Study on the characteristics of Trimaran?s surf-riding in stern waves by a hybrid method

In this paper, a hybrid method coupling potential flow method and viscous flow method is applied to simulate the autopilot trimaran in stern waves. The aim is to study the process of being captured by waves and the surf-riding characteristics of the trimaran. The FNPT-based QALE-FEM is used to simulate the wave tank of the external field, and the viscous flow method is used to simulate the autopilot of the trimaran in the wave tank. The sailing and 6DOF motion of the trimaran in waves of different parameters is simulated. The autopilot of a trimaran in stern waves of different lengths and steepness is simulated to study the characteristics of the trimaran's surfriding in waves. When studying the effect of wave steepness, the wavelength is constant, and various forward speeds of trimaran could change the encounter frequency. However, the trimaran's wave steepness and forward speed are kept constant when the wavelength changes. By the computed results, it is found that the high speed and large wave steepness could significantly increase the vulnerability of trimaran's surf-riding in stern waves, and the wave passing the transom stern and side hulls could accelerate the trimaran to reach the wave celerity.