This thesis involved a numerical study of the impact of wind-assisted propulsion on the hydrodynamic and propulsion characteristics of a bulk carrier. The problem was simulated using computational fluid dynamics by means of the OpenFOAM software package. The mathematical model was based on the Reynolds-averaged Navier-Stokes equations, and the k-ω SST turbulence model was used. Ship heeling simulations were validated against available experimental data from the literature. A method for estimating the required rudder deflection and ship drift angle during wind-assisted sailing at a speed of 12.5 knots was developed. Furthermore, self-propulsion simulations were conducted to obtain more realistic values of the forces and moments acting on the ship, with the propeller being modeled as an Actuator disk. The forces and moments acting on the ship with and without self-propulsion were analyzed, and a discussion on the use of self-propulsion in determining these forces and moments was provided. The influence of incorporating an un-deflected rudder on the hydrodynamic characteristics was also analyzed, and a comparison was made with simulations without the presence of the rudder. Finally, the self-propulsion of the ship under real wind-assisted propulsion conditions was analyzed to calculate the delivered power to the ship’s propeller, which is directly related to fuel consumption. It was demonstrated that sails generate a significant lateral force on the ship, causing it to drift and altering the symmetric flow of fluid around the hull, resulting in the ship yawing into the wind. The veering needs to be corrected by rudder deflection, which in turn affects an increase in the ship’s resistance. Nevertheless, it was shown that significant fuel savings can still be achieved despite a substantial increase in hydrodynamic resistance.