Performance of a Multibody Point Absorber with a Damper Plate in Irregular Waves

Wave energy converters (WECs) behave differently when operating in irregular waves than in regular waves. Although numerous studies have described WEC dynamics in regular waves, the ocean experiences irregular waves, making it essential to evaluate the performance under such conditions. A multibody WEC has mixed motion, adding complexity to system dynamics. In this study, a multibody floating-point absorber WEC equipped with a damper plate was designed and tested for irregular wave conditions in a wave basin at IIT Madras. The wave conditions varied, with significant wave heights ranging from 0.15 to 0.23 m and peak periods from 1 to 2.5 s. Hydrodynamic coefficients such as the Response Amplitude Operator (RAO), excitation force, radiation damping, and added mass were computed using the panel method. A multibody dynamics solver was used to calculate the power absorption. Additionally, a new buoy configuration with a deeper draft was designed and compared with the buoy equipped with a damper plate. The point absorber with a damper plate achieved a maximum power output of 14.05 W at Hs = 0.23 m and TP = 2.5 s. The highest absorption efficiency was 48.2% at Hs = 0.20 m and TP = 2.5 s.