Simulation Refinements of European Reusable StagedCombustion Rocket Engine SLME

Kurzfassung

The full-flow staged combustion cycle rocket engine with a moderate 15 to 17 MPa range in nominal chamber pressure called SpaceLiner Main Engine (SLME) has been under investigation by numerical simulations since several years. The SLME is today not only foreseen as the SpaceLiner’s main propulsion but also used as reference for closed cycle LOX-LH2-engines in several studies of future European RLV. The launcher system highlevel requirements on the main propulsion system as well as the engine system level requirements have been defined by DLR. The Swiss company SoftInway and DLR successfully completed in 2024 a de-risk study under contract to the European Space Agency (ESA) to preliminarily consolidate a staged combustion engine design. Major findings of the pre-design of the turbomachinery, valves and lines, preburners and main combustion chamber, regenerative cooling using the commercial AxSTREAM® Platform and DLR-tools are summarized in the paper. Contributions to the next iterative design step are addressed via refined simulations. The steady-state cycle analyses are improved on the powerhead side to mitigate certain shortcomings of the previous model. SoftInway’s predesign data of the AxSTREAM® turbo-machinery sizing and heat-transfer analyses using engineering tools like TDK support the refinement of this updated engine cycle modelling. The study is complemented by simplified simulations of an engine control architecture for nominal sequences of operations.