“AERODYNAMIC PERFORMANCE ANALYSIS OF LOW SPEED WIND TURBINE AEROFOILS WITH INVERTED DIMPLES”.

Abstract

A clean, fuel-free source of the energy wind turbines obviously create energy without generating the damaging pollutants that result from burning coal, gas and other fossil fuels. Even though we have various renewable energy sources, Wind energy has become one of the key solutions to the prevailing energy crisis. To economically produce the maximum power by using wind turbines the aerodynamic parameters of the blade profile must be assessed. The key parameters in the wind turbine blade performance are lift and drag coefficient. NACA-0015 and NACA-0018 airfoils were highly preferred for horizontal wind turbine blade under low Reynolds number configuration. Analysis of the effects of flow over NACA-0015 airfoil with and without inverted dimples and NACA0018 were done by using computational fluid dynamics methods. The widely used CAE software ANSYS CFX was used for analysis and simulation. Three models were analyzed for lift and drag performance i.e. one with the regular surface of NACA0015, other with inverted dimples on the upper surface of NACA0015 aerofoil, and the last with a regular surface of NACA0018 aerofoil. The depth of the dimples was selected as 3mm i.e. 1% of the chord length and was placed at a distance of 210mm i.e. 70% of the chord length from the leading edge. The ratio of the coefficient of lift and coefficient of drag, coefficient of performance was calculated by numerical methods at a various angle of attacks. With the advancement of highly configured computational methods, the flow behaviors of the fluid and its effects were accurately analyzed. The difference between the ratio of the coefficient of lift and coefficient of drag were compared. Due to the addition of inverted dimples over the upper surface of the airfoil, it was found that there was an increase of 5% efficiency in the performance.