Numerical simulation of near-wake flow in wind turbines considering nacelle

The near-wake flow characteristics significantly influence blade root fatigue loads and nacelle velocimeter positioning. This study employs numerical simulations to investigate the flow field within the near-wake region, with particular emphasis on this area. Due to the interaction between the nacelle and blade root, the flow field exhibits strong spatiotemporal variations, the mechanisms of which are analyzed in detail. Results under different incoming flow velocities reveal common features: velocities change drastically with vertical height near the nacelle surface, attributable to combined effects of nacelle friction and separation-induced vortices. Beyond this zone, velocity variations become smoother. Blade azimuth angle further critically affects velocity distributions. The evolution of nacelle and blade root vortices is visualized using the Q-criterion. This mechanistic analysis deepens the understanding of near-wake flow dynamics and provides valuable guidance for optimizing nacelle velocimeter placement.