Study on the surf-riding and broaching of trimaran in oblique stern waves

The trimaran is a high-performance ship of excellent seakeeping performance and stability, which makes it less vulnerable to capsizing. In recent years, strong survivability has increased the applicability of trimaran in unmanned ships. However, compared with the stability and seakeeping, side hulls and the larger width make the trimaran's maneuverability not as good as the traditional monohull. The unified study on trimaran's course keeping and broaching in waves is still limited. In this paper, the navigation of trimaran in oblique stern waves is simulated, and the force and moment by the water-jet impetus and nozzle reflection are simplified. The hybrid method coupling FNPT and CFD is applied to simulate the process of surf-riding and broaching. The characteristics of the surf-riding and broaching of the autopilot trimaran in oblique stern waves are analyzed by changing the working condition of initial forward speed, wave parameters, and initial wave heading