基于反应欧拉方程投影算法的广域尺度气体爆炸数值模拟研究

Wide-area scale gas blast accident has become more severe recently; therefore, it is urgent to develop effective numerical methods to simulate the propagation of the explosion wave and the structural effect to forecast and estimate the damage. Herein, the reactive Euler equation with an extremely stiff source term is used to describe a wide-area scale gas blast. A numerical method based on the operator-splitting technique, using a high-resolution scheme for shock capturing and a novel projection method for the stiff source term, is proposed to handle the multiscale problem in reactive flows with extreme chemical reactions. Some one-dimensional (1D) detonation examples are successfully simulated to demonstrate that the proposed numerical method can capture the propagation process of the detonation wave in an underresolved mesh. The examination of the reconstruction methods implies that the proposed method is robust and unaffected by the spatial reconstruction schemes. Furthermore, the numerical model is extended to a 2D gas blast problem with complex structures. Several 2D detonation examples are simulated to show that the proposed numerical method can accurately capture the propagation and scatter behavior of detonation in high dimensions with a coarse mesh. Finally, a wide-area scale blast wave example that contains complex structures is simulated to provide the evolution of the gas blast wave and its interaction with structures in a coarse mesh. The numerical method proposed herein is a promising tool that can simulate the gas blast on a wide-area scale to provide pressure and temperature for city safety assessment under gas explosion accidents.