基于耦合欧拉-拉格朗日算法的航行体缓冲头帽冲击性能

航行体在入水过程中会受到强烈的冲击载荷,过高的冲击载荷极易造成结构破坏和内部设备失灵,研究结构高速入水降载技术具有十分重要的意义.设计一种以预制裂纹碳纤维材料作为外罩、泡沫铝作为内部缓冲材料的缓冲头帽.基于有限元方法,采用耦合欧拉-拉格朗日求解器研究缓冲头帽的降载效果,通过对比数值结果与小球入水实验图像验证数值方法的有...

Impact Performance of Cushion Nose Cap of Underwater Vehicle Based on CEL Method

The underwater vehicle will be subjected to strong impact load in the process of water entry，and the excessive impact load can easily cause structural damage and internal equipment failure. The technology of load reduction during high-speed water entry is studied. A cushion nose cap with prefabricated cracked carbon fiber material as outer cover and foamed aluminum as inner cushion material is designed.The numerical simulation is based on the finite element method，and the coupled Euler-Lagrange solver is used to study the load reduction effect of cushion nose cap.The effectiveness of the numerical method is verified by comparing the numerical results with the experimental images of a sphere entering into the water.The impact resistance，damage mode of cushion nose cap and the evolution process of cavitation bubble at different water entry speeds and angles are analyzed. The results show that the cushion nose cap shatters along the prefabricated cracks after hitting the water surface. The foamed aluminum is compressed and absorbs energy.As the cavitation bubble below the free surface expands outward，the broken nose cap spreads around the inner wall of cavitation bubble. The cushion nose cap has a good load-reduction effect on underwater vehicle at different water entry speeds，and water entry angles. Under the worst condition of vertical water entry，the load reduction rate is more than 75%.