Suggestions for Improving Wind Turbines Blade Characteristics

Abstract

Suggestions for improving the efficiency and life expectancy of wind turbine blades are proposed in this paper. A new airfoil shape with wide leading edge nose and large camber has been investigated by numerical simulation with a range of attack angles. The results show that the lift-drag ratio of the airfoil is greater than that of the conventional airfoil at large attack angles (α>20°). Changing the local roughness on blade surfaces to improve the wind turbine performance is discussed in the paper. A new mechanism and method of analysing life expectancy of a blade with flow induced vibration in oscillating flow has been given. It is proved that the damping of blade material and structure has great influence on the endurance lifetime of blades. The investigation indicates further that the equilibrium amplitude of vibration greatly influences the lifetime of blades. Changing the damping characteristic of a blade may significantly vary its equilibrium amplitude, so extending the life expectancy of blades. This paper provides the foundations for further study.