On the Components of Ship Wave Resistance

Abstract

Applying Prof. Havelock's method of analysis the author studies the relative importance of the transverse- and diverging-wave systems which are produced by a ship of Michell's type. Special reference is given to the effects of the depth or the width of a water upon the wave resistance, and the numerical calculations are made for the three cases:(a) deep water (h=∞, b=∞), (b) shallow water (h=finite, b=∞), (c) restricted water (h=finite, b=finite), where h denotes the depth of water, b the width.The main results obtained are as follows:1°. In (a), the contribution from the diverging wave system to the total wave resistance is lound as given by a steppedly increasing function of Froude number, with each step taking place at the hollows on the curve of the transverse wave resistance.2°. In (b), the resistance component due to the transverse waves attains its maximum at the speed just lower than the critical speed or the solitary wave velocity V=√gh, while the diverging wave resistance has its peak just at the critical speed.3°. In the case (c), the side-walls are found as affecting inverse effects upon the two contributions of the wave resistance : the transverse wave resistance being augmented, while the diverging wave resistance being reduced, in comparison with the case (b).