Free motion of a cylinder moving below and through a free surface

摘要

This paper presents the fully non-linear inviscid-flow calculations of the deformations of an initially calm freesurface caused by the free motion of a horizontal cylinder startingfrom rest from a prescribed depth. The following cases are studied:(a) Upwards motion of a cylinder of specific gravity M_b<1.(b) Downwards motion of a cylinder with M_b>1.(c) Motion of a cylinder with M_b=1, started with an impulsivehorizontan velocity.(d) Downwards motion of a cylinder with M_b>1, initially half-submerged. The complete engulfment of the cylinder, so that itchanges from being surface-piercing to being totally submerged,requires special numerical treatment.