Unsteady Swirling Flows in Gas Turbines

Abstract

This annual report covers the second phase of investigations into the unsteady swirling flows. The overall objective of the entire program is to acquire fundamental understanding of a phenomenon characterized by violent fluctuations occurring in swirling flows in gas turbines; this flow instability, dubbed here as 'Vortex Whistle' is known to be capable of causing severe fatigue failure in gas turbine components. Although the phenomena of 'Vortex Whistle' have never remained unrecognized, perhaps for the reason that they appeared in seemingly unrelated incidents under various disguise, no comprehensive investigation appears to have been embarked upon. In addition, in spite of the fact that the vortex whistle is a pure tone noise and distinctly audible, its role as a source of aircraft engine noise has never been recognized. Furthermore, when the vortex whistle becomes intense, it induces a change in the steady flow field, the total temperature being spontaneously separated in the radial direction (the Ranque-Hilsch effect). Not only its implications to the study aero design of turbomachines are of obvious importance, but also this appears to offer an unmistakable clue to the puzzling Ranque-Hilsch effect.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1981
Accession Number
ADA102852

Entities

People

  • M. Kurosaka

Organizations

  • University of Tennessee Space Institute

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircraft Engines
  • Eddies (Fluid Mechanics)
  • Engine Components
  • Engine Noise
  • Flow Fields
  • Flow Rate
  • Fluid Dynamics
  • Fluid Mechanics
  • Frequency
  • Gas Turbines
  • Guide Vanes
  • Hilsch Tubes
  • Inlet Guide Vanes
  • Standing Waves
  • Steady Flow
  • Turbine Components
  • Turbines

Readers

  • Acoustics.
  • Aerodynamics.
  • Educational Psychology