Objectives  This study analyzes the hydrodynamic loads of a typical cross-section structure of a high-speed M-boat during water entry.

  Methods  Based on the smooth particle dynamics (SPH) liquid-gas two-phase flow algorithm, simulations of both flat plate and arced structure water entry are carried out to verify the accuracy of the algorithm. On this basis, a typical cross-section structure water entry of the high-speed M-boat is simulated, and the results are compared with the experimental data available in literatures.

  Results  The simulation results of both flat plate and arced structure water entry are in good agreement with the experimental data. A second slamming phenomenon occurs during water entry of the high-speed M-boat, that is, a larger dead-rise angle of main hull would make the first slamming load smaller, but if the dead-rise angle is too large, the load on the structure during the second slamming will increase significantly.

  Conclusions  The SPH two-phase flow algorithm can accurately simulate the water entry of a high-speed M-boat. It is suggested that the dead-rise angle of a high-speed M-boat should be designed appropriately.