measures in the sense of the overlaps to satisfy the M\\'ezard-Parisi ansatz for the distribution of spins. Unfortunately, what is still missing is a description of the general full-RSB asymptotic Gibbs measures. If one could show that the general case can be approximated by finite-RSB case in the right sense then one could a posteriori remove the small modification of the Hamiltonian to recover the M\\'ezard-Parisi formula for the original model.
Puckett, A.D.
2000-09-01T23:59:59.000Z
The ability to model wave propagation in circular cylindrical bars of finite length numerically or analytically has many applications. In this thesis the capability of an explicit finite element method to model longitudinal waves in cylindrical rods with circular cross-sections is explored. Dispersion curves for the first four modes are compared to the analytical solution to determine the accuracy of various element sizes and time steps. Values for the time step and element size are determined that retain accuracy while minimizing computational time. The modeling parameters are validated by calculating a signal propagated with a broadband input force. Limitations on the applicability are considered along with modeling parameters that should be applicable to more general geometries.
Transport and dispersion of pollutants in surface impoundments: a finite difference model
Yeh, G.T.
1980-07-01T23:59:59.000Z
A surface impoundment model by finite-difference (SIMFD) has been developed. SIMFD computes the flow rate, velocity field, and the concentration distribution of pollutants in surface impoundments with any number of islands located within the region of interest. Theoretical derivations and numerical algorithm are described in detail. Instructions for the application of SIMFD and listings of the FORTRAN IV source program are provided. Two sample problems are given to illustrate the application and validity of the model.
Critical analysis of quark-meson coupling models for nuclear matter and finite nuclei
Horst Mueller; Byron K. Jennings
1998-07-09T23:59:59.000Z
Three versions of the quark-meson coupling (QMC) model are applied to describe properties of nuclear matter and finite nuclei. The models differ in the treatment of the bag constant and in terms of nonlinear scalar self-interactions. As a consequence opposite predictions for the medium modifications of the internal nucleon structure arise. After calibrating the model parameters at equilibrium nuclear matter density, binding energies, charge radii, single-particle spectra and density distributions of spherical nuclei are analyzed and compared with QHD calculations. For the models which predict a decreasing size of the nucleon in the nuclear environment, unrealistic features of the nuclear shapes arise.
Building relativistic mean field models for finite nuclei and neutron stars
Wei-Chia Chen; J. Piekarewicz
2014-08-18T23:59:59.000Z
Background: Theoretical approaches based on density functional theory provide the only tractable method to incorporate the wide range of densities and isospin asymmetries required to describe finite nuclei, infinite nuclear matter, and neutron stars. Purpose: A relativistic energy density functional (EDF) is developed to address the complexity of such diverse nuclear systems. Moreover, a statistical perspective is adopted to describe the information content of various physical observables. Methods: We implement the model optimization by minimizing a suitably constructed chi-square objective function using various properties of finite nuclei and neutron stars. The minimization is then supplemented by a covariance analysis that includes both uncertainty estimates and correlation coefficients. Results: A new model, FSUGold2, is created that can well reproduce the ground-state properties of finite nuclei, their monopole response, and that accounts for the maximum neutron star mass observed up to date. In particular, the model predicts both a stiff symmetry energy and a soft equation of state for symmetric nuclear matter--suggesting a fairly large neutron-skin thickness in Pb208 and a moderate value of the nuclear incompressibility. Conclusions: We conclude that without any meaningful constraint on the isovector sector, relativistic EDFs will continue to predict significantly large neutron skins. However, the calibration scheme adopted here is flexible enough to create models with different assumptions on various observables. Such a scheme--properly supplemented by a covariance analysis--provides a powerful tool to identify the critical measurements required to place meaningful constraints on theoretical models.
Meso-scale turbulence in living fluids
Henricus H. Wensink; Jörn Dunkel; Sebastian Heidenreich; Knut Drescher; Raymond E. Goldstein; Hartmut Löwen; Julia M. Yeomans
2012-08-21T23:59:59.000Z
Turbulence is ubiquitous, from oceanic currents to small-scale biological and quantum systems. Self-sustained turbulent motion in microbial suspensions presents an intriguing example of collective dynamical behavior amongst the simplest forms of life, and is important for fluid mixing and molecular transport on the microscale. The mathematical characterization of turbulence phenomena in active non-equilibrium fluids proves even more difficult than for conventional liquids or gases. It is not known which features of turbulent phases in living matter are universal or system-specific, or which generalizations of the Navier-Stokes equations are able to describe them adequately. Here, we combine experiments, particle simulations, and continuum theory to identify the statistical properties of self-sustained meso-scale turbulence in active systems. To study how dimensionality and boundary conditions affect collective bacterial dynamics, we measured energy spectra and structure functions in dense Bacillus subtilis suspensions in quasi-2D and 3D geometries. Our experimental results for the bacterial flow statistics agree well with predictions from a minimal model for self-propelled rods, suggesting that at high concentrations the collective motion of the bacteria is dominated by short-range interactions. To provide a basis for future theoretical studies, we propose a minimal continuum model for incompressible bacterial flow. A detailed numerical analysis of the 2D case shows that this theory can reproduce many of the experimentally observed features of self-sustained active turbulence.
Simulation of dynamic fracture using peridynamics, finite element modeling, and contact.
Littlewood, David John
2010-11-01T23:59:59.000Z
Peridynamics is a nonlocal extension of classical solid mechanics that allows for the modeling of bodies in which discontinuities occur spontaneously. Because the peridynamic expression for the balance of linear momentum does not contain spatial derivatives and is instead based on an integral equation, it is well suited for modeling phenomena involving spatial discontinuities such as crack formation and fracture. In this study, both peridynamics and classical finite element analysis are applied to simulate material response under dynamic blast loading conditions. A combined approach is utilized in which the portion of the simulation modeled with peridynamics interacts with the finite element portion of the model via a contact algorithm. The peridynamic portion of the analysis utilizes an elastic-plastic constitutive model with linear hardening. The peridynamic interface to the constitutive model is based on the calculation of an approximate deformation gradient, requiring the suppression of possible zero-energy modes. The classical finite element portion of the model utilizes a Johnson-Cook constitutive model. Simulation results are validated by direct comparison to expanding tube experiments. The coupled modeling approach successfully captures material response at the surface of the tube and the emerging fracture pattern. The coupling of peridynamics and finite element analysis via a contact algorithm has been shown to be a viable means for simulating material fracture in a high-velocity impact experiment. A combined peridynamics/finite element approach was applied to model an expanding tube experiment performed by Vogler, et al., in which loading on the tube is a result of Lexan slugs impacting inside the tube. The Lexan portion of the simulation was modeled with finite elements and a Johnson-Cook elastic-plastic material model in conjunction with an equation-of-state law. The steel tube portion of the simulation was modeled with peridynamics, an elastic-plastic material model, and a critical stretch bond damage model. The application of peridynamics to the tube portion of the model allowed the capture of the formation of cracks and eventual fragmentation of the tube. The simulation results yielded good agreement with the experimental results published by Vogler, et al., for the velocity and displacement profiles on the surface of the tube and the resulting fragment distribution. Numerical difficulties were encountered that required removal of hexahedron elements from the Lexan portion of the model over the course of the simulation. The significant number of inverted and nearly-inverted elements appearing over the course of the simulation is believed to be a result of irregularities in the contact between the Lexan and AerMet portions of the model, and was likely exacerbated by the ultra-high strength of the AerMet tube. Future simulations are planned in which the Lexan portion of the simulation is modeled with peridynamics, or with an alternative method such as smoothed particle hydrodynamics, with the goal of reducing these numerical difficulties.
Leng, Wei [Chinese Academy of Sciences; Ju, Lili [University of South Carolina; Gunzburger, Max [Florida State University; Price, Stephen [Los Alamos National Laboratory; Ringler, Todd [Los Alamos National Laboratory,
2012-01-01T23:59:59.000Z
The numerical modeling of glacier and ice sheet evolution is a subject of growing interest, in part because of the potential for models to inform estimates of global sea level change. This paper focuses on the development of a numerical model that determines the velocity and pressure fields within an ice sheet. Our numerical model features a high-fidelity mathematical model involving the nonlinear Stokes system and combinations of no-sliding and sliding basal boundary conditions, high-order accurate finite element discretizations based on variable resolution grids, and highly scalable parallel solution strategies, all of which contribute to a numerical model that can achieve accurate velocity and pressure approximations in a highly efficient manner. We demonstrate the accuracy and efficiency of our model by analytical solution tests, established ice sheet benchmark experiments, and comparisons with other well-established ice sheet models.
Pedram, Massoud
Composite Sequence Compaction for Finite-State Machines Using Block Entropy and High-Order Markov an effective technique for accurate modeling of the external input sequences that affect the behavior of Finite propose an effective approach to compact an initial sequence into a much shorter, equivalent one
Boyer, Edmond
- 1 - Implementation of surface tension with wall adhesion effects in a three-dimensional finite element modelling of surface tension. The external stress vectors associated with surface tension a drop of liquid on a plane is treated. Keywords : surface tension, finite element method, average
Renormalization Group Analysis of Finite-Size Scaling in the $?^4_4$ Model
R. Kenna; C. B. Lang
1992-10-08T23:59:59.000Z
A finite-size scaling theory for the $\\phi^4_4$ model is derived using renormalization group methods. Particular attention is paid to the partition function zeroes, in terms of which all thermodynamic observables can be expressed. While the leading scaling behaviour is identical to that of mean field theory, there exist multiplicative logarithmic corrections too. A non-perturbative test of these formulae in the form of a high precision Monte Carlo analysis reveals good quantitative agreement with the analytical predictions.
Finite Element Model of Training in the superconducting quadrupole magnet SQ02
Caspi, Shlomo; Ferracin, Paolo
2007-11-01T23:59:59.000Z
This paper describes the use of 3D finite element models to study training in superconducting magnets. The simulations are used to examine coil displacements when the electromagnetic forces are cycled, and compute the frictional energy released during conductor motion with the resulting temperature rise. A computed training curve is then presented and discussed. The results from the numerical computations are compared with test results of the Nb{sub 3}Sn racetrack quadrupole magnet SQ02.
Glider Path-Planning for Optimal Sampling of Mesoscale Eddies
Smith, Ryan N.
Glider Path-Planning for Optimal Sampling of Mesoscale Eddies Daniel Hernandez1 , Ryan Smith2 these, mesoscale eddies are of particular interest due to the relevance they have in many oceano
An enriched finite element model with q-refinement for radiative boundary layers in glass cooling
Mohamed, M. Shadi [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Seaid, Mohammed; Trevelyan, Jon [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom)] [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Laghrouche, Omar [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)
2014-02-01T23:59:59.000Z
Radiative cooling in glass manufacturing is simulated using the partition of unity finite element method. The governing equations consist of a semi-linear transient heat equation for the temperature field and a stationary simplified P{sub 1} approximation for the radiation in non-grey semitransparent media. To integrate the coupled equations in time we consider a linearly implicit scheme in the finite element framework. A class of hyperbolic enrichment functions is proposed to resolve boundary layers near the enclosure walls. Using an industrial electromagnetic spectrum, the proposed method shows an immense reduction in the number of degrees of freedom required to achieve a certain accuracy compared to the conventional h-version finite element method. Furthermore the method shows a stable behaviour in treating the boundary layers which is shown by studying the solution close to the domain boundaries. The time integration choice is essential to implement a q-refinement procedure introduced in the current study. The enrichment is refined with respect to the steepness of the solution gradient near the domain boundary in the first few time steps and is shown to lead to a further significant reduction on top of what is already achieved with the enrichment. The performance of the proposed method is analysed for glass annealing in two enclosures where the simplified P{sub 1} approximation solution with the partition of unity method, the conventional finite element method and the finite difference method are compared to each other and to the full radiative heat transfer as well as the canonical Rosseland model.
Accessing biology's toolbox for the mesoscale biofabrication of soft matter
Raghavan, Srinivasa
Accessing biology's toolbox for the mesoscale biofabrication of soft matter Gregory F. Payne,bf James N. Culverag and William E. Bentley*ab Biology is a master of mesoscale science, possessing will provide a biocompatible approach to mesoscale science and yield products that are safe, sustainable
MPO 663 -Convective and Mesoscale Meteorology Brian Mapes, Spring 2008
Miami, University of
MPO 663 - Convective and Mesoscale Meteorology Brian Mapes, Spring 2008 I intend for students and mesoscale phenomena. 2. Working understanding of several of these tools, cultivated via homework, including. A sense of how convective and mesoscale phenomena fit into larger scales, gained via short current
MESOSCALE EDDIES Peter B. Rhines, University of Washington,
MESOSCALE EDDIES Peter B. Rhines, University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195 7940, USA Copyright ^ 2001 Academic Press doi:10.1006/rwos.2001.0143 Mesoscale eddies that strongly feel viscosity, to `mesoscale eddies' that strongly feel the Earth's rota- tion, to great `gyres
GLOBAL PATTERN OF MESOSCALE VARIABILITY IN SEA SURFACE HEIGHT
Kaplan, Alexey
GLOBAL PATTERN OF MESOSCALE VARIABILITY IN SEA SURFACE HEIGHT AND ITS DYNAMICAL CAUSES Alexey separate the mesoscale variability of sea surface heights into its spatial and temporal components of mesoscale variability in different areas to dynamical causes. Major portion of it can be explained
Remotely sensed mesoscale oceanography and the distribution of Illex argentinus
Pierce, Graham
Remotely sensed mesoscale oceanography and the distribution of Illex argentinus in the South consider the in¯uence of mesoscale oceanographic processes around the Falkland Islands (Islas Malvinas remotely sensed satellite images were used as an indicator of mesoscale oceanographic activity and compared
Mesoscale analysis of segmental dynamics in microphase-segregated polyurea
Grujicic, Mica
Mesoscale analysis of segmental dynamics in microphase- segregated polyurea M. Grujicic · B-atom molecular dynamics techniques. To overcome this problem, mesoscale coarse-grain simulation methods of constituent atom-size particles. Within the mesoscale methods, on the other hand, this atomistic description
Numerical Simulation in Applied Geophysics. From the Mesoscale to the
Santos, Juan
Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale Juan E. Santos Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale p. #12;Introduction. I layering, fractures and craks at the mesoscale (on the order of centimeters) are common in the earth
HYBRID DECADE-MEAN GLOBAL SEA LEVEL WITH MESOSCALE RESOLUTION
HYBRID DECADE-MEAN GLOBAL SEA LEVEL WITH MESOSCALE RESOLUTION Nikolai A. Maximenko1 and Pearn P of twin-satellite mission GRACE and mesoscale sea level tilt derived from the momentum balance as seen 55 #12;sea level exhibits excellent accuracy on mesoscale, but may contain significant systematic
Computational upscaling of inertia effects from porescale to mesoscale
Peszynska, Malgorzata
Computational upscaling of inertia effects from porescale to mesoscale Malgorzata Peszy´nska1 for computational upscaling of flow from porescale (microscale) to lab scale (mesoscale). In particular, we solve laboratory for porous me- dia which delivers data needed for mesoscale simulations by performing microscale
Hyperparameter estimation for uncertainty quantification in mesoscale carbon dioxide inversions
Paris-Sud XI, Université de
Hyperparameter estimation for uncertainty quantification in mesoscale carbon dioxide inversions-validation (GCV) and x2 test are compared for the first time under a realistic setting in a mesoscale CO2 estimation, uncertainty quantification, mesoscale carbon dioxide inversions 1. Introduction The atmosphere
Mesoscale morphologies in polymer thin films.
Ramanathan, M.; Darling, S. B. (Center for Nanoscale Materials)
2011-06-01T23:59:59.000Z
In the midst of an exciting era of polymer nanoscience, where the development of materials and understanding of properties at the nanoscale remain a major R&D endeavor, there are several exciting phenomena that have been reported at the mesoscale (approximately an order of magnitude larger than the nanoscale). In this review article, we focus on mesoscale morphologies in polymer thin films from the viewpoint of origination of structure formation, structure development and the interaction forces that govern these morphologies. Mesoscale morphologies, including dendrites, holes, spherulites, fractals and honeycomb structures have been observed in thin films of homopolymer, copolymer, blends and composites. Following a largely phenomenological level of description, we review the kinetic and thermodynamic aspects of mesostructure formation outlining some of the key mechanisms at play. We also discuss various strategies to direct, limit, or inhibit the appearance of mesostructures in polymer thin films as well as an outlook toward potential areas of growth in this field of research.
