Transition Delay in Hypervelocity Boundary Layers By Means of CO2/Acoustic Instability Interaction

Abstract

The potential for hypervelocity boundary layer stabilization was investigated using the concept of damping Mack's second mode disturbances by vibrational relaxation of carbon dioxide (CO2) within the boundary layer. Experiments were carried out in the Caltech T5 hypervelocity shock tunnel and the Caltech Mach 4 Ludwieg tube. The tests used 5-degree half-angle cones (at zero angle of attack) equipped near the front of the cone with an injector consisting of either discrete holes or a porous section. Gaseous CO2, argon (Ar) and air were injected into the boundary layer and the effect on boundary layer stability was evaluated by optical visualization, heat flux measurements and numerical simulation.

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Document Details

Document Type
Technical Report
Publication Date
Dec 16, 2014
Accession Number
ADA619007

Entities

People

  • Joseph E. Shepherd

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Sensors
  • Space

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Boundary Layer
  • Boundary Layer Control
  • Boundary Layer Transition
  • Computational Fluid Dynamics
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Heat Transfer
  • Hydrodynamics
  • Hypervelocity Flow
  • Reynolds Number
  • Shock Tunnels
  • Shock Waves
  • Test Facilities
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Boundary Layers
  • Hypersonics - Hypersonic Flight