Analysis of a Wedge Wave-Maker in a Tank of Finite Depth

The analysis of the performance of a wedge-type wavemaker in a tank of finite depth is presented. The analytical technique is somewhat different than those applied previously to performance studies of wave-makers. Those techniques include the assumption of a product solution of the Laplace equation. This assumption leads to combinations of sinusoidal and hyperbolic functions of the wave number. Here, following Yeung (1981), both product and summation solutions are assumed. This assumption is based on the fact that the fluid beneath the wave-make is confined by the wave-maker, the backwall and the tank floor. From potential-flow theory, the streamlines of the oscillatory flow of this confined fluid are well defined. Yeung (1981), in a three-dimensional analysis of hydrodynamic coefficients of a heaving, vertical, circular cylinder, makes this assumption without stating so. Using the experimental data of Wang (1974) for comparison, results of the analysis are presented for various combinations of wave-maker draft, breadth and water depth for a triangular wedge. The results show that the effects of the evanescent waves are of second-order. Close to the wedge, results are presented resulting from the inclusion of four evanescent waves. The technique is of value because of its relatively simple form and its versatility.