Parallel 3D Finite Element Numerical Modelling of DC Electron Guns
Prudencio, E.; Candel, A.; Ge, L.; Kabel, A.; Ko, K.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; /SLAC
2008-02-04T23:59:59.000Z
In this paper we present Gun3P, a parallel 3D finite element application that the Advanced Computations Department at the Stanford Linear Accelerator Center is developing for the analysis of beam formation in DC guns and beam transport in klystrons. Gun3P is targeted specially to complex geometries that cannot be described by 2D models and cannot be easily handled by finite difference discretizations. Its parallel capability allows simulations with more accuracy and less processing time than packages currently available. We present simulation results for the L-band Sheet Beam Klystron DC gun, in which case Gun3P is able to reduce simulation time from days to some hours.
Finite temperature spin-dynamics and phase transitions in spin-orbital models
Chen, C.-C.
2010-04-29T23:59:59.000Z
We study finite temperature properties of a generic spin-orbital model relevant to transition metal compounds, having coupled quantum Heisenberg-spin and Ising-orbital degrees of freedom. The model system undergoes a phase transition, consistent with that of a 2D Ising model, to an orbitally ordered state at a temperature set by short-range magnetic order. At low temperatures the orbital degrees of freedom freeze-out and the model maps onto a quantum Heisenberg model. The onset of orbital excitations causes a rapid scrambling of the spin spectral weight away from coherent spin-waves, which leads to a sharp increase in uniform magnetic susceptibility just below the phase transition, reminiscent of the observed behavior in the Fe-pnictide materials.
Moist multi-scale models for the hurricane embryo
Majda, Andrew J. [New York University; Xing, Yulong [ORNL; Mohammadian, Majid [University of Ottawa, Canada
2010-01-01T23:59:59.000Z
Determining the finite-amplitude preconditioned states in the hurricane embryo, which lead to tropical cyclogenesis, is a central issue in contemporary meteorology. In the embryo there is competition between different preconditioning mechanisms involving hydrodynamics and moist thermodynamics, which can lead to cyclogenesis. Here systematic asymptotic methods from applied mathematics are utilized to develop new simplified moist multi-scale models starting from the moist anelastic equations. Three interesting multi-scale models emerge in the analysis. The balanced mesoscale vortex (BMV) dynamics and the microscale balanced hot tower (BHT) dynamics involve simplified balanced equations without gravity waves for vertical vorticity amplification due to moist heat sources and incorporate nonlinear advective fluxes across scales. The BMV model is the central one for tropical cyclogenesis in the embryo. The moist mesoscale wave (MMW) dynamics involves simplified equations for mesoscale moisture fluctuations, as well as linear hydrostatic waves driven by heat sources from moisture and eddy flux divergences. A simplified cloud physics model for deep convection is introduced here and used to study moist axisymmetric plumes in the BHT model. A simple application in periodic geometry involving the effects of mesoscale vertical shear and moist microscale hot towers on vortex amplification is developed here to illustrate features of the coupled multi-scale models. These results illustrate the use of these models in isolating key mechanisms in the embryo in a simplified content.
Efficient Computation of Info-Gap Robustness for Finite Element Models
Stull, Christopher J. [Los Alamos National Laboratory; Hemez, Francois M. [Los Alamos National Laboratory; Williams, Brian J. [Los Alamos National Laboratory
2012-07-05T23:59:59.000Z
A recent research effort at LANL proposed info-gap decision theory as a framework by which to measure the predictive maturity of numerical models. Info-gap theory explores the trade-offs between accuracy, that is, the extent to which predictions reproduce the physical measurements, and robustness, that is, the extent to which predictions are insensitive to modeling assumptions. Both accuracy and robustness are necessary to demonstrate predictive maturity. However, conducting an info-gap analysis can present a formidable challenge, from the standpoint of the required computational resources. This is because a robustness function requires the resolution of multiple optimization problems. This report offers an alternative, adjoint methodology to assess the info-gap robustness of Ax = b-like numerical models solved for a solution x. Two situations that can arise in structural analysis and design are briefly described and contextualized within the info-gap decision theory framework. The treatments of the info-gap problems, using the adjoint methodology are outlined in detail, and the latter problem is solved for four separate finite element models. As compared to statistical sampling, the proposed methodology offers highly accurate approximations of info-gap robustness functions for the finite element models considered in the report, at a small fraction of the computational cost. It is noted that this report considers only linear systems; a natural follow-on study would extend the methodologies described herein to include nonlinear systems.
Particle-Based Mesoscale Hydrodynamic Techniques
Hiroshi Noguchi; Norio Kikuchi; Gerhard Gompper
2006-10-31T23:59:59.000Z
Dissipative particle dynamics (DPD) and multi-particle collision (MPC) dynamics are powerful tools to study mesoscale hydrodynamic phenomena accompanied by thermal fluctuations. To understand the advantages of these types of mesoscale simulation techniques in more detail, we propose new two methods, which are intermediate between DPD and MPC -- DPD with a multibody thermostat (DPD-MT), and MPC-Langevin dynamics (MPC-LD). The key features are applying a Langevin thermostat to the relative velocities of pairs of particles or multi-particle collisions, and whether or not to employ collision cells. The viscosity of MPC-LD is derived analytically, in very good agreement with the results of numerical simulations.
Comparison of finite-difference and ray-theory seismograms in the elastic SEG/EAGE Salt Model,
Cerveny, Vlastislav
Comparison of finite-difference and ray-theory seismograms in the elastic SEG/EAGE Salt Model, shot-difference seismograms for a selected shot and two receiver configurations com- puted in the elastic SEG/EAGE Salt Model-waves and converted S-waves in the smoothed elastic SEG/EAGE Salt Model are computed. Keywords Elastic velocity model
Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas
2014-04-23T23:59:59.000Z
Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).
Low frequency eddy current finite element model validation and benchmark studies
Cherry, M.; Knopp, J. [Materials and Manufacturing Directorate, Air Force Research Laboratory (United States); Mooers, R.; Boehnlein, T. [University of Dayton Research Institute, Dayton, OH (United States); Aldrin, J. C. [Computational Tools, Gurnee, IL (United States); Sabbagh, H. A. [Victor Technologies, LLC, Bloomington, IN (United States)
2011-06-23T23:59:59.000Z
A finite element method (FEM) model was created to calculate the change in impedance of a coil due to the presence of a notch in a plate. The rectangular notches were created via electrical discharge machining (EDM) in a thick aluminum plate and were positioned at normal and oblique angles (10, 20, and 30 degrees) with respect to the vertical axis of the coil. The FEM method was chosen for this model due to its ability to solve problems in complicated geometries with the use of irregular mesh elements to discretize the solution domain. The change in impedance was calculated from the field variables in the simulation for each probe position along the parallel axis of the plate. The error between the model and the experimental data was approximately 5% for the majority of cases. The validated model was used to investigate more complex problems.
Geosci. Model Dev., 6, 12751298, 2013 www.geosci-model-dev.net/6/1275/2013/
Boyer, Edmond
for the 3-D cloud-resolving mesoscale model Meso-NH with application to idealized cases M. Leriche, J-dimensional cloud resolv- ing mesoscale model. This module includes gaseous- and aqueous-phase chemical reactions
Finite Mixture of ARMA-GARCH Model for Stock Price Prediction Him Tang, Kai-Chun Chiu and Lei Xu
Xu, Lei
Finite Mixture of ARMA-GARCH Model for Stock Price Prediction Him Tang, Kai-Chun Chiu and Lei Xu mixture of autore- gressive generalized autoregressive conditional het- eroscedasticity (AR-GARCH) models to extend the mixture of AR-GARCH model (W.C. Wong, F. Yip and L. Xu, 1998) to the mixture of ARMA- GARCH
Barham, M; White, D; Steigmann, D; Rudd, R
2009-04-08T23:59:59.000Z
Recently a new class of biocompatible elastic polymers loaded with small ferrous particles (magnetoelastomer) was developed at Lawrence Livermore National Laboratory. This new material was formed as a thin film using spin casting. The deformation of this material using a magnetic field has many possible applications to microfluidics. Two methods will be used to calculate the deformation of a circular magneto-elastomeric film subjected to a magnetic field. The first method is an arbitrary Lagrangian-Eulerian (ALE) finite element method (FEM) and the second is based on nonlinear continuum electromagnetism and continuum elasticity in the membrane limit. The comparison of these two methods is used to test/validate the finite element method.
Universal Model of Finite-Reynolds Number Turbulent Flow in Channels and Pipes
L'vov, Victor S; Rudenko, Oleksii; 10.1103/PhysRevLett.100.054504
2009-01-01T23:59:59.000Z
In this Letter we suggest a simple and physically transparent analytical model of the pressure driven turbulent wall-bounded flows at high but finite Reynolds numbers Re. The model gives accurate qualitative description of the profiles of the mean-velocity and Reynolds-stresses (second order correlations of velocity fluctuations) throughout the entire channel or pipe in the wide range of Re, using only three Re-independent parameters. The model sheds light on the long-standing controversy between supporters of the century-old log-law theory of von-K\\`arm\\`an and Prandtl and proposers of a newer theory promoting power laws to describe the intermediate region of the mean velocity profile.
Universal Model of Finite-Reynolds Number Turbulent Flow in Channels and Pipes
Victor S. L'vov; Itamar Procaccia; Oleksii Rudenko
2007-12-07T23:59:59.000Z
In this Letter we suggest a simple and physically transparent analytical model of the pressure driven turbulent wall-bounded flows at high but finite Reynolds numbers Re. The model gives accurate qualitative description of the profiles of the mean-velocity and Reynolds-stresses (second order correlations of velocity fluctuations) throughout the entire channel or pipe in the wide range of Re, using only three Re-independent parameters. The model sheds light on the long-standing controversy between supporters of the century-old log-law theory of von-K\\`arm\\`an and Prandtl and proposers of a newer theory promoting power laws to describe the intermediate region of the mean velocity profile.
Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
2014-03-14T23:59:59.000Z
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
Finite Element Modeling and Validation of Residual Stresses in 304 L Girth Welds
Dike, J.J.; Ortega, A.R.; Cadden, C.H.; Rangaswamy, P. Brown, D.
1998-06-01T23:59:59.000Z
Three dimensional finite element simulations of thermal and mechanical response of a 304 L stainless steel pipe subjected to a circumferential autogenous gas tungsten arc weld were used to predict residual stresses in the pipe. Energy is input into the thermal model using a volumetric heat source. Temperature histories from the thermal analysis are used as loads in the mechanical analyses. In the mechanical analyses, a state variable constitutive model was used to describe the material behavior. The model accounts for strain rate, temperature, and load path histories. The predicted stresses are compared with x-ray diffraction determinations of residual stress in the hoop and circumferential directions on the outside surface of the pipe. Calculated stress profiles fell within the measured data. Reasons for observed scatter in measured stresses are discussed.
Hall, Sharon J.
in the modeling domain was calculated as part of the energy balance equation according to: E = a C CuM[qs(Tg) -qs MM5. The single urban category in the existing 25-category United States Geological Survey (USGS surface energy fluxes and ground temperature. Planetary boundary layer processes were included via the MRF
Houze Jr., Robert A.
1 Precipitation Hydrometeor Type Relative to the Mesoscale Airflow in Oceanic Deep located relative to mesoscale air motions Heavy rain and riming occur downstream of mesoscale Abstract Composite analysis of near-equatorial oceanic mesoscale convective systems (MCSs
Heymsfield, A.
1997-09-01T23:59:59.000Z
The overall purpose of this research was to exploit measurements in clouds sampled during several field programs, especially from experiments in tropical regions, in a four-component study to develop and validate cloud parameterizations for general circulation models, emphasizing ice clouds. The components were: (1) parameterization of basic properties of mid- and upper-tropospheric clouds, such as condensed water content, primarily with respect to cirrus from tropical areas; (2) the second component was to develop parameterizations which express cloud radiative properties in terms of basic cloud microphysical properties, dealing primarily with tropical oceanic cirrus clouds and continental thunderstorm anvils, but also including altocumulus clouds; (3) the third component was to validate the parameterizations through use of ground-based measurements calibrated using existing and planned in-situ measurements of cloud microphysical properties and bulk radiative properties, as well as time-resolved data collected over extended periods of time; (4) the fourth component was to implement the parameterizations in the National Center for Atmospheric Research (NCAR) community climate model (CCM) II or in the NOAA-GFDL model (by L. Donner GFDL) and to perform sensitivity studies.
Three-dimensional finite-difference modeling of non-linear ground notion
Jones, E.M. [Los Alamos National Lab., NM (United States); Olsen, K.B. [California Univ., Santa Barbara, CA (United States). Inst. for Crustal Studies
1997-08-01T23:59:59.000Z
We present a hybrid finite-difference technique capable of modeling non-linear soil amplification from the 3-D finite-fault radiation pattern for earthquakes in arbitrary earth models. The method is applied to model non-linear effects in the soils of the San Fernando Valley (SFV) from the 17 January 1994 M 6.7 Northridge earthquake. 0-7 Hz particle velocities are computed for an area of 17 km by 19 km immediately above the causative fault and 5 km below the surface where peak strike-parallel, strike-perpendicular, vertical, and total velocities reach values of 71 cm/s, 145 cm/s, 152 cm/s, and 180 cm/s, respectively. Selected Green`s functions and a soil model for the SFV are used to compute the approximate stress level during the earthquake, and comparison to the values for near-surface alluvium at the U.S. Nevada Test Site suggests that the non-linear regime may have been entered. We use selected values from the simulated particle velocity distribution at 5 km depth to compute the non-linear response in a soil column below a site within the Van Norman Complex in SFV, where the strongest ground motion was recorded. Since site-specific non- linear material parameters from the SFV are currently unavailable, values are taken from analyses of observed Test Site ground motions. Preliminary results show significant reduction of spectral velocities at the surface normalized to the peak source velocity due to non-linear effects when the peak velocity increases from 32 cm/s (approximately linear case) to 64 cm/s (30-92%), 93 cm/s (7-83%), and 124 cm/s (2-70%). The largest reduction occurs for frequencies above 1 Hz.
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...
A mesoscale analysis of the Rayleigh-Plateau instability.
Pao, Wenxiao (BU); Soteriou, Marios (UTRC); Li, Xiaoyi (UTRC); Karniadakis, George (BU); Arienti, Marco
2010-11-01T23:59:59.000Z
Capillary pinch-off results carried out with the Many-Body Dissipative Particle Dynamics (MDPD) method are compared with the two-phase continuum discretization of hydrodynamics. The MDPD method provides a mesoscale description of the liquid-gas interface -- molecules can be thought of as grouped in particles with modeled Brownian and dissipative effects. No liquid-gas interface is explicitly defined; surface properties, such as surface tension, result from the MDPD interaction parameters. In side-to-side comparisons, the behavior of the MDPD liquid is demonstrated to replicate the macroscale behavior (thin interface assumption) calculated by the Combined Level Set-Volume of Fluid (CLSVOF) method. For instance, in both the continuum and mesoscale discretizations the most unstable wavelength perturbation leads to pinch-off, whereas a smaller wavelength-to-diameter ratio, as expected, does not. The behavior of the virial pressure in MDPD will be discussed in relation to the hydrodynamic capillary pressure that results from the thin interface assumption.
Detecting the Causes of Ill-Conditioning in Structural Finite Element Models
Higham, Nicholas J.
