Vortex Motions and Forces about a Horizontal Cylinder Advancing beneath the Waves

Abstract

The flowfield about a horizontal cylinder advancing beneath the regular waves with its axis parallel to the crests is studied both experimentally and numerically. The force measurement shows that a component with the period double of the wave period is of significant magnitude around the resonant frequency. The flow visualization and the numerical simulation by the TUMMAC-V_WV method based on the Navier-Stokes equation reveal the variation of the complicated vortex motions due to the change of frequency relation. The interaction of waves and vortices is also elucidated.