Hydroelastic analysis of a semi-submerged propeller using simultaneous solution of Reynolds-averaged Navier-Stokes equations and linear elasticity equations

摘要

Numerical analysis of fluid-structure interaction in semi-submerged propellers is considered as one of the complex problems in multiphase flow simulation. This study utilizes a coupled numerical simulation for Reynolds-averaged Navier-Stokes equations and elasticity equations in order to analyze the hydroelastics of a semi-submerged propeller. Also, the free surface effects and existence of cavitation by which the problem may be simulated in a more realistic situation are considered. The governing equations of the fluid and structural parts are discretized based on finite volume and finite element methods, respectively, and solved using the ANSYS software. Validity of the numerical simulation is assessed by comparing its results against available results of semi-empirical equations. This comparison displays good agreement. Hydrodynamic and hydroelastic analyses are performed for a wide range of advanced and submerged ratios. It is clarified that frequency, which is five times greater than that of the shaft speed, is a dominant factor in the oscillations. It is also observed that the existence of cavity patterns and ventilation have a major role in variations in fluctuation amplitudes. Moreover, it is concluded that larger advanced ratio leads to an increase in the displayed oscillations. Based on the current simulation, it is detected that the determined failure point is located at an expected place. It is also observed that distribution of von Mises stress significantly depends on water surface profile. Finally, it is concluded that the Cavitation number has a direct relation with the stress.