南通大学学报（自然科学版）

采用二维守恒元与求解元方法(简称CE/SE方法)对脉冲爆轰发动机汽油/空气两相爆轰内流场进行数值模拟,获得了脉冲爆轰发动机内流场的变化规律.分别研究了不同点火能量、点火位置和点火方式对燃烧转爆轰过程(简称DDT过程)的影响.计算结果表明,点火能量越大形成稳定爆轰波所需要的时间越短,即燃烧转爆轰时间和距离越短,并且当点火能量过小时则不能形成燃烧转爆轰过程;从不同位置处点火计算得出,存在一个最佳的点火位置,使得燃烧转爆轰形成距离最短,形成时间最少,文章所研究尺寸结构的脉冲爆轰发动机的最佳点火位置为距封闭端2倍管径处;通过两点点火和单点点火的计算结果比较发现,适当的多点点火可以诱导爆轰的形成,能够缩短燃烧转爆轰的时间和距离.以上研究结果可以为脉冲爆轰发动机的点火起爆及燃烧转爆轰的实验研究提供理论指导,并为发动机的结构改进提供参考.

The method of two-dimensional conservation element and solution element was employed to simulate the gasoline/air interior flow field of pulse detonation engine. The characteristics and the change rules of the interior flow field of pulse detonation engine were studied. The deflagration to detonation transition(DDT) process has been studied with different ignition energy, different ignition positions and different ignition methods. The numerical calculation results showed that less time is required to form the stable detonation wave when ignition energy increases. And when ignition energy is too small, the DDT process cannot form. A best ignition position exists that makes the shortest DDT distance and the least DDT time. The best ignition position of the size and structure of pulse detonation engine is the site which is twice diameter of the tube away from the left closed end. Appropriate multi-point ignition can induce the formation of detonation. By using multi-point ignition method, both distance and time of DDT are shortened. The present findings can shed some light on the ignition and DDT experiment of pulse detonation engine theoretically and present reference for the improvement of engine structure.