Streamwise Vortices in Heated Boundary Layers

Abstract

The nonlinear instability of the boundary layer on a heated plate placed in an oncoming flow is investigated. Such flows are unstable to stationary vortex instabilities and inviscid traveling wave disturbances governed by the Taylor-Goldstein equation. For small temperature differences the Taylor-Goldstein equation reduces to Rayleigh's equation. When the temperature difference between the wall and free stream is small the preferred mode of instability is a streamwise vortex. It is shown in this case that the vortex, assumed to be of small wavelength, restructures the underlying mean flow to produce a profile which can be massively unstable to inviscid traveling waves. The mean state is shown to be destabilized or stabilized to inviscid waves depending on whether the Prandtl number is less or greater than unity.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1992
Accession Number
ADA253369

Entities

People

  • Philip Hall

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Boundary Layer Flow
  • Buoyancy
  • Computers
  • Differential Equations
  • Eigenvalues
  • Engineering
  • Equations
  • Flow
  • Free Stream
  • Instability
  • Layers
  • Mechanics
  • Prandtl Number
  • Pressure Gradients
  • Waves

Fields of Study

  • Physics

Readers

  • Control Systems Engineering.
  • Fluid Mechanics and Fluid Dynamics.