Research On Hydrodynamic Performance And Self-propelled Performance Prediction Of Pod Propeller In Ice Area

In recent years,as the international community's attention to the exploration of Arctic waterways and polar resources has gradually increased,research on ice vessels has received more attention.The multiple working conditions of ice vessels have made the working environment of the thruster device more competitive.Conventional ships are very different.When sailing in the ice area,the resistance is large.At the same time,due to the possibility of the propeller being surrounded and blocked by external ice,it is necessary for the propeller to send enough thrust at a lower speed to support the ship's ice-breaking navigation.Torque propulsion system.The propulsion motor of the pod propeller has high torque characteristics,which can produce maximum torque even at low propeller speed,and the pod propeller has extremely high overload resistance and ice breaking ability,so it is widely used in polar ships.Therefore,it is necessary to study the hydrodynamic performance of the pod propeller in the ice area.At the same time,as the ship's voyage,the stern accompanying flow will affect the flow field near the propeller of the pod propeller,resulting in a complex accompanying field in front of the propeller,so studying the effect of ship accompanying flow on the pod propeller is a forecast The self-propelled performance of ships in ice areas is very important.In this paper,the CFD calculation method is mainly used to study the hydrodynamic performance of the target pod propeller under open water conditions,ice blockage conditions and stern flow conditions.The HEXPRESS grid module and FINE calculation module based on FINE/Marine fluid calculation software are used to carry out numerical simulation and prediction of the real-scale and reduced-scale model of the pod thruster,and use the sliding mesh method to deal with the propeller relative to the crane.The problem of the rotation of the cabin and the interaction of information between the slip plane,the research and analysis of the hydrodynamic performance of the pod propeller under different conditions,the specific research content is as follows:(1)Numerical method verification of pod thruster.Select the pod propeller model in a certain project in the reference literature,obtain the simulation data by using the CFD numerical calculation method,and compare it with the experimental data provided in the project to verify the feasibility of the numerical calculation method.The results show thatthe crane The numerical calculation results of the cabin propeller model are in good agreement with the test results,and the errors of the instantaneous average values of the thrust and torque coefficients of the two are less than 5% and 2.31%,respectively..(2)Research on the hydrodynamic performance of the pod propeller in open water.The study calculated the axial force of the target pod thruster in the range of 0?0.9.And the interaction between the propeller and the pod under the range of common advance speed coefficient(J=0.3?0.7)of the pod propeller is discussed.(3)Research on the hydrodynamic performance of the pod propeller under ice blocking conditions.The axial force of the pod propeller under two typical advance speeds under three different ice density and five different ice paddle spacings was studied,and the hydrodynamic force of the pod propeller under multiple working conditions was obtained.Performance,and the instantaneous data of the pod propeller and ice block obtained by monitoring under unsteady conditions are converted into frequency domain signals through Fourier transform,and its change law is summarized.(4)Research on the hydrodynamic performance of the pod propeller under the wake of the ship.The influence of wake wake on the hydrodynamic performance of the pod propeller is studied through a scaled model.The effects of wake and nominal wake in the self-propelled state coupled with the propeller are calculated and studied respectively.