The primary objective of this study is to compare the differences molecular weight has on the mixing and penetration of an injectant gas into a supersonic crossflow. Helium and argon gas were chosen as injectants because of the large differences in molecular weights. Also, mixing enhancement was observed by injecting the traverse gas jet parallel to the compression face of a ramp. Color schlieren photography was used to identify the shock structures and interactions in the flow field. Measurements of mean flow properties were used to establish the jet plume size, penetration, and concentration and to quantify the total pressure loss.
Results indicate greater mixing and plume expansion can be achieved with helium compared to argon.