A VORTEX-ELEMENT METHOD FOR THE CALCULATION OF WAVES AND SHIP MOTION EFFECTS ON PROPELLER PERFORMANCE

K. Belibassakis, School of Naval Architecture and Marine Engineering (NTUA)

Presented at the 34th International Ocean and Polar Engineering Conference, Rhodes – June 2024

ABSTRACT

Ship propulsion performance in environmental conditions corresponding to moderate and more severe sea states is significantly affected due to ship motions and added wave resistance, as well as wind resistance and other factors. All the above cause significant additional energy losses that sometimes could drive the propulsion system at its limits, resulting in involuntary speed reduction and excessive fuel consumption. In this work the effects of wave-induced vertical oscillatory stern motion of the ship on the modification of propulsive thrust and efficiency are examined by means of Unsteady Vortex Element model used for the analysis of propeller(s) operating in the wake field of the ship, in conjunction with seakeeping analysis in regular and irregular waves.