Implementation of Simple Throttling for Liquid Rocket Engine ECX1000H2-4

Liquid rocket engine commonly uses a throttling system to control thrust in various condition depending on its mission. In this study, a simple throttling system has been conducted to the liquid rocket engine ECX1000H2-4 using on-off valves in order to prevent an explosion at the beginning of ignition due to excessive accumulation of unburned propellants and to understand the affected phenomenon of the combustion process. The throttling system uses 2 valves for fuel flow and 2 valves for oxidizer flow and has been tested in the firing test. The test results show that the slight explosion in the starting process of combustion can be suppressed. However, at the first step of throttling, the combustion chugged at approximately 33 Hz, which is growing from low amplitude to higher amplitude ranged between 14 to 23 bar.