Thermal characteristics of inclined plate impinged by underexpanded sonic jet

The impingement of an underexpanded jet onto a solid object can be found in engineering applications. Takeoff and landing of V/STOL aircraft, and launching systems on a spaceship for solid rocket motors are some examples related to this complex phenomenon. Because most of the dynamic energy is converted to thermal energy when a high-speed flow is decelerated in front of a protruded solid body, impingement of the high-speed flow produces a severe thermal load to the body surface as well as aerodynamic loads on it. In this experimental study, the thermal characteristics on an inclined plate impinged by an underexpanded sonic jet were investigated. The recovery factor was retained by infrared thermography while the pressure distribution was measured using pressure transducers. Experiments were performed for four different inclinations of impinged plate, ranging from 0° to 30°. In addition, the effect of nozzle-to-plate distance was studied. From the results, the axi-symmetric pattern of recovery factor on an impinged surface is broken and the low recovery factor zone shifts to the downward region as the inclination angle increases. In addition, the cooling effect is weakened overall as the inclination angle increases.