无人水下航行器海底停驻流体动力特性分析

为了研究无人水下航行器(UUV)在海底停驻时水流侧向流过时的受力特性以及垂推对其的影响，采用计算流体力学（CFD）方法，用ANSYS ICEM对海底定点停驻UUV有、无垂推两种模型在距离海底不同距离以及海底不同倾角时的状况进行结构化网格划分，并利用CFX对其在不同水流速度下的流场进行了数值模拟，得到了其侧向力、升力随水流速度、距海底距离及海底倾角的变化曲线，并对计算结果进行了分析。最后，根据有、无垂推两种模型的受力仿真结果，分析了垂推对海底定点停驻UUV流体动力特性的影响。分析结果表明：侧向力受近壁面影响较小，而升力受其影响很大；侧向力和升力均随着水流速度的增大而迅速增大；侧向力随着海底倾角绝对值的增大总体呈减小的趋势，其升力则随着倾角的增大迅速增大；UUV有垂推时所受侧向力比无垂推时要大5%~15%，而升力则大数倍。

Hydrodynamic Characteristics Analysis of UUV Parking on Seabed

In order to obtain the hydrodynamic characteristics of the unmanned underwater vehicle (UUV) parking on the seabed and the effect of vertical thrusters on it, two kinds of UUV, with and without vertical thrusters respectively, were modeled and meshed using the software ANSYS ICEM in different distances from the seabed and different seabed oblique angles, and the flow fields around these UUVs were simulated by using CFX. From the simulation, the lateral forces and lifts of these two UUVs under different conditions were obtained and the curves of lateral forces and lifts changing with distance from the seabed, oblique angle and water velocity were analyzed. Finally, the effect of vertical thrusters on the hydrodynamic characteristics was analyzed according to the simulation results. The results reveal that the effect of the distance from the seabed on the lateral forces is minor while that on lifts is great; both of the lateral forces and lifts increase rapidly with the increase of water velocity; the lateral forces decease slowly with the increase of the absolute value of seabed oblique angle while lifts increase rapidly; the lateral forces of UUV with vertical thrusters are 5%~15% larger than that if UUV without vertical thrusters while lifts are several times larger.