Experimental and Numerical Investigation of Controlled, Small-Scale Motions in a Turbulent Shear Layer

Abstract

The effects of high-frequency fluidic actuation on the evolution of small- and large-scale motions in a turbulent shear layer downstream of a backward-facing step are investigated experimentally and numerically. The flow behind the step is characterized in the spatial and spectral domain by high-resolution diagnostic tools. Model stability problems with increasing complexity mimic the experimental setup and actuations and describe local and global flow behaviour. It is demonstrated that dissipative, high-frequency actuation effects the shear layer evolution through three domains: I - a localized dissipative, small scales domain having enhanced turbulent kinetic energy production and dissipation rate, II - a stabilized domain marked by concomitant suppression of turbulent kinetic energy production and dissipation rate, and III - a domain of re-emerging inviscid instability at lower natural frequencies and larger scales.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2007
Accession Number
ADA515442

Entities

People

  • A. Glezer
  • Bojan Vukašinović
  • Z. Rusak

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Base Flow
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Energy Production
  • Energy Transfer
  • Flow Fields
  • Fluid Dynamics
  • Fluid Mechanics
  • Mechanics
  • Near Field
  • Power Spectra
  • Resonant Frequency
  • Reynolds Number
  • Turbulent Mixing
  • Two Dimensional
  • Viscous Flow

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.
  • Robotics and Automation.