Research On Influence Of Splash Bars And Interceptors On Hydrodynamic Performance Of Planing Craft

At the beginning of the 21 st century,with the development of society and the demand for resources,people’s efforts to develop marine resources are increasing,which inevitably encounter bad sea conditions,so high-performance ships are more and more popular.As a high-performance ship,planing boat is characterized by flat bottom,only part of the hull contacts the water surface at high speed,and the bottom of the hull compresses water forward to form hydrodynamic lift to support the weight of the hull.Because of its good rapidity,planing boat is a common platform for surface unmanned boats,which has a wide range of military and civil applications,but its seakeeping performance in waves is poor.In order to improve the hydrodynamic performance of planing craft in high sea conditions,appendages,such as splash bars and baffles,can be applied to the hull to improve the flow field around the hull through reasonable design and combination.In this paper,star-ccm + software based on computational fluid dynamics is used to study the influence of splash bars and baffles on the hydrodynamic performance of planing craft.Firstly,a series of numerical simulation methods of planing boat motion are introduced.A small planing boat is selected as the research object.The appropriate control equations,discretization method,free surface treatment,mesh size,boundary conditions and turbulence mode are selected by using the computational fluid dynamics software star-ccm +.At the same time,combined with the motion characteristics of planing boat,the calculation method of this paper is preliminarily established.Then,the multi speed motion of the planing boat model in regular waves is simulated.Referring to the comparison between the time-domain solution of the ship’s response to waves based on the simplified 2D + T theory and the experimental data in the relevant literature,the overlapping grid method can reliably simulate the motion of the planing boat in waves.Finally,the effects of splash bars with different lengths,depths and installation positions,baffles with different depths and widths and the combination of two appendages on the resistance and seakeeping performance of planing craft at four speeds are calculated and analyzed.