Title: FUEL INJECTION IN SCRAMJETS: MIXING ENHANCEMENT AND COMBUSTION CHARACTERIZATION EXPERIMENTS

A two-part experimental study was conducted to address the issues of supersonic fuel mixing enhancement and efficient combustor development. The first part of the study involved quantitative characterization of fuel-air mixing in a non-reacting supersonic flowfield. Two flow configurations were compared: i.) a baseline case with normal fuel injection and ii.) a case with an acoustically open cavity placed downstream of the injection in order to excite mixing. Direct measurements of local atomic fuel-air ratio were acquired using Laser Induced Breakdown Spectroscopy (LIBS), which was applied for the first time in a supersonic flowfield. Indirect measurements of fue