The trimaran has received increasing attention for its excellent resistance and maneuverability. Based on the in-house ship hydrodynamics CFD solver naoe-FOAM-SJTU, the seakeeping performance of trimaran in regular waves when Fr=0.18 is simulated. Firstly, grid convergence verification is carried out. Then, the seakeeping performance of the trimaran on different wavelengths is carried out by numerical methods, and the calculation results including heave and pitch motion of trimaran are compared with the experimental results. Studies have shown that the amplitudes of heave and pitch motion get larger with the increase of wavelength on the whole. The numerically simulated results agreed very well with the experimental data which the experiment work is in progress and the report is not officially published. Their agreement shows that the naoe-FOAM-SJTU solver can be used to predict the seakeeping performance of the trimaran and provide data support for the design process of the trimaran.
Trimaran has become more and more popular due to its excellent maneuverability and resistance in recent years. It consists of a main hull and two side-hulls, which leads to a larger deck area. With the development of computer technology, Computer Fluid Dynamics (CFD) based on viscous theory has been widely applied in hydrodynamic problems of trimarans. Compared to traditional mono-hull, the hydrodynamic performance of trimaran in waves is more complicated. Besides, accurately predicting the motion response of trimaran in waves is a prerequisite for trimaran's design. However, the nonlinearity between main hull and side-hulls is high so that the potential flow theory is not suitable to study the seakeeping performance of trimaran. Therefore, the computer fluid dynamics (CFD) based on viscous theory is used to study the seakeeping performance of trimaran in this paper.
Unlike navigating in calm water, trimaran navigating in waves will dissipate more energy. This additional energy consumption is called added resistance (Arribas, 2020). Consequently, when studying the seakeeping performance of trimaran, the added resistance in waves will also be considered. Gong, Yan and Ma (2020) apply a hybrid method to study the trimaran's added resistance and seakeeping performance in oblique waves. The results show that the wave steepness and wave incident will affect the trimaran's added resistance and seakeeping performance in waves. Gong, Li and Fu (2021) study the trimaran's seakeeping performance in waves of various headings at various speeds and find that the sailing speed has larger effect on added resistance than motion. Besides, some scholars try to improve trimaran's seakeeping performance by changing the layout of side-hulls (Wang, Ma and Duan, 2018; Nazemian, Ghadimi P, 2021; Wang, Duan, 2021; Ghadimi, Nazemian and Ghadimi, 2019). The results show that the trimaran will gain suitable dynamics and reduce the added resistance by reasonably setting the side-hulls’ arrangement.
