Numerical and Experimental Investigation of Multiple Shock Wave/Turbulent Boundary Layer Interactions in a Rectangular Duct

Abstract

Multiple shock wave/turbulent boundary layer interactions in constant or nearly constant area supersonic duct flows occur in a variety of devices including scramjet inlets, gas ejectors, and supersonic wind tunnels. For sufficiently high duct exit pressures, a multiple shock wave/turbulent boundary layer interaction or shock train may form in the duct and cause a highly nonuniform, and possibly unsteady, flow at the duct exit. In this report, the mean flow characteristics of two shock train interactions, one with an initial Mach number of 2.5 the other at Mach 1.6, are investigated using spark Schlieren photography, surface oil flow visualization, and mean wall pressure measurements. The Mach 2.5 interaction was oblique and asymmetric in nature. A large separation occurs after the first oblique shock. The top and bottom wall boundary layer separation has been investigated, revealing that the shape of the reattachment lines and surface flow patterns for the two separation regions are quite different. This oblique shock flow pattern occurs in a neutrally stable fashion with each type of opposing separation region alternately existing on either the top or bottom wall during the course of a run. A small scale unsteadiness in the shock train location, with movement on the order of a boundary layer thickness, is also observed. In contrast, the Mach 1.6 interaction consists of repeated, symmetric normal shocks. The initial, bifurcated normal shock has a small separation region at its foot while the following weaker shocks do not separate the boundary layer. The number of shocks in the train and the overall length of the interaction increase as the boundary layer thickens in the duct.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jan 06, 1988
Accession Number
ADA190772

Entities

People

  • B. F. Carroll
  • J. C. Dutton

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Boundary Layer Flow
  • Computational Fluid Dynamics
  • Computational Science
  • Computer Programs
  • Differential Equations
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Geometry
  • Measurement
  • Mechanics
  • Navier Stokes Equations
  • Pressure Distribution
  • Pressure Measurement
  • Supersonic Combustion Ramjet Engines

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Boundary Layers
  • Hypersonics - Hypersonic Flow