Comparison of CN in the Boundary Layer of Ablating Graphite in High-Temperature Air and Nitrogen Flows using PLIF

Planar laser-induced fluorescence (PLIF) is used to study the distribution and temperature of the cyano radical (CN) present in the reacting boundary layer of ablating graphite. The graphite ablation is induced in the high-temperature plume of the 50 kW inductively-coupled plasma (ICP) torch at The University of Texas at Austin under two flow compositions: ablation induced by a high-temperature air flow, and induced by a high-temperature nitrogen flow. The different flow compositions will offer insight into the production of CN due to surface nitridation versus gas-phase reaction mechanisms. Optical emission spectroscopy (OES) will also be taken in order to compare the two experimental methods.