Effect of a straight coast on the hydrodynamics and performance of the Oscillating Wave Surge Converter

• We model the effect of a straight coast on the hydrodynamics of the wave energy device-Oscillating Wave Surge Converter.
• Extremes in the hydrodynamic coefficients are observed for certain specific locations of the device.
• The presence of the coast has both – favourable and detrimental effects on the device performance.
• When located very close to the coast, the device consistently achieves much higher levels of efficiency than it would do in an open ocean.

This paper describes the behaviour of a flap-type oscillating wave energy converter near a straight coast. The mathematical formulation is based on a linear potential flow model. Application of Green׳s theorem to a semi-infinite fluid domain yields a hypersingular integral equation for the velocity potential which is solved using a series expansion of Chebyshev polynomials. Extremes in the hydrodynamic characteristics of the system are shown to occur at certain wave periods when the device is located at specific distances from the coast. This dynamics can have either detrimental or favourable effects on the performance of the converter, depending on the system parameters. Surprisingly, when the device is located very close to the coast, the qualitative behaviour of the system resembles that of a single device in the open ocean. In addition, the analysis shows that under such circumstances, the device consistently achieves much higher levels of efficiency than it would in an open ocean.