Forces and moments on a restrained model in regular waves

Abstract

This report presents the experimental forces and moments acting on a five-foot model tanker when it was towed on five headings in a regular seaway. The seaway consisted of regular deep-water waves whose length varied from 0. 5 to 2. 0 times the model length. The wave steepness was varied from 1/40 to 1/20 height-length ratio. All motions of the model except uniform forward translation were restrained and the forces and moments relative to a moving towing carriage were measured with a six-component balance. The forces and moments were divided into steady-state and oscillatory forces and moments. The steady-state forces and moments are generally analogous to the forces and moments which would result if the model were towed in calm water. The oscillatory forces and moments are induced by the waves.