论文部分内容阅读
以脉冲爆震发动机(PDE)用曲管爆震燃烧室为应用背景,对气相(乙烯/空气)燃烧波在U型方管实验器中的传播过程进行了实验研究。通过改变实验器中弯曲段进口气流入射激波强度,基于弯曲段内压力、波速的测量及高速摄影实验得到了U型方管实验器中半圆型弯段内的爆燃向爆震转变(DDT)特性。结果表明,弯曲段中DDT特性受到入射激波速度的影响:当入射激波速度小于794m/s(43.6%VCJ,VCJ为理论Chapman-Jouguet爆震波速),在弯曲段内不能形成爆震;当入射激波速度介于870~908m/s(47.8%VCJ~50.0%VCJ)之间,弯曲段内首先会产生局部爆炸,并最终形成爆震;当入射激波速度大于934m/s(51.3%VCJ),爆燃波可以直接在弯曲段入口转化为爆震波。
The propagation of gas phase (ethylene / air) combustion wave in a U-shaped square tube test device was experimentally studied on the basis of a pulse detonation engine (PDE) with a curved tube detonation chamber. By changing the incident shock intensity at the inlet of the curved section in the experimental apparatus, the detonation to detonation transition (DDT) in the semicircular curved section of the U-shaped square tube test instrument was obtained based on the measurement of the pressure and wave velocity in the curved section and the high-speed photogrammetry. characteristic. The results show that the DDT characteristics in the curved section are affected by the incident shock velocity: when the incident shock wave velocity is less than 794m / s (43.6% VCJ, VCJ is the theoretical Chapman-Jouguet detonation wave velocity), no detonation can occur in the curved section. When the incident shock wave velocity is between 870 ~ 908m / s (47.8% VCJ ~ 50.0% VCJ), the local explosion will occur firstly in the curved section and eventually form a detonation. When the incident shock wave velocity is more than 934m / s (51.3 % VCJ), the deflagration wave can be transformed into a detonation wave directly at the entrance of the curved section.