Back-pressure Effect on Shock-Train Location in a Scramjet Engine Isolator

Abstract

The isolator of the scramjet decelerates the incoming high Mach flow to a lower Mach number and stabilizes the flow before it enters the combustor. Because of the unsteady combustion phenomenon and inconsistent completeness of the combustion, pressures within the combustor can vary drastically. These pressure variations can propagate forward and affect the flow field in the isolator - worst case unstarting the inlet. In this research, the shock train location VS. the back-pressure is examined experimentally. The back-pressure is artificially created by symmetric (top & bottom) ramps that can close the flow area. Raising/lowering ramps result in higher/lower back-pressure. Higher back-pressure moves the shock train forward, with too high a back-pressure causing un-start. This experiment is conducted for a variation in Reynolds number, ramp angle, and two incoming Mach #s, and will result in a relationship between back-pressure and shock train location for various airflow conditions.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2010
Accession Number
ADA517638

Entities

People

  • Richard I. Paek

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Actuators
  • Air Force
  • Aircraft Equipment
  • Aircrafts
  • Boundary Layer
  • Combustion
  • Computational Fluid Dynamics
  • Control Systems
  • Fluid Dynamics
  • Mach Number
  • Pressure Distribution
  • Pressure Measurement
  • Ramjet Engines
  • Reynolds Number
  • Supersonic Combustion Ramjet Engines
  • Test Facilities
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Materials Science.
  • Mathematics or Statistics