Hydroelastic analysis of surface-piercing propeller through one-way and two-way coupling approaches

Abstract

Semi-submerged operation of surface-piercing propellers can cause severe structural stress and deflection due to the high-rate variation of the hydrodynamic loads on each blade in one cycle of revolution. Therefore, a proper hydroelastic analysis regarding these propellers seems imperative. Accordingly, in this article, hydrodynamic performance of a surface-piercing propeller is studied by considering the structural flexibility. The one-way and two-way coupled unsteady Reynolds-averaged Navier–Stokes equations (finite volume method used for the fluid analysis) and direct finite element method (used for the structural analysis) are utilized to analyze an 821-b surface-piercing propeller model. The obtained ventilation patterns and hydrodynamic loads on a single blade of this propeller are compared with the published experimental data. ANSYS multiphysics solvers are used to conduct the targeted simulations. The results are presented for different velocity ratios in the range of [0.8, 1.2] and Froude number Fr = 6.0. The blade maximum deformation and von Mises stress are presented in one cycle of revolution. Based on the obtained results, one may conclude that both the adopted approaches predict the propeller transient hydrodynamic characteristics with good accuracy, compared with the experimental data. However, the two-way approach displays lower maximum structural displacement and stress than one-way simulation. This is attributed to the fact that the two-way approach takes into consideration the added mass and damping effects of the surrounding fluid around the blade.