Preliminary experiment on LOX/LH2 high pressure expander cycle engine

Abstract

The expander cycle has high performance and high reliability. This has been verified by the Pratt & Whitney RL 10 engine that is used to power the Centaur upper stage. Some limitations, however, exist in this cycle on increasing both chamber pressure and thrust because it uses only the heat energy absorbed by the fuel as it cools the thrust chamber and nozzle extension to power the fuel and oxidizer turbopumps. We have proposed the advanced concept chamber with an internal heat exchanger at the 35th IAF congress, Lausanne in order to pick up the large amount heat from combusion energy. This paper describes the brief features of high pressure expander cycle engine using an internal heat exchanger and the results of preliminary tests on the thrust chamber with internal heat exchanger. The average heat flux in heat exchager became about 70% of the value calculated by Bartz's correlation. The combusion performance was not affected significantly by installing a heat exchanger within a combustion chamber.