Application Of Hydrostatics Calculation Based On Space Point Cloud In Hull Form Optimization

At present,ship hull form optimization based on simulation is widely researched and applied.In this technology,a kind of ship modification methods is used to modify the ship hull form lines,a CFD-solver is used to predict the hydronamic performance of the ship,hydrostatics parameters are used to constraint the ship modification,and a kind of algorithms is used to optimizate the hydrodynamics performance of the ship.So that a optimized ship hull form with contraints could be gotten.In order to meet the needs of ship hull form optimization,the ship hydrostatics calculation method used in hull form optimization needs to satisify the requirements of the fast calculation speed,high accuracy,easly integration,automatic calculation,coordination with the ship hull surface transformation method and so on.At present,the existing methods of ship hydrostatic calculation have some problems,for example,the result of hydrostatics calculate method used points directly would have a low precision if the number of points it used is few;the method using spline curves to fit points on ship surface has a higher requirement to the location of the points and it would create more points in calculation which increased the calculating time and amout;the method based on commercial softwares secondary development would increase the difficulty and cost of the platform integration,which limits the use of the platform and has a bad effect on the later promotion of the platform.In order to ensure that the ship hydrostatic calculation method can meet the requirements of ship hull form optimization,this paper proposes a kind of ship hydrostatic calculation method that used points cloud on the ship surface to ensure the new ship generated in ship optimization can meet the constraints.Specific research is as follow:1)Elaborating the method of the discreting of point cloud,several typical ships are discreted as examples and the accuracy of these point clouds are proved.The feasibility and reliability of the discreting method are validated.2)The theory of the ship hydrostatics calculation method based on point cloud is introduced,and the shape functions used in calculation are researched to improve the accuracy of the method.The properties and the application scopes of the several ship hydrostatics calculation methods are also studied3)The ship hydrostatics calculation method is used in different ship hull form optimization processes,such as a monohull,a trimaran and a submarine,to test and verify the applicability and the accuracy of the method.Through the above research,this paper proposes a hydrostatics calculation based on point cloud which has high accuracy and good applicability,can calculate the hydrostatics of large of ships automatically and meet the need of the optimization of the ship engineering.