Samuele Gatto, Karel Van den Borre, Bayindir H. Saracoglu
DOI Number: N/A
Conference number: HiSST-2025-267
Reliable and efficient propulsion systems are critical for advancing civil hypersonic transportation. Air Turbo-Rocket (ATR) engines provide high specific thrust and impulse across a broad range of altitudes and Mach numbers, making them particularly effective for the acceleration phase. Furthermore, Expander-type ATRs extend the operational range by isolating the turbine from the hot airflow path associated with high flight Mach numbers, lifting a thermal constraint. Decoupling the turbine from the airflow path increases degrees of operational freedom. However, it leads to a more extensive variety of operating conditions in the turbines, making conventional scaling procedures for publicly available
turbine performance maps impractical. This work performs a multi-fidelity design and optimisation of a hydrogen turbine to expand its feasible operational envelope. The approach combines a low-fidelity mean-line design with empirical loss correlations, which feeds a high-fidelity CFD optimisation using the in-house CADO optimisation. The optimised turbine geometry is evaluated across multiple operating conditions to generate a turbine performance map that is useable in thermodynamic engine simulations.