The Research On Enlarging And Motion Prediction Technique Of Hybrid Monohull

With the fast development of modern shipbuilding technology the importance of seakeeping performance has been indubitability.The hybrid monohull with build-up stabilizing appendages is a new type of ship which can efficiently reduce its longitudinal motion,and the effect has been validated from the ships below one kiloton.This paper will report the ships' longitudinal motion performance which are changed from some 3500 tons ship and fixed build-up stabilizing appendages using new strip method to discuss the feasibility of extending this technology to 4 kilotons big ships.This paper reported the longitudinal motion of three types of ship.They are the deep-V ship which is changed by mother ship,the two deep-V monohulls fixing build-up stabilizing appendages I and II.New strip method is used on reporting,and the hydrodynamic coefficients of every sections are calculated separately by source/dipole mixed-distribution method which is based on potential theory and RANS method which counting viscosity effect.RANS method is to calculate the surging forces of every section,and then the hydrodynamic coefficients can be separated from the forces.Put the hydrodynamic coefficients which are calculated by the two methods into the ships' longitudinal motion equations,and then we can get the results of the ships' longitudinal motion.From the results of predicting using the two methods we can see that the result getting by potential theory can't reflet the effect of stabilizing the longitudinal motion,however,the method counting viscosity effect can do it obviously,and it's almost the same as the results getting by model testing.This method can be used for theory predicting of hybrid monohull's longitudinal motion,and it can offer technical reference for the compounding technique.