Development of an Experimental Method to Assess the Performance of a High Speed Craft : 3rd Report : The Effect of Suction by Waterjet Propulsion on Hydrodynamic Forces Acting on Hull

Abstract

An experimental system to measure the effect of suction by waterjet propulsion of high speed planing craft on hydrodynamic forces acting on the hull is developed. Using the system the hydrodynamic forces acting on a captured model at Froude number up to 6.0 are measured. The measured results show that the effect of the water flow through the duct of a waterjet propulsion on the hydrodynamic forces on the hull is significant even when the pump does not work, and that it can change the attitude and the resistance. It is found that the increase of the suction by increasing the revolution of the pump causes the decrease of the drag and lift forces acting on the hull.