高初始压力下脉冲爆震发动机工作特性的实验研究

To investigate the effect of high initial pressure on the initiation and propagation characteristics of detonation waves in pulse detonation engines, and to further explore the stability propagation characteristics of detonation with high-frequency, experimental studies were conducted in a 10mm inner diameter detonation tube with ethylene as fuel and oxygen-enriched air (40% by volume) as oxidizer. The initial high-pressure conditions were successfully achieved in the detonation combustion using different contraction ratios, with a maximum initial pressure of 0.68 MPa obtained. The results show that an increase in contraction ratio and supply pressure, will increase the initial pressure of the combustion. As the contraction ratio increases, the initial pressure increases, and the DDT distance first decreases and then increase, reaching a minimum value at the contraction ratio of 2.04. When the contraction ratio is less than 2.04, the peak pressure of the detonation wave increases linearly with the initial pressure. As the initial pressure increases, the range of stable detonation frequency broaden, but the peak pressure fluctuations of detonation wave increases. When the contraction ratio exceeds 2.04, an increase in initial pressure will cause the stable detonation mode to change to the unstable detonation mode.