추력실 길이에 따른 하이드라진 추력기의 저주파 연소불안정 특성

A test and evaluation was carried out to make a close examination into the combustion instability for the 70 N-class hydrazine thruster under development. In order to investigate the effects of thrust chamber configuration on combustion stability, ground hot-firing tests for the development models were performed with variation of lower catalyst-bed length. As a result, it was identified that low-frequency pressure instability appears in the test models. This instability was primarily affected by the dynamic nature of propellant spray which is consequence of coupling between thrust chamber pressure and propellant supply characteristic.