Evolution characteristics of shock waves in the muzzle flow field of an underwater gun in series launch

The muzzle flow field of underwater guns involves the interaction and reflection of shock waves within the propellant gas jet. When underwater guns are fired in series, the evolution of the shock wave structure in the muzzle flow field becomes more complex due to the superposition effect of the propellant gas jets. This study establishes a transient two-dimensional axisymmetric muzzle flow field computational model to simulate the dynamics of the muzzle flow field as it evolves during series launch of an underwater gun. The results show that the initial propellant gas jet expands further due to the impelling effect of the subsequent projectile. In the strong coupling series launch mode, the axial size of the bottle-shaped shock structure of the initial propellant gas jet exhibits a dynamic change of “growth decay.” However, in conventional coupling and weak coupling series launch conditions, the axial expansion of the bottle-shaped shock structure shows a single “growth” process. For the subsequent launch, in all three launch modes, the subsequent propellant gas jet will form two oblique shock waves under the compression of the gas–liquid interface and undergo several “shock reconstruction” processes at the axis, ultimately forming a stable bottle-shaped shock wave structure.