MACH DISK PLATFORM FOR STUDYING RADIATING FLOWS

摘要

A new approach for studying radiation in expansion tubes has been developed using conical converging shocks to create a Mach disk in the free-stream flow. This method allows unobstructed optical access to the flow behind the normal shock to investigate the relaxation processes occurring behind the shock. Previous work on conical converging flows had concentrated on ideal gas flows and hence a CFD analysis, which included high temperature gas effects, was undertaken to confirm the desired shock structure formation in the high enthalpy flow created in expansion tubes. This was also tested experimentally, verifying the formation of the Mach disk with luminosity imaging using high speed video camera. Sample spectra from a Titan atmosphere test gas is presented demonstrating the viability of this method for obtaining spectral information of extra-terrestrial planetary atmospheres.