Strength Experimets on Head and Cooling Channel Specimens of a Preburner

․ Insang Moon* ․ Soo Yong Lee**ABSTRACT A preburner for the high performance, staged combustion cycle liquid rocket engine is being developed. For the structural design processes, strength experiments and finite element analyses on specimens simulating the brazing joints of the preburner, were performed and compared. Total two kinds of the specimen were manufactured for the tests. One simulated the joints between the oxygen injectors and the head junctioned by the conventional vacuum br azing. The another was made to test the brazing surfaces by vacuum compression between the combusti on chamber cooling channel and the outer wall. During the burst experiments, it was observed that the fractures were occurred not at the brazed joining but in the middle of the face plate and the cool ing wall. In addition, the analysis showed that the predicted fracture locations and the strains were well matched with the experiment results.초 록 고성능 로켓엔진에 사용되는 다단연소싸이클의 주요 부품인 예연소기 개발 과정에서 브레이징 접합부를 모사하는 시편에 대한 강도 시험을 수행하고 유한 요소 해석 결과와 비교하였다. 진공 브레이징되는 헤드의 산화제 분사기 및 진공 가압 브레이징되는 냉각채널 접합부를 모사할 수 있는 시편을 설계 및 제작하고 파단 시험을 수행하였다. 두 시편 모두 접합부가 아닌 모재에서 파단이 발생하였다. 그리고 해석을 통하여 예측된 파단 부위와 변형율이 시험 결과와 잘 일치하였다. Key Words: Liquid Rocket Engine(액체로켓엔진), Preburner(예연소기), Head(헤드), Cooling Channel(냉각 채널), Strength Experiment(강도 시험), FE Analysis(유한요소 해석)