爆炸塔内120kgTNT当量爆炸载荷的数值分析

Numerical studies on 120kg TNT equivalence blast loadings in an explosion tower

爆炸塔设计中常采用等当量集中装药估算爆炸塔内部载荷。为研究该方法的合理性,本文采用有限体积方法离散求解积分型Euler方程组;利用瞬时爆轰模型描述炸药爆炸初场,分别计算了乳化炸药和TNT集中装药爆炸对爆炸塔的内部加载情况;给出了塔体及封头内壁面9个特征点的压力时间曲线。结果表明:可以采用集中装药模拟乳化炸药对爆心截面处的超压作用,但不可以采用集中装药模拟乳化炸药对封头中心处的超压作用。因为在封头中心处乳化炸药爆炸会聚产生的超压极值约为TNT集中装药的2倍;塔体柱段的爆心截面处与封头中心处为超压作用最强的部位,两处冲量大致相当;压力最大值出现在封头中心处,由反射冲击波会聚产生。建议塔体建筑设计时对封头中心处和塔体爆心截面处采取相应的防护措施。

Equivalent evaluation method is often used in assessment internal loading inside an explosion tower for the explosion tower design.To study the rationality of this method,the finite volume method is adopted to solve the integral Eulerian equation system,the instantaneous detonation method is used to describe the explosion,the explosion flow fields of emulsion explosives and TNT concentrated charges are computed separately.As a result,pressure history curves at 9 characteristic points along the tower and its head are provided.Analysis shows that overpressures at the blasting center section are similar in these two cases,while overpressures at the center of the head are much different,the emulsion explosives explosion leads a maximum overpressure to be twice as big as the TNT concentrated explosives do.The blasting center section and the head center are the strongest impact sections for both locations endure similar impulsion loads.All the maximum overpressures produced by the reflected shock waves convergence occur at the head center.Thus reinforce protection at the head center and the blasting center section is suggested.