AIAA 2003-1171 Reactive Flow Phenomena in Pulse Detonation Engines

This paper describes oneand two-dimensional numerical simulations, with simplified as well as full reaction kinetics, of a single cycle pulse detonation engine (PDE). Focus of the present studies is on 1) the presence of a nozzle extension at the end of the tube, and its effect on performance parameters as well as noise characteristics, 2) critical “spark ignition” energies associated with the initiation of a detonation in the PDE tube, and 3) quantification of performance parameters associated with full kinetics simulations of the PDE and comparison of these data sets with available experimental data. The present simulations demonstrate the ability to predict PDE reactive flow phenomena and associated performance and noise characteristics, and hence have promise as a predictive tool for the evolution of future PDE designs. Introduction and Background The Pulse Detonation Wave Engine (often called the Pulse Detonation Engine or PDE) is a device which allows periodic ignition, propagation, and transmission of detonation waves within a detonation tube, with associated reflections of expansion and compression waves which can act in periodic fashion to produce thrust 1, 2 . A summary of the relevant gasdynamics within the PDE tube is shown in Figure 1. The figure indicates ignition and propagation of the detonation out of the PDE tube (Figures 1a-c), reflection of an expansion fan into the tube (Figures 1de), reflection of the expansion fan from ∗Graduate Researcher †Professor; Associate Fellow, AIAA. Corresponding author ([email protected]). ‡Copyright (c) 2003 by X. He Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. the thrust wall (Figures 1ef), allowing reactants to be drawn into the tube, and propagation of the expansion fan out of the tube (Figures 1gh), with simultaneous reflection of a compressive disturbance into the tube (Figures 1hij), which reflects from the thrust wall, ignites the fresh reactants, and reinitiates the cycle. Because the PDE concept holds promise for high thrust density in a constant volume device requiring little or no rotating machinery, a number of groups have been exploring PDEs for propulsion applications. This exploration has built on fundamental PDE work over several decades 1–4 , so that modern experimental diagnostic as well as computational methods may be used to bring about significant advances in the state of the art 2,4–6 . Performance parameters commonly used to characterize the pulse detonation engine include the impulse, I, typically defined as