拓扑优化技术在抑制流体晃荡中的数值模拟研究

流体晃荡问题广泛存在于船舶与海洋工程领域，任何部分载液的储罐运载装备在运动过程中均存在晃荡问题.当外界激励频率接近液舱内流体自由液面的固有频率时，很容易产生剧烈的晃荡，产生极大的冲击力，进而引起结构损害.因此，研究有效的减晃方案，以抑制流体晃荡带来的冲击具有重要意义.该文研究了基于自主研制的数值程序模拟长方体液舱内的流体晃荡问题.该数值程序采用有限差分法求解均质不可压缩的三维非定常Navier-Stokes方程，利用VOF/PLIC方法对自由液面进行捕捉，并结合基于最优控制理论的拓扑优化程序对液舱内隔板进行优化设计.数值计算了液舱内固定形状的双隔板以及拓扑优化的双隔板的晃荡问题，分析了增设双隔板后流场的运动学和动力学特性.结果表明，拓扑优化后的双隔板抑制流体晃荡的效果更好，为船舶与海洋工程领域和航空航天领域中的晃荡问题提供了一种新的研究思路.

Numerical Simulation of Topology Optimization Technique for Tank Sloshing Suppression

The problem of liquid sloshing exists widely in the fields of ships and ocean engineering. When the external excitation frequency is close to the natural frequency of the fluid in the tank, it is easy to produce violent sloshing and great forces, thus causing structural damage. Therefore, it is of great significance to study the effective method to control the impact of liquid sloshing. A numerical program was developed to study the sloshing problem in rectangular tanks with the topology optimization technique. In the numerical program the finite difference method was used to solve the homogeneous and incompressible 3D unsteady Navier-Stokes equations. The free surface was captured with the VOF/PLIC method and a topology optimization program based on the optimal control theory was applied to optimize the shape of baffles in the tank. The sloshing problem with given-shape double baffles and topologically optimized double baffles in the tank was calculated respectively and the kinematics and dynamic characteristics of the flow field with baffles were analyzed. The results show that, the topology optimization of the baffle shape brings better effects of sloshing suppression, which provides a new research idea for the sloshing problems in the fields of ships, ocean engineering and aerospace.