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in subjects: "Direct Numerical Simulation"  
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Intermittent Turbulence in the Very Stable Ekman Layer

Description: INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends t… more
Date: January 5, 2001
Creator: Barnard, James C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Simulations of Turbulent Flows with Strong Shocks and Density Variations

Description: In this report, we present the research efforts made by our group at UCLA in the SciDAC project “Simulations of turbulent flows with strong shocks and density variations”. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-… more
Date: December 13, 2012
Creator: Zhong, Xiaolin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry: Spray Simulations

Description: The Terascale High-Fidelity Simulations of Turbulent Combustion (TSTC) project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of the approach is direct numerical simulation (DNS) featuring the highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a u… more
Date: April 26, 2009
Creator: Rutland, Christopher J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Recovery Discontinuous Galerkin Jacobian-free Newton-Krylov Method for all-speed flows

Description: There is an increasing interest to develop the next generation simulation tools for the advanced nuclear energy systems. These tools will utilize the state-of-art numerical algorithms and computer science technology in order to maximize the predictive capability, support advanced reactor designs, reduce uncertainty and increase safety margins. In analyzing nuclear energy systems, we are interested in compressible low-Mach number, high heat flux flows with a wide range of Re, Ra, and Pr numbers.… more
Date: July 1, 2008
Creator: Park, HyeongKae; Nourgaliev, Robert; Mousseau, Vincent & Knoll, Dana
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Numerical and Physical Modelling of Bubbly Flow Phenomena - Final Report to the Department of Energy

Description: This report describes the main features of the results obtained in the course of this project. A new approach to the systematic development of closure relations for the averaged equations of disperse multiphase flow is outlined. The focus of the project is on spatially non-uniform systems and several aspects in which such systems differ from uniform ones are described. Then, the procedure used in deriving the closure relations is given and some explicit results shown. The report also contains a… more
Date: December 21, 2004
Creator: Prosperetti, Andrea
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry

Description: This SciDAC project enabled a multidisciplinary research consortium to develop a high fidelity direct numerical simulation (DNS) software package for the simulation of turbulent reactive flows. Within this collaboration, the authors, based at CMU's Pittsburgh Supercomputing Center (PSC), focused on extensive new developments in Sandia National Laboratories' "S3D" software to address more realistic combustion features and geometries while exploiting Terascale computational possibilities. This wo… more
Date: October 15, 2004
Creator: Reddy, Raghurama; Gomez, Roberto; Lim, Junwoo; Wang, Yang & Sanielevici, Sergiu
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Direct Numerical Simulation of Boiling Multiphase Flows: State-of-the-Art, Modeling, Algorithmic and Computer Needs

Description: The state-of-the-art for Direct Numerical Simulation (DNS) of boiling multiphase flows is reviewed, focussing on potential of available computational techniques, the level of current success for their applications to model several basic flow regimes (film, pool-nucleate and wall-nucleate boiling -- FB, PNB and WNB, respectively). Then, we discuss multiphysics and multiscale nature of practical boiling flows in LWR reactors, requiring high-fidelity treatment of interfacial dynamics, phase-change… more
Date: April 1, 2007
Creator: Nourgaliev, R.; Knoll, D.; Mousseau, V. & Berry, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Influence of fluid-property variation on turbulent convective heat transfer in vertical annular channel flows.

Description: Influence of strongly-varying properties of supercritical-pressure fluids on turbulent convective heat transfer is investigated using direct numerical simulation. We consider thermally-developing upward flows in a vertical annular channel where the inner wall is heated with a constant heat flux and the outer wall is insulated. CO2 is chosen as the working fluid at a pressure to 8 Mpa, and the inlet Reynolds number based on the channel hydraulic diameter and the bulk velocity is Re0 = 8900. It i… more
Date: October 1, 2005
Creator: McEligot, D. M.; Bae, J. H.; Yoo, J. Y.; Choi, H. & Wolf, James R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Simple and Efficient Diffuse Interface Method for Compressible Two-Phase Flows

Description: In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. For many reasons, to be discussed, there is growing interest in the application of two-phase flow models to provide diffuse, but nevertheless resolved, simulation of interfaces between two immiscible compressible fluids – diffuse interface method (DIM). Because of its ability to dynamically create interfaces and to solve interfaces se… more
Date: May 1, 2009
Creator: Berry, Ray A.; Saurel, Richard & Petitpas, Fabien
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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