.6 of the finite element-based structural analysis package Oasys GSA was released. A new feature in this release
Paris-Sud XI, Université de
Click Here for Full Article Detecting and characterizing mesoscale and submesoscale structures mesoscale and submesoscale structures of Mediterranean water from joint seismic and hydrographic the imaged structures in terms of mesoscale and submesoscale eddies, of homogeneous layers and of lateral
Miami, University of
MESOSCALE OCEANOGRAPHY Instructors: Igor Kamenkovich, Arthur Mariano and Donald B. Olson of ocean mesoscale variability, including its properties in different oceanic regimes, the dynamics will learn basic concepts on ocean mesoscale processes and perspectives on current research topics from
Observational Analysis of the Predictability of Mesoscale Convective Systems ISRAEL L. JIRAK (Manuscript received 30 December 2005, in final form 4 October 2006) ABSTRACT Mesoscale convective systems of usefulness in operational forecasting. 1. Introduction Mesoscale convective systems (MCSs) frequently de
A wildland fire modeling and visualization environment , Jonathan D. Beezley
Utah, University of
: · The wildland fire simulation code SFIRE coupled with a mesoscale atmospheric simulation code, the Weather by the coupling of a mesoscale weather model with a simple 2D fire spread model (Clark et al. 1996a,b, 2004; Coen
Modeling of Alpine Atmospheric Dynamics II
Gohm, Alexander
: mesoscale convective system 17-18 April 2004: Sierra hydraulic jump case 21 January 2005: the "Universiade) Results and discussion (synoptic scale overview, mesoscale structure, comparison of model and measurements
Stefanelli, Ulisse
FOR SHAPE-MEMORY ALLOYS SERGIO FRIGERI AND ULISSE STEFANELLI Abstract. We prove the global existence of solutions for a shape-memory alloys constitutive model at finite strains. The model has been presented within a constructive time-discretization procedure. 1. Introduction Shape-memory alloys (SMAs) show
Hanson, Floyd B.
Optimal control of drug delivery to brain tumors for a PDE driven model using the Galerkin finite is used to examine the optimal drug delivery to brain tumors. The PDE driven mathematical model and the drug concentration. An optimal control problem is formulated keeping in mind the primary goals
Phase Reduction Models for Improving the Accuracy of the Finite Element Solution of
Boyer, Edmond
, acoustic scattering, short-wave problem, finite element method, pollution, accuracy, On-Surface Radiation in view of a numerical finite element solution. It is well-known that pollution error causes inaccuracies the pollution error in the finite element solution of time-harmonic scattering problems. The pollution error
Dynamical aspects of the plane-wave matrix model at finite temperature
Naoyuki Kawahara; Jun Nishimura; Kentaroh Yoshida
2006-04-25T23:59:59.000Z
We study dynamical aspects of the plane-wave matrix model at finite temperature. One-loop calculation around general classical vacua is performed using the background field method, and the integration over the gauge field moduli is carried out both analytically and numerically. In addition to the trivial vacuum, which corresponds to a single M5-brane at zero temperature, we consider general static fuzzy-sphere type configurations. They are all 1/2 BPS, and hence degenerate at zero temperature due to supersymmetry. This degeneracy is resolved, however, at finite temperature, and we identify the configuration that gives the smallest free energy at each temperature. The Hagedorn transition in each vacuum is studied by using the eigenvalue density method for the gauge field moduli, and the free energy as well as the Polyakov line is obtained analytically near the critical point. This reveals the existence of fuzzy sphere phases, which may correspond to the plasma-ball phases in N=4 SU(\\infty) SYM on S^1 X S^3. We also perform Monte Carlo simulation to integrate over the gauge field moduli. While this confirms the validity of the analytic results near the critical point, it also shows that the trivial vacuum gives the smallest free energy throughout the high temperature regime.
Element-based concrete design with three-dimensional finite element models
O'Leary, M.; Huberty, K.; Winch, S. [Nuclear Power Technologies Div., Sargent and Lundy, 55 East Monroe, Chicago, IL 60603 (United States)
2012-07-01T23:59:59.000Z
A shell element based design of a typical shear wall using analytical results from a three-dimensional finite element model subjected to a combination of vertical and lateral loads is evaluated. The axial and flexural force resultants from each element for every load combination are used to calculate the required reinforcing for each element. Strength for axial loads (P) and out-of-plane flexure (M) in structural walls is determined according to the same P-M interaction procedures used for columns. After each element has been evaluated, a required reinforcing map for each face of each element in the wall is presented along with a constructible reinforcement pattern enveloping the required reinforcing. In order to determine whether the element-based approach meets the requirements of the section cut approach to design, which is typically employed in manual calculations, the total in-plane moment (M) and total vertical axial force (P) across the entire length of the wall is calculated and the P-M points are plotted on an in-plane P-M interaction diagram. It is concluded that element-based design for a structural wall ensures that reinforcement is provided where required by the three-dimensional finite element analysis while still providing sufficient reinforcing to satisfy the section cut approach to design. (authors)
Transport coefficients of off-lattice mesoscale-hydrodynamics simulation techniques
Hiroshi Noguchi; Gerhard Gompper
2008-04-14T23:59:59.000Z
The viscosity and self-diffusion constant of particle-based mesoscale hydrodynamic methods, multi-particle collision dynamics (MPC) and dissipative particle dynamics (DPD), are investigated, both with and without angular-momentum conservation. Analytical results are derived for fluids with an ideal-gas equation of state and a finite-time-step dynamics, and compared with simulation data. In particular, the viscosity is derived in a general form for all variants of the MPC method. In general, very good agreement between theory and simulations is obtained.
Mesoscale harmonic analysis of homogenous dislocation nucleation
Asad Hasan; Craig E. Maloney
2012-05-08T23:59:59.000Z
We perform atomistic computer simulations to study the mechanism of homogeneous dislocation nucleation in two dimensional (2D) hexagonal crystalline films during indentation with a circular nanoindenter. The nucleation process is governed by the vanishing of the energy associated with a single normal mode. This critical mode is largely confined to a single plane of adjacent atoms. For fixed film thickness, L, the spatial extent, \\xi, of the critical mode grows with indenter radius, R. For fixed R/L, the spatial extent \\xi, grows roughly as \\xi ~ L^0.4. We, furthermore, perform a mesoscale analysis to determine the lowest energy normal mode for mesoscale regions of varying radius, r_{meso}, centered on the critical mode's core. The energy, \\lambda_{meso}, of the lowest normal mode in the meso-region decays very rapidly with r_{meso} and \\lambda_{meso} ~= 0 for r_{meso} >~ \\xi. The lowest normal mode shows a spatial extent, \\xi_{meso}, which has a sublinear power-law increase with r_{meso} for r_{meso} mesoscale analysis gives good estimates for the energy and spatial extent of the critical mode \\emph{only} for r_{meso} >~ 1.5 \\xi. In this sense homogeneous dislocation nucleation should be understood as a quasi-local phenomenon.
NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array
Asher, Sanford A.
i" /} , NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array Structures Utilizing Smart *National Research Council hitrodoetion Mesoscale Periodic Arlay Structures (MPAS, also known as crystalline
Mesoscale regulation comes from the bottom-up: intertidal interactions between consumers
Nielsen, Karina J.
REPORT Mesoscale regulation comes from the bottom-up: intertidal interactions between consumers variation in nutrient supply to shift community structure over mesoscales. Keywords Macroalgae, upwelling
Sethna, James P.
Mesoscale Theory of Grains and Cells: Crystal Plasticity and Coarsening Surachate Limkumnerd a mesoscale theory of dislocation motion. It provides a quantitative description of deformation and rotation
Lisal, Martin
Mesoscale simulation of polymer reaction equilibrium: Combining dissipative particle dynamics. R. Smith, J. Chem. Phys. 125, 16490 2006 , a mesoscale simulation technique for studying polymer
A unified morphological description of Nafion membranes from SAXS and mesoscale simulations
Elliott, James
A unified morphological description of Nafion membranes from SAXS and mesoscale simulations James A with mesoscale simulations of the morphology of Nafion using Dissipative Particle Dynamics (DPD) parameterized
Hyperbolic reformulation of a 1D viscoelastic blood flow model and ADER finite volume schemes
Montecinos, Gino I.; Müller, Lucas O.; Toro, Eleuterio F.
2014-06-01T23:59:59.000Z
The applicability of ADER finite volume methods to solve hyperbolic balance laws with stiff source terms in the context of well-balanced and non-conservative schemes is extended to solve a one-dimensional blood flow model for viscoelastic vessels, reformulated as a hyperbolic system, via a relaxation time. A criterion for selecting relaxation times is found and an empirical convergence rate assessment is carried out to support this result. The proposed methodology is validated by applying it to a network of viscoelastic vessels for which experimental and numerical results are available. The agreement between the results obtained in the present paper and those available in the literature is satisfactory. Key features of the present formulation and numerical methodologies, such as accuracy, efficiency and robustness, are fully discussed in the paper.
Mesoscale polycrystal calculations of damage in spallation in metals
Tonks, Davis L [Los Alamos National Laboratory; Bingert, John F [Los Alamos National Laboratory; Livescu, Veronica [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Bronkhorst, C A [Los Alamos National Laboratory
2010-01-01T23:59:59.000Z
The goal of this project is to produce a damage model for spallation in metals informed by the polycrystalline grain structure at the mesoscale. Earlier damage models addressed the continuwn macroscale in which these effects were averaged out. In this work we focus on cross sections from recovered samples examined with EBSD (electron backscattered diffraction), which reveal crystal grain orientations and voids. We seek to understand the loading histories of specific sample regions by meshing up the crystal grain structure of these regions and simulating the stress, strain, and damage histories in our hydro code, FLAG. The stresses and strain histories are the fundamental drivers of damage and must be calculated. The calculated final damage structures are compared with those from the recovered samples to validate the simulations.
Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.
Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay
2012-01-01T23:59:59.000Z
Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.
Combined simulation of whirl and stick-slip phenomena using a nonlinear finite element model
Schmalhorst, B. [Baker Hughes INTEQ GmbH, Celle (Germany); Baumgart, A. [Technical Univ. Braunschweig (Germany)
1997-07-01T23:59:59.000Z
A time domain drillstring dynamics model allows the prediction of BHA dynamics related to torsional and two plane lateral vibrations. The model considers a nonlinear Finite Element approach that takes into account arbitrarily shaped assemblies during drilling of curved boreholes. Each nodal point represents a stabilizer, a collar connection or a wear knot moving viscously dampled inside open hole or a casing. In the case of wall contact, restitution forces from the formation act on the string and contact velocity dependent friction forces are introduced. The torsional and the lateral degrees of freedom (d.o.f.) are therefore coupled. The authors introduce a nonlinear relationship between the cutting forces at the PDC bit and the angular velocity of the bit. Bit and BHA whirl, rotational Stick-Slip phenomena and normal drilling conditions are solved numerically. Results show that the drilling process is always transient. Commonly used static models only can provide the drilling engineer with rough estimates of the loading. Evaluation of BHA failures sometimes reveal an ultra high dynamic loading of the BHA components that can be analyzed and predicted with this time domain application.
A voxel-based finite element model for the prediction of bladder deformation
Chai Xiangfei; Herk, Marcel van; Hulshof, Maarten C. C. M.; Bel, Arjan [Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands); Radiation Oncology Department, Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands)
2012-01-15T23:59:59.000Z
Purpose: A finite element (FE) bladder model was previously developed to predict bladder deformation caused by bladder filling change. However, two factors prevent a wide application of FE models: (1) the labor required to construct a FE model with high quality mesh and (2) long computation time needed to construct the FE model and solve the FE equations. In this work, we address these issues by constructing a low-resolution voxel-based FE bladder model directly from the binary segmentation images and compare the accuracy and computational efficiency of the voxel-based model used to simulate bladder deformation with those of a classical FE model with a tetrahedral mesh. Methods: For ten healthy volunteers, a series of MRI scans of the pelvic region was recorded at regular intervals of 10 min over 1 h. For this series of scans, the bladder volume gradually increased while rectal volume remained constant. All pelvic structures were defined from a reference image for each volunteer, including bladder wall, small bowel, prostate (male), uterus (female), rectum, pelvic bone, spine, and the rest of the body. Four separate FE models were constructed from these structures: one with a tetrahedral mesh (used in previous study), one with a uniform hexahedral mesh, one with a nonuniform hexahedral mesh, and one with a low-resolution nonuniform hexahedral mesh. Appropriate material properties were assigned to all structures and uniform pressure was applied to the inner bladder wall to simulate bladder deformation from urine inflow. Performance of the hexahedral meshes was evaluated against the performance of the standard tetrahedral mesh by comparing the accuracy of bladder shape prediction and computational efficiency. Results: FE model with a hexahedral mesh can be quickly and automatically constructed. No substantial differences were observed between the simulation results of the tetrahedral mesh and hexahedral meshes (<1% difference in mean dice similarity coefficient to manual contours and <0.02 cm difference in mean standard deviation of residual errors). The average equation solving time (without manual intervention) for the first two types of hexahedral meshes increased to 2.3 h and 2.6 h compared to the 1.1 h needed for the tetrahedral mesh, however, the low-resolution nonuniform hexahedral mesh dramatically decreased the equation solving time to 3 min without reducing accuracy. Conclusions: Voxel-based mesh generation allows fast, automatic, and robust creation of finite element bladder models directly from binary segmentation images without user intervention. Even the low-resolution voxel-based hexahedral mesh yields comparable accuracy in bladder shape prediction and more than 20 times faster in computational speed compared to the tetrahedral mesh. This approach makes it more feasible and accessible to apply FE method to model bladder deformation in adaptive radiotherapy.
Reduced order Modeling of Heat Exchangers Using High Order Finite Control Volume Models
Gupta, Abhishek
.................................................................................................... 83 Figure 6. 1: Model Validation: Compressor RPM ........................................................... 93 Figure 6. 2: Model Validation: Evaporator Pressure ........................................................ 93 Figure 6.3: Model... is projected to increase by 57 percent from 2004 to 2030. The non-renewable share of total world energy use was about 93 percent in 2004 [1]. Besides, combustion of fossil fuels produces CO2 which is by far the largest contributor to global warming...
Atomistic and mesoscale modeling of dislocation mobility
Cai, Wei, 1977-
2001-01-01T23:59:59.000Z
Dislocation is a line defect in crystalline materials, and a microscopic carrier of plastic deformation. Because dislocation has both a localized core and a long-range stress field, linking atomistic and meso scales is ...
Nano- and mesoscale modeling of cement matrix
Yu, Zechuan
Atomistic simulations of cementitious material can enrich our understanding of its structural and mechanical properties, whereas current computational capacities restrict the investigation length scale within 10 nm. In ...
Kirchner, James W.
Inferring catchment precipitation by doing hydrology backward: A test in 24 small and mesoscale September 2012; published 10 October 2012. [1] The complexity of hydrological systems and the necessary simplification of models describing these systems remain major challenges in hydrological modeling. Kirchner
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
2004-01-01T23:59:59.000Z
an short-tube using a finite element model International Journal of Refrig Vol 27 No 2, pp. 176-183The short-tube is used by United States heat pump manufactures as an expansion device because of its lowAnalyse de l’e´coulement d’un frigorige`ne et...
Demeio, Lucio
Virtual Laboratories > 12. Finite Sampling Models > 1 2 3 4 5 6 7 8 9 7. The Coupon Collector of a coupon collector: each time the collector buys a certain product (bubble gum or Cracker Jack, for example} In terms of the coupon collector, this random variable gives the number of products required to get k
Regueiro, Richard A.
, hydrofracturing, or oil shale production. Current macro- scale and multiscale models do not account simultaneouslyFinite element analysis of grain-matrix micro-cracking in shale within the context of a multiscale-cracking in shale at grain-matrix inter- faces, assuming constituents are composed of quart silt grains
Generation of mesoscale convective structures in tokamak edge plasma
Krasheninnikov, S. I.; Smolyakov, A. I. [University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States); University of Saskatchewan, 116 Science Place, Saskatoon, Saskatchewan S7N 5E2 (Canada)
2007-10-15T23:59:59.000Z
It is shown that the interplay of the interchange drive and nonlinear effects of Reynolds stress and inverse cascade of drift wave turbulence select a range of plasma parameters (plasma pressure), for which mesoscale perturbations of a certain transverse length scale become unstable. It is suggested that the blob formation is a result of these mesoscale instabilities.
Boyer, Edmond
-bounded positive-definite matrix-valued random fields in the context of mesoscale modeling of heterogeneous elastic; Heterogeneous materials; Apparent elasticity tensor; Mesoscale modeling; Random field; Non-Gaussian. $ J
Insepov, Z.; Norem, J. [Argonne National Lab, Argonne, IL 60439 (United States); Vetizer, S.; Mahalingam, S. [Tech-X Corp., Boulder, CO (United States)
2011-12-23T23:59:59.000Z
Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gradient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.
