Nihar Shah

Date of Award


Document Type


Degree Name

Master of Science in Aeronautical Engineering


Department of Aeronautics and Astronautics

First Advisor

Paul I. King, PhD.


Detonation-based combustors leverage the higher thermodynamic efficiency of the Atkinson cycle compared to the traditional deflagration-based combustion of the Brayton cycle. The rotating detonation engine (RDE) has one or more shock waves rotating around an annulus. The RDE can theoretically be 20% more thermally efficient than a traditional deflagration-based cycle. A RDE was modeled in Numerical Propulsion System Simulation (NPSS) based on a model developed in Microsoft Excel. The thermodynamic analysis of the RDE in these models is broken into four streams. Empirical models were used to find the percentage of the total flow in each stream. The pre-detonation pressure was iterated until the entrance mass flow calculations matched the exit mass flow calculations. A parametric analysis was used to compare the variation in specific impulse from the NPSS model to the Microsoft Excel model and other published results. The RDE has a peak air-breathing engine specific impulse of approximately 5,500 sec and a peak rocket engine specific impulse of approximately 150 sec.

AFIT Designator


DTIC Accession Number