Numerical and experimental investigation of the dynamic responses of an integrated semi-submersible floating wind-wave energy converter

Abstract

\ua9 2025 Elsevier LtdThis paper introduces an integrated floating wind-wave energy conversion system, with a heave-type WEC attached to a semi-submersible braceless wind turbine\u27s central column. Numerical simulations and a 1/80 scale physical model test were used to evaluate its dynamic responses under combined wind and wave conditions. Free decay tests confirmed the numerical model\u27s accuracy in predicting the platform\u27s natural periods for surge, heave, and pitch motions, with errors under 5 %. In regular waves, numerical and experimental results for motion responses and mooring tensions were highly consistent, with maximum errors not exceeding 15 %. Under irregular waves, the maximum errors in motion responses and mooring tensions were within 19 %. In combined wind-wave conditions, except for pitch motion, the maximum errors in other responses were no more than 20 %. In high wind speed combined wind-wave conditions (23.8 m/s), the pitch error reached 40.52 %. The findings confirm the reliability of the proposed integrated system design and underscore the importance of considering the coupled effects of wind and waves on the system\u27s dynamic response, providing valuable insights for the design and optimization of offshore renewable energy systems