储罐内爆碎片多相耦合计算方法与抛射轨迹研究

Study on multiphase coupling calculation method and projectile trajectory of implosion debris in storage tank

以球形储罐为研究对象,考虑罐内气体-球罐(碎片)-罐外气体的多相耦合以及爆炸载荷的传递方式,采用CEL(耦合欧拉-拉格朗日法)流固耦合算法建立储罐内爆三维有限元模型,通过粘结单元的失效间接描述球罐材料的破坏,保证了球罐材料的质量守恒,进而对内爆载荷作用下球罐的动力响应、碎片的产生以及碎片抛射轨迹开展研究。以1600 m^(3)球罐为例,其计算结果表明:在空罐状态下球罐产生碎片的数量为14个,碎片的速度在61.2~75.6 m/s之间分布,考虑碎片不同初始位置以及空气阻力的影响,求解得到最大抛射高度为231 m、最大抛射距离为548 m;对比蒙特卡洛方法,多相耦合计算方法得到了碎片的具体数量、形状和质量;爆炸总能量到碎片动能的能量转化效率比蒙特卡洛方法中的最小值偏小35.5%,碎片的最大抛射高度偏小12.2%,最大抛射距离偏小8.7%。该多相耦合方法可为储罐内爆破碎研究提供参考。

With spherical tank as the research object and considering the multiphase coupling of gas in the tank-spherical tank(debris)-air outside the tank and transmission way of the explosion load,the CEL(Coupled Eulerian-Lagrangian method)fluid-structure coupling algorithm was used to establish the three-dimensional finite element model of the storage tank implosion.The failure of the cohesive element was used to describe the damage of the spherical tank material indirectly,which guarantees the mass conservation of the spherical tank material,and then the dynamic response of the spherical tank under the action of implosion load,the generation of debris and the projectile trajectory of debris were studied.Taking 1600 m^(3)spherical tank as an example,the calculation results show that 14 fragments are created in the empty tank,and the velocity of debris falls in the range of 61.2~75.6 m/s.Considering the influence of different initial positions of debris and air resistance,the maximum projectile height is 231 m and the maximum projectile distance is 548 m through solution.Compared with Monte-Carlo method,the quantity,shape and mass of debris were obtained by the multiphase coupling method.The energy conversion efficiency of total explosion energy to debris kinetic energy is 35.5%lower than the minimum value in Monte-Carlo method.The maximum projectile height of debris is 12.2%smaller and the maximum projectile distance is 8.7%smaller.The multiphase coupling method can provide a reference for the study of implosion debris in storage tanks.