Garstang, M.; Nnaji, S.; Pielke, R.A.; Gusdorf, J.; Lindsey, C.; Snow, J.W.
1980-03-01T23:59:59.000Z
This report describes a method of determining coastal wind energy resources. Climatological data and a mesoscale numerical model are used to delineate the available wind energy along the Atlantic and Gulf coasts of the United States. It is found that the spatial distribution of this energy is dependent on the locations of the observing sites in relation to the major synoptic weather features as well as the particular orientation of the coastline with respect to the large-scale wind.
Martins, R. A. [Centro de Analise Matematica, Geometria e Sistemas Dinamicos, Departamento de Matematica, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal)
2007-08-15T23:59:59.000Z
The recent extension of the standard model to include massive neutrinos in the framework of noncommutative geometry and the spectral action principle involves new scalar fields and their interactions with the usual complex scalar doublet. After ensuring that they bring no unphysical consequences, we address the question of how these fields affect the physics predicted in the Weinberg-Salam theory, particularly in the context of the electroweak phase transition. Applying the Dolan-Jackiw procedure, we calculate the finite temperature corrections, and find that the phase transition is first order. The new scalar interactions significantly improve the stability of the electroweak Z string, through the 'bag' phenomenon described by Vachaspati and Watkins ['Bound states can stabilize electroweak strings', Phys. Lett. B 318, 163-168 (1993)]. (Recently, cosmic strings have climbed back into interest due to a new evidence.) Sourced by static embedded strings, an internal space analogy of Cartan's torsion is drawn, and a possible Higgs-force-like 'gravitational' effect of this nonpropagating torsion on the fermion masses is described. We also check that the field generating the Majorana mass for the {nu}{sub R} is nonzero in the physical vacuum.
Jackson, Jason R.
1996-01-01T23:59:59.000Z
described in the ASTM procedure 412. The specimens were then loaded into an Instron Model 4202 with the series IX Version 4. 02 software. Testing was done on an Instron 200 pound load cell. The two data files from Federal Mogul Corporation contained... stress values. The two columns containing the stress and strain data points were saved to a text file in a comma delimited format for subsequent insertion into the ABAQUS input file. Two options are available in ABAQUS for specifying the elastomer...
Adaptive Finite Element Modeling Techniques for the Poisson-Boltzmann Equation
Michael Holst; James Andrew McCammon; Zeyun Yu; Yongcheng Zhou; Yunrong Zhu
2010-09-30T23:59:59.000Z
We develop an efficient and reliable adaptive finite element method (AFEM) for the nonlinear Poisson-Boltzmann equation (PBE). We first examine the regularization technique of Chen, Holst, and Xu; this technique made possible the first a priori pointwise estimates and the first complete solution and approximation theory for the Poisson-Boltzmann equation. It also made possible the first provably convergent discretization of the PBE, and allowed for the development of a provably convergent AFEM for the PBE. However, in practice the regularization turns out to be numerically ill-conditioned. In this article, we examine a second regularization, and establish a number of basic results to ensure that the new approach produces the same mathematical advantages of the original regularization, without the ill-conditioning property. We then design an AFEM scheme based on the new regularized problem, and show that the resulting AFEM scheme is accurate and reliable, by proving a contraction result for the error. This result, which is one of the first results of this type for nonlinear elliptic problems, is based on using continuous and discrete a priori pointwise estimates to establish quasi-orthogonality. To provide a high-quality geometric model as input to the AFEM algorithm, we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures, based on the intrinsic local structure tensor of the molecular surface. The stability advantages of the new regularization are demonstrated using an FETK-based implementation, through comparisons with the original regularization approach for a model problem. The convergence and accuracy of the overall AFEM algorithm is also illustrated by numerical approximation of electrostatic solvation energy for an insulin protein.
Ionic Polymer-Metal Composites: Thermodynamical Modeling and Finite Element Solution
Arumugam, Jayavel
2012-10-19T23:59:59.000Z
cantilever beams involving pure bending which could be used in the characterization of the material parameters. A linear finite element solution along with a staggered time stepping algorithm is provided to numerically solve the governing equations...
Thompson, Anne
with small amount of moisture, dry dynamic gravity wave modes continue to dominate. However, convective-permitting simulations with the Weather Research and Forecast (WRF) model are performed to study mesoscale gravity waves/negative), and 7-km dynamic tropopause (turquoise lines). Wave Identification Figure 3. Comparison of WP5 at 132 h
Anne-Ly Do; Johannes Höfener; Thilo Gross
2012-07-05T23:59:59.000Z
The dynamics of networks of interacting systems depends intricately on the interaction topology. When the dynamics is explored, generally the whole topology has to be considered. However, we show that there are certain mesoscale subgraphs that have precise and distinct consequences for the system-level dynamics. In particular, if meso-scale symmetries are present then eigenvectors of the Jacobian localise on the symmetric subgraph and the corresponding eigenvalues become insensitive to the topology outside the subgraph. Hence, dynamical instabilities associated with these eigenvalues can be analyzed without considering the topology outside the subgraph. While such instabilities are thus generated entirely in small network subgraphs, they generally do not remain confined to the subgraph once the instability sets in and thus have system-level consequences. Here we illustrate the analytical investigation of such instabilities in an ecological meta-population model consisting of a network of delay-coupled delay oscillators.
Yeh, G.T.
1982-10-01T23:59:59.000Z
This report documents a training course conducted for the US Nuclear Regulatory Commission (NRC) on the implementation of a Finite Element Model of WASTE transport through saturated-unsaturated porous media (FEMWASTE) - ORNL-5601. In addition to presenting basic program operations (Appendices A-V through A-VII), the course also covers the following topics: (1) Heuristic derivation of governing equations based on physical and chemical principles, (2) finite element derivation of FEMWASTE, (3) various numerical schemes provided by FEMWASTE, (4) FEMWASTE program structure, and (5) running of three samples problems to demonstrate various options the FEMWASTE can handle. The purpose of the training seminar is to enable NRC staff to use the model (and to be able to modify the code, if necessary) for checking information provided by a licensee, for evaluating alternative sites and designs for burial, and for comparing their results from other methods of solution.
C H A P T E R E I G H T E E N Modeling of Growth Factor-Receptor
Popel, Aleksander S.
-specific receptor binding 472 3. Mesoscale Single-Tissue 3D Models: Simulation of In Vivo Tissue Regions 474 3receptor interactions at and near the endothelial cell surface; mesoscale single-tissue 3D models can simulate
Mesoscale Quantization and Self-Organized Stability
Randall D. Peters
2005-06-16T23:59:59.000Z
In the world of technology, one of the most important forms of friction is that of rolling friction. Yet it is one of the least studied of all the known forms of energy dissipation. In the present experiments we investigate the oscillatory free-decay of a rigid cube, whose side-length is less than the diameter of the rigid cylinder on which it rests. The resulting free-decay is one of harmonic motion with damping. The non-dissipative character of the oscillation yields to a linear differential equation; however, the damping is found to involve more than a deterministic nonlinearity. Dominated by rolling friction, the damping is sensitive to the material properties of the contact surfaces. For `clean' surfaces of glass on glass, the decay shows features of mesoscale quantization and self-organized stability.
Phase Effects on Mesoscale Object X-ray Absorption Images
Martz, Jr., H E; Aufderheide, M B; Barty, A; Lehman, S K; Kozioziemski, B J; Schneberk, D J
2004-09-24T23:59:59.000Z
At Lawrence Livermore National Laboratory particular emphasis is being placed on the nondestructive characterization (NDC) of 'mesoscale' objects.[Martz and Albrecht 2003] We define mesoscale objects as objects that have mm extent with {micro}m features. Here we confine our discussions to x-ray imaging methods applicable to mesoscale object characterization. The goal is object recovery algorithms including phase to enable emerging high-spatial resolution x-ray imaging methods to ''see'' inside or image mesoscale-size materials and objects. To be successful our imaging characterization effort must be able to recover the object function to one micrometer or better spatial resolution over a few millimeters field-of-view with very high contrast.
Evolution of moisture convergence in a mesoscale convective complex
Bercherer, John Phillip
1990-01-01T23:59:59.000Z
Committee: Dr. Keuneth C. Brundidge Two separate Mesoscale Convective Complexes (MCCs) were investigated to determine if a characteristic surface moisture convergence (MC) signature existed on the mesoscale during their lifecycle. The first storm (Case 1... convergence, a bandpass filtering technique was utilized. It was found that MC could identify the general area of initial thunderstorm activity 2 h prior to its development for both cases. During the initial development stage of Case 1, advection...
Analysis of azimuthal mode dynamics of mesoscale eddies
McCalpin, John David
1984-01-01T23:59:59.000Z
ANALYSIS OF AZIMUTHAL MODE DYNAMICS OF MESOSCALE EDDIES A Thesis by UOHN DAVID MCCALPIN Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1984... Major Subject: Oceanography ANALYSIS OF AZIMUTHAL MODE DYNAMICS OF MESOSCALE EDDIES A Thesis by JOHN DAVID MCCALPIN Approved as to style and content by: rew . as ano (Chairman of Committee) o ert . ei (Member) uy . rancesc &ni (Member) Robert...
Mesoscale phenomena in solutions of 3-methylpyridine, heavy water, and an antagonistic salt
Jan Leys; Deepa Subramanian; Eva Rodezno; Boualem Hammouda; Mikhail A. Anisimov
2013-08-22T23:59:59.000Z
We have investigated controversial issues regarding the mesoscale behavior of 3-methylpyridine (3MP), heavy water, and sodium tetraphenylborate (NaBPh4) solutions by combining results obtained from dynamic light scattering (DLS) and small-angle neutron scattering (SANS). We have addressed three questions: (i) what is the origin of the mesoscale inhomogeneities (order of 100 nm in size) manifested by the "slow mode" in DLS? (ii) Is the periodic structure observed from SANS an inherent property of this system? (iii) What is the universality class of critical behavior in this system? Our results confirm that the "slow mode" observed from DLS experiments corresponds to long-lived, highly stable mesoscale droplets (order of 100 nm in size), which occur only when the solute (3MP) is contaminated by hydrophobic impurities. SANS data confirm the presence of a periodic structure with a periodicity of about 10 nm. This periodic structure cannot be eliminated by nanopore filtration and thus is indeed an inherent solution property. The critical behavior of this system, in the range of concentration and temperatures investigated by DLS experiments, indicates that the criticality belongs to the universality class of the 3-dimensional Ising model.
Mesoscale and Large-Eddy Simulations for Wind Energy
Marjanovic, N
2011-02-22T23:59:59.000Z
Operational wind power forecasting, turbine micrositing, and turbine design require high-resolution simulations of atmospheric flow over complex terrain. The use of both Reynolds-Averaged Navier Stokes (RANS) and large-eddy (LES) simulations is explored for wind energy applications using the Weather Research and Forecasting (WRF) model. To adequately resolve terrain and turbulence in the atmospheric boundary layer, grid nesting is used to refine the grid from mesoscale to finer scales. This paper examines the performance of the grid nesting configuration, turbulence closures, and resolution (up to as fine as 100 m horizontal spacing) for simulations of synoptically and locally driven wind ramping events at a West Coast North American wind farm. Interestingly, little improvement is found when using higher resolution simulations or better resolved turbulence closures in comparison to observation data available for this particular site. This is true for week-long simulations as well, where finer resolution runs show only small changes in the distribution of wind speeds or turbulence intensities. It appears that the relatively simple topography of this site is adequately resolved by all model grids (even as coarse as 2.7 km) so that all resolutions are able to model the physics at similar accuracy. The accuracy of the results is shown in this paper to be more dependent on the parameterization of the land-surface characteristics such as soil moisture rather than on grid resolution.
Hornsby, W. A.; Peeters, A. G.; Snodin, A. P.; Casson, F. J.; Camenen, Y.; Szepesi, G. [Department of Physics, Centre for Fusion, Space, and Astrophysics, University of Warwick, Coventry (United Kingdom); Siccinio, M.; Poli, E. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching bei Muenchen (Germany)
2010-09-15T23:59:59.000Z
The interaction between small scale turbulence (of the order of the ion Larmor radius) and mesoscale magnetic islands is investigated within the gyrokinetic framework. Turbulence, driven by background temperature and density gradients, over nonlinear mode coupling, pumps energy into long wavelength modes, and can result in an electrostatic vortex mode that coincides with the magnetic island. The strength of the vortex is strongly enhanced by the modified plasma flow response connected with the change in topology, and the transport it generates can compete with the parallel motion along the perturbed magnetic field. Despite the stabilizing effect of sheared plasma flows in and around the island, the net effect of the island is a degradation of the confinement. When density and temperature gradients inside the island are below the threshold for turbulence generation, turbulent fluctuations still persist through turbulence convection and spreading. The latter mechanisms then generate a finite transport flux and, consequently, a finite pressure gradient in the island. A finite radial temperature gradient inside the island is also shown to persist due to the trapped particles, which do not move along the field around the island. In the low collisionality regime, the finite gradient in the trapped population leads to the generation of a bootstrap current, which reduces the neoclassical drive.
Mesoscale Systems: weather associated with circulation systems of horizontal scales of 5 to 1,000 km
Weber, Rodney
Mesoscale Systems: weather associated with circulation systems of horizontal scales of 5 to 1 faster at night #12;Dispersion in Mesoscale Systems Mesoscale systems can have large effects on pollution
Praveen, E., E-mail: svmstaya@gmail.com; Satyanarayana, S. V. M., E-mail: svmstaya@gmail.com [Department of Physics, Pondicherry University, Puducherry-605014 (India)
2014-04-24T23:59:59.000Z
Traditional definition of phase transition involves an infinitely large system in thermodynamic limit. Finite systems such as biological proteins exhibit cooperative behavior similar to phase transitions. We employ recently discovered analysis of inflection points of microcanonical entropy to estimate the transition temperature of the phase transition in q state Potts model on a finite two dimensional square lattice for q=3 (second order) and q=8 (first order). The difference of energy density of states (DOS) ? ln g(E) = ln g(E+ ?E) ?ln g(E) exhibits a point of inflexion at a value corresponding to inverse transition temperature. This feature is common to systems exhibiting both first as well as second order transitions. While the difference of DOS registers a monotonic variation around the point of inflexion for systems exhibiting second order transition, it has an S-shape with a minimum and maximum around the point of inflexion for the case of first order transition.
T. Manos; M. Robnik
2015-03-26T23:59:59.000Z
We study the quantum kicked rotator in the classically fully chaotic regime $K=10$ and for various values of the quantum parameter $k$ using Izrailev's $N$-dimensional model for various $N \\le 3000$, which in the limit $N \\rightarrow \\infty$ tends to the exact quantized kicked rotator. By numerically calculating the eigenfunctions in the basis of the angular momentum we find that the localization length ${\\cal L}$ for fixed parameter values has a certain distribution, in fact its inverse is Gaussian distributed, in analogy and in connection with the distribution of finite time Lyapunov exponents of Hamilton systems. However, unlike the case of the finite time Lyapunov exponents, this distribution is found to be independent of $N$, and thus survives the limit $N=\\infty$. This is different from the tight-binding model of Anderson localization. The reason is that the finite bandwidth approximation of the underlying Hamilton dynamical system in the Shepelyansky picture (D.L. Shepelyansky, {\\em Phys. Rev. Lett.} {\\bf 56}, 677 (1986)) does not apply rigorously. This observation explains the strong fluctuations in the scaling laws of the kicked rotator, such as e.g. the entropy localization measure as a function of the scaling parameter $\\Lambda={\\cal L}/N$, where $\\cal L$ is the theoretical value of the localization length in the semiclassical approximation. These results call for a more refined theory of the localization length in the quantum kicked rotator and in similar Floquet systems, where we must predict not only the mean value of the inverse of the localization length $\\cal L$ but also its (Gaussian) distribution, in particular the variance. In order to complete our studies we numerically analyze the related behavior of finite time Lyapunov exponents in the standard map and of the 2$\\times$2 transfer matrix formalism. This paper is extending our recent work.
Davidson, Timothy Ross
1994-01-01T23:59:59.000Z
regionally corresponds with the northern limit of the Paleozoic carbonates, at the contact of the Eleana Formation, a Paleozoic aquitard. This study investigates, using finite difference modeling, the relationship between the steep hydraulic gradient...
