瓦斯爆炸压力与波前瞬态流速演化特征及其定量关系

为了建立爆炸波前的瞬态流速和超压的定量关系，采用数值模拟的方法分别研究了开口型方管内瓦斯爆炸超压和瞬态流速传播特征。研究结果表明:开口型方管内，波前瞬态流速和超压的波形曲线的峰值个数不一样，而且超压峰值总是早于波前瞬态流速峰值出现。大部分情况下，方管横截面边长越大，其超压峰值相对较小，并且超压峰值沿传播方向呈现降低趋势。波前瞬态流速峰值沿传播方向呈不断增长趋势，而且方管横截面边长越大，其峰值也相对较小。长径比(方管长度与横截面边长之比)小于125时，超压峰值与波前瞬态流速峰值的定量关系始终呈现线性反比关系；大于或等于125时，超压峰值和波前瞬态流速峰值的定量关系呈分段关系。研究结果可为爆炸冲击波扬尘的研究提供基础数据。

Quantitative relationship between flow speed and overpressure of gas explosion in the open-end square tube

The main objective of this study is to establish the quantitative relationship between overpressure and flow speed in the open-end square tube by the numerical simulation. It is found that the numbers of the peak value of overpressure and flow speed at the same measured point are different. The peak overpressure always appears earlier than peak flow speed in time scale. In mast cases, larger side lenth of square tube corresponds to smaller peak overpressure, and the peak flow speed goes down slowly along the propagation direction. The peak overpressure decreases with the increasing of the distance far from ignition end. However, the peak flow speed increases with the stream wise distance. When normalized distance is less than 125, the peak overpressure and peak flow speed always presents an inverse relationship. Otherwise, the relationship is piecewise-linear. The results may provide reference for the study on evaluating the dust lifting ability behind shock wave in the limited spaces.