Characteristics of Supersonic Impinging Moist Air Jets

Abstract

Supersonic impinging Jets, such as those occurring in the space launch vehicle systems, multi-stage rocket separation, jet-engine exhaust impingement, terrestrial rocket launch, and in the next generation short take off and vertical landing (STOL) aircraft, generate a highly oscillatory flow with very high unsteady loads on the near by structures and the landing surfaces. These high-pressure and acoustic loads are also accompanied by a dramatic loss in lift during aircraft hover. Previous studies of supersonic impinging jets suggest that the highly unsteady behavior of the impinging jets is due to a feedback loop between the fluid And acoustic fields, which leads to these adverse effects, In actual supersonic jet flow, usually the working gas nu be condensable gas such as steam or moist air. In these cases, the non-equilibrium condensation may occur in the region between nozzle exit and an object. The jet flow with non-equilibrium condensation may be quite different from that without condensation, In the present study, characteristics of under-expanded axisymmetric supersonic impinging moist air jets on a vertical flat plate were investigated numerically.