De Castro, Carlos Armando
2011-01-01T23:59:59.000Z
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.
Yu-Kui Zhou
1995-06-08T23:59:59.000Z
The fused six-vertex models with open boundary conditions are studied. The Bethe ansatz solution given by Sklyanin has been generalized to the transfer matrices of the fused models. We have shown that the eigenvalues of transfer matrices satisfy a group of functional relations, which are the $su$(2) fusion rule held by the transfer matrices of the fused models. The fused transfer matrices form a commuting family and also commute with the quantum group $U_q[sl(2)]$. In the case of the parameter $q^h=-1$ ($h=4,5,\\cdots$) the functional relations in the limit of spectral parameter $u\\to \\i\\infty$ are truncated. This shows that the $su$(2) fusion rule with finite level appears for the six vertex model with the open boundary conditions. We have solved the functional relations to obtain the finite-size corrections of the fused transfer matrices for low-lying excitations. From the corrections the central charges and conformal weights of underlying conformal field theory are extracted. To see different boundary conditions we also have studied the six-vertex model with a twisted boundary condition.
Regueiro, Richard A. (University of Colorado, Boulder, CO); Borja, R. I. (Stanford University, Stanford, CA); Foster, C. D. (Stanford University, Stanford, CA)
2006-10-01T23:59:59.000Z
Localized shear deformation plays an important role in a number of geotechnical and geological processes. Slope failures, the formation and propagation of faults, cracking in concrete dams, and shear fractures in subsiding hydrocarbon reservoirs are examples of important effects of shear localization. Traditional engineering analyses of these phenomena, such as limit equilibrium techniques, make certain assumptions on the shape of the failure surface as well as other simplifications. While these methods may be adequate for the applications for which they were designed, it is difficult to extrapolate the results to more general scenarios. An alternative approach is to use a numerical modeling technique, such as the finite element method, to predict localization. While standard finite elements can model a wide variety of loading situations and geometries quite well, for numerical reasons they have difficulty capturing the softening and anisotropic damage that accompanies localization. By introducing an enhancement to the element in the form of a fracture surface at an arbitrary position and orientation in the element, we can regularize the solution, model the weakening response, and track the relative motion of the surfaces. To properly model the slip along these surfaces, the traction-displacement response must be properly captured. This report focuses on the development of a constitutive model appropriate to localizing geomaterials, and the embedding of this model into the enhanced finite element framework. This modeling covers two distinct phases. The first, usually brief, phase is the weakening response as the material transitions from intact continuum to a body with a cohesionless fractured surface. Once the cohesion has been eliminated, the response along the surface is completely frictional. We have focused on a rate- and state-dependent frictional model that captures stable and unstable slip along the surface. This model is embedded numerically into the element using a generalized trapezoidal formulation. While the focus is on the constitutive model of interest, the framework is also developed for a general surface response. This report summarizes the major research and development accomplishments for the LDRD project titled 'Cohesive Zone Modeling of Failure in Geomaterials: Formulation and Implementation of a Strong Discontinuity Model Incorporating the Effect of Slip Speed on Frictional Resistance'. This project supported a strategic partnership between Sandia National Laboratories and Stanford University by providing funding for the lead author, Craig Foster, during his doctoral research.
Boyer, Edmond
2001-01-01T23:59:59.000Z
to investigate the evolution of the climate (DOE, 1996) while at the regional scale, mesoscale models are weather. In the case of rainfall forecasting, some combination of the mesoscale forecast and a finer scale advection
Nesting large-eddy simulations within mesoscale simulations for wind energy applications
Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B; Lundquist, K A
2008-09-08T23:59:59.000Z
With increasing demand for more accurate atmospheric simulations for wind turbine micrositing, for operational wind power forecasting, and for more reliable turbine design, simulations of atmospheric flow with resolution of tens of meters or higher are required. These time-dependent large-eddy simulations (LES), which resolve individual atmospheric eddies on length scales smaller than turbine blades and account for complex terrain, are possible with a range of commercial and open-source software, including the Weather Research and Forecasting (WRF) model. In addition to 'local' sources of turbulence within an LES domain, changing weather conditions outside the domain can also affect flow, suggesting that a mesoscale model provide boundary conditions to the large-eddy simulations. Nesting a large-eddy simulation within a mesoscale model requires nuanced representations of turbulence. Our group has improved the Weather and Research Forecasting model's (WRF) LES capability by implementing the Nonlinear Backscatter and Anisotropy (NBA) subfilter stress model following Kosovic (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005). We have also implemented an immersed boundary method (IBM) in WRF to accommodate complex terrain. These new models improve WRF's LES capabilities over complex terrain and in stable atmospheric conditions. We demonstrate approaches to nesting LES within a mesoscale simulation for farms of wind turbines in hilly regions. Results are sensitive to the nesting method, indicating that care must be taken to provide appropriate boundary conditions, and to allow adequate spin-up of turbulence in the LES domain.
Hiroaki Kohyama
2008-04-30T23:59:59.000Z
We construct the phase diagram of the chiral and diquark condensates at finite temperature and density in the 1+1 dimensional (2D) two flavor massless Gross Neveu model. The resultant phase diagram shows (I) the chiral condensed phase at low temperature and density, (II) the diquark condensed phase at low temperature and high density, and (III) the chiral and diquark coexisting phase at low temperature and intermediate density. This phase structure is also seen in the 3D Gross Neveu model and the 4D Nambu Jona-Lasinio (NJL) model. Thus the phase diagrams of the chiral and diquark condensates in the NJL-type models do not change qualitatively in 2D, 3D and 4D.
Predicting reptile distributions at the mesoscale: relation to climate and topography
Richner, Heinz
Predicting reptile distributions at the mesoscale: relation to climate and topography Antoine at a mesoscale level. A more detailed knowledge of these relationships, in combination with maps of the potential
DOI: 10.1002/adma.200601882 Spontaneous Formation of Mesoscale Polymer Patterns
Lin, Zhiqun
DOI: 10.1002/adma.200601882 Spontaneous Formation of Mesoscale Polymer Patterns in an Evaporating of intriguing, ordered structures. Herein, we report on the spontaneous formation of well-or- ganized mesoscale
Course MA59800: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale.
Santos, Juan
Course MA59800: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale matrix properties, fine layering, frac- tures and craks at the mesoscale (on the order of centimeters
Course: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale
Santos, Juan
Course: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale Professor variations in the fluid and solid matrix properties, fine layering, frac- tures and craks at the mesoscale
Mesoscale Origin of the Enhanced Cycling-Stability of the Si...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Mesoscale Origin of the Enhanced Cycling-Stability of the Si-Conductive Polymer Anode for Li-ion Batteries. Mesoscale Origin of the Enhanced Cycling-Stability of the Si-Conductive...
Structure of polyamidoamide dendrimers up to limiting generations: A mesoscale description
Goddard III, William A.
Structure of polyamidoamide dendrimers up to limiting generations: A mesoscale description Prabal K, while reducing the degrees of freedom by tenfold. This mesoscale description has allowed us to study
Geissler, Phillip
the Mesoscale Variability in Arabidopsis Thylakoids Bibiana Onoa1 , Anna R. Schneider2 , Matthew D. Brooks3 Quantitatively Delineate the Mesoscale Variability in Arabidopsis Thylakoids. PLoS ONE 9(7): e101470. doi:10
A distributional approach to the geometry of 2D dislocations at the mesoscale
Lisbon, University of
A distributional approach to the geometry of 2D dislocations at the mesoscale Part A: General introduce the meso-scale as defined by some average distance between the dislocations. The laws governing
The Regional Atmospheric Modeling System (RAMS): Development for Parallel Processing Computer
Cirne, Walfredo
on the mesoscale (horizontal scales from 2 km to 2000 km) for purposes ranging from operational weather forecasting and simulating convective clouds, mesoscale convective systems, cirrus clouds, and precipitating weather systems models that had a great deal of overlap, the CSU cloud/mesoscale mode (Tripoli and Cotton, 1982
Analysis and behavioral modeling of the Finite State Machines of the Xpress Transfer Protocol
Madduri, Venkateswara Rao
1994-01-01T23:59:59.000Z
OF THE 3. 4 SPECIFICATION OF THE XTP FINITE STATE MACHINES . A. XTP Context Manager State Machine B. XTP Output State Machine C. XTP Sync State Machine. D. XTP Rate Control State Machine E. XTP Control-Send State Machine. . . F. XTP Input State... control parameters 26 II XTP context manager state transition table[12]. III XTP output state machine transition table [12]. IV XTP sync state machine transition table[12]. 40 V XTP rate control state machine transition table[12]. VI XTP control...
Roemer, Milton Harry
1964-01-01T23:59:59.000Z
of the impulse response are defined as follows: Zeroth moment (I- 3) Ftrst mons ent Second moment. 0 The zeroth moment Ms is simply the area under the res ponst curve. If the response or solute concentration function has been properly reduced such that a...P dx (11-16) Finite; x ~ & 0 (II- 1 7) 8y 0; x-1; 7&0 ax (II- I 8) These equations can be solved by separation of variables methods or Laplace transform methods. Brenner (8) gives a good account of both methods, The Laplace transformation from tue...
Wind ringing of the ocean in presence of mesoscale eddies P. Klein and G. Lapeyre
Lapeyre, Guillaume
Wind ringing of the ocean in presence of mesoscale eddies P. Klein and G. Lapeyre Laboratoire de scales related to oceanic mesoscale eddies. Results show that a turbulent eddy field does not affect Oceanography: Physical: Eddies and mesoscale processes; 4572 Oceanography: Physical: Upper ocean processes
THE ROLE OF CLOUD MICROPHYSICS PARAMETERIZATION IN THE SIMULATION OF MESOSCALE CONVECTIVE SYSTEMS in the Simulation of Mesoscale Convective Systems and Anvil Clouds in the Tropical Western Pacific K. Van Weverberg1 cloud microphysics in the simulation of mesoscale convective systems (MCSs) in the tropical western
Practical and Intrinsic Predictability of Severe and Convective Weather at the Mesoscales
Practical and Intrinsic Predictability of Severe and Convective Weather at the Mesoscales at the mesoscales using convection-permitting ensemble simulations of a squall line and bow echo event during the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment (BAMEX) on 910 June 2003. Although most
Charge rearrangement by sprites over a north Texas mesoscale convective system
Cummer, Steven A.
Charge rearrangement by sprites over a north Texas mesoscale convective system William W. Hager,1 is analyzed for a mesoscale convective system (MCS) situated in north Texas and east New Mexico on 15 July. Lapierre (2012), Charge rearrangement by sprites over a north Texas mesoscale convective system, J. Geophys
Near-Inertial Wave Wake of Hurricanes Katrina and Rita over Mesoscale Oceanic Eddies
Miami, University of
Near-Inertial Wave Wake of Hurricanes Katrina and Rita over Mesoscale Oceanic Eddies BENJAMIN; Jaimes and Shay 2009, hereafter JS09). These robust mesoscale oceanic features are present at any time (Jaimes 2009). This mesoscale ocean variability imposed important dynamical constraints on the OML
Mixed Layer Cooling in Mesoscale Oceanic Eddies during Hurricanes Katrina and Rita
Miami, University of
Mixed Layer Cooling in Mesoscale Oceanic Eddies during Hurricanes Katrina and Rita BENJAMIN JAIMES. Introduction Isotherm topography and energetic geostrophic flow in mesoscale oceanic features in the Gulf. 2000; Shay et al. 2000). The dependence of hurricane-induced OML cooling on the presence of mesoscale
A Climatology of Midlatitude Mesoscale Convective Vortices in the Rapid Update Cycle
Johnson, Richard H.
A Climatology of Midlatitude Mesoscale Convective Vortices in the Rapid Update Cycle ERIC P. JAMES of mesoscale convective vortices (MCVs) occurring in the state of Oklahoma during the late spring and summer, true MCVs represent only about 20% of the mesoscale relative vorticity maxima detected by the algorithm
ach year across the US, mesoscale weather events--flash floods, tornadoes, hail,
Plale, Beth
E ach year across the US, mesoscale weather events--flash floods, tornadoes, hail, strong winds of mesoscale weather research; its disparate, high-volume data sets and streams; or the tremendous urgent need for a comprehensive national cyberinfrastructure in mesoscale meteorology--particularly one
Numerical Simulation of Mesoscale Circulations in a Region of Contrasting Soil Types
Raman, Sethu
Numerical Simulation of Mesoscale Circulations in a Region of Contrasting Soil Types SETHU RAMAN,1 AARON SIMS,1,2 ROBB ELLIS,1 and RYAN BOYLES 1 Abstract--Mesoscale processes that form due to changes on mesoscale processes are examined. Climatological analyses indicate increased convective precipitation
Patterns of Precipitation and Mesolow Evolution in Midlatitude Mesoscale Convective Vortices
Johnson, Richard H.
Patterns of Precipitation and Mesolow Evolution in Midlatitude Mesoscale Convective Vortices ERIC P manifestations of mesoscale convective vortices (MCVs) that traversed Oklahoma during the periods MayAugust 2002 Profiler Network data. Forty-five MCVs that developed from mesoscale convective systems (MCSs) have been
A SCALABLE FULLY IMPLICIT COMPRESSIBLE EULER SOLVER FOR MESOSCALE NONHYDROSTATIC SIMULATION OF
Cai, Xiao-Chuan
A SCALABLE FULLY IMPLICIT COMPRESSIBLE EULER SOLVER FOR MESOSCALE NONHYDROSTATIC SIMULATION for the mesoscale nonhydrostatic simulation of atmospheric flows governed by the compressible Euler equations is of interest as in mesoscale and cloud-resolving atmospheric simulations, fast and efficient solution
Author , Short title EFFECTS OF MESOSCALE TEXTURE ON APPARENT SURFACE GLOSS
Ferwerda, James A.
Author , Short title 1 EFFECTS OF MESOSCALE TEXTURE ON APPARENT SURFACE GLOSS James A. Ferwerda to it. We first measure both the microscale reflectance properties and mesoscale texture of flat, latex these images as stimuli in perceptual experiments to systematically study how surface mesoscale properties
Cochlan, William P.
Persistence of iron limitation in the western subarctic Pacific SEEDS II mesoscale fertilization t The cumulative evidence from more than a dozen mesoscale iron-enrichment studies in high nitrate low chlorophyll diatoms, vary greatly among these mesoscale experiments even though similar amounts of iron were added
Spatio-temporal segmentation of mesoscale ocean surface dynamics using satellite data
Paris-Sud XI, Université de
Spatio-temporal segmentation of mesoscale ocean surface dynamics using satellite data Pierre Tandeo Temperature (SST) provide a wealth of information about ocean circulation, espe- cially mesoscale ocean an observation-driven framework, we investigate the extent to which mesoscale ocean dynamics may be decomposed
Development of a Piezoelectrically-Actuated Mesoscale Robot Quadruped Michael Goldfarb, Michael approach that offers a high locomotive efficiency, and is therefore well suited to mesoscale robot design actuated mesoscale robot quadruped. The design described utilizes a lightly damped skeletal structure
Howat, Ian M.
Real-Time Forecasting for the Antarctic: An Evaluation of the Antarctic Mesoscale Prediction System. MANNING AND JORDAN G. POWERS Mesoscale and Microscale Meteorology Division, National Center.S. Antarctic Program's field operations, the Antarctic Mesoscale Prediction System (AMPS) was implemented in Oc
PROBCAST: A Web-Based Portal to Mesoscale Probabilistic Forecasts Clifford Mass1
Mass, Clifford F.
