Experimental investigation of acoustic self-oscillation influence on decay process for underexpanded supersonic jet in submerged space

Abstract

Intensification of mixing between the gaseous working body ejected through a jet nozzle with ambient medium is an important scientific and technical problem. Effective mixing can increase the total efficiency of power and propulsion apparatuses. The promising approach, although poorly studied, is generation of acoustic self-oscillation inside the jet nozzle: this impact might enhance the decay of a supersonic jet and improve the mixing parameters. The paper presents peculiar properties of acoustic self-excitation in jet nozzle. The paper presents results of experimental study performed for a model injector with a set of plates placed into the flow channel, enabling the excitation of acoustic self-oscillations. The study reveals the regularity of under-expanded supersonic jet decay in submerged space for different flow modes. Experimental data support the efficiency of using the jet nozzle with acoustic self-oscillation in application to the systems of gas fuel supply. Experimental results can be used for designing new power apparatuses for aviation and space industry and for process plants.