A simulation study on airfoils using VAWT design for low wind speed application

Abstract

This paper presents the simulation study on the airfoil based on the vertical axis wind turbine (VAWT) for low wind speed application ranging 2 to 8 meter per seconds. The main advantage VAWT compared to the horizontal axis wind turbine (HAWT) is the ability to capture wind from any direction. Therefore, the yaw system is not required to turn the rotor towards the wind direction. Furthermore, the noise level produced during the rotation making it suitable to be installed on residential and urban environment. However, the major drawbacks of VAWT over HAWT are less efficient due to drag and turbulent force that the blade produces and low starting torque. The aim of this study is to develop a VAWT design equipped with the advantages mentioned and to overcome the VAWT drawbacks. The National Advisory Committee of Aeronautics (NACA) for both airfoil series 0012 and 0015 were analyzed using simulation provided in the Qblade software. The graphical relation between optimal angles of attack (AoA) and the Reynolds number which predicts the flow patterns of the wind is analyzed. Based on this, the AoA that generate high lift over drag ratio (Cl/Cd) can be identified. The ratio of Cl/Cd for the airfoils; NACA 0012 and NACA 0015 are used to analyze the relationship between Tip Speed Ratio (TSR) and the Power Coefficient (Cp) performance. The number of blades is also tested to justify the effect on the power produced in low wind speed condition. Comparison of the simulated airfoils is presented in this paper. A simulated design of small scale size VAWT is made to test the effect of the blades number and their respective Cp and TSR versus wind speed. With the proper airfoils design that suits the low wind speed condition, the turbine can functions efficiently as well as maximize the power produced by turbine.