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

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