The Development Of Ship Rudder Design System And Numerical Simulation Of The Hydrodynamic Performance

CATIA secondary development refers to the expansion of existing software functions or the combination of expansion according to special needs to form more professional or new functions,so as to make CATIA functions more convenient and efficient for technicians.In this paper,CAA C + + redevelopment technology is used to develop a rudder design system on CATIA V6 platform,which can realize the functions of two different rudder types.One of the subsystems is for the NACA type cross-section semi suspended rudder.According to the requirements of the design specification,the designer can input the corresponding data through the interactive dialog operation interface according to the space of the stern and the position of the rudder shaft and generate the rudder geometry model with appropriate size by parameterization.Another set of subsystem is for the balance rudder and suspension rudder system of NACA cross section.In order to get the size parameters of the relevant rudder equipment matching the rudder blade,as a reference for the preliminary design,this paper studies the lift performance of rudder after ship and propeller by using the computational fluid dynamics software STAR-CCM+.Taking NACA0015 airfoil profile rudder as the research object,KCS as the ship and KP505 as the propeller,the hydrodynamic coefficients of open water rudder,rudder behind ship,rudder behind propeller,and rudder behind ship and propeller are calculated by the finite volume method and SST k-ω turbulence model.The numerical simulation results show that the lift performance predicted by the empirical formula is too conservative,while the deviation of the lift performance predicted by the empirical formula is smaller under the single action of the ship wake and the single action of the propeller wake.The reason is that the empirical formula simply connects the action of ship and propeller,neglects the favorable effect of ship and propeller wake,seriously underestimates the lift of the rudder behind ship and propeller.,which will lead to the increase of the rudder area and the size of the relevant rudder equipment when designing the rudder,resulting in waste.In the rudder design system of this paper,the lift performance of the rudder is mainly based on the experimental data of the open water rudder.On the basis of the influence coefficients of the ship wake and the propeller wake proposed by the empirical formula,and according to the results of the numerical simulation of the rudder behind ship and propeller.A correction factor of 2-fold is added,which not only ensures the ship’s requirements for the lift performance of the rudder,but also does not cause waste due to underestimation of the lift performance of the rudder.