气相爆轰波绕射流场显示研究  

Flow-field visualization for gaseous detonation diffraction experiments

作　　者：王昌建[1] 徐胜利[1] 费立森[1] 

机构地区：[1]中国科学技术大学力学和机械工程系,安徽合肥230026

出　　处：《爆炸与冲击》2006年第1期27-32,共6页Explosion and Shock Waves

基　　金：国家自然科学基金项目(10172083);中国工程物理研究院联合基金(10076018);北京理工大学爆炸科学与技术国家重点实验室开放基金(KFJJ03-2)

摘　　要：采用基于红宝石激光器(波长694.3 nm)的纹影系统,对气相爆轰波绕射进行了初步的流场显示研究。采用单色激光和合适半带宽(15 nm)的滤光片,有效地消除了爆轰波自发光对流场显示的影响。合理设置激光器同步控制系统的触发延时,得到了序列的爆轰波阵面纹影照片。结果表明:图像清晰地显示了爆轰波阵面的诱导激波、横波及化学反应区。当爆轰波在左尖点处绕射,受稀疏波作用,诱导激波与化学反应区明显分离,导致爆轰波衰减为爆燃。分离的诱导激波和折皱的化学反应区在纹影图上清晰可见。诱导激波在垂直支管右壁面反射,诱导二次起爆。畸变爆轰波在水平和垂直支管中均发生马赫反射。提高初压,爆轰波受分叉口几何属性的影响减小,畸变爆轰波在水平和垂直支管下游较易恢复为自持爆轰波。Based on a Ruby-laser schlieren system, the flow-field of detonation diffraction in a bifurcated tube has been experimentally studied. By employing the ruby laser and a bandpass filter of 15 nm FWHM, the combustion luminescence was successfully removed in experiments. By setting proper predetermined time delay of the synchronization unit, schlieren image series at the different time were obtained. The results show that the transverse waves, leading shock and reaction zone can be clearly observed in the consecutive images. Influenced by the rarefaction waves from the left sharp corner, the leading shock was disturbed and separated from the reaction zone. Therefore, the detonation wave was degenerated into a deflagration wave. The decoupled leading shock and the winkled reaction front can also be identified in the schlieren images. Re-initiation was induced by the leading shock reflection on the right wall in the vertical branch. Math reflections of the disturbed detonation waves occur in both the vertical and the horizontal branches. With increasing the initial pressure of the premixed mixture, it was earlier for the disturbed detonation waves to be recovered to self-sustaining detonation waves in the vertical and horizontal branches.

关 键 词：爆炸力学 爆轰波绕射 纹影照相 气相爆轰 二次起爆 马赫反射 

分 类 号：O381[理学—流体力学]