Numerical Simulations of Blast Wave Propagation After a High-Energy Explosion

In this study, we developed a finite-volume-based three-dimensional (3D) compressible flow solver for blast wave propagation simulation after a high-energy explosion. The developed solver considers various initial conditions, the real gas equations of state, and radiation heat transfer effects, and employs an implicit/explicit algorithm to solve the radiation-hydrodynamic equations. Euler’s equations are solved based on Roe’s approximate Riemann solver with a monotone upstream-centered scheme for conservation laws, whereas the 3D radiation equations are solved using the alternating-direction implicit method. The proposed method was validated by simulating one-dimensional weak- and strong-point explosion problems and a shock-tube problem considering the real gas effect. Further, we investigated the formation of an initial fireball with spherical symmetry after a high-energy explosion. Subsequently, three different fireball conditions at a breakaway point were considered for 3D blast-wave propagation over flat ground. The results indicate that the peak overpressure and shock arrival time predicted under the fireball condition by considering real gas and radiation effects are approximately 23.25 and 11.41% lower, respectively, than those predicted under the ideal gas assumption.