A Study on Cruising Performance of Planing Craft with Outboard Motor 2011-32-0548
In this study, to improve the cruising performance of planing craft with outboard motor, we have examined a estimation method of the hull attitude angle at cruising and resistance in case of changing the tilt angle and mounting position of the outboard motor by the tank test using a scale model of a hull and an outboard motor in the ship testing tank. Planing craft with outboard motor have different characteristics from large vessels. The characteristics are shown below.
The hull attitude angle at cruising is different in each forward speed.
The thrust accounted for a large percentage of hull weight. And the flow field around the hull changes along with the operation of the propeller.
The hull attitude angle at cruising is changed by the rigging state of the outboard motor.
In this study, we calculated the hull attitude angle at cruising in each forward speed by the hydrodynamic forces measured from the fully captive model test that systematically varied the trim angle and rise of small scale model ship. We considered the self propulsion factors in the calculated hull attitude angle at cruising, and recalculated the hull attitude angle at cruising and resistance. So we could obtain the estimated result that the error margin is within 10% against the measurements of actual planing craft.