爆炸驱动颗粒多相材料形成射流的实验研究

为研究近场过程中射流结构的发端和成长，通过高速摄影技术记录干燥及未饱和沙壳在爆炸流场中的动态破碎过程，得到了沙壳破碎发端的临界条件，不同饱和度的沙壳形成射流的数目和平均质量，以及射流体质量的累积分布. 研究结果表明，少量的间隙液体，即使质量分数仅为3.22%，也足以明显推迟未饱和沙壳破碎的发生，使得所形成的射流结构明显增密，这种增密效应一直延续到液体的饱和度达到64.8%. 同时随着饱和度的增加，射流的质量分布也明显收窄，趋向于其特征质量. 炸药的类型对爆炸驱动形成的射流结构也有明显的影响，高爆速的8701驱动的颗粒射流结构明显比TNT驱动的射流结构更细密，且分布更均匀.

Experimental Study on the Formation of Multi-phase Powder Jets Driven by Explosive Loadings

In order to investigate the onset and development of the granular jetting in the near field, the dynamics of the fragmentation in both dry and wet sand shells subject to the explosive loadings via high-speed photography was recorded, and further the critical conditions of the fragmentation onset, the number and average mass of jets formed from wet shells with different saturation, and the cumulative mass distribution of the jets were derived. The results shows that a small amount of interstitial fluid, only accounting for 3.22% by mass, is conducive to the significant postpone of the shell fragmentation, leading to a pronounced denser jetting structure. This trend persists with increasing saturation until the saturation degree of the wet sand reaches 64.8%. Meanwhile the mass distribution of wet jets gets narrower and shifts towards the characteristic mass. The structure of jetting is dependent on the explosives as well, because the jets driven by the explosive 8701, which has higher detonation speed than TNT, become finer and more even than those formed by the explosion of TNT.