Numerical analysis of water droplet impact on the curved surface of wind turbine blades

At present, the studies in simulating water droplet impact on the surface of wind turbine blades (WTBs) are mainly based on the assumption of simplifying the blade surface to a flat surface, while neglecting the influence of blade surface curvature. When the size of water droplet is comparable to the curvature of leading edge surface, the calculation accuracy will be influenced by the flat surface assumption. In the present study, a dynamic model for high velocity water droplet impact on the curved surface is established in LS-DYNA, and the influence of surface curvature of WTB on the impact dynamic performance is analysed. Results show that when water droplet impacts the curved surface, plastic damage is mainly caused by the compression of water droplet, hence the plastic damage appears earlier; when it impacts the flat surface, plastic damage is mainly caused by the lateral jetting of water droplet, hence the plastic damage appears much later. Therefore, during the analysis of the leading edge erosion (LEE) of WTBs, if the curvature of the leading edge surface is relatively small, the curvature cannot be neglected, as this will cause large calculation errors. The simulation results can provide guidance for the LEE research of WTBs.