Assessment of wind hazard at wind turbine sites based on CFD simulation under tropical cyclone conditions

In this study, a new TC wind hazard assessment framework at wind turbine sites was established based on a newly developed CFD model that accounts for the rotational effects of the mesoscale wind field in the TC boundary layer. The CFD-simulated wind field was proved to agree well with the nacelle measurements within the wind farm with a correlation coefficient above 0.85. Then, a modified composite risk index (CRI) was proposed by incorporating turbulence intensity (I). The CRI at wind turbine sites was found to be primarily controlled by horizontal wind speed (V) and I. When the TC center was close to the wind farm (< 65 km), V significantly increased and contributed more than 70 % of CRI as a dominant factor. Comparatively, when the TC center was far away and V was relatively small, I emerged as the dominant factor and contributed over 60 % of CRI. In addition, hazard factors related to changes in wind direction accounted for 10-20 % of CRI during the impact of TC, highlighting their importance as non-negligible hazard factors. This hazard assessment method is expected to provide a reference for wind farm microsite and wind turbine selection under TC conditions.