Numerical simulation of the hydrodynamic interference characteristics of three amphibious vehicles in longitudinal formation navigation

This work systematically investigates the hydrodynamic interference characteristics of three amphibious vehicles (AVs) in longitudinal formation. By varying the longitudinal distances x1 between AV #1 and AV #2 and x2 between AV #2 and AV#3, the hydrodynamic characteristics of different vehicles are analyzed, and the mechanism of wave interactions is explored. Computational fluid dynamics based on Reynolds-averaged Navier–Stokes equations and the Shear Stress Transport k–ω turbulence model is employed for numerical simulation of the viscous flow field. After the computational domain is divided using a meshing strategy, three overlapping grids are used to analyze the motion of the three AVs. Results show that when x1 is 0.25 L, and x2 is 0.25 L (L is the length of the AV), the total resistance on the three AVs reaches a minimum value of 1349.4 N, representing a decrease in 22.1% compared with 3R0 (the resistance of a single AV during navigation is denoted as R0), i.e., three times the resistance of a single AV. When x1 is 1.5 L and x2 is 1.5 L, the total resistance on the three AVs reaches a maximum value of 2147.8 N, representing an increase in 24.0% compared with 3R0. The study also reveals the mechanisms by which the free surface, pressure distribution, and velocity profile influence the flow field during longitudinal formation, providing theoretical guidance for improving the navigation efficiency of AVs in this configuration.