NUMERICAL AND EXPERIMENTAL ANALYSES OF TRANSVERSE STATIC STABILITY LOSS OF PLANING CRAFT SAILING AT HIGH FORWARD SPEED

This paper reports a study on the transverse stability loss of a planing craft sailing forward at a high speed. The major challenge involved in the hydrodynamic study of a planing craft is the difficulty in applying traditional ship theory and potential flow programs to the unstable high-speed planing surface of a two-phase flow. To overcome this, we developed a numerical simulation method based on the RANS-VOF solver and used it to analyse the hydrodynamic performance of a planing craft sailing in calm water with fixed heel angles or moments. A series of towing tank tests was carried out to observe the transverse stability loss of a planing craft model at different forward speeds. The numerical and experimental results both indicated that the transverse stability significantly decreased at high Froude numbers. It was found that the transverse instability over a wide range of speeds was closely related to the trim angles of the planing craft. Because the longitudinal position of the center of gravity is a key design parameter that affects the trim angle of a planing craft, the effects of its position on the transverse instability was studied through numerical simulation.