Flow fields and aerodynamic loads of wind turbine considering yaw effect under wind and rain interaction

The wind field of wind turbine considering 6 yaw angles (0, 5, 10, 20, 30 and 45 degrees) under the worst blade stop position was simulated based on computational fluid dynamics (CFD) method in order to analyze the flow field characteristics and aerodynamic performance of large-scale wind turbines under complex operating conditions in severe storms and rainstorms. A 5 MW wind turbine researched independently by Nanjing University of Aeronautics and Astronautics was taken as an example. The discrete phase model (DPM) was added and the wind-rain coupling synchronous iterative calculation was conducted. Then the effects of different yaw angles on the characteristics of wind field and rain field around wind turbines were analyzed. The new models of wind-rain equivalent pressure coefficient were constructed, and corresponding calculation formulas were presented. The equivalent pressure coefficient of tower and blades were systematically analyzed for different yaw angles conditions under wind and rain interaction. Results show that the effect of additional rain load on the pressure on the windward side of the blade and the 40 degrees on both sides of the windward side of the tower cannot be neglected. © 2019, Zhejiang University Press. All right reserved.