Thermal Response of Supersonic Airflow to a Fin Protrusion Situated on a Curved Surface

Aerodynamic heating of an airfoil with a short fin attached to its surface is computationally investigated. This research is motivated by the fact that the gap fillers inserted between the insulation tiles of the space shuttle thermal protection system may sometimes get loose and extend beyond the surface and cause an uneven aerodynamic heating of the surface. It is often difficult for engineers to determine whether the protruded gap filler would cause an undesirable effect in the boundary layer including early turbulence transition or shockwaves that could cause an unsafe increase in surface temperature. In this investigation, the supersonic flow over NACA 0012 airfoil on which a short fin is attached is studied using a computational approach. The method is validated by the experimental data available in published literature. The results indicate a significant increase in the surface temperature in the vicinity of the fin. This elevated temperature extends downstream beyond the location of the fin and covers a large portion of the airfoil downstream of the fin. The fin induces an oblique shockwave followed by an expansion wave.