Flow Beneath a Ship at Small Underkeel Clearance

Abstract

This article looks at the case of a large, flat-bottomed ship, such as a bulk carrier, moving in close proximity to a flat sea floor. It is shown that the flow beneath the ship can be modeled as a shear flow between two parallel plates, one of which is moving. The resulting flow can be represented using laminar Couette flow at low Reynolds numbers (possible at model scale) or the very different turbulent Couette flow at high Reynolds numbers (full scale). Implications of these flow models on squat and viscous resistance are discussed.