FATIGUE LIFE OPTIMIZATION OF WIND TURBINE BLADE

Satishkumar V Tawade, Sachin B Todkar, Ashwinikumar S Hade

Abstract: Wind Turbine is one of the most useful non-conventional energy sources in today’s energy crisis scenario. But the initial cost of the Wind Turbine plant is very high. The manufacturing cost of the Wind Turbine blade is about 15-20% of the Wind Turbine plant cost. So it is likely to reduce the investment cost of the Wind Turbine blade by maximizing the service life of the Wind Turbine blades. Different types of loads acting on the Wind Turbine blade and consequential stresses developed in blade are studied. The Finite Element model of Wind Turbine blade is analyzed by using ANSYS software. Fatigue stresses are developed on the Wind Turbine blade due to change in wind speed. The maximum wind speed range (from cut-in to cut-out wind speed) is considered for design of blade as well as predicting the fatigue life of the blade. Morrow’s equation is used for calculating the fatigue life of wind turbine blade. The parameters which govern the fatigue life of the blade are the chord length; blade length and the twist angle. For optimizing the fatigue life of the Wing Turbine blade, the length of blade, the chord length and the twist angle, these parameters are varied. Constrained Gradient (Steepest ascent method) method is used for fatigue life optimization of the blade. The twist angle is very sensitive to the fatigue life of the blade than the chord length and the blade length. The fatigue life increases exponentially with the increase in twist angle, while there is parabolic relation between the fatigue life of the blade and the chord length. The fatigue life decreases with increase in the blade length linearly. Due to increase in fatigue life of the blade, the cost of the wind turbine plant gets reduced with more reliability

Keywords: Fatigue life, Optimization, Wind turbine blade

DOI: https://doi.org/10.15623/ijret.2014.0315160