Stochastic Estimation of Coherent Structures and Their Dynamics in Transitional and Turbulent Boundary Layers

Abstract

The structure of transitional and turbulent boundary layers was investigated experimentally using the stochastic estimation technique. The two- point space-time full correlation tensor was measured at various Reynolds numbers in the near wall region of a boundary layer, and the outer region of a regular and LEBU manipulated boundary layer. It was found that multi-point stochastic estimates yield a far more realistic picture of the turbulent structures than conventional one-point conditional averages. A new technique was developed, whereby the pseudo-dynamic evolution of the flow field is reconstructed by means of the stochastic estimation for a measured time sequence of velocity at one or more points. This yields a very realistic kinematic evolution of the flow structures. Prospects for deriving dynamical evolution equations for the stochastic estimates have also been explored.

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Document Details

Document Type
Technical Report
Publication Date
Apr 24, 1991
Accession Number
ADA236231

Entities

People

  • N. Trigui
  • T. J. Gieseke
  • Y. G. Guezennec

Organizations

  • Ohio University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Data Storage Systems
  • Databases
  • Dynamics
  • Engineering
  • Equations
  • Flow
  • Flow Fields
  • Fluid Flow
  • Layers
  • Measurement
  • Mechanical Engineering
  • Reynolds Number
  • Stratified Fluids
  • Three Dimensional
  • Turbulent Flow

Fields of Study

  • Physics

Readers

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

Technology Areas

  • Space