Influence of support conditions on the flow field overpressure inside the crew compartment of a truck-mounted howitzer under muzzle blast

During firing of a truck-mounted howitzer, the crew compartment structure deforms elastically due to the muzzle blast load, creating pressure disturbances in the internal flow field of cabin. The resulting overpressure causes a significant threat to personnel and equipment safety. To meet driving requirements, the crew compartment of the truck-mounted howitzer is suspended on the chassis frame via an elastic support structure. At the same time, the stiffness and damping of the support structure are important factors affecting the deformation response of the cabin structure under the impact of the muzzle blast load. Therefore, adjusting the support parameters to optimize the flow field environment inside the crew compartment demonstrates high practical utility. To investigate the effects of different cabin support conditions on the flow field overpressure inside the crew compartment of a truck-mounted howitzer, a foreign trade type of equipment was taken as the object. An entire path numerical model simulating the shock wave propagation from the cannon's muzzle to the interior of the cabin under extreme firing conditions was established. Systematic validation tests were conducted, capturing overpressure data in both the external and internal flow fields of the crew compartment, as well as the acceleration of the cabin structure. Based on the validated numerical model, simulations were performed to calculate the structural responses and internal flow field overpressures under eight different support conditions. The results indicate that while different areas within the cabin exhibit varying sensitivity to changes in support conditions, increasing the support stiffness leads to significant reductions in the peak acceleration and velocity of the cabin structure, as well as a decrease in the peak overpressure within the internal flow field. However, the presence of damping in the support structure significantly enhances the acceleration response of the cabin structure, yet it further diminishes its velocity response and lower the peak overpressure in the internal flow field of the crew compartment.