Application of a Spectroscopic Measuring Technique to Plasma Discharge in Hypersonic Flow

摘要

Spatially resolved rotational temperatures have been obtained within the boundary layer of a flat plate model in a Mach 5.1 flow using emission spectroscopy. The temperatures were obtained by matching the measured nitrogen second positive 0-2 rovibrational band with a calculated one. Temperature profiles are given above the cathode and the anode. The maximum temperature obtained above the cathode did not correspond to the surface of the model, but rather at an elevation 0.55 mm above the surface. This indicates that heat is traveling from the discharge into the plate for a period of time after the discharge is ignited. This characteristic in the temperature profile sheds light on some of the effects a plasma has on the flow field as determined by Pitot probe measurements and total lift measurements.