Analysis of shock waves in a supersonic wind tunnel at the AFRL Aero-Effects Laboratory

The Air Force Research Laboratory (AFRL) Directed Energy Directorate has built a supersonic wind tunnel in order to characterize aero-optical effects. Aero-optics is the study of the effect of aircraft-induced and atmospheric disturbances on the efficiency of optical imaging and laser systems. The Aero-Effects Laboratory (AEL) at AFRL consists of a supersonic wind tunnel with the capability of imaging the turbulent flow with large optical access of its test section. In order to gain access to the area of interest, we must first send a beam of light through the access windows of the wind tunnels test section to measure and visualize the flow. Initial measurements have been made and shockwaves between the mating plates of the test section and nozzle have been observed. This paper describes the optical system designed for resolving these shockwaves with a Schlieren imaging system.