A Study on Bow-Diving for Planing Craft

Criteria of Bow-Diving Occurring

Abstract

The purpose of this paper is to clarify the cause of occurrence of Bow-Diving for planing craft. First, measurements of Bow-Diving using a scale model of planing craft are carried out and they confirm that Bow-Diving occurs in calm water and waves. From this experiment result, the relative position of the hull to the water surface at Bow-Diving occurring is shown. Next, the hydrodynamic forces acting on the model are measured by fully captive model tests with wide range of attitude including the running attitude at Bow-Diving occurring to obtain the restoring forces acting on the model, and the characteristic of them are investigated. Consequently, it is shown that the restoring forces play an important role to Bow-Diving occurring and a method of obtaining the criteria of Bow-Diving occurring based on the restoring forces is proposed. Furthermore, the diagnoses of Bow-Diving occurring are proposed.