CFD Analysis of Wind Turbine Blade With Winglets

This study is aimed at investigating the aerodynamic performance of the wind turbine blade with winglets and compares its performance in terms of the power generated with a regular straight blade without winglet. Adding a winglet to the wind turbine blade improves the power production without increasing the projected rotor area. A parameter study is carried out where two of the key parameters which describe a winglet design namely the cant angle and the winglet height are varied. The winglet is bent towards the pressure (upstream) side. Pro/ENGINEER is used to generate a straight wind turbine blade which is then modified in SPACECLAIM to attach a winglet to it. Single blade analysis approach is chosen to carry out the computation, as this involves less computational time and low cost. Results show that adding a winglet to a straight blade increases its power output by 2% to 20%. In addition, winglet which has a cant angle of 45° performs better, generating more power than the winglet which is perpendicular to the blade (cant angle 90°). Also, the power generation increases with the increase in the winglet height. Amongst the four winglet designs discussed, the design W4 with cant angle of 45° and winglet height of 4% rotor radius performs the best resulting in 20% improvement in the power generation when added to a straight blade.