Research On Calculation Methods Of Ship Selfpropulsion Prediction Based On RANS-BEM Coupling Method

Propellers are the most common propulsion for current applications.The interaction between ship and propeller will interfere the performance of each other.Reach on ship-propeller interaction is significant to optimization of ship profile and performance.Ship-propeller interaction CFD methods are mainly consist of integral modeling method and body force methods.The purpose of this paper is to explore the iterative body force method based on the RANS-BEM coupling,and to explore its application prospects by comparing with the integral modeling and the prescribed body force method.First of all,compared with the experimental value,the calculation of the resistance of the naked hull and the calculation method of the propeller surface area method are verified,in order to determine the reliability of solution of the RANS equation for the hull section and the propeller part of the BEM code.The integral modeling method,prescribed body force method and RANS-BEM coupled iterative body force method were used to calculate the propulsive performance of KCS ship model and the self-propulsion point on full scale.Self propulsion factors from results of these method were also discussed in this paper.Among them,the RANS-BEM iterative body force method optimizes the iterative mechanism and adopts a new method without nested iteration,reducing the number of steps required.The calculation results showed good agreement with the model test results.The integral modeling method is representation of the flow field detail information and the analysis of the wake field on propeller plane.The body force methods have unique advantages on the computational efficiency of performance evaluation,both ship and propeller.The calculation results show that the iterative body force method is feasible in self-propelled simulation.Since there is no problem of scale effect in theoretically potential flow propeller calculation,a large number of complex grids can be reduced during the calculation.The possibility of simulating the possibility of real ship self-propulsion by this method can be expected.