1 PROBCAST: A Web-Based Portal to Mesoscale Probabilistic Forecasts Clifford Mass1 , Susan Joslyn over the Pacific Northwest. PROBCAST products are derived from the output of a mesoscale ensemble-processing of mesoscale, short-range ensembles. The NAS report also noted current deficiencies in the communication
Raman, Sethu
Sensitivity of Mesoscale Surface Dynamics to Surface Soil and Vegetation Contrasts over in mesoscale summertime precipitation over this region. Numerical simulations are analyzed to investigate the relationships between mesoscale surface dynamics and the transition from clay to sandy soils over this region
Studies on non-premixed flame streets in a mesoscale channel
Ju, Yiguang
Studies on non-premixed flame streets in a mesoscale channel Bo Xu *, Yiguang Ju Department of channel width, wall temperature, and flow rate on the dynamics of non-premix flames in a mesoscale The Combustion Institute. Published by Elsevier Inc. All rights reserved. Keywords: Mesoscale combustion; Non
ATM678, Mesoscale Dynamics, Spring 2014 Class time: TR 11:30am to 1pm
Moelders, Nicole
ATM678, Mesoscale Dynamics, Spring 2014 Class time: TR 11:30am to 1pm Classroom: Elvy auditorium, Akasofu 319 Course Description: The class provides a comprehensive explanation of mesoscale air motions their phenology, basic physics and mechanisms, why they build and how mesoscale motions interact with the micro
Prentiss, Mara
Mesoscale Self-Assembly of Hexagonal Plates Using Lateral Capillary Forces: Synthesis Using examines self-assembly in a quasi-two-dimensional, mesoscale system. The system studied here involves-assembly from the molecular to the mesoscale, (ii) the demonstration of a system in which small objects can
Mesoscale eddies northeast of the Hawaiian archipelago from satellite altimeter observations
Qiu, Bo
Mesoscale eddies northeast of the Hawaiian archipelago from satellite altimeter observations; published 16 March 2010. [1] Enhanced mesoscale eddy activity northeast of the Hawaiian archipelago by 5° longitude subregions revealed the dominant mesoscale periods ranging from 90 days near 18°N
Levi, Anthony F. J.
2011-01-01T23:59:59.000Z
PHYSICAL REVIEW A 83, 043827 (2011) Quantum fluctuations and saturable absorption in mesoscale in mesoscale lasers. The time evolution of the density matrix is obtained from numerical integration and field behavior of mesoscale lasers. Using only semiclassical master equations and specific device parameters
Zhou, Quanlin
Analysis of a mesoscale infiltration and water seepage test in unsaturated fractured rock: Spatial 2006 Abstract A mesoscale (21 m in flow distance) infiltration and seepage test was recently conducted flow in fractured rock at mesoscale or a larger scale is not necessarily conditional explicitly
Mesoscale distribution of zooplankton biomass in the northeast Atlantic Ocean determined Available online 2 June 2009 Keywords: Zooplankton Biomass Size distribution Mesoscale eddies Optical plankton counter Pelagic environment Northeast Atlantic Ocean a b s t r a c t We examined the mesoscale
MESOSCALE ANALYSIS OF A CAROLINA COASTAL FRONT SETHU RAMAN, NEERAJA C. REDDY and DEVDUTTA S. NIYOGI
Niyogi, Dev
MESOSCALE ANALYSIS OF A CAROLINA COASTAL FRONT SETHU RAMAN, NEERAJA C. REDDY and DEVDUTTA S. NIYOGI the shore. Key words: GALE, Coastal front, Atmospheric boundary layer, Gulf Stream, Mesoscale analysis turbulent heat fluxes. These strong gradients in heat fluxes enhance mesoscale circulation
Xie, Shang-Ping
Satellite observations of mesoscale ocean features and copropagating atmospheric surface fields speed and sea surface temperature (SST) over mesoscale ocean features in certain frontal regions. The aim of this study is to determine to what extent mesoscale ocean dynamics modifies the surface wind
Droegemeier, Kelvin K.
1 Draft Chapter from Mesoscale Dynamic Meteorology By Prof. Yu-lang Lin, North Carolina State University Chapter 1 Overview 1.1 Introduction The so-called mesometeorology or mesoscale meteorology as mesoscale phenomena by others (e.g. Orlanski 1975; Thunis and Bornstein 1996). Therefore, a more precise
Mesoscale Simulation of Grain David Kinderlehrer, Jeehyun Lee, Irene Livshits and Shlomo Ta'asan
Mesoscale Simulation of Grain Growth David Kinderlehrer, Jeehyun Lee, Irene Livshits and Shlomo Ta'asan WILEY-VCH Verlag Berlin GmbH September 4, 2003 #12;2 0.1 Introduction The mesoscale simulation of grain of the statistics it provides, we are led to the companion issue of coarse graining in mesoscale simulations. We
CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt
Hunt, Julian
CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt ¢¡ £ ,A. Orr , D. Cresswell layer or inversion layer, is developed for idealised and steady, but typical, mesoscale atmospheric estimates for a wide range of perturbed mesoscale flows, especially where the surface conditions change
Heat transport and weakening of atmospheric stability induced by mesoscale flows
Pielke, Roger A.
Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time
Martín-Solís, José Ramón
Mesoscale transport properties induced by near critical resistive pressure diffusive equation for mesoscale tracer-particle transport. The indices of the fractional derivates a mesoscale regime. That is, for time scales above the fluctuation scales reaching to the trans- port scales
Mesoscale energetics and ows induced by sea-land and mountain-valley contrasts
Paris-Sud XI, Université de
Mesoscale energetics and ¯ows induced by sea-land and mountain-valley contrasts S. Federico1 , G. A in determining the development of thermally forced mesoscale circula- tions (TFMCs) over a mountainous peninsula dynamics (climatology; mesoscale meteorology) 1 Introduction In the early hours of the morning the sun
On the role of mesoscale eddies in the ventilation of Antarctic intermediate water
Fischlin, Andreas
On the role of mesoscale eddies in the ventilation of Antarctic intermediate water Zouhair Lachkar Mesoscale eddies CFC-11 Ventilation Southern Ocean a b s t r a c t The spatial distribution of Antarctic and ventilation are substantially affected by mesoscale eddies. To diagnose the role of eddies, we made global CFC
Mesoscale Simulation of Tropical Cyclones in the South Pacific: Climatology and Interannual is shown to reproduce a wide range of mesoscale convective systems. Tropical cyclones grow from the most related to mesoscale in- teractions, which also affect TC tracks and the resulting occurrence. 1
Asymmetric Catalysis at the Mesoscale: Gold Nanoclusters Embedded in Chiral Self of the catalytically active metallic sites and the surrounding chiral SAM for the formation of a mesoscale the catalytically active site from the nanoscale to the mesoscale, which implies a principle of operating systems
Deriving Mesoscale Surface Current Fields from Multi-Sensor Satellite Data , B. Seppke b
Hamburg,.Universität
Deriving Mesoscale Surface Current Fields from Multi-Sensor Satellite Data M. Gade a , B. Seppke b of mesoscale surface currents in the southestern Baltic Sea (Southern Baltic Proper). Marine surface films of the two-dimensional data sets may therefore allow for the calculation of mesoscale ocean current fields
Segmentation of mesoscale ocean surface dynamics using satellite SST and SSH observations
Paris-Sud XI, Université de
1 Segmentation of mesoscale ocean surface dynamics using satellite SST and SSH observations Pierre about ocean circulation, espe- cially mesoscale ocean dynamics which may involve strong spatio- temporal to which mesoscale ocean dynamics may be decomposed into a mixture of dynamical modes, characterized
Generation of strong mesoscale eddies by weak ocean gyres by Michael A. Spall1
Generation of strong mesoscale eddies by weak ocean gyres by Michael A. Spall1 ABSTRACT The generation of strong mesoscale variability through instability of the large-scale circulation in the interior with the scaling theory. 1. Introduction It is now well recognized that the kinetic energy of the mesoscale
Mesoscale eddies in the northeastern Pacific tropical-subtropical transition zone: Statistical February 2012; revised 24 August 2012; accepted 6 September 2012; published 24 October 2012. [1] Mesoscale cycle. Although mesoscale eddies in these areas have been previously reported, this study provides
Mesoscale and clusters of synchrony in networks of bursting neurons Igor Belykh1
Belykh, Igor
Mesoscale and clusters of synchrony in networks of bursting neurons Igor Belykh1 and Martin Hasler2 with relatively large clusters, leading potentially to cluster synchronization at the mesoscale network level. We represent the microscale level, cooperative rhythms of neuronal subpopulations define the mesoscale level
Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1
Bergen, Universitetet i
Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1 O. Amm,2 C. C. Chaston; revised 22 June 2010; accepted 28 June 2010; published 7 October 2010. [1] We present small and mesoscale. Good agreement could be reached for the mesoscale arc properties. A qualitative analysis
Qiu, Bo
Seasonal Mesoscale and Submesoscale Eddy Variability along the North Pacific Subtropical abundant in mesoscale eddies, but also exhibits prominent submesoscale eddy features. Output from a 1 the seasonal STCC variability in the mesoscale versus submesoscale ranges. Resolving the eddy scales of .150 km
Spiga, Aymeric
Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena Keywords: Mesoscale meteorology Katabatic winds Boundary layer convection Comparative planetology a b s t r a c t Terrestrial and Martian atmospheres are both characterised by a large variety of mesoscale
Finite Element Analysis Skateboard Truck
De, Suvranu
Finite Element Analysis Of a Skateboard Truck #12;2 Executive Summary: Engineering is and always is an element of the `truck,' which holds the wheels. Finite Element analysis will be conducted on this piece a combination of SolidWorks (for modeling) and ABAQUS (for finite element analysis). It is evident from
Ernest Valeo, Jay R. Johnson, Eun-Hwa and Cynthia Phillips
2012-03-13T23:59:59.000Z
A wide variety of plasma waves play an important role in the energization and loss of particles in the inner magnetosphere. Our ability to understand and model wave-particle interactions in this region requires improved knowledge of the spatial distribution and properties of these waves as well as improved understanding of how the waves depend on changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a two-dimensional, finite element code that solves the full wave equations in global magnetospheric geometry. The code describes three-dimensional wave structure including mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional axisymmetric background plasma with general magnetic field topology. We illustrate the capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from external, solar wind compressions; and wave structure and mode conversion of electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which propagate along the magnetic field lines toward the ionosphere. We also discuss advantages of the finite element method for resolving resonant structures, and how the model may be adapted to include nonlocal kinetic effects.
Mesoscale symmetries explain dynamical equivalence of food webs
Aufderheide, Helge; Gross, Thilo
2012-01-01T23:59:59.000Z
A present challenge in complex systems is to identify mesoscale structures that have distinct dynamical implications. In this paper we present a detailed investigation of a previously observed dynamical equivalence of certian ecological food webs. We show that this equivalence is rooted in mesoscale symmetries that exist in these webs. Certain eigenvectors of the Jacobian describing dynamical modes of the system, such as specific instabilities or responses to perturbations, localize on these symmetric motifs. On the one hand this means that by removing a symmetry from the network one obtains a system which has identical dynamics except for the removal of the localized mode. This explains the previously observed equivalence. On the other hand it means that we can identify dynamical modes that only depend on the symmetric motif. Symmetric structures thus provide an example for mesoscale network motifs having distinct and exact implications for the dynamics.
Modeling and Verification for Timing Satisfaction of Fault-Tolerant Systems with Finiteness
Cheng, Chih-Hong; Esparza, Javier; Knoll, Alois
2009-01-01T23:59:59.000Z
The increasing use of model-based tools enables further use of formal verification techniques in the context of distributed real-time systems. To avoid state explosion, it is necessary to construct a verification model that focuses on the aspects under consideration. In this paper, we discuss how we construct a verification model for timing analysis in distributed real-time systems. We (1) give observations concerning restrictions of timed automata to model these systems, (2) formulate mathematical representations how to perform model-to-model transformation to derive verification models from system models, and (3) propose some theoretical criteria how to reduce the model size. The latter is in particular important, as for the verification of complex systems, an efficient model reflecting the properties of the system under consideration is equally important to the verification algorithm itself. Finally, we present an extension of the model-based development tool FTOS, designed to develop fault-tolerant system...
Goudon, Thierry, E-mail: thierry.goudon@inria.fr [Team COFFEE, INRIA Sophia Antipolis Mediterranee (France) [Team COFFEE, INRIA Sophia Antipolis Mediterranee (France); Labo. J.A. Dieudonne CNRS and Univ. Nice-Sophia Antipolis (UMR 7351), Parc Valrose, 06108 Nice cedex 02 (France); Parisot, Martin, E-mail: martin.parisot@gmail.com [Project-Team SIMPAF, INRIA Lille Nord Europe, Park Plazza, 40 avenue Halley, F-59650 Villeneuve d'Ascq cedex (France)] [Project-Team SIMPAF, INRIA Lille Nord Europe, Park Plazza, 40 avenue Halley, F-59650 Villeneuve d'Ascq cedex (France)
2012-10-15T23:59:59.000Z
In the so-called Spitzer-Haerm regime, equations of plasma physics reduce to a nonlinear parabolic equation for the electronic temperature. Coming back to the derivation of this limiting equation through hydrodynamic regime arguments, one is led to construct a hierarchy of models where the heat fluxes are defined through a non-local relation which can be reinterpreted as well by introducing coupled diffusion equations. We address the question of designing numerical methods to simulate these equations. The basic requirement for the scheme is to be asymptotically consistent with the Spitzer-Haerm regime. Furthermore, the constraints of physically realistic simulations make the use of unstructured meshes unavoidable. We develop a Finite Volume scheme, based on Vertex-Based discretization, which reaches these objectives. We discuss on numerical grounds the efficiency of the method, and the ability of the generalized models in capturing relevant phenomena missed by the asymptotic problem.
Eddy heat fluxes at Drake Passage due to mesoscale motions
Rojas Recabal, Ricardo Luis
1982-01-01T23:59:59.000Z
EDDY HEAT FLUKES AT DRAKE PASSAGE DUE TO MESOSCALE MOTIONS A Thesis by RICARDO LUIS ROJAS RECABAL Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May... 1982 Major Subject: Oceanography EDDY HEAT FLUXES AT DRAKE PASSAGE DUE TO MESOSCALE NOTIONS A Thesis by RICARDO LUIS ROJAS RECABAL Approved as to style and content by: was )W-~ Member em er May 1982 ABSTRACT Eddy Heat Fluxes at Drake Passage...
Raftery, Adrian
permission. Calibrated Probabilistic Mesoscale Weather Field Forecasting: The Geostatist... Yulia Gel; Adrian
Johnson, Richard H.
October 1986 R. H. Johnson 721 Lower-Tropospheric Warming and Drying in Tropical Mesoscale components of tropical mesoscale convective systems. It is found that while the apparent heat source Q1 of mesoscale downdrafts within the mesoscale convective systems. The warming and drying at low levels
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhou, Linjiong; Bao, Qing; Liu, Yimin; Wu, Guoxiong; Wang, Wei-Chyung; Wang, Xiaocong; He, Bian; Yu, Haiyang; Li, Jiandong
2015-03-01T23:59:59.000Z
This paper documents version 1 of the Finite-volume Atmospheric Model of the IAP/LASG (FAMIL1), which has a flexible horizontal resolution up to a quarter of 1°. The model, currently running on the ‘‘Tianhe 1A’’ supercomputer, is the atmospheric component of the third-generation Flexible Global Ocean-Atmosphere-Land climate System model (FGOALS3) which will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition to describing the dynamical core and physical parameterizations of FAMIL1, this paper describes the simulated characteristics of energy and water balances and compares them with observational/reanalysis data. The comparisons indicate that the model simulates well the seasonalmore »and geographical distributions of radiative fluxes at the top of the atmosphere and at the surface, as well as the surface latent and sensible heat fluxes. A major weakness in the energy balance is identified in the regions where extensive and persistent marine stratocumulus is present. Analysis of the global water balance also indicates realistic seasonal and geographical distributions with the global annual mean of evaporation minus precipitation being approximately 10?? mm d?¹. We also examine the connections between the global energy and water balance and discuss the possible link between the two within the context of the findings from the reanalysis data. Finally, the model biases as well as possible solutions are discussed.« less
Cambridge, University of
Element Analysis, H. K. D. H. Bhadeshia Lecture 3: Finite Elements Steadystate heat flow through A and length L. The finite element representation consists of two nodes i and j. Heat flow in one. The temperatures T1 and T2 are maintained constant. The finite element representation consists of a single element
Lee, Sang Hoon
2012-02-14T23:59:59.000Z
coupled thermo-poro-mechanical FEM simulation was used to model damage/fracture propagation and microseismic events caused by fluid injection. These studies considered wellbore geometry in small-scale modeling and point-source injection, assuming...
