两步起爆过程中爆震波衍射特性研究

Investigation on Diffraction of Detonation in Two-step Detonation Initiation Process

为了研究两步爆震起爆过程,通过数值模拟研究了填充条件和预爆管出口伸进扩张过渡段的长度L对爆震波衍射特性的影响规律。结果表明:L越小扩张过渡段对爆震起爆的加强作用越明显,但预爆管与扩张过渡段间的渐扩通道对爆震波回传的阻滞作用越弱;L越大,则结果相反。因此,应选择合适的L使扩张过渡段与渐扩通道对爆震波传播的增强作用达到最大。同时,在L=35 mm时,爆震波能够较早地与扩张过渡段壁面作用形成高温、高压区,从而加强了爆震波的传播,且预爆管与扩张过渡段之间的渐扩通道能对回传的爆震形成一定的阻滞作用。

In order to investigate two - step detonation initiation process, the pre - detonators with different L （ distance between transition section inlet and pre -detonator outlet） inserted transition section are simulated. The results indicate that the smaller the L, the more obvious the enhanced effect of the transition section is, but the effect caused by gradually outspread passage is weaker. When L turns longer, the trend is opposite. So it is necessary to choose a suitable L for the transition section and the gradually outspread passage to optimize the enhanced effect of detonation wave transition. When L is equal to 35 mm, the numerical simulated results indicate that the high ternperature and high pressure area can be formed earlier to reinforce the detonation wave transition. The gradually out- spread passage between pre -detonator and area expansion can form a better retardant effect on the return detonation wave, which prevents the excessively augment of the pressure in blender of the main combustor tube, then the two - step initiation of detonation can be successfully achieved.