| Summary: | 碩士 === 國立虎尾科技大學 === 飛機工程系航空與電子科技碩士班 === 104 === Humpback whales utilize extremely mobile, wing-like flipper for banking and turning. The tubercles on the leading edge act as passive-flow control devices that improve performance and maneuverability of flipper.The 3-D numerical simulation is performed in this study to thoroughly investigate the flow structure and aerodynamic characteristics of the designed wavy wing with different amplitude, wave length, thickness and aspect ratio, which is simulated from the tubercles flipper on humpback whales. This study integrated the SST k-ω turbulence module into the computational fluid finite volume method to explore the variation of the flow fields and aerodynamic performance of a pitching wing as well as VAWT.
The flow separation is more serious at the wave trough than at the wave crest due to the counter rotate vortex induced by the flow pass through the wavy leading edge. Comparing with the smooth leading edge, the lift coefficient of wavy wing is lower in low angle of attack, but is better at higher angle of attack. The lift increases as the amplitude of wavy leading edge is increase. The lift coefficient is firstly raised as wave length is increased in higher angle of attack region, but is decreased as wave length greater than 0.4c. The thinner of the thickness as well as the larger of aspect ratio of the wavy wing will enhance the aerodynamic performance more clearly.
For the pitching wing cases, the aerodynamic performance enhancement of wavy wing is obvious in the lower pitching rotating speed and αm= 20° at high angle of attack region. For the single blade VAWT, the thinner of the thickness of the wavy wing will enhance the aerodynamic performance more clearly. Comparing with the smooth leading edge, the average torque coefficient CQ enhancement of wavy wing are 38.5%、894.5%、345.1% as TSR=0.5、1.5、2 respectively.
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