Numerical Study on the Aerodynamic Characteristics and Performance Enhancement of the Gurney Flap Applied on Blade in the Vertical Axis Wind Turbine

• Main Authors: Guo-Yang Rao, 饒國揚
• Other Authors: 鄭仁杰
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/es5jkc

碩士 === 國立虎尾科技大學 === 航空與電子科技研究所 === 103 === The vertical axis wind turbines(VAWT) have an advantage over the horizontal axis wind turbines such as easy installation, less susceptibility to wind shift and low noise. They are very suitable to be installed in urban and suburban region. The VAWT has great potential for promoting green energy in residential life. This study intends to investigate the flow structure and aerodynamic characteristics by installing the Gurney flap on the turbine blades of a three straight-blades VAWT system. The efforts of this study are devoted to the influences of the installation types (Upward, Downward, T-type), height of the flap, and tip speed ratio (TSR) on the torque and efficiency of the wind turbine. In the 2D VAWT, Gurney flap with height H/c≦2% has better performance improvement in most case of different TSR and installation types. In the three installation types, T-type is the best installation type. The maximum average Cq is occurred at TSR=2.5; The Cq is increase with TSR as TSR<2.5, and then decrease as TSR>2.5. The performance of T-type is good when TSR=1 and TSR=1.5. Upward is better only at TSR=1.5. Upward type is the worst of the three installation types. The best performance of Upward is occurred when TSR=1.5. The performance of Downward type is better than others at TSR=2 and worst in TSR=1.5. Within the scope of our investigation, the best average torque coefficient can improve about 88.5%. (TSR=1~TSR=2.5, Gurney-flap height 1~4%c) In the 3D VAWT, Gurney flap with height H/c≦2% has better performance improvement in most case of different TSR and installation types. In the three installation types, T-type is the best installation type. The maximum average CQ is occurred at TSR=2; The CQ is increase with TSR as TSR<2, and then decrease as TSR>2. The performance of T-type is good when TSR=1 and TSR=1.5.The performance is going down when TSR≧2. Upward has optimal performances occurred only when TSR=1 and TSR=1.5 with flap height is 1%c and 2%c. The best performance of Upward is occurred when TSR=1.5. Downward is not going well in 3D cases. It has better performances occurred only when TSR=1 and flap height ≦2%c. Within the scope of our investigation, the maximum average torque coefficient enhancement of the wind turbine for the situations with and without Gurney flap on the blades is higher as TSR=1.5 and can be up to 28.6% for T-type flap with 4% c height.