Transition and Transport in Turbomachinery

Abstract

The interaction of discrete and continuous Orr-Sommerfeld modes in a boundary layer is studied by computer simulation. The discrete mode is an unstable Tollmein-Schlichting wave. The continuous modes generate jet-like disturbances inside the boundary layer. Either mode alone does not cause transition to turbulence; however, the interaction between them does. The continuous mode jets distort the discrete modes, producing Lambda shaped vortices. Breakdown to turbulence is subsequent. The lateral spacing of the Lambda's is sometimes the same as that of the wavelength continuous modes, sometimes it differs, depending on the ratio of wavelength to boundary layer thickness.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2012
Accession Number
ADA562553

Entities

People

  • Paul A. Durbin

Organizations

  • Iowa State University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Boundary Layer Transition
  • Compressor Blades
  • Computational Science
  • Computer Simulations
  • Flow
  • Fluid Flow
  • Free Stream
  • Geometry
  • Layers
  • Simulations
  • Three Dimensional
  • Transitions
  • Turbomachinery
  • Turbulence
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Spectroscopy.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster