Evaluation of Geometrical Influence on the Hydrodynamic Characteristics and Power Absorption of Vertical Axisymmetric Wave Energy Converters in Irregular Waves

Abstract To obtain the mechanical energy of waves from arbitrary directions, vibration absorbers wave converters (WEC) are usually vertically axisymmetric. In such case, wave-body interaction hydrodynamics is an essential research topic to high-efficiency energy. this paper, a semi-analytical method decomposing complex axisymmetric boundary into several ring-shaped stepped surfaces based upon approximation (BAM) introduced and examined. The hydrodynamic loads parameters, as excitation forces, added mass radiation damping vertical oscillating buoys, can then be achieved by using new discretisation method. calculations forces coefficients show good convergence with number increases. Comparison between constringent results conventional also verifies feasibility Then, simulations comparisons motions power conversions buoys series draught displacement ratios in regular irregular conducted. calculation that geometrical shape has great effect on conversion performance absorber. waves, though concave buoy lowest efficiency, it largest frequency bandwidth for given ratio, while truncated cylindrical best conversion, buoy, shows ability.