The Wave-Making Resistance of High Speed Boats : The First Report : Displacement Type Ships

Abstract

This is a study to search optimum ship forms in a range covering Froude number from 0.4 to 1.4 with respect to their wave-making resistance of displacement type ships by the so-called thin ship theory. As well known the thin ship theory predicts fairly well the wave-making resistance of displacement type ships in the neighbourhood of last hump speed. Numerical studyes minimizing the wave-making resistance are carried out on three types of ship. The first type is a wall-sided model and its solution is stable and gradually joins to the foregoing theorectical result. The second type is Maier form model and this solution is also fairly stable and the wave resistance is somewhat larger than the above. The last case is a bulbous bow type ship forms. Is this case, the more the number of terms representing its half breadth, the less its wave resistance becomes. However, it happens that its half breadth curve has a negative value, so that the number of terms might be confined in small with regard to the speed and draught.