CFD study of a container ships nominal wake fields in oblique regular waves

Accurate estimation of the actual nominal wake behind the ship in waves is important for propeller design. The present CFD study investigates the nominal wake fields of the Kriso Container Ship (KCS) ship in regular waves with wavelength equal to the ship length with five different headings. The ship is sailing at design speed and the wave steepness is 1/60. The results show that when sailing in the studied waves, the nominal wake fraction fluctuate up to 39% of the mean nominal wake fraction. The mean nominal wake is higher than in calm water for all headings besides head sea waves. The heading with maximum mean nominal wake fraction is the stern quartering sea waves, with a 16% higher mean nominal wake fraction than in calm water. It is found that the transient bilge vortex and shadow from the skeg have a significant influence on the nominal wake field. It is estimated that the angle of attack on some points on the r/R=0.7 circle in the propeller plane varies up to 5 degrees.