Improved Hydrodynamic Analysis of 3-D Hydrofoil and Marine Propeller Using the Potential Panel Method Based on B-Spline Scheme

Chen-Wei Chen,Ming Li

doi:10.3390/sym11020196

Abstract

In this paper, the hydrodynamic performance of lift-body marine propellers and hydrofoils is analyzed using a B-spline potential-based panel method. The potential panel method, based on a combination of two singularity elements, is proposed, and a B-spline curve interpolation method is integrated with the interpolation of the corner points and collocation points to ensure accuracy and continuity of the interpolation points. The B-spline interpolation is used for the distribution of the singularity elements on a complex surface to ensure continuity of the results for the intensity of the singular points and to reduce the possibility of abrupt changes in the surface velocity potential to a certain extent. A conventional cubic spline method is also implemented as a comparison of the proposed method. The surface pressure coefficient and lift the performance of 2-D and 3-D hydrofoils of sweepback and dihedral type with different aspect ratios are analyzed to verify the rationality and feasibility of the present method. The surface pressure distribution and coefficients of thrust and torque are calculated for different marine propellers and compared with the experimental data. A parametric study on the propeller wake model was carried out. The validated results show that it is practical to improve the accuracy of hydrodynamic performance prediction using the improved potential panel method proposed.

Highlights

The panel method has been widely used as a powerful tool in the aerodynamic and hydrodynamic fields since the successful work presented by Hess and Smith in 1967 [1]
There are some differences between the calculated results and experimental data for NACA6412 and NACA4418, but the trend of the pressure coefficient curve obtained through calculation is in good agreement with the experimental data [33]
The David Taylor Model Basin (DTMB) series propellers with different values of rake and skew were selected for calculation of hydrodynamic performance using the panel methods with the present method and the conventional cubic spline scheme

Summary

Introduction

The panel method has been widely used as a powerful tool in the aerodynamic and hydrodynamic fields since the successful work presented by Hess and Smith in 1967 [1]. The velocity potential method transforms the Laplace equation using the Green formula, which transforms an integral problem into a surface integral problem of the object, and the velocity potential is used as the unknown quantity. The panel method based on the velocity potential normally requires the Dirichlet boundary condition (B.C.) to solve the governing equation matrix, and the Dirichlet boundary condition requires the virtual velocity potential in the interior region of the object to be constant. Based on the results reported by Belibassakis et al [9], it was assumed in the present research that the internal velocity potential of a three-dimensional object is equal to the perturbation velocity potential at infinity, the intensity distribution of the source on the surface of the object can be determined, and the governing equation, i.e., the Laplace equation, for each collocation point can be solved

Methods

Results

Conclusion