- 期刊
Experimental Investigation on Drag Characteristics of HAWT Tower Due to Tower Shadow
摘要
In Horizontal Axis Wind Turbines (HAWT), the interference between the wind turbine rotor blade and the tower is a pervasive problem that affects the tower as well as blades, structures, and power performances; hence, the study of the physical mechanism needs engineering attention. This interference phenomenon influences the flow field and excites the complex unsteady wind loads acting on the tower. Towers of the wind turbines have the potential geometry such as lattice, tubular, hybrid but this study focuses on cylindrical towers. The Wind tunnel experiment is carried out on scaled down three bladed wind turbine model with S809 aerofoil section blade to investigate the flow physics for tower alone and tower with rotating rotor for the Reynolds number ranging from 102 to 104. The aerodynamic drag force acting on the wind turbine tower with the rotating rotor is in increasing trend than the single tower without interference, which is almost constant. The results show that at low Reynolds number the coefficient of drag on the tower alone is more than the tower with rotating rotor whereas this case reverses as the Reynolds number increases. The drag force acting on the tower under the blade rotation effect has been investigated, and an aerodynamic term (Drag ratio) is proposed, which will be helpful for guiding the structural designer of the wind turbines.