Thermodynamic Performance Results for Rotating Detonation Rocket Engine with Distributed Heat Addition using Cantera
Jason R. Burr, Eric J. Paulson
Abstract
View Video Presentation: https://doi.org/10.2514/6.2021-3682.vid A new performance model of rotating detonation rocket engine (RDRE) is developed in this study to investigate the impact of distributed heat addition on combustor operation. Conservation equations and equilibrium chemistry are employed to evaluate detonation-relevant metrics, such as wave compression strength and propagation velocity, as a function of heat addition preceding and trailing a Chapman-Jouguet (CJ) detonation wave. Additional performance measurements including specific impulse are computed for a variety of combustion cycle configurations to determine the sensitivity of engine performance to non-detonative heat addition. Deflagration preceding the detonation increases the reactant sound speed while concurrently decreasing the compressive benefit attributed to detonation, thereby lowering cycle performance; examination of the detonation wave speed reveals that it does not uniquely map to the specific impulse, and that numerous detonative heat loads are capable of producing equivalent specific impulses. Alternative parameters that more succinctly correlate with the detonation heat addition independent of deflagration processes, such as wave Mach number and wave compression strength, are instead better predictors of the cycle performance. Further analysis of the thermodynamic model indicates the relative sensitivities of the performance metrics to model inputs; combustor specific impulse is 4.6-8.6 times more sensitive to deflagration preceding the detonation wave than deflagration following the wave. This work serves as a basis for future RDRE thermodynamic studies that may lead to greater insights on the combustion processes within the annulus and on propellant mixing methods that mitigate the greatest performance losses.