跨介质航行器高速斜入水跳弹现象研究

目的 揭示跨介质航行器高速入水跳弹行为的机理，提高航行器的突防能力。方法 基于STAR-CCM+流体仿真软件，采用VOF多相流模型以及Schnerr-Sauer空化模型，计算航行器跳弹过程的空化流场，并运用重叠网格技术，耦合六自由度弹道方程，求解航行器的运动特性。利用所建立的计算模型，研究航行器在不同入水速度和角度下的空泡演化、水动力和弹道特性，揭示航行器产生跳弹现象的原因和规律。结果 航行器在小角度高速入水时，水下运动轨迹会发生很大的变化，经历了入水、浸水、出水3个阶段。结论 产生跳弹现象的主要原因是航行器在入水后，头部上下缘以及弹尾两侧受力不均，形成了向上的偏转力矩，使得航行器的俯仰角发生了较大的改变，并且随着航行器的入水速度加快，入水角度减小，跳弹现象越容易产生。

Ricochet Phenomenon of Tans-media Vehicle at High-speed Oblique Water-entry

In order to reveal the ricochet mechanism of the trans-media vehicle entering water at high speed, and improve the penetration ability of the trans-media vehicle. Based on STAR-CCM+ fluid simulation software, the cavitation flow fields were calculated during the ricochet process of the vehicle by use of the VOF multiphase flow model and Schnerr-Sauer cavitation model. The motions of the vehicle were calculated using the overset mesh technique to couple the six-degree-of-freedom algorithm. Using the established computational model, the cavitation evolution, hydrodynamic and ballistic characteristics of the vehicle under different water entry speeds and angles were studied, and the causes and laws of the ricochet phenomenon of the vehicle were revealed. The results showed that when the vehicle enters the water at a small angle and high speed, the underwater motion trajectory will change greatly. It has experienced three stages:entering the water, soaking in the water and leaving the water. The main reason for ricochet was that after entering the water, the forces on the upper and lower edges of the head and on sides of the tail of the vehicle are uneven, forming an upward deflection moment, which greatly changes the pitch angle of the vehicle, and as the speed of the vehicle entering the water is faster, the smaller the angle of entering the water, the easier it is to produce ricochet.