Airfoil parameterization evaluation based on a modified PARASEC method for a H-Darrious rotor

Abstract

The airfoil research is one of the most essential issue which has great influence on the vertical axis wind turbine (VAWT) performance. Thus, a comprehensive research was conducted in this study with the objective of evaluating the effect of the twelve airfoils' controlling parameters on a Darrieus rotor's performance. The airfoil parameterization method, orthogonal algorithm and computational fluid dynamic (CFD) prediction were intergtated to fulfill this objective. A modification was conducted for the airfoil parameterization method to avoid trailing edge crossing and make controlling parameter's geometrical meaning more explicitly. The analysis results sorted the effect of design parameters by impact weight or contribution ratio. A remarkable finding was that the design parameters on the lower surface have greater influence than those on the upper surface. Orthogonal analysis gained a best airfoil whose power coefficient (CP) is 13.26% larger than that of NACA 0015. Flow field analysis found that a tiny positive vortex was enlarged intensively with the increasing of the azimuth angle, which degrades the rotor's performance.