Analysis Of The Sealing Characteristics Of An Underwater Gun's Launch Port

This thesis studies sealing characteristics of underwater gun.Major work focus on interior ballistic numerical calculation of underwater gun,shock wave characteristic before the projectile,gas-liquid two-phase flow formed by shock wave interact with water,gas-liquid two-phase flow formed by gunpowder gas interact with water,the whole system structure design of the sealing mechanism and structure stiffness and strength analysis of crucial parts.Firstly,the mathematical model of interior ballistics is established and calculated by MATLAB.The velocity curve and chamber pressure curve of projectile is obtained.Then,the flow field calculation model is established in the flow field simulation software.The formation and variation laws of the front shock,the muzzle flow field formed by the interaction of shock wave and water and gas-liquid two-phase muzzle flow field formed by the interaction of gunpowder gas and water are obtained.The volume of water entering through the arc is also studied.The flow field simulation results can be used to guide the design of sealing structure.Subsequently,the whole structure of sealing mechanism has been designed.The seal mechanism model is introduced into the kinetic analysis software.The curve of the projectile and the sealing disk are obtained,and the result proves that the sealing characteristics of the structure are good.Finally,the stiffness and strength of the drive shaft and the sealing disc are analyzed by finite element analysis software.It is included that the key component meets the design requirement in shooting state.The research methods and results have a certain reference value for selection of seal method for underwater gun and design of muzzle seal mechanism.