Effect of floating boxes on the hydrodynamic performance of an amphibious transport vehicle

In this study, computational fluid dynamics is used to examine the effect of the floating box length LFB on the hydrodynamic performance of amphibious transport vehicles (ATVs). The results indicate that the floating box length considerably impacts the ATV resistance, pitch, and heave. Within the high-speed range (Fr = 0.66–1.04), the optimal configuration (LFB = 7.5 m) results in the lowest resistance, which is approximately 12.11% lower than the minimal length case (LFB = 7.5 m). At fixed speed, the resistance decreases with increasing LFB. For Fr < 0.66, lower LFB values (4.5–6.5 m) yield reduced heave, indicating a linear negative correlation. However, for Fr values ranging from 0.66 to 1.04, higher LFB values (6.5–7.5 m) help maintain a stable buoyancy state, whereas lower LFB values cause 18.2% greater heave fluctuations. The trim angle peaks at intermediate LFB values (5.5–6.5 m) and decreases at both extremes (4.5 and 7.5 m). Optimal navigation stability occurs at specific LFB values (4.5 and 7.5 m), with LFB = 7.5 m maximizing the overall performance for this ATV type.