The Mixing of the Liquid Spray with Mach 2 Supersonic Cross Flow

Abstract

Abstract An experimental investigation of JP-4 injection in a supersonic cross flow of air is presented in this paper Shock tunnel operation was used to create a high-enthalpy supersonic cross flow (Mach 2 Tt = 1750 K Pt = 12 bars) A flat plate mounted with a single orifice model was used and JP-4 fuel was injected into the supersonic flow through the 0 5-mm orifice The exit velocity of the JP-4 was controlled at 78–100 m/s corresponding to a moment flux ratio of 4 1–6 8 A high-speed Schlieren imaging (100 000 fps) technique was used to observe and analyze the interactions between the liquid jet and supersonic air flow Laser Mie scattering was also used to observe top-view spray behavior Observation of the Schlieren images indicated significant vaporization of liquid on the windward side of the spray and both high-speed Schlieren and top-view Mie scattering video revealed that the liquid spray’s whipping motion crucially affects the mixing behavior between the liquid and air Spray dissipation distance is used in this research to justify the mixing effectiveness between spray and supersonic air flow The observations show that the spray dissipation distance decreases with increasing momentum flux ratio and angle of forward inclination of the liquid jet Detailed analysis indicates that the source of the whipping motion crucial effect on dissipation distance is from the unstable bow shock/boundary separation shock interaction as well as the occurrence of the vortex surrounding the spray To verify this effect on mixing a simple double injection module was used to create different shock/shock interactions and the results indicate that by managing the flow rates between the double-orifice injector the dissipation distance or the mixing behavior between the liquid jet and the supersonic airflow can be controlled

Date of Award	2016 Aug 30
Original language	English
Supervisor	Hsiao-Feng Yuan (Supervisor)