Numerical investigation on a floating multi-chamber pneumatic wave energy conversion device with three sub-units

Large-scale and multi-chamber pneumatic wave energy conversion devices have the potential to further reduce the levelized cost of energy and accelerate its commercialization process. In this study, a floating multi-chamber pneumatic wave energy conversion device with three wave energy conversion converters was examined, each with a backward bend duct. The computational fluid dynamics (CFD) technology was used to investigate the effects of transverse spacing between two adjacent units on its capture width ratio, flow field, motion responses, and wave attenuation performance. The findings revealed that the formation of energy depressions surrounding the floating multi-chamber device not only helps it absorb wave energy within its width but also enables it to capture energy from the surrounding sea area. Moreover, the energy efficiency of the multi-chamber device exhibits an increase with the transverse spacing, demonstrating that the relative capture width ratio increased by up to 26.3 % from the dimensionless transverse spacing Ds/w0 = 0 to Ds/w0 = 0.5. As the transverse spacing further increases, the relative capture width ratio begins to obviously diminish.