Flow Mechanism Investigation Of The Supersonic Projectiles Water Entry With Self-interference

The "dense array" system and the fast airborne mine suppression system have been the hotspots of weapon research in recent years.Due to the high initial velocity of the projectiles and the huge number of projectiles,they can eliminate water and underwater threats,and have broad research prospects and great military significance.The "dense array" system involves not only the supersonic water entry of single projectile,but also the series and parallel water entry of projectile.In this paper,the numerical simulation method is used to study the cavitation multiphase flow,force characteristics and ballistic characteristics of single projectile,tandem projectile and parallel projectile in the process of supersonic water entry.The main research contents are as follows:(1)Using CFD software,based on RANS equation,introducing VOF multiphase flow and cavitation model,and combining with dynamic grid technology,embedding liquid compressible equation into user-defined function,the numerical calculation method of supersonic projectile entering water is established,and then the grid number independence is verified.And from two aspects of theoretical analysis and experimental research,the validity of the numerical model established in this paper is verified.(2)The numerical simulation of the supersonic vertical water entry process of a single projectile is carried out,and the influence of the different head shape and initial water entry speed of the projectile on the ballistic characteristics of the water entry process,the development of the water entry cavity shape and the flow field details such as pressure field and velocity field are analyzed.(3)The numerical simulation of the vertical water entry process of the tandem supersonic projectile is carried out,mainly aiming at the different jet caused by the different initial water entry velocity,different initial water entry time interval and different projectile head type parameters.The different influences of the resistance characteristics,pressure distribution and liquid density distribution of the second projectile under the same working condition are analyzed And research.(4)The numerical simulation of the vertical water entry process of parallel supersonic projectile is studied,which mainly aims at the different influence of different initial water entry velocity,different initial water entry position interval and different projectile head shape parameters on the superposition of flow field,and analyzes the ballistic characteristics of the water entry process of supersonic projectile,the development of water entry cavitation shape and the change rule of flow field flow details.