考虑流固耦合的管道爆炸后果预测与分析

Consequences prediction and analysis of pipe explosion considering fluid-structure interaction

针对管道爆炸后果模拟中存在的伴随变形与断裂的流固耦合问题,提出一种计及计算稳定性的流固耦合算法,对在内部气体爆炸作用下的管道动态断裂及爆炸流场发展进行耦合仿真.采用单元删除技术并植入应变率-应变双变量失效准则来模拟管道的裂纹扩展,将模拟得到的管道断裂形貌及压力历程与试验结果进行对比验证.分析管道爆炸的后果,并将管道外峰值压力的模拟值与现有方法的计算值进行对比.结果表明:考虑流固耦合效应时管道外2个测点的峰值压力分别为不考虑该效应时的83.1%和62.2%.相比难以计及爆炸流场与管道相互作用的半经验模型和传统计算流体力学方法,所提出的方法可以更加合理地预测管道内气体爆炸的后果.

A stability-based coupling approach was proposed to solve the fluid-structure interaction（FSI）problem encountered in the consequences modeling of pipe explosion.By applying this approach,the propagation of blast wave and the dynamic fracture of pipe were simulated synchronously.Element deletion technique and the bivariate failure criterion for high-strain-rate conditions were employed to model the dynamic crack growth of pipe.The simulated pressure histories in the pipe and final fracture patterns were compared and validated with the experimental data.The consequences of explosion in pipes were analyzed;the simulated peak pressures out of the pipe were compared with the results calculated by existing methods.Results show that the two predicted peak pressures with considering the FSI effect are83.1% and 62.2% of those without considering the FSI effect.The proposed method can more rationally predict the consequences of explosion occurring in pipes compared with semi-empirical models and traditional computational fluid dynamics（CFD）methods where the interaction between blast wave andpipe cannot be taken into account.