Multiscale coupling wake simulations for a horizontal-axis wind turbine mounted in complex terrains

Investigating wake characteristics for wind turbines situated in complex terrains holds substantial importance for the sustainable advancement of wind energy. In this study, a multiscale simulation framework is established for wake simulations, combining the mesoscale WRF and microscale LES, which incorporates turbulent inflow. The findings reveal that inlet turbulence accelerates the recovery process of the wake, particularly at a distance of 10D downstream from the turbine, where the wake deficit area influenced by inlet turbulence is notably smaller than that affected by the terrain. Moreover, neither inlet turbulence nor terrain conditions alter the wake’s mean velocity, but they elevate the turbulence intensity (TI) values in the turbine’s near-wake region. Specifically, in the absence of inlet turbulence, the wake turbulence intensity remains at approximately 2% within the 2D to 4D downstream range. The wake TI is significantly higher when inlet turbulence is considered, with a maximum value of 16%. Finally, the power increases by approximately 5.90% with terrain conditions, decreasing by about 13.69% with inlet turbulence. These results indicate that terrain conditions enhance turbine power generation, whereas inlet turbulence significantly reduces it. This high-fidelity numerical framework holds promise as an effective instrument for wind farm siting.