Design and analysis of liquid rocket engine regenerative cooling jackets: Emphasis on computational modeling

An analytical computational procedure was developed in MATLAB to efficiently design the coolant channel height profile of a regeneratively cooled liquid rocket engine using the chamber wall temperature as the primary design point. The procedure employs a linear control volume marching scheme proceeding from the coolant channel inlet up through the chamber wall to the main injector face, successively iterating on the primary fluid variables. A conjugate analysis is used to accurately capture the heat transfer interaction between the hot combustion gases in the chamber and the cryogenic liquid fuel in the coolant passages. Verification of the procedure was achieved by comparing analytical results with exact solutions and another existing fluid analysis procedure in addition to published experimental data from the RL10 engine. A design trade study focusing on the main descent engine for the Altair Lunar Lander was carried out to explore the coolant channel design capabilities of the procedure at varying chamber pressures and mixture ratios as well using different chamber materials. The results of this trade study pointed to lower pressures and moderate mixture ratios as providing the best results. A copper chamber, as opposed to a stainless steel chamber, also resulted in beneficial lower pressure losses and slightly higher levels of heat pickup in the coolant channels in several cases. Overall, the procedure was successful in both designing coolant channel height profiles and in analyzing existing channels in an accurate and timely fashion while maintaining a sufficient level of flexibility and expansion capabilities.