Towing of Huge Floating Structure Unit

Abstract

Towing problems of a box-shaped unit of the huge floating structure are studied experimentally by towing an unit model. The effects on the towing tension, bending moment and motion are investigated by varying the wavelength, the towing speed, and the draft of the unit model. The experimental transfer functions of the wave bending moment and the vertical displacement are compared with those from the numerical calculations based on the pressure distribution method. The experimental transfer function of the surge motion is compared with the theoretical calculations based on the strip theory. The added towing resistance in waves is also investigated by comparing the experimental results with the numerical results. Moreover, the reduction of towing resistance is proved by attaching either cut-up type or forward-plate type appendage in front of the unit model. The reduction of towing resistance is supposed to be more effective on the full-scale unit; than on the model unit.