Supersonic Film Cooling on a Flat Plate

High-temperature, supersonic flows are encountered in many modern aircraft propulsive systems such as Rotating Detonation Engines (RDE). These platforms require cooling to handle the high heat loads generated. Consequently, film cooling—a cooling method traditionally applied to combustor walls and turbine surface components in subsonic flow—has gained interest as a viable technique in the supersonic flow regime. The Air Force Institute of Technology’s Small Supersonic Wind Tunnel was modified to facilitate film cooling experimentation. Two flat plates made from different materials were used for testing cylindrical cooling holes. Adiabatic wall temperatures and heat transfer coefficients were computed in a 1.77 freestream Mach number flow at BR's of 0.4, 0.8, 1.2, and 1.6. Schlieren imaging was used to understand the interaction of shock waves with the coolant holes. Infrared camera results showed the difficulty in accurately determining the adiabatic wall temperature in a transient supersonic environment.