Unsteady and Separated Flows

Abstract

In these investigations, simple geometries were studied. Experiments and simulations examined the addition of unsteady motions, of flat plates inclined normal to the flow, and circular cylinders, to the conventional-steady motions of these bodies. The simulations also investigated the (three-dimensional) interactions of vortex rings and the startup flow of a square flat plate oriented normal to the direction of motion (bluff body configuration). Laboratory experiments and measurements on flow past flat plates nominally normal to the direction of motion were performed. The objectives of this research were to elucidate the dynamics of large vortical structure in globally steady and unsteady separated flows, and to develop techniques to modify their behavior and control them for desired effect. In-line accelerations and transverse oscillations of flat plates were evaluated to modify the flow structure. These investigations examined the behavior of the large vortical structures in the resulting unsteady and separated flow, and the associated forces on the flat plate. Vortex methods were used to study two- and three-dimensional flows. The objectives of this research were to develop methods to examine the large-scale separated vortices in the wake of bluff bodies, study the influence of transient motions of the body on these dynamics, and investigate control strategies to produce desired effects.

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Document Details

Document Type
Technical Report
Publication Date
Apr 10, 1992
Accession Number
ADA250606

Entities

People

  • Anatol Roshko
  • Anthony W. Leonard
  • Paul E. Dimotakis

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Convection
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Geometry
  • Hydrodynamics
  • Measurement
  • Mechanical Properties
  • Physics Laboratories
  • Reynolds Number
  • Simulations
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.