Pulse-Detonation-Engine Simulations with Alternative Geometries and Reaction Kinetics

This paper describes numerical simulations, with simplified as well as full reaction kinetics, used to study a single-cycle pulse detonation engine (PDE) with alternative features. The focus of the present studies was on the influence of several characteristics of the PDE on performance and noise generation, including the presence of a nozzle extension at the end of the PDE tube, the influence of the complexity of the combustion reaction, and use of a quasi-one-dimensional simulation vs a full two-dimensional/axisymmetric simulation. Simplified reaction kinetics and quasi-one-dimensional simulations were in fact able to sufficiently capture important gasdynamic processes in the PDE as compared with complex reaction kinetics and two-dimensional/axisymmetric simulations; hence, reasonable estimates of engine performance could be made using simplified modeling. The presence of a divergent nozzle is seen to contribute to an overall increase in impulse for the PDE as compared with that for a straight nozzle, despite a resulting reduction in the differential pressure at the thrust wall. The presence of a convergent nozzle is seen to have the opposite effect, with a reduced overall impulse. There is also evidence that PDE tubes with a divergent nozzle can generate lower near-field sound pressure levels than the baseline configuration with a straight nozzle, suggesting the potential for optimization of PDE performance based on nozzle geometry.