Ddt Process Simulation, Pulse Detonation Engine Ignition

Pulse detonation engines (PDE) is a new concept propulsion device which utilizes high temperature and pressure gas produced by intermittent or pulsed detonation wave to generate thrust. One of its key technologies is reduction of DDT time. It has a full significance to study the DDT process which initiated by different ignition systems for direct initiation of detonation successfully.In this paper,the DDT courses of PDE initiated by conventional spark ignition (CSI) system and flame jet ignition (FJI) system have been studied using numerical simulations.FJI system consists of a preignition cavity with a spark plug and a conversing nozzle attached to a main detonation tube,burned gas in the preignition cavity is jetted into the main detonation tube through the nozzle to ignite premixed reactants in the main detonation tube.The numerical method is coupled-explicit solver.The chemical reaction for the stoichiometric hydrogen-air mixture is modeled by one-step Arrhenius kinetics.This study mainly include following two aspects:In the first aspect,numerical investigations of the DDT courses initiated by the two different systems with appropriate ignition energy have been performed,and the detailed analysis of the differences between the two DDT courses show that the FJI system has a high burning speed and can shorten the DDT time effectively.In the second aspect,a series of DDT courses initiated by FJI systems of various configuration sizes have been studied,the effect rules of the FJI system's configuration sizes to DDT time have been provided,and the configuration size of FJI system made the shortest DDT time in the range of 0.95～12.90 cm~3 in FJI system's volume has been obtained,all of this are expected to give some references in design of FJI system for the future.