Energy conversion efficiency and cost-effectiveness crucially influence the advancement and application of oscillating water column (OWC) wave energy conversion technology. This research studies the geometric factors of the OWC that affect the two indicators and the quantitative relationships between them. A two-dimensional numerical model of wave and OWC interactions is established based on the computational fluid dynamics method for initial data calculation. The data are sampled, and a surrogate model is established to process the sampled data for further prediction and multi-objective optimization without actual hydrodynamic calculation. The parameters of the OWC are analyzed and optimized for optimal hydrodynamic efficiency and mass of the OWC. The results show that the width of the OWC has the greatest influence on the hydrodynamic efficiency, whereas the width of the orifice and the draft of the OWC have smaller and similar effects. The optimized performance has significantly improved, with the maximum efficiency of OWC reaching 0.73 and the maximum power per unit mass increasing by 260.4%. The analysis of the Pareto frontier reveals two pivotal thresholds in the relationship between efficiency and device quality, and simultaneously obtained the functional expressions related to both of them. Their relationship shows a three-stage trend: from a steady to a linear increase and to an exponential increase. These findings may provide reference and guidance for the optimization design and practical application of OWCs.
Huang et al. (Tue,) studied this question.