Considerations for bilge keel force models in potential flow simulations of ship maneuvering in waves

Abstract

Requirements for ship operations, both naval and commercial, may result in increased exposure to heavy weather and the occurrence of large amplitude motions. In order to enable evaluation of hull form designs, or to develop detailed ship specific operator guidance for these critical conditions, potential flow sectional, or strip-theory based, approaches remain the most practical method for fast ship motions simulations. However, some essential physical effects regarding the bilge keels are not captured by potential flow sectional formulations. To examine the relative importance of these effects, a series of unsteady RANS (URANS) computations were performed for the ONR Tumblehome model experiencing large amplitude roll motion at both zero and forward speed conditions, in calm water and in waves.