波浪环境下航行器高速入水流固耦合特性分析OA

In real ocean environments,vehicles inevitably experience the effects of waves during trans-medium water entry process.To investigate the fluid-structure interaction(FSI)characteristics of a vehicle during water entry under wave environments,a numerical model for high-speed water entry was established based on numerical wave generation technology and the FSI method.The differences between the FSI method,which accounts for fluid-structure coupling effects,and the traditional CFD method in simulating the high-speed water entry process were compared.Numerical simulations were conducted at a water entry velocity of 150 m/s with varying wave heights and entry locations to investigate cavity evolution and impact load characteristics.The results indicate that when FSI is considered,the vehicle undergoes elastic deformation during high-speed water entry,absorbing part of the impact energy.Consequently,the peak impact acceleration and peak head pressure are reduced by 14.0％and 12.7％,respectively,compared to those obtained with CFD method,while the decay of the water entry velocity becomes slower.As wave height increases,the flow velocity near the free surface increases while the pressure decreases,promoting cavity expansion and delaying cavity closure.However,since the wave propagation speed is much lower than the vehicle's water entry speed,the effect of wave height on the impact loads is relatively small.When the vehicle enters the water at different locations relative to the wave phase,the cavity expansion is enhanced at the wave crest but suppressed at the wave trough.An asymmetric cavity forms when entering on the windward or leeward side of the wave,with surface closure consistently occurring first on the side closer to the wave crest.Furthermore,the vehicle is subjected to an additional radial force,the peak value of which is approximately one-tenth of the peak axial force.