Abstract
In the present paper, the radiation and scattering by an elliptic disc submerged in infinite-depth water are investigated. The problems are solved by reducing them to two-dimensional hyper-singular integral equations over the surface of the disc. A spectral method is used to solve the integral equation numerically. Numerical results are presented for different hydrodynamic quantities related to scattering and radiation by the disc. Initially, the formulation is validated against published results for a circular disc. Once it is found satisfactory, a rigorous parametric study is conducted for the elliptic disc. The primary focus of the presented study is to investigate the dependence of several physical quantities such as added mass, damping coefficient, and exciting forces on the depth and geometry of the disc. From the results, it is observed that when the body is near the free surface, the pressure field around the body changes abruptly and resonance occurs. Also, by solving the radiation problem, it is seen that for the elongated body, that is, where the ratio of the semi-major axis to the semi-minor axis is high, added mass and damping coefficient change significantly. The present study may be useful as a benchmark study. Also, in the domain of ocean energy, this study can give a rough idea about the design of an oscillator. At present, bases of all the oscillators are modelled as circular. This study reveals that an elliptic base might be useful as well.
