Numerical Calculation Of LOX/Kerosene Rocket Engine And Analysis Of Combustion Instability

Liquid rocket engine has the advantage of large thrust and specific impulse, which is widely used in launch vehicle, missile system, attitude control and so on. However, combustion instability happens frequently during the development process of liquid rocket engine, high frequency combustion instability will damage the engine seriously. Since 1930s, the combustion instability appears in rocket engine, a lot of work have been conducted by researchers all over the world. However, the origin of combustion instability and how to eliminate have not have an unanimous conclusion, costly experiments are still the main method in engineering. Numerical simulation has the advantage of high efficiency and low cost, implement the numerical simulation of LOX/kerosene liquid rocket engine, investigation the factors of combustion instability have reference value in engineering.LOX/kerosene liquid rocket engine is a focused research areas in recent years. The main objects of study in this paper are two LOX/kerosene liquid rocket engines. Simplified reaction mechanisms are used in calculation. The reaction characteristic of kerosene in high temperature and high pressure is analyzed, the result shows the reaction characteristic time is significantly reduced, deeming that in combustor conditions reaction complete immediately, reaction is controlled by mixing process. Three dimension models of combustors are built, and the combustion instability is captured without manual perturbation by numerical calculation. Acoustic characteristic and pressure oscillation frequency are analyzed, judging the high frequency pressure oscillation coupled with acoustic cavity happened.Injection condition is one of the main factors affects combustion stability, the effects of different injection factors are compered. The results show combustion instability is easy to occur when particle size is small; increasing half angle of injection is helpful to weaken combustion instability but not to eliminate; the effect of initial temperature of fuel particle is not obvious. Numerical result shows the combustion instability disappear after bulkhead is added in combustor model, which is consistent with engineering experience. This work provides a reference of combustion instability for the development of liquid rocket engine.