Numerical Simulation of Two-Dimensional Spatially-Developing Mixing Layers

Abstract

Two-dimensional, incompressible, spatially developing mixing layer simulations are performed at Re = 10 2 and 10 4 with two classes of perturbations applied at the inlet boundary; (1) combinations of discrete modes from linear stability theory, and (2) a broad spectrum of modes derived from experimentally measured velocity spectra. The effect of the type and strength of inlet perturbations on vortex dynamics and time-averaged properties are explored. Two-point spatial velocity and autocorrelations are used to estimate the size and lifetime of the resulting coherent structures and to explore possible feedback effects. The computed time-averaged properties such as mean velocity profiles, turbulent statistics, and spread rates show good agreement with experimentally measured values. It is shown that by forcing with a broad spectrum of modes derived from an experimental energy spectrum many experimentally observed phenomena can be reproduced by a 2-D simulation. The strength of the forcing merely affected the length required for the dominant coherent structures to become fully-developed. Thus intensities comparable to those of the background turbulence in many wind tunnel experiments produced the same results, given sufficient simulation length. Mixing layers, Numerical simulation, Spatial simulation.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1994
Accession Number
ADA281683

Entities

People

  • A. O. Demuren
  • R. V. Wilson

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Computational Fluid Dynamics
  • Equations
  • Fluid Dynamics
  • Fluid Mechanics
  • Mechanics
  • Mixing
  • Power Spectra
  • Reynolds Number
  • Statistics
  • Stratified Fluids
  • Three Dimensional
  • Turbulence
  • Turbulent Flow
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

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