The Study about Conditions for Stable Engine Startup on Launch Vehicle

발사체 엔진의 안정적인 시동 조건에 대한 연구

Launch vehicle for injecting the satellite into its orbit is composed with propulsion system, guidance and navigation system, telemetry and so on. Among the others, the propulsion system is the most important part, because that is the key factor of failure of launch vehicle. Especially, the most of failures were occurred in time of engine startup. Therefore, the study of the conditions for stable engine startup is needed at the first step of development. The many researches were accomplished for mathematical modeling, stable startup engine and control of liquid propellant rocket engine. But the cavitation problem that can be occurred at an inlet of pump associated with propellant feeding system wasn't considered in these works. In this paper, propulsion system model was integrated with clustered engines and propellant feeding system for the simulations of engine startup. As the results of simulations, the requirements were deduced for the stable engine startup without the cavitation at an inlet of pump.