DefinePK

Abstract

Renewable energy has received large attention in both developed and developing countries in the world as an alternative to the fossil fuel based energy. Wind energy is becoming one of the popular means to harness energy from renewable sources. Although abundant research had previously been undertaken for high Reynolds number, research on different viscous models at low Reynolds number is limited in the world. As such, in this paper a numerical study is performed for low speed wind turbine blades where five viscous models such as laminar, RNG k-e model, SST k-?, Transitional SST, and Transitional k-kl-?, and four airfoils, namely NACA-4412, NACA-4421, NACA-4418 and NACA-2412 are chosen for comparative study. Numerical simulation was done via finite volume based software. The result shows that laminar, RNG k-e and SST k-? models are able to predict general behavior of both profiles, whereby laminar and SST k-? models are able to capture stall angle. Whilst all the viscous models predicts well the pressure coefficient on lower surface of the airfoil, but only laminar and RNG k-e models perform better in the upper surface of airfoil. The drag is found to be higher with the increase of angle of attack (AOA). The lift to drag ratio increases with increase of AOA but decrease after a certain point.