Influence of Muzzle Pressure on Muzzle Flow Field Characteristics of Underwater Launching

Abstract

In order to study the influence of muzzle gas injection pressure on the distribution characteristics of muzzle flow-field of underwater gun firing, based on computational fluid dynamics software Fluent, a two-dimensional axisymmetric simulation model of underwater muzzle flow-field was established by using structured mesh and dynamic mesh technology. For the 14.5 mm gun, the numerical simulation of the underwater sealed launching muzzle flow-field was carried out with the gas injection pressure of 30 MPa, 45 MPa and 60 MPa respectively. The calculation results show that, under the three kinds of muzzle gas injection pressure conditions, a jet expansion zone forms rapidly after the gas is sprayed out of the muzzle, and the axial pressure of the muzzle decreases sharply. The gas expansion process is greatly hindered by water and projectile, resulting in gas accumulation in the space behind the projectile, and the pressure increases again. While the gas injection pressure is in the range of 30~60 MPa, the initial formation of the Mach disk is slightly different. For about 145~152 ?s, the smaller the pressure is, the earlier the Mach disk forms, and the sooner the projectile breaks away from the gunpowder gas. Under the three kinds of pressure conditions, the position of the Mach disk at the center of the muzzle distributes exponentially with time.