用于爆轰驱动的射流起爆实验研究

Experimental study on jet initiation for detonation driver

爆轰驱动激波风洞的自由来流模拟范围与驱动气体的爆轰极限密切相关,爆轰极限越宽则模拟范围越大。驱动气体一般是通过点火管进行起爆的,提高点火管的起爆能力可以拓宽爆轰极限。为了提高点火管起爆能力,就点火管口径、点火气体爆轰敏感性和单/双点火管3种因素的影响进行了实验研究。在不同的点火管初始条件下,对驱动段波速进行了测量。结论如下:(1)提高点火管口径可以显著提升起爆能力;(2)点火气体爆轰敏感性对起爆能力有影响,点火管为缩径内型面时,低敏感性气体起爆能力更强,点火管为等径内型面时则低敏感性气体和高敏感性气体的起爆能力大体持平;(3)在保证射流同步的前提下,双点火管能够提高起爆能力,为保证射流同步性需使用化学恰当比的氢氧混气等爆轰敏感性强的点火气体。

The free-flow simulation range of the detonation driven shock tunnel is closely related to the detonation limit of the driving gas. The wider the detonation limit, the larger the simulation range. The driving gas is generally detonated through the igniter (ignition tube). Increasing the detonation capability of the ignition tube can broaden the detonation limit. In order to improve the ignition capacity of the igniter, the effects of three factors, the diameter of the ignition tube, the detonation sensitivity of the ignition gas, and the single/double igniter tube, were investigated experimentally. The velocity of the driven segment was measured under different initial conditions in the igniters. The conclusions are as follows. Firstly, improving the caliber of the ignition tube can significantly enhance the ability to initiate. Secondly, the ignition gas detonation sensitivity has an impact on the detonation capability: when the igniter is a reduced-diameter internal profile, the low-sensitivity gas has a stronger detonation capability;when the igniter pipe is of the same diameter internal profile, the result is reversed. Finally, if the synchronization of the jets can be ensured, the double igniters can improve the detonation ability. In order to ensure the synchronization, it is necessary to use a sensitive ignition gas like hydrogen oxygen mixtures of equivalent ratio.