航行体跨音速斜射入水流动特性数值模拟研究

Numerical Investigation of Hydrodynamic Characteristics of Vehicle in Transonic Oblique Water Entry

目的研究航行体跨音速斜射入水的流动特性,获得不同入水攻角下航行体跨音速可压缩入水特性。方法建立跨音速航行体的几何模型,采用VOF(Volume of Fluid)均相流模型、SST k-ω湍流模型和Zwart空化模型进行数值模拟,并进行液相可压缩修正,对比不同入水攻角下的入水可压缩流动特性,分析绕航行体空泡的发展规律与航行体姿态和受力特性。结果计算了不同入水攻角下航行体跨音速斜射入水可压缩流动特性,入水攻角对空泡直径几乎没有影响,但不同攻角下,空泡形态随时间的发展明显不同,并且随着正负攻角的增加,空泡的完整性遭到破坏。航行体弹道轨迹偏移量,随正攻角的增大而增加,随负攻角的增大先增加、后减小。航行体水平和垂直受力随正攻角的增大而减小,随负攻角的增大先增大、后减小。结论在不同入水攻角下,航行体跨音速入水流动结构的发展具有相似性,但是随着攻角的变化,入水空泡结构、弹道偏移、受力特性都发生明显变化。

This paper aims to study the transonic oblique water entry characteristics of the vehicle,and to obtain the transonic compressible water entry characteristics of the vehicle at different angles of attack.The geometric model of transonic vehicle is established with the numerical simulation adopting VOF(volume of fluid)homogeneous flow model,SST k-ωturbulence model,and Zwart cavity model.And then the correction of liquid compressibility is carried out.The compressible characteristics of water entry under different angles of attack are compared,and the development of cavity around the vehicle,and the attitude and force characteristics on the vehicle are analyzed.The compressible characteristics of transonic oblique water entry of vehicle at different angles of attack are determined.The angles of attack have little effects on the diameter of cavity,but the shape of cavity changing with time at different angles of attack are significantly different,and the integrity of cavity is destroyed with the increase of positive and negative angles of attack.The trajectory offset of the vehicle increases with the increase of the positive angle of attack.Moreover,the trajectory offset increases first with the increase of the negative angle of attack,and then decreases.The horizontal and vertical forces on the vehicle decrease with the increase of the positive angle of attack.Besides,the forces increase first and then decrease with the increase of the negative angle of attack.Under the different water entry angles of attack,the development of transonic water entry structure of vehicle is similar.But with the change of angle of attack,the cavity structure,trajectory offset,and force characteristics change significantly.