The Application of Godunov SPH in the Simulation of Energetic Materials

The numerical study of detonation of high explosives has been the interest of researchers over decades. Due to its special advantages in tracking free surface and dealing with large deformation, smoothed particle hydrodynamics (SPH) has been a powerful tool to investigate detonation phenomenon. SPH is a Lagrangian mesh-free method with extensive applications in fluid mechanics and solid mechanics. In the early development of SPH method, artificial viscosity is introduced to suppress unphysical fluctuation. However, the parameters of artificial viscosity often need to be tuned for some simulation, which can be quite time-consuming. Herein, a Riemann solver is integrated in traditional SPH algorithm to eliminate artificial viscosity, which is known as Godunov SPH. First, shock tube problem is studied using the Godunov SPH. The simulation result is compared with that obtained by traditional SPH with artificial viscosity, finite volume method (FVM) and experiment. Then, the Godunov SPH is implemented to investigate the detonation of 1D and 2D polymer-bonded explosive PBX 9501. Various factors that may influence simulation are studied, such as particle density and smoothing length. It is demonstrated that the proposed method is accurate and reliable for the study of detonation of high explosives.