investigation of cryogenic pressure surges in the dlr lumen project
- Paper number
IAC-19,C4,10,x51664
- Year
2019
- Abstract
Water hammer phenomena are of great interest in the field of rocket propulsion engineering. Closing a valve rapidly to shut down a rocket engine or stop the chill down procedure can generate high amplitude pressure waves in the feedline system can damage it. This caused the loss of the N1 rocket at its 4th flight [2]. It was also investigated in the Atlas II during staging in a variable –g environment[3][4]. At the qualification campaign for the ATV pressure peaks around 220 to 230 bars due to water hammer have been measured. They added a re-priming network to solve this problem [1]. \newline The target of the DLR LUMEN (liquid upper stage demonstrator engine) project is to develop and operate a modular LOX/LNG engine with 25 kN of thrust [5]. Ignition tests were performed at the test facility P8 in Lampoldshausen. \newline While start up the combustion chamber the purge valves in the LOX and LNG lines are closed to end the chill down procedure. This causes a pressure surge travelling over a T-piece towards the injector head and the tanks. The lines are equipped with dynamic pressure sensors to track the wave front over the T-piece. A static pressure sensor and a thermal sensor are also mounted. \newline The data evaluation focusses on the wave propagation over the T-piece in a cryogenic environment. The pressure peaks are also analysed since they can damage the hardware. Furthermore it is of interest if the appearance of the water hammer has an influence on the ignition.\\ \newline [1] V. L'Hullier, „Propulsion in the ATV Spacecraft System - Lessons Learnt,“ in 45th {AIAA}/{ASME}/\newline{SAE}/{ASEE} Joint Propulsion Conference {\&}amp$\mathsemicolon$ Exhibit, 2009.\newline [2] C. Lardier, „The soviet manned lunar program N1-L3,“ Acta Astronautica, Bd. 142, pp. 184-192, 2018. \newline [3] T. Walters und J. Walker, „Propellant line waterhammer analysis during staging,“ in 28th Joint Propulsion Conference and Exhibit, 1992. \newline [4] T. W. Walters, „Rocket Propellant Line Waterhammer Transients in a Variable-g Environment,“ in Forum on Unsteady Flow, 1990. \newline [5] J. Deeken, M. Oschwald und S. Schlechtriem, „Current status of the DLR LUMEN Project,“ in Space Propulsion Conference, Seville, 2018.- Abstract document
- Manuscript document
(absent)