Experimental and numerical studies on fuel injection and combustion of Solid-Liquid Rocket Ramjet

In order to study the process of liquid fuel injection and combustion of Solid-Liquid Rocket Ramjet, a subscale test is conducted. Weak combustion effect is obtained according to the wall pressure of the test engine. Some three-dimensional numerical simulations about the experimental engine on the experimental operation condition are conducted to investigate the weak combustion effect. In the simulations, fuel mixture, evaporation and combustion are included, the liquid fuel droplets are tracked by solving Lagrangian equations of motion and transport for the life histories of individual droplet groups, and single-step reaction system is applied. It is indicated that the combustion efficiency is greatly affected by liquid fuel injector positions. When fuel injectors are imposed close to the air inlets, the strong air inlet stream can take liquid fuel into the center region of the chamber, but its momentum along the chamber shortens the residence time of fuel droplets. When fuel injectors are located in the front of the chamber head, the vortex caused by fuel-rich gas of gas generator contributes to transverse motion of the fuel droplets which promotes the droplets to evaporate and combust.