Research On Fairing Of Hull Curves And Surfaces Based On Local Energy Minima

During the process of ship design,the smooth degree of ship hull possesses great influence on ship hydrodynamic but also on ship construction and cost control.As a result,that how to improve ship curves and surface smooth degree has been the research hot spot in ship field.This paper has conducted an in-depth research on the principles and methods of curves and surface smooth degree.Based on this research,a mathematical model of smoothness of curves and surfaces has been made.Furthermore,a set of curves and surfaces fairing system is also formulated through programming.The system is based on the curvature of the rod curvature of curves and surfaces,as well as energy to determine the size of smoothness.Then,the hull surface points along the hull surface can be modified in order to achieve smoothness of curves and surfaces of the hull fairing.This paper analyzes the theory of NURBS and makes ascending order towards lines and curves and free-up curves which has already achieved the fit of hull lines curves and surfaces.On this basis,in-depth analysis of the smoothness of curves and has been held.The curve and surface fairing model has been built based on local energy minim.The author also compiles the calculation method and designs the hull curve and surface fairing system.In the sub-system of straight-line light,the automatic and manual smoothing functions are established.For smoothing problem of manual type,length and density level of the curvature bar is judged and manual-type fairing is made.For the automatic fairing problem,the author establishes local energy minima curve fairing mathematical model based on existing energy law and Kejlander law,as well as hull curves.Such model is applied to curve software and proves the excellence of this method by comparing the overall energy method and the proposed method.As to hull surface for light systems,based on a mathematical model of the curve smoothing,we will transform surface fairing problem into two directions.At the same time,we also establish a mathematical model of surface fairing curve and demonstrate that the mathematical model has a good smooth surface effect through practical evidence.Finally,this paper makes a brief introduction to the advantages and disadvantages of Matlab and VC hybrid programming language.A hybrid programming model for data conversion is built.It also makes an overall design of the system,describes the function of each module of the application system.And hull fitting curves and surfaces through VC + +and OpenGL in the user window is fitted and the successful smoothness is also made.