Validation of Turbulence Models for the Beggar Code in Unsteady Flows

Abstract

Validation of the turbulence models in the CFD code Beggar for unsteady turbulent flow are discussed. Six validation cases of the code are considered, three cases with the intent of validating the code without the turbulence model and three cases to validate the turbulence model itself. Finally, a more realistic simulation of a simplified store is examined. The turbulence models considered are the Baldwin-Lomax, Spalart-Allmaras, and a DES model. The conclusions made deal with necessary prerequisites to properly simulating unsteady turbulent flow and model selection. The prerequisites necessary in the Beggar code are a second order temporal discretization and the calculation of at least three Newton dt-iterations per time step. Baldwin-Lomax overpredicts unsteady effects. The Spalart-Allmaras model was found to not properly simulate unsteady turbulent flow and is possible written incorrectly in Beggar. A recommendation of whether to use the DES model or not cannot be made due to time and computational constraints and temporary problems within the Beggar code.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2005
Accession Number
ADA437548

Entities

People

  • Kevin G. Storm

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Euler Equations
  • Fluid Dynamics
  • Fluid Flow
  • Large Eddy Simulation
  • Mechanical Properties
  • Navier Stokes Equations
  • Reynolds Number
  • Shock Tubes
  • Steady State
  • Test And Evaluation
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Educational Psychology
  • Fluid Mechanics and Fluid Dynamics.