Flatback Airfoil의 공력학적 특성 및 이를 적용한 수평축 풍력발전기의 성능변화

Abstract

In recent years, the new and renewable energy became more important to mitigate the global warming. Especially, considering the commercial aspects, the wind energy is now in the spot light among those alternative resources. In this circumstance, the pioneered and advanced countries have been concentrating enormous efforts to develop a state of the art wind energy technologies. To improve the economics of the wind turbine system, the progress of the blade efficiency is the one of the most important factor even though all the other components should be considered from all angles. In past decades, a lot of studies have been devoted to enhance the wind turbine blade performance.This study focuses on the aerodynamic characteristics of an airfoil applied the blunt edge at the root region, or called flatback edge, to investigate its performance. For the mesh generation and numerical simulation, the FLUENT, a commercial CFD software, and ICEM-CFD are used respectively. S809 airfoil and NREL Phase Ⅵ blade are selected as baseline models. Based on the experimental data presented by NREL(National Renewable Energy Laboratory, USA), the identical experiment conditions of the airfoil and blade are used for this study. The models for numerical analysis are blunt trailing-edge airfoils of the trailing-edge thickness to chord ratio of 1%, 5% and 10%. These airfoils and blades are modified from S809 airfoil and NREL Phase Ⅵ blade. To produce the comparable results to the S809 wind tunnel experiment data, the numerical simulation has performed for the angle of attack of 0°, 1.02°, 5.13°, 9.22°, 14.24° and 20.15°. Inaddition, the numerical analysis for blades has performed for the wind speed of 7m/s, 10m/s, 15m/s, 20m/s, and 25m/s respectively. The calculated results for modified airfoils and blades are compared against those of the baseline blade.