Prediction of Hydrodynamic Performances of Ducted Controllable Pitch Propellers

A numerical method is developed to predict the steady performance of ducted controllable pitch propllers.A vortex lattice method is used for the propeller and a surface panel method is applied for the duct.The hydrodynamic interaction between the propeller and the duct is solved by an iterative method.A modified trailing vortex wake model of propeller is introduced to describe the distortion and separation of the trailing vortex sheet.By using the present method,the effect factors on the prediction of performance are investigated systematically,and in the meantime boss effect is considered.Numerical calculations are carried out for JD simplified ducted propeller series and JD-CPP series with JD duct.The numerical results are compared with experimental data and good agreement is obtained.