Flow field distribution and overpressure characteristics inside the crew compartment of a truck-mounted howitzer under the effect of muzzle blast

The muzzle blast overpressure induces disturbances in the flow field inside the crew compartment (FFICC) of a truck-mounted howitzer during the artillery firing. This overpressure is the primary factor preventing personnel from firing artillery within the cab. To investigate the overpressure characteristics of the FFICC, a foreign trade equipment model was used as the research object, and a numerical model was established to analyze the propagation of muzzle blast from the muzzle to the interior of the crew compartment under extreme firing condition. For comparative verification, the muzzle blast experiment included overpressure data from both the flow field outside the crew compartment (FFOCC) and the FFICC, as well as the acceleration data of the crew compartment structure (Str-CC). The research findings demonstrate that the overpressure–time curves of the FFICC exhibit multi-peak characteristics, while the pressure wave shows no significant discontinuity. The enclosed nature of the cab hinders the dissipation of pressure wave energy within the FFICC, leading to sustained high-amplitude overpressure. The frame-skin structure helps attenuate the impact of muzzle blast on the FFICC. Conversely, local high overpressure caused by the convex or concave features of the cab's exterior significantly amplifies the overpressure amplitude within the FFICC.