Some results from a new time-domain bilge keel force model

Abstract

A new non-linear, time domain bilge keel force model was recently developed for inclusion in the new time-domain seakeeping/maneuvering in waves code TEMPEST, being developed by NSWCCD. This bilge keel force model combines a full unsteady extension of Bollay’s non-linear low aspect ratio lifting surface theory for cases with adequate forward speed with a more conventional approach for cases with zero or low forward speed, using Morison’s equation. This paper presents some representative results from the new bilge keel force model for a surface combatant for various roll amplitudes, roll periods, and forward speeds.