To investigate the influence of the structure of multi-cycle pulse detonation engine(PDE) on its operation performance

experiments of ethylene-air and gasoline-air mixtures initiation process in the aero-valve PDE of 1050mm length and 40mm inner diameter were performed.The results show that the detonation wave can be successfully initiated in the ethylene-air with frequency of 25

30Hz and 40Hz

and C-J(Chapman-Jouguet) detonation wave can be achieved at the frequency of 40Hz with detonation wave propagation velocity of 1724m/s(less 5.6% than the C-J detonation wave velocity theoretical value 1832.45m/s) and peak wave pressure of 3.01MPa(higher 7.88% than the C-J detonation wave pressure theoretical value 2.79MPa).While the deflagration to detonation transition failed to complete in gasolene-air.By comparison of the two results

it was found that the evaporation process dominated the initiation process in liquid fuels

thus slowering the flame acceleration process in the detonation tube.More novel and optimized-designed reinforced-combustion devices for accelerating the flame should be developed

which may cause higher total pressure loss.Thus

atomization and evaporation to improve the quality of the mixture is a key technology for detonation in the liquid fuel.