Experimental Study of Stability Limits of Wind Turbine Blades Subjected to Site Specification Conditions

Abstract

In our planet earth, there is lot of natural energy source which makes it very comfortable for human life to live and survive. Among these energy sources is the wind energy. This free energy source comes with challenging characteristics i.e. it’s very unpredictable because the strength of wind and its direction is dynamic. To produce useful amounts of power, wind turbines generally need to be large and tall, this makes the wind turbine blades longer and slender too, which is a great source of instability. Therefore, the need to experimentally determine the stability limit of wind turbine blades for different operating condition and the study location is important. In this study, three different materials (Al-alloy, wood and PVC) were used to fabricate the blades and was installed on the hub of mini HAWT at three different angles (5°, 10°, 15°) and wind speeds (2, 4, 6)m/s to analysed the stability limit of the blades. The experiment was on a static motion, where the deflection of the blades were analysed, simulated on Solidworks and recorded. In all cases tested, the data collected indicated that the PVC blade produced highest deflection of 11.41mm which is equivalent to 3.8% of the blade length. The blade is stable because this is less than 5% of the blade length. The Al-alloy and wood blade produced 1.6% each which makes them more stable. Al-alloy produce the lowest deflection of 0.0006293mm with low wind speed of 2m/s at an angle of 5°. The good agreement between the deflections computed by the Solidworks package and the experimental data has been used in the validation process where it indicates that the research can be used to estimate the stability limit of a wind turbine blade.