Numerical Research On Water Entry Of High-speed Supercavitating Projectile

Supercavitating projectile is generally launched by airplane or submarine.In order to meet the conditions of supercavitation,the launch speed must be very high.In actual combat,for the sake of increasing the mobility of the battle and the operational area,we usually launch the supercavitating projectile from air into water.This process will be affected by unsteady flow and turbulence.In this paper,the flow field characteristics of supercavitating projectiles entering water at high speed are numerically simulated by choosing appropriate theoretical methods and control models.The specific contents are as follows:The theoretical model of numerical simulation method for high-speed water entry of projectiles is introduced concisely.VOF multiphase flow model,SST turbulence model,Schnerr and Sauer cavitation model are introduced.Triangular mesh is selected to divide the moving object and the surrounding flow field.UDF definition of water entry is compiled by C++.By comparing the numerical simulation results with the experimental results in the literature,good consistency is obtained,which verifies the rationality and confidence of the numerical model in this paper.The high-speed vertical inflow process of projectile was simulated and the development law of cavitation and the dynamic characteristics of flow field during the inflow process were analyzed.The effects of dynamic parameters and structural parameters of the projectile on the water entry cavitation,underwater velocity,surface pressure and underwater navigation resistance are obtained.On the basis of studying the vertical inflow of the projectile,the cavitation characteristics and the dynamic characteristics of the flow field produced by the oblique inflow of the projectile are analyzed.The influence of water entry angle,water entry velocity and the density of projectile on the development of bubble contour and the distribution of water vapor and gas in the oblique water entry are obtained.