Investigation of seakeeping analysis methods of trimaran displacement ships

Sea environmental conditions including wave and wind, influence the ship performance parameters like speed, safety, dynamics loads acting on ship srtucture and etc. ship motion prediction for proper vessel operational planning and utilization is considered by ship designers. In this article, motions of a trimaran ship in design speed are predicted by maxsurf software, 3D panel method. Besides, motions of trimaran ship are simulated by computational fluid dynamic (CFD) using Flow-3D software. In order to modeling the irregular waves in sea state 5, Bert schnider spectrum is used. 3D panel method calculations are implemented in frequency domain and CFD software calculations are implemented in time domain; then results are transformed from time domain to frequency domain by Fourier transform. for validation of calculations we used results of a reference tested model. according to achieved results the panel method is quiet well for investigation of trimaran motions and we can use it for complex hull forms and multihulls and in various maritime cases like wave encounter angle, ship speed and wave conditions