Regression Modeling of surface piercing propeller performance based on trailing edge geometrical parameters using CFD method

Abstract

The geometry of the surface piercing propeller has been designed experimentally, and no comprehensive studies are available to identify the influential parameters to attain systematic formulations. This study aims to evaluate the feasibility of presenting systematic relations between the geometric parameters of the blade section and its hydrodynamic characteristics through combined methods of computational fluid dynamics and design of experiments. In this regard, the propeller's parametric geometry is designed based on the cubic B-spline method. Hence, a series of SPPs with different trailing edges is generated according to the coordinates of control points based on the D-optimal response surface methodology. The propeller performance was investigated using URANS numerical simulation method in accordance with the VOF method and sliding mesh technique.ANOVA analyses of the quadratic regression models of hydrodynamic coefficients in terms of edge height (Y) and protrusion length (X), based on a 95% confidence interval, indicate these models have prediction adequacy of more than 90%. The main factor (X) is the only significant factor in both models. Increasing it will reduce the hydrodynamic coefficients. As a result, trailing edge variations can significantly affect torque and thrust coefficients by up to 40%, while efficiency changes are about 7%.