Numerical simulation and experiments on muzzle blast overpressure in large-caliber weapons

Abstract

A blast wave, especially from muzzle-loaded weapons, actually causes serious harm to gunners and weapons, as well as the surrounding environment. Therefore, accurate evaluation of high-pressure blast wave is considered a critical issue. The blast overpressure produced by muzzle blast wave in large-caliber weapons was performed numerically and experimentally in this study to resolve the problem above. First, two 3D computational models were constructed: one with a precursor flow field and the other without one. The muzzle flow field with a complicated projectile was simulated numerically. A second-order upwind scheme and multi-domain structured grids were employed to solve Navier-Stokes governing equations, and the Spalart-Allmaras model was utilized for turbulent flow calculation. Second, the muzzle blast overpressure over time in these two cases was calculated thoroughly. Finally, the values of the muzzle blast overpressure at different key points were tested by experiments. Results show that the peak overpressure in the area near the muzzle is larger when the precursor flow is considered. Moreover, the simulation values with the precursor flow are closer to the experimental values than those without the precursor flow. When the tested point is closer to the muzzle, its overpressure is affected greater by the precursor flow. Thus, precursor flow should be considered in the design of the muzzle device but should be neglected in the analysis of the far field. This study is meaningful and significant in studying the process of muzzle shockwave and in designing muzzle devices.