Design of Low Speed Low Reynolds Number Wind Turbine Blade

Abstract

This paper investigates the viability of using a small scale wind turbine to harvest electricity in domestic region. The focus is to design a blade for horizontal axis wind turbine under low speed and low Reynolds number condition. The major design parameters such as the chord length, twist angle and airfoil design are taken into consideration. Based on the domestic environment and basic blade size, Reynolds number around 25000 has been considered throughout the design. The QBlade software has been used to test various airfoils out of which BE50 airfoil is chosen.The numerical analysis is performed to obtain and the co-efficient of lift and co- efficient of drag values. A Computational Fluid Dynamics (CFD) analysis is performed to validate the results obtained from the QBlade software. A series of design iterations are performed to determine the optimal chord length and twist angle values. Various trial and error iterations are also performed to determine the chord length value that shows performance closer to Bertz Limit. Similarly, the twist angle is determined using the obtained chord values. These chord length and twist angle distribution are plotted as a graph and utilized to generate a 3D design of wind turbine blade model. It has been found that the blade designed using the obtained chord and twist distribution performed 39% better than the scaled model.