Aerothermodynamic Analysis of an RDE-Augmented Scramjet

This study presents a zero-dimensional thermodynamic analysis to evaluate the aerothermodynamic performance enhancements achievable by integrating a Rotating Detonation Engine (RDE) with a conventional scramjet. RDEs offer inherent pressure gain combustion and high-frequency detonation wave propagation, promising improved thermal efficiency and thrust-to-weight ratios compared to traditional deflagrative-based combustors. In this work, both airbreathing and rocket-mode RDE augmentation concepts are examined, representing distinct operational strategies across flight regimes and mission profiles. A station-based thermodynamic model is developed to assess key performance metrics, including specific thrust and specific impulse under a range of flight Mach numbers. Baseline scramjet configurations are compared against RDE-augmented variants, accounting for inlet variations, fuel types, and equivalence ratios. The results indicate that RDE integration can significantly increase thermal efficiency and augment net thrust, particularly in off-design or transitory flight conditions where conventional scramjet combustion is challenged by flame holding or low combustion efficiency. Additionally, the analysis highlights trade-offs in combustor back pressure and integration complexity, offering insight into viable implementation paths for RDE-augmented propulsion systems. This zero-dimensional study serves as a foundational performance screening tool, supporting future multidimensional modeling and experimental validation efforts aimed at advancing high speed propulsion technologies.