Numerical Simulation And Experimental Study Of Pulse Detonation Propulsion Applications

The Pulse Detonation Engine(PDE),being a new conceptual propulsion device, generates thrust by the high temperature and high pressure after the detonation wave propagation, which has a fascinating prospect to the explore its application on flight vehicles due to the advantages of the high circulatory thermal efficiency, the high ratio of thrust-weight and simple structure. There are many key technologies to be solved on the application of engineering. In this thesis, numerical calculation and experimental simulation were combined to investigate the waves processes and their interactions in a detonation circulation, including the characteristics and regularity of the working cycle, the influence of inflatable combustible mixture ratio’s in detonation tube to the detonation cycle, the influence of expanding nozzle to improve its dynamic performances, the regularity of the process of ignition and exhaust by the device of pulse detonation engine.According to the characteristic of working cycle of pulse detonation engine, the flow field, including formation, movement, interaction of the waves were discussed. The change of wave diaphragm and the simple calculation of thrust on the whole cycle by the method of theory analysis. The main research contents are summarized as following:(1) Because it is difficult to precisely control the ratio of combustible mixture into detonation tube, so the working cycle was simulated by changing the various filled rates of mixture to investigate the effect of the filling ratio of combustible mixture in detonation tube to the working cycle, so as to provide theoretical guidance for control of the engine intake.(2) In order to study the effect of nozzle to the power performance of pulse detonation engine, some kinds of expansion nozzle were numerically simulated to investigate the difference of its instantaneous thrust and the impulse between the uniform detonation tube and the tube with expansion nozzle in the working cycle. The results show that the detonation tube with expansion nozzle can obviously improve its dynamic performance.(3) For investigating the effect of the charge pressure to the process of ignition and exhaust of detonation products, experiments were carried out to visualize the processes by high speed schlieren technology. The experimental results show that with the increase of gas pressure, the strength of the shock wave on ignition process and the strength of detonation wave when the detonation wave overflowing the detonation tube are significantly enhanced.