Performance Studies of Rounded and Annular Pulse Detonation Engine Nozzles

摘要

Two-dimensional axisymmetric numerical simulation was carried out, using multi-cycle and detailed chemical reaction kinetics of hydrogen/air mixture, to investigate the effect of different nozzles on the rounded and annular pulse detonation engines. For the rounded pulse detonative duct, the largest instantaneous thrust is gained by diverging nozzle; the time-averaged thrust generated by the combined-nozzle with ejector is larger than that by the single-nozzle. The annular pulse detonative duct ejector performance is observed to be stronger than the rounded, which is confirmed from entrainment effect, mixing action, time-averaged mass flow rate of ejection. The process of unsteady ejection can be divided to four stages, and the performance of annular pulse detonation duct ejector is stronger than round pulse detonation duct ejector. Different structure and parameter result in different time-averaged thrust augmentation. By analyzing, the better interior surface, ejector length-to-diameter ratio and axial placement are obtained, which would offer references to augment the performance of pulse detonation engine.