Calm Water Resistance Characteristics of a Lift & Buoyancy-Supported Craft (1st Report) : Model Test Method

Abstract

A Lift & Buoyancy-Supported Craft (LBSC) is a variety of fully submerged type hydrofoil craft. A LBSC is supported by the buoyancy of a submerged body and the dynamic lift generated by the hydrofoil while cruising. This concept was envisaged to create a high speed and exceptional seaworthy craft of much bigger size, higher payload and longer cruising range than pure hydrofoil craft. This paper describes two kinds of model test methods and their results for LBSC in a towing tank, using a model without propulsion device. One is the captive model test to determine the hydrodynamic characteristics of the craft at an equilibrium of the forces and the moments at a steady running condition. This method can be used for studying the hydrodynamic performance of a LBSC or pure hydrofoil craft in calm sea conditions in various modes of operation. The other is a towing test with wire to examine the running attitude during Take-off stage. This method is useful for checking the longitudinal stability of the LBSC at Take-off state.