Abstract: The load characteristics of a vehicle entering into water at high-speed under wave conditions are key factors influencing the overall plan and structural design of vehicle. VOF multiphase flow model and dynamic grid technology are used to establish a numerical simulation method of high-speed water-entry, and the accuracy and applicability of the simulation method are verified by experiments. The influences of water entry angle and wave parameters on the axial impact load during high-speed water-entry events are numerically studied. The results show that the peak axial impact force coefficient increases with an increase in the water-entry angle, and has a linear relationship with the tangent function of water-entry angle. The different wave phases change the actual angle between the vehicle and the water surface at the water-entry moment. When entering into the water at 90° or 270° wave phase angle, there is little difference between the axial impact load and that in static water environment; when entering into the water at 0° wave phase angle, the peak value of axial impact load is the largest, and it is basically the same as the axial impact load at the corresponding water-entry angle on static water surface; when entering into the water at 180°wave phase angle, the axial impact load is the smallest, but it is prone to ‘jump’ and cause failure in the water-entry. The actual water-entry angle should be the coupling value of the wave inclination and the vehicle attitude at the entry point under wave conditions, the peak axial impact force coefficient can be obtained by interpolating the peak coefficient curve of impact load in static water environment.

Key words: vehicle, high-speedwater-entry, wave, water-entryangle, impactload