Numerical analysis on behavior of dilute water droplets in detonation
Numerical analysis on behavior of dilute water droplets in detonation
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DOI：
10.1016/j.proci.2020.07.141
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
H. Watanabe;A. Matsuo;A. Chinnayya;K. Matsuoka;A. Kawasaki;J. Kasahara
中科院分区：
文献类型：
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作者：
H. Watanabe;A. Matsuo;A. Chinnayya;K. Matsuoka;A. Kawasaki;J. Kasahara
基于欧拉-拉格朗日方法进行二维数值模拟，以模拟充满单分散水滴的气态爆炸。预混合混合物是低压下稍微稀释的化学计量氢氧混合物。分析了液滴破碎与细胞不稳定性和前导前沿后面的不均匀流动相互作用的结果。还使用水滴的瞬时流场和 Favre 平均剖面来分析模拟结果。破裂主要发生在爆炸前沿附近。无论主导激波的初始强度如何，也无论它是否低于或大于 Chapman-Jouguet 值，破碎过程结束时水滴的平均最终直径都是相同的。多分散性来自主导激波背后的局部现象，例如来自三相点碰撞的前向喷流、横波以及两者的组合。总破裂时间比根据冲击后条件估计的要长，目前的发现与之前的喷雾爆炸实验结果一致。
Two-dimensional numerical simulations are conducted based on the Eulerian-Lagrangian method to model a gaseous detonation laden with monodispersed water droplets. The premixed mixture is a slightly diluted stoichiometric hydrogen oxygen mixture at low pressure. The outcome of the interactions of the droplet breakup with the cellular instabilities and the non-uniform flow behind the leading front is analyzed. The simulation results are also analyzed using instantaneous flow fields and Favre average profiles for water droplets. Breakup occurs mainly near the detonation front. The mean final diameter of the water droplets at the end of the breakup process is the same regardless of the initial strength of the leading shock or whether it is lower or greater than the Chapman-Jouguet value. The polydispersity comes from local phenomena behind the leading shock, such as forward jets coming from triple point collisions, transverse waves and a combination of both. The total breakup time is longer than that estimated from post-shock conditions and the present finding is in line with the previous experimental results on spray detonation.