Combined Theoretical and Experimental Study of Phenomena Related to Limit Cycle Oscillations.

Abstract

A combined theoretical, computational, and experimental program has investigated situations where fluid motion and a flexible surface produce nonlinear interactions. The main cases of interest concern situations where an external flow field contains a significant disturbance, such as a vortex in subsonic flow or a shock wave in supersonic flow. This type of flow feature can produce pressure perturbations which may provoke movement in flexible panels on the surface, as well as unsteady viscous separation effects in the boundary layers, which are on all solid walls. The net result is a complex interaction between the external mainstream flow, the viscous boundary layers, and the flexible surface itself The aforementioned interactions produce complicated oscillations of the surface that are sometimes refereed to as limit cycle oscillations (LCO). When such events are observed, it is common for a significant flow disturbance, such as a shock wave or vortex, to be somewhere in the vicinity. The present research addresses a number of fundamental problems of LCO, with the goal of establishing cause and effect relationships in relatively simple environments. Several computational and experimental studies of selected simplified interactions are described in the body of the report.

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Document Details

Document Type
Technical Report
Publication Date
Oct 13, 1997
Accession Number
ADA330174

Entities

People

  • C. R. Smith
  • J. D. Walker
  • T. Delph

Organizations

  • Lehigh University

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Computational Fluid Dynamics
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Hydrodynamics
  • Layers
  • Mechanics
  • Oscillation
  • Physics Laboratories
  • Reynolds Number
  • Shock Waves
  • Subsonic Flow
  • Supersonic Flow
  • Waves

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Fluid Dynamics.
  • Systems Analysis and Design

Technology Areas

  • Hypersonics