An improved parametric model for marine propeller: iPM4MP

Abstract

This paper proposes an improved parametric model called iPM4MP to construct the CAD model of the marine propeller. iPM4MP is established through the marine structure feature parameters such as Diameter (D), Number of blades (Z), Area Ratio (AR) and Pitch (P). The series of radial feature curves are applied to represent the geometry of propellers. The designer can obtain the geometric definition of the propeller by setting these radial feature curves. Setting the marine structure feature parameters and the feature curves is the initial step of iPM4MP. The uniform Latin Hypercube Sampling (LHS) method is combined with the radial feature curves to obtain the 3D point cloud of the propeller. Finally, the CAD model of the propeller is obtained through Point Cloud to NURBS technique. Numerous numerical experiments to reconstruct the geometric model of the propeller illustrate that the iPM4MP is competitive with the other method. A numerical investigation of inaccuracies in Computational Fluid Dynamics (CFD) simulations caused by CAD models built using the iPM4MP and other methods was performed. Moreover, iPM4MP is applied to two propeller geometry generation works. The results demonstrate that the iPM4MP can build a valid CAD geometric and maintaining the generality of the shape while decreasing the number of free variables. iPM4MP is flexible and versatile. Furthermore, the CFD results show that iPM4MP has certain advantages in outlining the shape of the blade tip.