Research on Seakeeping Performance of Amphibious Rescue Vehicle Based on CFD

Amphibious vehicles are widely used in civil and military scenarios due to their excellent driving performance in water and on land, unique application scenarios and rapid response capabilities. In the field of civil rescue, the hydrodynamic performance of amphibious vehicles directly affects the speed and accuracy of rescue, and is also related to the life safety of rescuers. In the existing research on the hydrodynamic performance of amphibious vehicles, seakeeping performance has always been the focus of research by researchers and amphibious vehicle manufacturers, but most of the existing research focuses on the navigation performance of amphibious vehicles in still water. In actual application scenarios, amphibious vehicles often face complex water conditions when performing emergency rescue tasks, so it is very important to study the navigation performance of amphibious vehicles in waves. Aiming at the goal of studying the navigation performance of amphibious vehicles in waves, this paper first establishes a simplified model of amphibious vehicle. Then, based on computational fluid dynamics numerical simulation, the seakeeping performance of amphibious vehicles at different speeds and wavelengths were studied by using overlapping grid and numerical wave generation methods. Then obtained the data of resistance, vertical acceleration of the center of gravity, pitch and heave at different speed and wavelength, and the flow field and free surface waveform of the amphibious vehicle were also obtained. The results show that the driving resistance of low-speed amphibious vehicle in water increases with the increase of speed. With the increase of speed, the vertical acceleration RAO of the center of gravity, pitch RAO and heave RAO of the amphibious vehicle will also increase. The ratio of wavelength to vehicle length also has a profound influence on the longitudinal motion of amphibious vehicles. The maximum value of vertical acceleration RAO of the center of gravity appears when λ/L is 3.5, but the pitch RAO and heave RAO increase when value of λ/L increases.