PDF(Pubmed)
Abstract：
An investigation on the dispersal characteristics of the cylindrically packed material of dry powder particles driven by explosive load is presented. By establishing a controllable experimental system under laboratory conditions and combining with near-field simulation, the particle dispersal process is described. Additionally, Kelvin-Helmholtz instability is observed during the process of jet deceleration dispersal. The characteristic parameters of radially propagated particles are explored under different mass ratio of particle-to-charge (M/C). Results indicate that, when the charge mass remains constant, an increase in M/C leads to a decrease in dispersed jet number, void radius and maximum velocity, wherein the maximum velocity correlates with calculations by the porous Gurney model. The case of the smaller M/C always has a higher outer-boundary radius and area expansion factor. Findings indicate that when particles detach from the jet upon reaching minimum acceleration and entering low-speed far-field stage from high-speed near-field stage, the outer-boundary radius is 30~36 times the initial particles\' body radius under different M/C. In addition, particle concentration distribution over time and distance is qualitatively analyzed by the grayscale image method. This research can be referential for improving the fire-extinguishing capacity of extinguishing bombs and the damage property of fuel air explosive (FAE).
摘要：
对爆炸载荷驱动的干粉颗粒的圆柱形填充材料的分散特性进行了研究。通过在实验室条件下建立可控实验系统,并结合近场模拟,描述了颗粒分散过程。此外,在射流减速扩散过程中观察到Kelvin-Helmholtz不稳定性。在不同的颗粒电荷质量比（M/C）下，探索了径向传播颗粒的特征参数。结果表明,当电荷质量保持恒定时，M/C的增加导致分散射流数的减少，空隙半径和最大速度，其中最大速度与多孔Gurney模型的计算相关。较小M/C的情况总是具有较高的外边界半径和面积扩展因子。研究结果表明，当粒子在达到最小加速度并从高速近场阶段进入低速远场阶段时从射流中脱离时，不同M/C下的外边界半径是初始粒子体半径的30~36倍。此外,通过灰度图像方法定性分析了颗粒浓度随时间和距离的分布。该研究对提高灭火弹的灭火能力和燃料空气炸药（FAE）的破坏性能具有一定的参考价值。