Finite Temperature Effective Actions
Ashok Das; J. Frenkel
2009-08-27T23:59:59.000Z
We present, from first principles, a direct method for evaluating the exact fermion propagator in the presence of a general background field at finite temperature, which can be used to determine the finite temperature effective action for the system. As applications, we determine the complete one loop finite temperature effective actions for 0+1 dimensional QED as well as the Schwinger model. These effective actions, which are derived in the real time (closed time path) formalism, generate systematically all the Feynman amplitudes calculated in thermal perturbation theory and also show that the retarded (advanced) amplitudes vanish in these theories.
Characterization of Caribbean Meso-Scale Eddies Jose M. Lopez
Gilbes, Fernando
Characterization of Caribbean Meso-Scale Eddies Jose M. Lopez Department of Marine Sciences, P-term goal is to improve predictivity of physical, biogeochemical and optical properties of Eastern Caribbean, biological and optical variables across frontal and eddy boundaries in the Eastern Caribbean Sea Â· To develop
Mesoscale simulations of surfactant dissolution and mesophase formation
P. Prinsen; P. B. Warren; M. A. J. Michels
2002-04-22T23:59:59.000Z
The evolution of the contact zone between pure surfactant and solvent has been studied by mesoscale simulation. It is found that mesophase formation becomes diffusion controlled and follows the equilibrium phase diagram adiabatically almost as soon as individual mesophases can be identified, corresponding to times in real systems of order 10 microseconds.
LANSCE School on Neutron Scattering: Materials at the Mesoscale
1 11th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos. Please name the applicant for admission to the 11th LANSCE School on Neutron Scattering: Last, First LANSCE School on Neutron Scattering including: drive and motivation, ability to work with others
2013-01-01T23:59:59.000Z
Circulatory System Model of Heart Failure Jonathan F. Wenk,contracting regions of the heart. These single ventricledilation and help remodel the heart towards a normal state.
Moaveni, Babak; Conte, Joel P; Hemez, François M
2009-01-01T23:59:59.000Z
modeling error). A full factorial design of experiments iserror) (E). A full factorial design of experiments isnumerical). A full-factorial design of experiments is used
The XX-model with boundaries: Part I. Diagonalization of the finite ...
1998-12-15T23:59:59.000Z
The XX-model often appears as a special case of the XY-model. .... This approach has the major advantage that we have complete control over the wavefunctions .... These one-point functions decay into the bulk with a power law typical of conformally ... The partition functions correspond to conformally invariant systems, ...
Martini, Matus; Gustafson, William I.; Yang, Qing; Xiao, Heng
2014-11-27T23:59:59.000Z
Organized mesoscale cellular convection (MCC) is a common feature of marine stratocumulus that forms in response to a balance between mesoscale dynamics and smaller scale processes such as cloud radiative cooling and microphysics. We use the Weather Research and Forecasting model with chemistry (WRF-Chem) and fully coupled cloud-aerosol interactions to simulate marine low clouds during the VOCALS-REx campaign over the southeast Pacific. A suite of experiments with 3- and 9-km grid spacing indicates resolution-dependent behavior. The simulations with finer grid spacing have smaller liquid water paths and cloud fractions, while cloud tops are higher. The observed diurnal cycle is reasonably well simulated. To isolate organized MCC characteristics we develop a new automated method, which uses a variation of the watershed segmentation technique that combines the detection of cloud boundaries with a test for coincident vertical velocity characteristics. This ensures that the detected cloud fields are dynamically consistent for closed MCC, the most common MCC type over the VOCALS-REx region. We demonstrate that the 3-km simulation is able to reproduce the scaling between horizontal cell size and boundary layer height seen in satellite observations. However, the 9-km simulation is unable to resolve smaller circulations corresponding to shallower boundary layers, instead producing invariant MCC horizontal scale for all simulated boundary layers depths. The results imply that climate models with grid spacing of roughly 3 km or smaller may be needed to properly simulate the MCC structure in the marine stratocumulus regions.
Microphysical/mesoscale aspects of nuclear winter and new directions in assessments
Knox, J.B.
1985-06-01T23:59:59.000Z
Recent results of model studies and sensitivity tests have shown the degree to which the intensity and duration of ''nuclear winter'' depends on the mass of soot and dust suspended, its optical properties, its vertical distribution in the atmosphere, and the residence time. The soot from urban fires is viewed as evolving during its dispersion from the early fire induced plumes, to cloud scale systems, to the mesoscale and larger systems. Micro-physical processes are perceived as operating within these systems in a manner to enhance removal from the troposphere, and to alter the verical distribution of the soot or its subsequent, aging or evolving aerosol. Relevant observations and studies of these processes are presented and discussed. Critical inputs to the climate simulation models may well be altered significantly by these process effects, many of which are in need of better definition. Appropriate research needs to be initiated to address and better define these microphysical/mesoscale processes of potential importance in the altered atmospheric system after a major nuclear exchange. 11 refs., 2 figs.
Modeling of reactor components using FIDAP: a finite element computer code
Gangadharan, Anand
1989-01-01T23:59:59.000Z
of the Electric Power Research Institute (EPRI). The test famlity resembles a scaled model of a, high pressure injection of cold water into the cold leg and downcomer of s. pressurized water reactor (PWR). This experiment has current relevance because... DECK FOR EPRI/SAI THERMAL MIXING EXPERIMENT 66 B INPUT DECK FOR THE ADVANCED FUEL COOLING SYSTEM . 78 vn LIST OF TABLES Table Page 1 Constants used in the rc ? e model. 18 2 Experimental test values. 20 vsn LIST OF FIGURES Figure 1 Model...
Ionic Polymer-Metal Composites: Thermodynamical Modeling and Finite Element Solution
Arumugam, Jayavel
2012-10-19T23:59:59.000Z
This thesis deals with developing a thermodynamically consistent model to simulate the electromechanical response of ionic polymer-metal composites based on Euler-Bernoulli beam theory. Constitutive assumptions are made for the Helmholtz free...
Smart finite state devices: A modeling framework for demand response technologies
Turitsyn, Konstantin
We introduce and analyze Markov Decision Process (MDP) machines to model individual devices which are expected to participate in future demand-response markets on distribution grids. We differentiate devices into the ...
k - Version of Finite Element Method for Polymer flows using Giesekus Constitutive Model
Deshpande, Kedar M.
2008-01-31T23:59:59.000Z
and hence high Deborah number flows are invariably associated with higher flow rates and thus higher velocities. In many standard model problems such as couette flow, lid driven cavity, expansion, contraction etc, severe deborah number (De) limitations...
A multi-scale iterative approach for finite element modeling of thermal contact resistance
Thompson, Mary Kathryn, 1980-
2007-01-01T23:59:59.000Z
Surface topography has long been considered a key factor in the performance of many contact applications including thermal contact resistance. However, essentially all analytical and numerical models of thermal contact ...
Mongkolcheep, Kathira
2010-10-12T23:59:59.000Z
The purpose of this work is to present a methodology to predict vibrations of drilllstrings for oil recovery service. The work extends a previous model of the drill collar between two stabilizers in the literature to include drill collar flexibility...
A finite element model of the turbulent flow field in a centrifugal impeller
Hlavaty, Steven Todd
1993-01-01T23:59:59.000Z
, or for applications such as pumps utilizing a liquid as the working medium. Full ellipticity of the flow- governing equations throughout the computational domain is rigorously retained. As a result, the model is conceptually capable of predicting real-flow effects... such as flow separation and recirculation, regardless of whether such complex flow behavior is local or massive. Applicability of the model is illustrated using a typical pump impeller of the purely centrifugal type. In presenting the computed flow field...
Bower, Allan F; Sethuraman, Vijay A; 10.1016/j.jmps.2011.01.003
2011-01-01T23:59:59.000Z
We formulate the continuum field equations and constitutive equations that govern deformation, stress, and electric current flow in a Li-ion half-cell. The model considers mass transport through the system, deformation and stress in the anode and cathode, electrostatic fields, as well as the electrochemical reactions at the electrode/electrolyte interfaces. It extends existing analyses by accounting for the effects of finite strains and plastic flow in the electrodes, and by exploring in detail the role of stress in the electrochemical reactions at the electrode-electrolyte interfaces. In particular, we find that that stress directly influences the rest potential at the interface, so that a term involving stress must be added to the Nernst equation if the stress in the solid is significant. The model is used to predict the variation of stress and electric potential in a model 1-D half-cell, consisting of a thin film of Si on a rigid substrate, a fluid electrolyte layer, and a solid Li cathode. The predicted c...
Griffith, Daniel Todd; Segalman, Daniel Joseph
2006-10-01T23:59:59.000Z
A technique published in SAND Report 2006-1789 ''Model Reduction of Systems with Localized Nonlinearities'' is illustrated in two problems of finite element structural dynamics. That technique, called here the Method of Locally Discontinuous Basis Vectors (LDBV), was devised to address the peculiar difficulties of model reduction of systems having spatially localized nonlinearities. It's illustration here is on two problems of different geometric and dynamic complexity, but each containing localized interface nonlinearities represented by constitutive models for bolted joint behavior. As illustrated on simple problems in the earlier SAND report, the LDBV Method not only affords reduction in size of the nonlinear systems of equations that must be solved, but it also facilitates the use of much larger time steps on problems of joint macro-slip than would be possible otherwise. These benefits are more dramatic for the larger problems illustrated here. The work of both the original SAND report and this one were funded by the LDRD program at Sandia National Laboratories.
Crossing the mesoscale no-mans land via parallel kinetic Monte Carlo.
Garcia Cardona, Cristina (San Diego State University); Webb, Edmund Blackburn, III; Wagner, Gregory John; Tikare, Veena; Holm, Elizabeth Ann; Plimpton, Steven James; Thompson, Aidan Patrick; Slepoy, Alexander (U. S. Department of Energy, NNSA); Zhou, Xiao Wang; Battaile, Corbett Chandler; Chandross, Michael Evan
2009-10-01T23:59:59.000Z
The kinetic Monte Carlo method and its variants are powerful tools for modeling materials at the mesoscale, meaning at length and time scales in between the atomic and continuum. We have completed a 3 year LDRD project with the goal of developing a parallel kinetic Monte Carlo capability and applying it to materials modeling problems of interest to Sandia. In this report we give an overview of the methods and algorithms developed, and describe our new open-source code called SPPARKS, for Stochastic Parallel PARticle Kinetic Simulator. We also highlight the development of several Monte Carlo models in SPPARKS for specific materials modeling applications, including grain growth, bubble formation, diffusion in nanoporous materials, defect formation in erbium hydrides, and surface growth and evolution.
Computational Modeling of Self-organization of Dislocations and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Computational Modeling of Self-organization of Dislocations and Mesoscale Deformation of Metals Event Sponsor: Mathematics and Computing Science - LANS Seminar Start Date: Jun 19...
atmospheric models final: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Temperature received 25 October 2013, in final form 24 July 2014) ABSTRACT The wind speed response to mesoscale SST (COAMPS) atmospheric models. The SST- induced wind response...
Documentation of Hybrid Hydride Model for Incorporation into...
Office of Environmental Management (EM)
Strategy This report documents the development, demonstration and validation of a mesoscale, microstructural evolution model for simulation of zirconium hydride d-ZrH1.5...
Min, Kyoung
2013-07-16T23:59:59.000Z
are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering...
Finite element and nite volume discretizations of Drift-Di usion type uid models for semiconductors
Brezzi, Franco
Milano Via Bonardi 9, 20133 Milano, Italy z University of Western Australia Department of Mathematics and Statistics Nedlands, Western Australia 6907, Australia This paper is to appear as a Chapter of Numerical the initial/boundary conditions which complete the model. We also consider in more detail the Energy
Propagation of Kelvin waves along irregular coastlines in finite-difference models
are shore-trapped long gravity waves on a rotating plane in which geostrophic balance is maintained between a particular concern when model- ing baroclinic coastal waves and upwelling. As shown by Hsieh et al.1 in the Arakawa B-grid, but stays constant at the long gravity wave speed in the Arakawa C-grid in the inviscid
FINITE ELEMENT APPROXIMATION OF A PHASE FIELD MODEL FOR VOID ELECTROMIGRATION
Styles, Vanessa
;) 2 [ 1; 1]. The above, in the limit ! 0, models the evolution of voids by surface di#11;usion and interfacial tension cause surface di#11;usion; that is, atoms di#11;use from one part of the void boundary to another. The void e#11;ectively \\drifts" through the conductor, changing its shape as it does so
Styles, Vanessa
FOR SUPERCONDUCTIVITY C.M. ELLIOTT, D. KAY #3; AND V.STYLES y CENTRE FOR MATHEMATICAL ANALYSIS AND ITS APPLICATIONS long cylindrical superconductor subject to a transverse magnetic #12;eld. We prove an error between of an evolutionary variational inequality arising from a critical state model for a type-II superconductor
Optimization of relativistic mean field model for finite nuclei to neutron star matter
B. K. Agrawal; A. Sulaksono; P. -G. Reinhard
2012-04-12T23:59:59.000Z
We have optimized the parameters of extended relativistic mean-field model using a selected set of global observables which includes binding energies and charge radii for nuclei along several isotopic and isotonic chains and the iso-scalar giant monopole resonance energies for the $^{90}$Zr and $^{208}$Pb nuclei. The model parameters are further constrained by the available informations on the energy per neutron for the dilute neutron matter and bounds on the equations of state of the symmetric and asymmetric nuclear matter at supra-nuclear densities. Two new parameter sets BSP and IUFSU* are obtained, later one being the variant of recently proposed IUFSU parameter set. The BSP parametrization uses the contributions from the quartic order cross-coupling between $\\omega$ and $\\sigma$ mesons to model the high density behaviour of the equation of state instead of the $\\omega$ meson self-coupling as in the case of IUFSU* or IUFSU. Our parameter sets yield appreciable improvements in the binding energy systematics and the equation of state for the dilute neutron matter. The importance of the quartic order $\\omega-\\sigma$ cross coupling term of the extended RMF model, as often ignored, is realized.
Mesoscale simulation of shocked poly-(4-methyl-1-pentene) (PMP) foams.
Schroen, Diana Grace; Flicker, Dawn G.; Haill, Thomas A.; Root, Seth; Mattsson, Thomas Kjell Rene
2011-06-01T23:59:59.000Z
Hydrocarbon foams are commonly used in HEDP experiments, and are subject to shock compression from tens to hundreds of GPa. Modeling foams is challenging due to the heterogeneous character of the foam. A quantitative understanding of foams under strong dynamic compression is sought. We use Sandia's ALEGRA-MHD code to simulate 3D mesoscale models of pure poly(4-methyl-1-petene) (PMP) foams. We employ two models of the initial polymer-void structure of the foam and analyze the statistical properties of the initial and shocked states. We compare the simulations to multi-Mbar shock experiments at various initial foam densities and flyer impact velocities. Scatter in the experimental data may be a consequence of the initial foam inhomogeneity. We compare the statistical properties the simulations with the scatter in the experimental data.
Smart Finite State Devices: A Modeling Framework for Demand Response Technologies
Turitsyn, Konstantin; Ananyev, Maxim; Chertkov, Michael
2011-01-01T23:59:59.000Z
We introduce and analyze Markov Decision Process (MDP) machines to model individual devices which are expected to participate in future demand-response markets on distribution grids. We differentiate devices into the following four types: (a) optional loads that can be shed, e.g. light dimming; (b) deferrable loads that can be delayed, e.g. dishwashers; (c) controllable loads with inertia, e.g. thermostatically-controlled loads, whose task is to maintain an auxiliary characteristic (temperature) within pre-defined margins; and (d) storage devices that can alternate between charging and generating. Our analysis of the devices seeks to find their optimal price-taking control strategy under a given stochastic model of the distribution market.
Antoine, Xavier - Institut de MathÃ©matiques Ã?lie Cartan, UniversitÃ© Henri PoincarÃ©
Accepted 12 January 2009 Available online 21 January 2009 Keywords: Helmholtz equation Acoustic scattering Short-wave problem Finite element method Pollution Accuracy On-Surface Radiation Condition method a b- lems in view of a numerical finite element solution. It is well-known that pollution error causes
Thermodynamic properties of mesoscale convective systems observed during BAMEX
Correia, James; Arritt, R.
2008-11-01T23:59:59.000Z
Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.
James, Stephen M.
