EXPERIMENTAL TECHNIQUES FOR SUPERSONIC COMBUSTION RESEARCH IN A SHOCK TUNNEL
Abstract
The flight corridor for scramjet operation extends to about Mach 20 at altitudes up to 50,000 meters. Simulation of the combustion chamber conditions for research and development therefore requires air at extremely high enthalpy and pressure. The tailored interface shock tunnel is an economic test facility which can attain the required conditions, despite the short testing time. The supersonic combustion test chamber may be directly connected to the shock tunnel nozzle. Starting of the flow in the test section is accompanied by a transient shock whose strength may be reduced by pre-evacuation. Fuel (usually hydrogen) is injected into the test section and the mixing, reaction and aerodynamic processes are investigated. In addition to conventional pressure and shock speed instrumentation, the feasibility of the measurement of gas velocity by electromagnetic induction was studied and shown to be a promising technique at the higher speeds. The electrical conductivity of the gas limits the range of applicability and radio frequency probes were used to indicate its magnitude. High speed gas sampling values may be used to measure the fuel concentration in the mixing region, however care must be taken with probe design. The proven value of flow visualization techniques may be attained by high speed cine photography.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1967
- Accession Number
- AD0670609
Entities
People
- J. Swithenbank
- R. J. Parsons
Organizations
- University of Sheffield