LES Overview

Abstract

In the paper the different current approaches to the Large Eddy Simulations of turbulent flows are examined and critically discussed. A LES is usually defined as a numerical computation in which some scales are captured and others are modelled, but different procedures are used for such decomposition. As regards the modeling of the unresolved scales they are in the paper tentatively classified as exact modeling and statistical modeling. A third procedure, the dynamic modeling is examined as a technique based on the use of general relations that connect the subgrid scale turbulent stresses at different levels. Their implementation to standard models like the Smagoriusky eddy viscosity one, can improve the results and can efficiently extend the range of their application. The connections between LES and RANS, the simulations based on the Reynolds Averaged Navier-Stokes equations, are finally examined and some critical issues related to the extraction of the statistical averages from LES databases are discussed.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2001
Accession Number
ADP013620

Entities

People

  • M. Germano

Organizations

  • Polytechnic University of Turin

Tags

Communities of Interest

  • Air Platforms
  • C4I

DTIC Thesaurus Topics

  • Aeronautical Engineering
  • Computational Fluid Dynamics
  • Databases
  • Equations
  • Filters
  • Filtration
  • Flow
  • Fluid Flow
  • Heat Transfer
  • Identities
  • Information Science
  • Large Eddy Simulation
  • Probability
  • Probability Density Functions
  • Turbulence
  • Turbulent Flow
  • Two Dimensional

Readers

  • Computational Fluid Dynamics (CFD)
  • Systems Analysis and Design