2011-08-08T23:59:59.000Z
-dimensional axisymmetric beam-element code. ANSYS is used as a code to build three-dimensional non-axisymmetric solid-element casing models. The work done in this thesis opens the scope to incorporate complex non-axisymmetric casing models with XLTRC2....
Quantum fluctuations and saturable absorption in mesoscale lasers
Roy-Choudhury, Kaushik [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484 (United States); Levi, A. F. J. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484 (United States); Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089-2533 (United States)
2011-04-15T23:59:59.000Z
We present a quantum-mechanical treatment of fluctuations and saturable absorption in mesoscale lasers. The time evolution of the density matrix is obtained from numerical integration and field-field and intensity-intensity correlations are calculated to obtain steady-state linewidth and photon statistics. Inclusion of a saturable absorber in the otherwise homogeneous medium is shown to suppress lasing, increase fluctuations, and enhance spontaneous emission near threshold.
Lo, F. S.; Lee, T. H. [Department of Mechanical Engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan (China)] [Department of Mechanical Engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan (China); Lu, P. S. [NanoScience Simulation Laboratory, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan (China)] [NanoScience Simulation Laboratory, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan (China); Ragan-Kelley, B. [Applied Science and Technology, University of California, Berkeley, California 94720 (United States) [Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States); Minnich, A. [Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States); Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125 (United States); Lin, M. C., E-mail: mingchiehlin@gmail.com [NanoScience Simulation Laboratory, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan (China); Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States); Verboncoeur, J. P. [Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, University of California, Berkeley, California 94720 (United States); Department of Electrical and Computing Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)
2014-02-15T23:59:59.000Z
A thermionic energy converter (TEC) is a static device that converts heat directly into electricity by boiling electrons off a hot emitter surface across a small inter-electrode gap to a cooler collector surface. The main challenge in TECs is overcoming the space charge limit, which limits the current transmitted across a gap of a given voltage and width. We have verified the feasibility of studying and developing a TEC using a bounded finite-difference time-domain particle-in-cell plasma simulation code, OOPD1, developed by Plasma Theory and Simulation Group, formerly at UC Berkeley and now at Michigan State University. In this preliminary work, a TEC has been modeled kinetically using OOPD1, and the accuracy has been verified by comparing with an analytically solvable case, giving good agreement. With further improvement of the code, one will be able to quickly and cheaply analyze space charge effects, and seek designs that mitigate the space charge effect, allowing TECs to become more efficient and cost-effective.
Boundary Conditions of the Hydro-Cascade Model and Relativistic Kinetic Equations for Finite Domains
K. A. Bugaev
2004-01-29T23:59:59.000Z
A detailed analysis of the coupled relativistic kinetic equations for two domains separated by a hypersurface having both space- and time-like parts is presented. Integrating the derived set of transport equations, we obtain the correct system of the hydro+cascade equations to model the relativistic nuclear collision process. Remarkably, the conservation laws on the boundary between domains conserve separately both the incoming and outgoing components of energy, momentum and baryonic charge. Thus, the relativistic kinetic theory generates twice the number of conservation laws compared to traditional hydrodynamics. Our analysis shows that these boundary conditions between domains, the three flux discontinuity, can be satisfied only by a special superposition of two cut-off distribution functions for the ``out'' domain. All these results are applied to the case of the phase transition between quark gluon plasma and hadronic matter. The possible consequences for an improved hydro+cascade description of the relativistic nuclear collisions are discussed. The unique properties of the three flux discontinuity and their effect on the space-time evolution of the transverse expansion are also analyzed. The possible modifications of both transversal radii from pion correlations generated by a correct hydro+cascade approach are discussed.
Vortex arrays and meso-scale turbulence of self-propelled particles
Robert Grossmann; Pawel Romanczuk; Markus Bär; Lutz Schimansky-Geier
2014-05-30T23:59:59.000Z
Inspired by the Turing mechanism for pattern formation, we propose a simple self-propelled particle model with short-ranged alignment and anti-alignment at larger distances. It is able to produce orientationally ordered states, periodic vortex patterns as well as meso-scale turbulence. The latter phase resembles observations in dense bacterial suspensions. The model allows a systematic derivation and analysis of a kinetic theory as well as hydrodynamic equations for density and momentum fields. A phase diagram with regions of such pattern formation as well as spatially homogeneous orientational order and disorder is obtained from a linear stability analysis of these continuum equations. Microscopic Langevin simulations of the self-propelled particle system are in agreement with these findings.
Sudarshan, Raghunathan, 1978-
2005-01-01T23:59:59.000Z
We propose a simple and unified approach for a posteriori error estimation and adaptive mesh refinement in finite element analysis using multiresolution signal processing principles. Given a sequence of nested discretizations ...
Pontaza, Juan Pablo
2004-09-30T23:59:59.000Z
We consider the application of least-squares variational principles and the finite element method to the numerical solution of boundary value problems arising in the fields of solidand fluidmechanics.For manyof these ...
Reynolds, Amber Elizabeth
2009-05-15T23:59:59.000Z
Mesoscale convective vortices (MCVs), which typically form within the stratiform rain of some mesoscale convective systems (MCSs), may persist for days, often regenerating convection daily. Long-lived MCVs can produce as much precipitation as a...
Reynolds, Amber Elizabeth
2009-05-15T23:59:59.000Z
Mesoscale convective vortices (MCVs), which typically form within the stratiform rain of some mesoscale convective systems (MCSs), may persist for days, often regenerating convection daily. Long-lived MCVs can produce as much precipitation as a...
Dial, Greg Leander
1990-01-01T23:59:59.000Z
A CASE STUDY OF THE MESOSCALE AND SYNOPTIC-SCALE HEAT AND MOISTURE BUDGETS IN THE VICINITY OF A MESOSCALE CONVECTIVE COMPLEX A Thesis by GREG LEANDER DIAL Submitted to the Office of Graduate Studies of Texas A8 M University in partial...&j Leandor Dial Approved as lo style and content by: Kcnnctt& C, ftrunrti&lgc (Ctn&i& ol' Co&nn&ittcc) (I tcn&l&c&) Norman W. Na glc (Mcmbcr) E ar . ipscr (I les&I of Dcpartmcnt) I 1 a y I 9 &3 0 ABSTRACT A Case Study of the Mesoscale and Synoptic...
Inferring the mesoscale structure of layered, edge-valued and time-varying networks
Peixoto, Tiago P
2015-01-01T23:59:59.000Z
Many network systems are composed of interdependent but distinct types of interactions, which cannot be fully understood in isolation. These different types of interactions are often represented as layers, attributes on the edges or as a time-dependence of the network structure. Although they are crucial for a more comprehensive scientific understanding, these representations offer substantial challenges. Namely, it is an open problem how to precisely characterize the large or mesoscale structure of network systems in relation to these additional aspects. Furthermore, the direct incorporation of these features invariably increases the effective dimension of the network description, and hence aggravates the problem of overfitting, i.e. the use of overly-complex characterizations that mistake purely random fluctuations for actual structure. In this work, we propose a robust and principled method to tackle these problems, by constructing generative models of modular network structure, incorporating layered, attr...
Wilhelm, Steven W.
FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment to ocean physics. In summer 2003 we conducted FeCycle, a 10-day mesoscale tracer release in HNLC waters SE biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters, Global Biogeochem
Niyogi, Dev
Urban and land surface effects on the 30 July 2003 mesoscale convective system event observed/Atmosphere Mesoscale Prediction System (COAMPS 1 ) to investigate the impact of urban and land vegetation processes on the prediction of the mesoscale convective system (MCS) observed on 30 July 2003 in the vicinity of Oklahoma City
Kramer, Peter
Proceedings in Applied Mathematics and Mechanics, 31 October 2007 Parametrization for Mesoscale a mathematical approach based on homogenization theory toward representing the effects of mesoscale coherent in parameterizing the transport effects of sub-grid scale flow structures appearing in mesoscale oceanic turbulence
Anatomy and evolution of a cyclonic mesoscale eddy observed in the northeastern Pacific tropical and evolution of a cyclonic mesoscale eddy observed in the northeastern Pacific tropical-subtropical transition zone, J. Geophys. Res. Oceans, 118, doi:10.1002/ 2013JC009339. 1. Introduction [2] Mesoscale eddy
Cummer, Steven A.
in a mesoscale convective system Gaopeng Lu,1 Steven A. Cummer,1 Jingbo Li,1 Feng Han,1 Richard J. Blakeslee,2 positive cloud-to-ground (+CG) strokes in a mesoscale convective system. Although no high altitude images of large-charge-moment positive lightning strokes in a mesoscale convective system, Geophys. Res. Lett., 36
Hamburg,.Universität
THE USE OF SPATIAL CONSTRAINTS IN THE DERIVATION OF MESOSCALE SEA SURFACE CURRENT FIELDS FROM MULTI images are used for the computation of mesoscale surface currents in the Northern and Southern Baltic for the derivation of mesoscale sea surface currents using multi-sensor / multi-channel satellite images by means
Schlosser, Elisabeth
THE PRECIPITATION REGIME OF DRONNING MAUD LAND, ANTARCTICA, DERIVED FROM AMPS (ANTARCTIC MESOSCALE. Manning2) 1) Institute of Meteorology and Geophysics, University of Innsbruck, Austria 2) Mesoscale the temporal and spatial distribution of precipitation in DML using AMPS (Antarctic Mesoscale Prediction System
Webster III, Robert James
IEEE TRANSACTIONS ON ROBOTICS, VOL. 25, NO. 5, OCTOBER 2009 1047 A New Mechanism for Mesoscale for a novel mechanism for robotic legged locomotion at the mesoscale (from hundreds of microns to tens mesoscale locomotion tasks, in- cluding endoscopic capsule robot locomotion in the gastrointestinal tract
Raman, Sethu
Mesoscale Atmospheric Dispersion, 2001, Ed. Z. Boybeyi, WIT Publications, Southampton, UK, Advances surfaceatmosphere exchanges in mesoscale air pollution systems Devdutta S. Niyogi & Sethu Raman North-physiological leaf scaling approach. Finally, of particular relevance to mesoscale applications is the area averaging
Fairman, Robert
Characterization of Mesoscale Coiled-Coil Peptide-Porphyrin Complexes Brian J. Pepe-Mooney, Bashkim-assemble to form mesoscale filaments and serve as a scaffold for porphyrin interaction. In our earlier work mesoscale fibrils were formed, taking advantage of the types of porphyrin interactions that are present
: Interactions with Mesoscale Currents* C. CHAVANNE, P. FLAMENT, AND D. LUTHER School of Ocean and Earth Science in the light of the interaction of internal tides with energetic surface-intensified mesoscale currents locations at critical topographic slopes through idealized mesoscale currents approximating the observed
Guichard, Francoise
Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002, Boulder, Colorado (Manuscript received 4 September 2007, in final form 23 June 2008) ABSTRACT Mesoscale at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14
Rohrer, Gregory S.
Citation & Copyright (to be inserted by the publisher ) Mesoscale Simulation of the Evolution; Simulation; Grain boundary energy; Mullins Equation Abstract. A mesoscale, variational simulation of grain to the mesoscale simulation of grain growth in large two dimensional systems to study the evolution of the grain
Langerman, M.A.
1990-09-01T23:59:59.000Z
Steady-state modeling considerations for simulating the in situ vitrification (ISV) process are documented based upon the finite element numerical approach. Recommendations regarding boundary condition specifications and mesh discretization are presented. The effects of several parameters on the ISV process response are calculated and the results discussed. The parameters investigated include: (1) electrode depth, (2) ambient temperature, (3) supplied current, (4) electrical conductivity, (5) electrode separation, and (6) soil/waste characterization. 13 refs., 29 figs., 1 tab.
Combustion in Meso-scale Vortex Chambers Ming-hsun Wu*
Yang, Vigor
1 Combustion in Meso-scale Vortex Chambers Ming-hsun Wu* , Yanxing Wang, Vigor Yang and Richard A) #12;2 COMBUSTION IN MESO-SCALE VORTEX CHAMBERS Ming-hsun Wu, Yanxing Wang, Vigor Yang and Richard A with the chemical energy varying from 25 to 174W. For the largest combustion volume, hydrogen and hydrocarbons
Transient luminous events above two mesoscale convective systems: Charge moment change analysis
Rutledge, Steven
Transient luminous events above two mesoscale convective systems: Charge moment change analysis that were parents of transient luminous events (TLEs; mainly sprites) over two different storms: 9 May (20. A. Rutledge, and D. R. MacGorman (2011), Transient luminous events above two mesoscale convective
Phase behavior and mesoscale solubilization in aqueous solutions of hydrotropes
Deepa Subramanian; Mikhail A. Anisimov
2013-09-27T23:59:59.000Z
Hydrotropes are amphiphilic molecules that are too small to spontaneously form equilibrium structures in aqueous solutions, but form dynamic, noncovalent assemblies, referred to as clusters. In the presence of a hydrophobic compound, these clusters seem to get stabilized leading to the formation of long-lived, highly stable mesoscopic droplets, a phenomenon that we call mesoscale solubilization. In this work, we focus on the unusual mesoscopic properties of aqueous solutions of a nonionic hydrotrope, namely tertiary butyl alcohol (TBA), on addition of various hydrophobic compounds. Aqueous TBA solutions, in about 3 to 8 mol percent TBA concentration range and about 0 to 25 deg. C temperature range, show the presence of short-ranged (0.5 nm), short-lived (tens of picoseconds) molecular clusters which result in anomalies of the thermodynamic properties. These clusters are transient but do not relax by diffusion, thus distinctly different from conventional concentration fluctuations. In this concentration and temperature range, upon the addition of a third (more hydrophobic) component to TBA-water solutions, long-lived mesoscopic droplets of about 100 nm size are observed. In this work, we clarify the ambiguity behind the definition of solubility and elucidate the phenomenon of mesoscale solubilization. A systematic study of the macro and meso phase behavior of three ternary systems TBA-water-propylene oxide, TBA-water-isobutyl alcohol, and TBA-water-cyclohexane has been carried out. We differentiate between molecular solubility, mesoscale solubilization, and macroscopic phase separation. We have confirmed that practically stable aqueous colloids can be created from small molecules, without addition of surfactants or polymers. Such kind of novel materials may find applications in the design of various processes and products, ranging from pharmaceuticals to cosmetics and agrochemicals.
Customizing mesoscale self-assembly with 3D printing
M. Poty; G. Lumay; N. Vandewalle
2013-10-17T23:59:59.000Z
Self-assembly due to capillary forces is a common method for generating 2D mesoscale structures from identical floating particles at the liquid-air interface. Designing building blocks to obtain a desired mesoscopic structure is a scientific challenge. We show herein that it is possible to shape the particles with a low cost 3D printer, for composing specific mesoscopic structures. Our method is based on the creation of capillary multipoles inducing either attractive or repulsive forces. Since capillary interactions can be downscaled, our method opens new ways to low cost microfabrication.
Analytical Rescaling of Polymer Dynamics from Mesoscale Simulations
I. Y. Lyubimov; J. McCarty; A. Clark; M. G. Guenza
2011-03-10T23:59:59.000Z
We present a theoretical approach to scale the artificially fast dynamics of simulated coarse-grained polymer liquids down to its realistic value. As coarse-graining affects entropy and dissipation, two factors enter the rescaling: inclusion of intramolecular vibrational degrees of freedom, and rescaling of the friction coefficient. Because our approach is analytical, it is general and transferable. Translational and rotational diffusion of unentangled and entangled polyethylene melts, predicted from mesoscale simulations of coarse-grained polymer melts using our rescaling procedure, are in quantitative agreement with united atom simulations and with experiments.
Mesoscale simulations of polymer dynamics in microchannel flows
L. Cannavacciuolo; R. G. Winkler; G. Gompper
2007-09-24T23:59:59.000Z
The non-equilibrium structural and dynamical properties of flexible polymers confined in a square microchannel and exposed to a Poiseuille flow are investigated by mesoscale simulations. The chain length and the flow strength are systematically varied. Two transport regimes are identified, corresponding to weak and strong confinement. For strong confinement, the transport properties are independent of polymer length. The analysis of the long-time tumbling dynamics of short polymers yields non-periodic motion with a sublinear dependence on the flow strength. We find distinct differences for conformational as well as dynamical properties from results obtained for simple shear flow.