Research On Hydrodynamic Performance Of Azimuthing Propulsor Based On CFD

The azimuthing propulsor is a new type of marine propulsion device.Compared with the traditional propulsion mode,the azimuthing propulsor has a great advantage in terms of hydrodynamic performance,handling performance and maintenance management.At present,the application of azimuthing propulsor in various types of ships is very extensive.This paper uses computational fluid dynamics method,numerical calculation method.to study the influence of different elements on the hydrodynamic performance of azimuthing propulsors,so that various parameters can be selected during design.And point the way to improve the performance of the azimuthing propulsor.It has certain reference significance for the design and optimization of the azimuthing propulsor.In order to study the difference in hydrodynamic performance betvveen the pull and push type azimuthing propulsor.this paper firstly compares and analyzes the hydrodynamic performance of both the pull and push type azimuthing propulsors.In order to study the influence of pitch angle variation on the hydrodynamic performance of the full-turn propeller,the hydrodynamic performance of the variable-gap full-turn propeller is studied.The specific research contents are as follows.First,the modeling method of propeller blades is studied.The two-dimensional shape point coordinates of the propeller blade section are converted into three-dimensional space coordinates by the space coordinate conversion formula,thereby establishing a blade model.The numerical calculation model of two kinds of podded propulsor are established,and the hydrodynamic performance of the two propellers under direct and rotary conditions is calculated separately.Compared with the pool test results.it is proved that the numerical calculation method is used to analyze the pod-type full swing.The feasibility of the hydrodynamic performance of the propeller.Compare the difference in hydrodynamic performance between the two propulsors in direct and revolving conditions.Under the direct flight conditions,the efficiency of the towed propeller is higher than that of the push type.Under the rotating condition,the hydrodynamic performance of the two propellers shows different rules.The slip grid method is used to compare the unsteady hydrodynamic performance of the two propellers.As for the oscillation amplitude of the thrust of the pod propeller and the propulsor are smaller than the push type,and the propeller torque is larger than the pusher.Study the hydrodynamic performance of a controllable pitch pulling azimuthing propulsor.The three-dimensional model of the eontrollable pitch azimuthing propulsor at different Pitch deflection angles is established.Firstly,the influence of the caudal fin on the hydrodynamic performance of the azimuthing propulsor is analyzed.It is found that the caudal fin can slightly improve the efficiency of the propeller and increase the lateral stability of the propeller.To study the influence of the pitch angle variation on the hydrodynamic performance of the controllable pitch azimuthing propulsor.As the pitch deflection angle increases,the thrust coefficient and torque coefficient of the pitch paddle also increase,and the efficiency first increases and then decreases.There is an optimum pitch deflection angle at different speed coefficients.The unsteady force of the controllable pitch azimuthing propulsor increases with the increase of the pitch deflection angle,and the unsteady force of the low pitch ratio has a large amplitude.