Experimental modeling of trimaran to measure its motions in regular waves

Trimaran is a multi-hull ship that consisting of a main slender hull and two smaller outriggers. These outriggers are connected by a transverse cross deck to the main hull. The position and geometry form of the outriggers have a significant effect on the stability, dynamic motions and wave loads on this modern ship. In this paper, the effect of the outriggers geometry on heave and pitch motions of a trimaran ship, considering the inboard and outboard asymmetric geometry hull form are investigated. A model of ship has been tested in a towing tank at different speeds and different frequencies in forward sea. The results showed that due to the proper interaction between the main hull and the outriggers in terms of using the side body with the outboard asymmetric form, the responses are less than those of the inboard asymmetric hull. Also, there are local maximum and minimum points on ship responses in zero speed conditions due to the heave and pitch coupling in their respective frequencies.