experimental study of the wedge effects on the performance of a hard-chine planing craft in calm water

In this paper, effects of a wedge on the performance of planing craft in calm water are experimentally investigated. experiments were carried out on three different cases distinguished by the wedge type. the model, built of fiberglass, was a prismatic planing hull with deadrise angle of 24 degrees. towing tests were conducted at different froude numbers ranging from 0.21 to 2.1. the total trim angle, resistance, and rise-up at the cg as well as stern and bow, keel wetted length, chine wetted length, stagnation angle, and the length of stagnation line were measured. they were used to study the eect of installing a wedge on the performance and the effect of height on the hydrodynamic characteristics. based on the observations made, it was concluded that when the wedge was applied to the hull, the risk of the model exhibiting instability diminished, while total trim angle largely decreased, keel wetted length was enlarged, wetted surface became thinner, cg rise-up was lowered, and the resistance was reduced. moreover, experimental measurements and theoretical 2d+t theory were combined to bring deeper insight into physics of the ow and pressure distribution when a wedge was installed on the bottom of a planing hull.