Experimental and Numerical Investigation of Free Decay Motion of a Wave Energy Converter Model

Aiswaria, K. and Balaji, R., 2024. Experimental and numerical investigation of free decay motion of a wave energy converter model. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 629-633. Charlotte (North Carolina), ISSN 0749-0208. The future of renewable energy may include a large contribution from wave energy which has gained significant interest recently. The estimation of hydrodynamic parameters is essential in the performance assessment of wave energy converter devices. Physical experimental and numerical free heave decay tests are performed for a cylindrical wave energy converter device and the results are verified. The experiments are performed in a wave flume equipped with Qualisys motion-capture cameras which capture the heave decay motion of the model at high accuracy. The model is dropped freely from three known drop heights. The findings of the test can offer benchmark data for the validation of numerical models. The natural frequency and equivalent linear damping of the model are estimated using the logarithmic decrement method. The experimental test results are compared to the numerical model simulation results obtained based on the linear potential flow theory using WEC-Sim software. Numerical simulation results have good agreement with the experimental values confirming the applicability of the numerical model for such studies. The study provides insight into various hydrodynamic parameters relevant to the model's efficiency in absorbing energy. The findings of the study are valuable for acquiring a physical understanding of the system parameters and achieving higher device performances.