离心机水下爆炸缩比实验原理及数值研究

Experimental principle and numerical study of scaled-down underwater explosion model on a centrifuge apparatus

对离心机水下爆炸缩比实验方法进行探究,对离心机水下爆炸缩比实验的相似理论进行了推导,通过数值计算分析,探究了原模型、离心机缩比实验及常规缩比实验的冲击波载荷、气泡载荷以及气泡动力学行为。结果表明:常规缩比实验不能对气泡行为及垂直方向的近场载荷进行准确的预报,若要保证远场气泡脉冲峰值误差小于10%,则爆距需大于9.5倍气泡最大半径。而离心机缩比实验能够对原模型进行准确的预报,以小当量装药模拟大当量装药水下爆炸整个物理过程,且冲击波和气泡两个阶段完全相似。同时,水深也可以进行几何缩比,克服了常规缩比方法的缺陷。

In this paper,we investigated a novel method by carrying out a sclaed down underwater explosion experiment on a centrifuge apparatus and set up the similarity theory between the scaled down and actual underwater explosion experiment.Using numerical simulation,we also investigated the shock-wave load,the bubble load and bubble dynamic behaviors between original models,the novel scaled down experimental method and the conventional method.The results from our study indicate that the conventional scaled down model experiment is unable to accurately predict the bubble dynamics and the vertical near-field loading induced by the bubble collapse.When the deviation of the farfield bubble pulse is limited within 10%,the distance between the explosion source and the measuring point has to be larger than 9.5 times that of the maximum radius of the bubble.However,the novel experimental method can make a precise prediction for the original model.The experiment of a minicharge underwater explosion almost reproduces the whole physical process of a mass-charge underwater explosion with the completely similar stages of the shock wave and the bubble.In addition,the depth of the water can also be scaled down,thereby overcoming the disadvantages of the conventional method.The present study aims at providing a novel way to perform underwater explosion model experiments.