Experimental Study on High Frequency Combustion Instability with Coaxial Injector of Staged Combustion LOX/kerosene Rocket Engine.

A single-injector firing model is established for the high-frequency combustion instability of staged combustion LOX/kerosene rocket engine with high pressure and high temperature in the combustion chamber. The gaseous propellant components are used to provide aetuai volumentric flow rates at low pressure level praetieally equal to atmospheric pressure. A sealing-down combustion chamber model is designed and built based on the similarity theory, and single bipropellant coaxial injector specimens are installed on the combustion-chamber head. The effects of structural parameters and operating conditions on high-frequency combustion stability are obtained from pressure-oscillation decrements. The results show that the flames become short, and the high pressure oscillations and squealing appear when the high-frequency combustion instability is excited. The retraetive length of the injector would have crucial effect on the combustion instability boundaries and the margins, and have a optimal range. The results of simulation test could served in the engine design. [ABSTRACT FROM AUTHOR]