ABSTRACT
Based on CFD simulations, this paper conducts a quantitative study of the time-averaged and transient hydrodynamic performance of the propeller experiencing unsteady surge motion in regular head waves. As an approximate approach for simulating the actual surge motions in waves, this study utilizes the overset grid approach for simulating the rotation and the forced surge motions of the propeller and the VOF (Volume of Fluid) method for free surface tracking. The paper emphasizes on an effective method of investigating the effect of blade area ratio and pitch ratio on the hydrodynamic performance of propellers in waves. The numerical results indicate that, the unsteady surge motion can impose a negative or positive impact on the thrust and torque in different time periods within a wave period, and decreases the thrust and torque averaged over a wave period; when a propeller experiences the surge motion, its thrust and torque would increase with the blade area ratio and the pitch ratio, more rapidly the latter. The presented simulation approach and investigation method can be further improved and applied to propeller design and evaluation of ship propulsive performance in waves accordingly.
