CFD Analysis of Hydrodynamic Drag Characteristics in Amphibious Robots with Different Bow Angles

Abstract

To investigate the effect of bow angle on the hydrodynamic resistance characteristics of an amphibious robot during water navigation, CFD simulations were performed using the SST k-ω model. Five bow angles (30.00°, 45.00°, 60.00°, 75.00°, and 90.00°) were analyzed under six navigation speeds to compare their resistance performance in still water. The results indicate that the bow angle significantly influences water resistance, with the optimal angle varying with speed. At medium-low—speeds (≤2 knots(kn)), the 60° bow achieves the minimum resistance, with a maximum drag reduction of 47.20%. At high—speeds (≥ 3 kn), the 45.00° bow yields the lowest total resistance at 3 kn and 6 kn (maximum drag reduction: 16.09%), while the 30.00° bow is optimal at 4 — 5 kn (maximum drag reduction: 35.06%). The 90.00° bow exhibits the highest total resistance across all speeds. This study provides guidance for the optimal bow angle matching different speeds and directions for drag optimization in amphibious robot bow design under various navigation scenarios.