Raindrop and Film Distribution on Wind Turbine Blades Under Rainfall

This study employs the industry-standard NREL 5MW wind turbine model, integrated with a multiple reference frame (MRF) model and a discrete phase model (DPM), to numerically investigate raindrop occupancy rates and liquid film distribution on wind turbine blades under rainfall conditions. Numerical simulations were conducted to analyze raindrop spatial characteristics and liquid film dynamics across varying rainfall intensities. Key findings reveal that raindrops within the 1.5-5 mm diameter range dominate the impact process on blade surfaces, exhibiting significantly higher occupancy rates compared to other size ranges. Liquid film analysis demonstrates that thicker films preferentially accumulate near the leading edge region. These insights provide theoretical support for optimizing rain-erosion-resistant blade designs.