A numerical study of reactive flows in pulse detonation engines

Numerical predictions of the effects of partial fuel-fill on the pressure histories and performance of ethylene-air mixtures in a pulse detonation engine (PDE) were confirmed qualitatively by experiments conducted at Stanford University. Quantitative comparisons were not possible because the detonable mixture considered and the system parameters were different in the experiments and simulations. Here, we report computational results on the same mixture and geometric parameters used in the experiments and find the agreement to be good quantitatively. We use our current and past results to show that many major flow features and performance trends are similar for a range of geometric and mixture parameters. Furthermore, in this study, we focus on pressure waves generated at the interface between the detonable and non-reactive mixtures. We show that the interactions among the different sets of pressure waves: those generated from the tube exit and from the material interface and their reflections from the head-end of the tube dominate the flow development in the PDE and consequently, the pressure evolution and thrust production during a PDE cycle.