Rotating Detonation Rocket Engine Cycle Analysis: Hydrogen Expander and Electric Pump Architectures

A thermodynamic power cycle rocket engine model is developed to demonstrate the benefits of detonation-based electric pump and expander engine cycles using a distributed heat release combustor model. The cycle is modeled from the propellant tanks to the nozzle exit and includes the effects of simultaneous predetonation deflagration ([Formula: see text], termed precombustion), detonation ([Formula: see text]), and postdetonation deflagration ([Formula: see text], termed postcombustion) heat release modes. Comparisons are then made across equivalent flow conditions (i.e., same initial reactant temperature and pressure) at varying fractions of pre- and postcombustion in addition to detonation; this provides performance sensitivities spanning from an idealized detonation-based combustor with solely [Formula: see text] heat release to an equivalent deflagration combustor with no [Formula: see text] by treating deflagration as a combustion inefficiency in the detonation cycle. The detonation-based distributed combustor model is then used to investigate the benefit trade space of rotating detonation rocket engines in electric pump and expander power cycles by demonstrating power reduction (up to 19%) and length reduction (up to 95%), respectively. By analyzing the full cycle performance with detonation inefficiencies, this work helps inform the design and integration of rotating detonation rocket combustors across a wide range of flight regimes, including launch, hypersonic, upper-stage, and in-space propulsion devices.