Numerical Investigation of Surface Wettability Induced Liquid Water Flow on the Surface of Wind Turbine Blades

Abstract

Icing accumulation on wind turbine blades is a serious threat to the safety of wind power generation. Anti-icing techniques combined with superhydrophobic surfaces with low energy consumption have recently attracted increasing levels of interest. In this work, the anti-icing mechanism of superhydrophobic surfaces was investigated based on the phase field method (PFM) and a dynamic contact angle (DCA) model. It is found that the wettability of surfaces significantly influences the flow, break, and shedding behaviors of liquid water on the surfaces. An increase in contact angle (CA) leads to more frequent break and shedding behaviors, and the flow pattern of liquid water gradually transformed from continuous water film to fragmented droplets because of the vortical flow field. Moreover, the area cover by liquid water in 30 ms gradually decreased with increasing contact angle, which is beneficial to superhydrophobic-dry anti-icing. What’s important, the wettability should be responsible for the unique water flow patterns coupled with shear stress, which has been validated again, and previously proposed by our work. The results provide theoretical support for the incorporation of superhydrophobic surfaces in anti-icing technology applied to wind turbine blades, which is promising for solving the icing issue with low energy consumption.

Keywords: superhydrophobic surface, wind turbine blade icing, anti-icing, flow pattern