Cycloidal propellers can vary thrust arbitrarily within 360° by adjusting the eccentric point. The widening application of cycloidal propellers for ships can well solve the maneuvering performance. In this paper, the CFD method based on STAR-CCM+ software was used to calculate the hydrodynamic performance of cycloidal propellers. The overlapping grid method was used to simulate kinematics of the propeller. On this basis, taking the eccentric azimuth of 0°, 10°, 20° and 30° as examples, the impact of the eccentric point on the hydrodynamic performance was studied.
With the increasing demand for ship maneuverability, the studies on cycloidal propellers has received further attention.It is utilize for ships that require high maneuverability, including tugs, luxury yachts, ferries, minehunters (Jürgens et al,2007), etc.As early as the 1920 s, Kirsten-Boeing Propeller, the world ‘s first cycloidal propeller, came out (Sachse,1926). With the widening application of cycloidal propellers, relevant theoretical and experimental studies have also been carried out. Taniguchi (1962) proposed a quasi-steady flow theory to solve the induced velocity on the blade. However, the extensive experimental data (Nakonechny, 1961; Dickerson and Dobay, 1970.) show that Taniguchi's method is inaccurate under a large eccentricity. Zhu (1982) considered the influence of blade trajectory curve and blade rotation on induced velocity, which greatly improved the accuracy of calculation results under a large eccentricity.Bose(Bose and Lai,1989) carried out a large number of experiments to measure the thrust and torque at different advance coefficient.
The CFD method has been widely used in recent years,which is the abbreviation of computational fluid dynamics. It approximately represents the integral and differential terms in the Navier-Stokes equations as discrete algebraic forms, and then solves those discrete algebraic equations by computer to obtain the numerical solution at discrete time and space points. If one wants to study the flow structure disturbed by cycloidal propellers, the CFD simulation is preferred(Li et al,2021). Jürgens et al(2009) investigated cavitation behaviour of Voith Schneider propellers with the high lift profiles under the condition bollard pull condition.Hu J et al(2020)studied the hydrodynamic performance of cycloidal propellers under different working conditions.Bakhtiari et al(2020)predicted the open water hydrodynamic performance of a VSP for different propeller pitches and blade thicknesses. Sun Z et al(2021)studied the influence of flap on the hydrodynamic performance of cycloidal propellers. The results showed that when the flap rotated according to the anti-virtual camber law, it was beneficial to offset the lateral thrust, and when it rotated according to the sine law, it was helpful to improve the efficiency of the propeller at high speed coefficient.
