Offshore floating flexible photovoltaic typhoon-induced flow field driving mechanism and wind load extreme value model

Offshore floating photovoltaic (PV) is the technological commanding heights of the future development of the photovoltaic industry, especially under the action of extreme weather such as typhoons and huge waves, the flow field mechanism of offshore large-span floating flexible PV arrays is more complex, and there is a lack of effective offshore floating PV wind load prediction models in the relevant design codes of flexible PV in the world. Taking a typical flexible PV key demonstration project as the research object, a three-dimensional mesoscale Weather Research and Forecasting (WRF)- Simulating Waves Nearshore (SWAN)- Finite-Volume Coastal Ocean Model (FVCOM) real-time two-way coupling simulation method based on Mapped Contact Interface (MCT) coupler was proposed, a meso/small-scale nested typhoon-wave-flow numerical pool of PV array was established, the wind load distribution characteristics of single-row floating flexible PV were studied, the driving mechanism of inter-row flow field of floating large-span flexible PV array was compared and analyzed, and finally the value model of the lift/drag coefficient of PV array under extreme wind conditions was established. The results show that the average wind pressure of single-row floating flexible PV presents trapezoidal and L-shaped distribution rules under different wind direction angles, and the temporal instability and spatial discontinuity in the low wind speed area of the floating flexible PV array and the complex and disordered alternating vortex phenomenon are the main reasons for the inter-row interference, and the proposed fitting formula of two-dimensional lift/drag coefficient can encompass the extreme value of the actual wind pressure, and the maximum error is controlled within 10 %, which can provide a reference for the prediction of the design value of this kind of floating flexible PV wind load.