Hydrodynamic performance study of a land-based OWC under the action of irregular wave
To study the hydrodynamic performance of an oscillating-water-column(OWC)wave energy converter in a real sea,a two-dimensional nonlinear numerical model of the interaction between irregular waves and a land-based OWC device is developed based on the potential flow theory and the high-order boundary element method(HOBEM)in this paper.The irregular waves are generated based on the JONSWAP spectrum.The viscous damp-ing is introduced on the water surface boundary conditions inside the air chamber to consider the energy dissipation due to water viscosity.And physical modeling experiments are carried out in the wave-current flume at Dalian Uni-versity of Technology to validate the numerical model.It is found that the OWC hydrodynamic efficiency under ir-regular waves is reduced in comparison with that under regular waves,especially in the low-frequency wave region where the efficiency difference is the largest.The frequency corresponding to the peak efficiency under the action of irregular waves is larger than that under regular waves.The dimensionless surface elevation inside the chamber decreases,while the dimensionless air pressure inside the chamber increases with the significant wave heights.The OWC hydrodynamic efficiency is less affected by the significant wave height.The frequency corresponding to the peak efficiency is not dependent on wave nonlinearity.This work can provide a reference for the design of OWCs.
oscillating water columnwave energy converterirregular wavehigher-order boundary elementwave non-linearity