Hydrodynamic Study On Hydrodynamics Of Hybrid Monohull

The hybrid monohull is a new ship type which has a built-up stabilizing appendage on the bottom of the stem, and the built-up appendage consists of Semi-submerged Body and a pair of passive fin. In this paper, a-4000ton hybrid monohull as the research object, the following content was discussed on the base of theory calculation and model test.The hydrodynamics and wave loads calculation method which contains the lift force and viscosity of built-up appendage were established basing on potential flow theory. The hydrodynamic coefficients of the typical hybrid monohull were computed using FLUENT software. Based on three-dimensional linear potential flow theory, the wave loads of hybrid monohull was computed in the frequency domain. From the result of the towing tank test and the large scale model test in real sea, the nonlinear hydrodynamics of ship and the characteristics of the wave loads were analysed.The results of theory calculation and model test show that the resistance of hybrid momohull is close to that of ordinary ship, hybrid monohull is able to reduce pitching , heaving motions and especially bow acceleration considerably. The result of wave loads shows that wave-induced section loads of hybrid monohull is close to that of ordinary ship whenλ/L<1, but there is a certain difference whenλ/L>1;The pulsating press responses of hybrid monohull is smaller on the stem. By comparing with the result of towing tank test and large scale model test in real sea, the later has more obvious six-freedom motions and nonlinear phenomena. It will be important to research the nonlinear motion in the higher wave.