Numerical Analysis Of Open Water And Self-Propulsion Performance Of Controllable Pitch Propeller

Controllable pitch propeller can fully absorb the host power by adjusting the pitch according to the change of the load,it is suitable to be the propulsion of ships which work under multiple load cases.Studying the open water performance of controllable pitch propeller is useful for understanding its operating characteristics.The lift line method,the lift surface method and the surface element method are the traditional method of analyzing the open-water performance of the propeller.Although these methods can play the role of propeller hydrodynamic prediction,they can not overcome the shortcomings of neglecting the viscosity.With the development of computer hardware and software,computational fluid dynamics(CFD)has become an important tool for the analysis of propeller viscous flow field.In this paper,CFD technology is introduced to complete the following work:Firstly,the three-dimensional model of KAPPEL-KP505 was established.The three-dimensional coordinate of the blade surface was calculated by MATLAB programming based on the geometric relationship of blade profile and the coordinate transformation formula,and the solid model of the propeller was output into Gambit.Secondly,the KP505 propeller was used as the research object,and the open water performance was studied by numerical simulation based on the CFD method,the calculated thrust coefficient,torque coefficient and open water efficiency were compared with the experimental values.The blade pressure profile,the chord pressure distribution and the propeller wake flow were investigated.The CFD numerical model is more validated to study the reliability of propeller in open water performance.The effects of different turbulence models,steady and unsteady calculations on the open-water calculation are also considered,which provide technical guidance for subsequent calculation work.Thirdly,the KP505 is used as the master-type paddle,and the KP505 is controlled by defining the rotating shaft and the set rotation angle.The geometrical states of the blades under different pitch ratios are obtained,and the hydrodynamic performance is calculated and analyzed at different pitch ratios,The variation of CPP hydrodynamic performance with pitch ratio was obtained.Fourthly,taking the KCS ship and the pitching pitch as the object of study,the numerical simulation of the self-propulsion test of the ship fitted with controllable pitch propeller is carried out,and the pitch ratio and the relevant self-propulsion factor are obtained.Based on the results of ship model self-propulsion test,based on the 1978ITTC standard forecasting method to forecast the performance of the ship,to explore the feasibility of using the CFD method to predict the self-propelled performance of the ship fitted with controllable pitch propeller.