The Effect of Curvature on the Evolution of a Boundary Layer Subjected to a Strong Adverse Pressure Gradient

Abstract

Negligible wall shear stress provides the criterion that minimizes the distance over which boundary layer can decelerate without separating from the surface. Over the past few years, we have been carefully investigating the boundary layer that is continuously maintained on the verge of separation, without actually being allowed to separate 1. The experimental facility that was used consists of a contraction, a constant area throat, and a two-dimensional variable geometry expansion inserted into the 2' by 3' test section of a low speed wind tunnel (figure 1). The expansion is corrected of Lexan supported by electric actuators mounted on gimbals and capable of distorting the surface under computer control. The surface geometry can vary over a wide range of pressure gradients and streamline curvature. The transition between the throat and the test surface is accomplished by means of a circular cylinder to which the lexan surface is attached, thereby establishing the initial slope of the test surface. The side-wall boundary layers were removed by using suction and the measurements were made on the boundary layer developing on the curved surface.

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Document Details

Document Type
Technical Report
Publication Date
Sep 17, 2001
Accession Number
ADA394280

Entities

People

  • Israel J. Wygnanski

Organizations

  • University of Arizona

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Convection
  • Equations Of Motion
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Geometry
  • Hydrodynamics
  • Measurement
  • Mechanics
  • Pressure Distribution
  • Reynolds Number
  • Stratified Fluids
  • Turbulent Flow
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.