Simulation Study On Added Resistance And Motions Of Small Waterplane Catamaran In Waves

With the increasing appeal of the international community for environmental protection,the research on the construction of ecological friendly ships has become one of the hottest topics in the shipping industry.The Small Waterplane Area Twin-hull Ship has attracted wide attention in shipbuilding industry for its excellent seagoing and maneuverability.So it is of great importance to design the SWATH ship form which is energy-saving,green and effective At present,there are few studies on the added resistance of SWATH ship,and most of the studies on the motion responses of SWATH ships are based on the premise of a single degree of freedom without considering the coupling effect between the motions.There is still a lack of research on motions with multiple degrees of freedom.Therefore,the research of added resistance characteristics and motion simulation of SWATH has great significance In this paper,a SWATH is taken as the research object.The main work contents includes:(1)The still water resistance of SWATH is numerically researched based on the CFD software STAR CCM+.The uncertainty analysis of the influence of mesh density on the calculation results of the still water resistance is analyzed.Then the effect of SWATH strut spacing,strut inclination,double struts on the single side and wave-piercing single strut on the still water resistance of SWATH is explored.(2)The effect of the strut forms on the SWATH added resistance and motion response is studied.Three-dimensional numerical wave pool is simulated.Based on the study of the still water resistance,the effect of the strut forms on the added resistance of SWATH in the heading sea is discussed,and the effect of the strut forms on the SWATH motion responses(pitch,heave)is analyzed using the DFBI method at the same time.(3)Numerical prediction of added resistance and motion responses of SWATH in oblique waves.The optimum form of SWATH of added resistance in the heading sea and the initial SWATH are selected to computed the added resistance and motion responses by considering multiple wave directions in a circular oblique wave numerical pool.The rapidity and seakeeping performance of the SWATH in oblique seas considering three degrees of freedom(roll,pitch and heave)are discussed.The research content of this paper is helpful to understand the effect of SWATH’s added resistance and sea keeping performance.The results of the study will provide references for the CFD numerical calculation of SWATH,the design and optimization of SWATH ship form.