An Analytical Methodology for Aerodynamic Analysis of Vertical Axis Wind Turbine

Abstract

This study describes an effectively analytic methodology to investigate fully aerodynamic performance of H vertical axis wind turbine (H-VAWT). An in-house code based on double multiple streamtube theory (DMST) coupled with dynamic stall and wake correction is implemented to estimate power coefficient. A separated optimization of airfoil shape is first conducted to study the influences of dynamic stall and turbulent wakes. Airfoil shape is universally investigated by using Class/Shape function transformation method. The wind turbine solidity, tip speed ratio and pitch angle of the blade are then studied along with airfoil shape to optimize power coefficient. The airfoil study shows that upper curve tends to be less convex than lower cure in order to extract more energy of the wind in the upstream and generate less drag of the blade in the downstream. The optimal results show that the power coefficient increase by 6.5% with the new airfoil shape and 8.2% when considering solidity, pitch and airfoil together.