Objectives   In order to study how dynamic motion of explosive, initial interface disturbance and grid size affect the overpressure load of internal explosion,

  Methods   the spatial and temporal terms of the two-dimensional compressible Euler equations are discretized numerically using the fifth-order WNEO finite difference scheme and the third-order TVD Runge-Kutta scheme. Based on Fortran platform, an in-house high-precision numerical calculation program of blast wave in confined space was developed. The impacts of the overpressure load of the internal explosion were preliminarily discussed adopting the developed program.

  Results   The results show that, increasing charge movement speed, selecting a specific interface disturbance and decreasing the size of the grid can significantly increase shock wave peaks of internal explosion, but has little effect on quasi-static overpressure load.

  Conclusions   The research in this paper can provide certain reference and basis for the design of anti-explosion structure and the evaluation of internal explosion damage.