Research on launching, water exiting, and river crossing of an amphibious vehicle

The main focus of this paper is the amphibious vehicle's water-land trans-media capability, specifically its ability to efficiently carry out transportation tasks in rivers and nearshore areas. This capability relies on three key processes: launching, water exiting, and river crossing. To study these processes, hydrodynamic numerical simulations are conducted. The Reynolds-averaged Navier–Stokes) equation, simplified terra mechanics model, and body force method are adopted to analyze the trans-media and self-propulsion processes. Results indicate that the optimal launching speed is around 15 km/h, with a stable trim and heave, and a launching angle range of 15°–25° for insubmersibility and stability. Furthermore, high-speed water exiting enhances insubmersibility and imposes lower requirements on road adhesion conditions, outperforming low-speed water exiting. In terms of self-propelled river crossing, higher heading angles and faster river currents improve hydrodynamic lift, with the fastest crossing achieved at a 10° heading angle for a current speed of 2.5 m/s and a forward speed of 30 km/h.