A novel construction method of computational domains on large-scale near-ground explosion problems

The development of a novel Adaptive Mesh Enlargement (AME) method with ordinary Weight Essentially Non-Oscillatory (WENO) scheme for large-scale explosion problems is presented. The novel AME method adaptively adjusts the size of computational domains to accommodate the development of an explosion event which initially starts in a small domain. The grid resolution is verified by solving a simple one-dimensional (1-D) partial differential equation. The accuracy of AME methods is evaluated by calculations of 1-D Burgers equations and shock tube tests. It is found that the accuracy of AME methods depends on the number of enlargement operations. Numerical solutions with a reasonable number of enlargements are consistent with those of the fixed mesh method. At the same time, AME methods with multiple enlargements reduce the computational cost by several orders of magnitude. A three-dimensional (3-D) symmetric model with the AME method operating five enlargements is further developed to simulate the large-scale near-field explosion and validated against experiments. Propagation of the rarefaction and shock waves as well as the reflected wave are analyzed. The predicted peak incident pressures yield a variation of ∼3% compared to experiments indicating that the AME method is an effective construction method of computational domains for the problem of large-scale fluid dynamics.