Research on Instabilities and Transition in Three-Dimensional Boundary Layers, with Emphasis on Gas-Turbine-Blade Flows

Abstract

Absolute instability of (Gortler vortices on the severely curved concave pressure side of a gas-turbine blade is the main thrust of the third-year work under this grant. For the most part, the Gortler vortices have been investigated in an incompressible boundary layer over thin-wing sections or artificial inserts on an otherwise flat plate. The cascade of modern aircraft engines operate in the high subsonic Mach number regime with velocity fields strongly affected by centrifugal forces maintained by the large curvature of profiles. Unsteady spiral-type vortices developing in these environments provoke the absolute instability in the streamwise direction of the boundary layer leading to earlier transition. An effort undertaken after the meeting in Shalimar (May 29-31, 2002) show that the heat transfer coefficient is even more susceptible to enhancing oscillations in the upstream moving wave packets than the pressure.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2000
Accession Number
ADA407942

Entities

People

  • Olef S. Ryzhov

Organizations

  • University of California, Davis

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Centrifugal Force
  • Coefficients
  • Fluid Mechanics
  • Gas Turbine Blades
  • Gas Turbines
  • Heat Transfer
  • Heat Transfer Coefficients
  • Layers
  • Mach Number
  • Stratified Fluids
  • Thin Wings
  • Three Dimensional
  • Turbine Blades
  • Turbines
  • Wave Packets

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Fluid Mechanics and Fluid Dynamics.
  • Technical Research and Report Writing.