中文摘要：

为了减小脉冲爆震发动机PDE（pulse detonation engine）单次循环时间,缩短爆燃向爆震转变DDT（deflagration to detonation transition）距离是关键.为此,提出了一种在头部添加球形点火腔的新型爆震管道结构设计方案,并采用丙烷和空气为可爆混合物,通过对新型爆震管DDT过程的二维数值模拟,研究其对DDT距离以及DDT时间的影响.数值模拟结果表明,头部采用球形点火腔后,点火腔中的压缩波经过多次反射后,能够在爆震管中更快地促使爆震波形成,DDT距离大大缩短;当球形点火腔直径为1.5倍等直爆震管直径时,相对于常规等直管爆震管结构,其DDT距离和过程时间分别减少了14%和16.26%.

英文摘要：

The length of deflagration to detonation transition （DDT） is the key influential parameter to the single cycle time of pulse detonation engines （PDE）.In order to reduce PDE＆#39;s single cycle time,a new type detonation tube was designed by adding a spherical ignition chamber at the head of traditional detonation tube,meanwhile propane and air were used as fuel to study the effect of spherical ignition chamber on DDT process by 2-D numerical simulation.The numerical simulation results show that,the compression wave were frequently reflected in the ignition chamber,and then the detonation wave was formed quickly in the straight detonation tube,the length of DDT was significantly shortened.Compared with the conventional straight detonation tube,the length and time of DDT process reduced about 14% and 16.26% respectively,when the spherical ignition chamber＆#39;s diameter was 1.5 times of the straight pipe＇s diameter.