| 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 === 105 === 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. Theexperiment and 3-D numerical simulation are performed in this study to thoroughly investigate the flow structure and aerodynamic characteristics of 3-blade VAWT applyingthe designed wavy wing with different amplitude, wave lengthand aspect ratio, which is simulated from the tubercles flipper on humpback whales.
For the static single blade cases withV∞=12m/s, the flow separation is stronger at the wave trough than at the wave crest due to the counter-rotating 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 superior at higher angle of attack. The effect of the wavy wing strongly depends on the wave length and amplitude of the wavy leading edge. For higher wave length cases, the average lift is rise as amplitude isincreased. Similarly, the improvement is more obvious for lower wave length case as amplitude is decreased.
For the three blades vertical axis wind turbine cases withV∞=6m/s, R/c=1.726, 0.05c ≦ A ≦to 0.3c, 0.5c≦ WL ≦ to 3c and tip speed ratio 0.095≦ TSR≦1,the wind turbineperformance of wavy wing is obviouslyimproved.Comparing with the smooth leading edge, the maximum average torque coefficient CQ enhancement of wavy wing with amplitude variationare20.02%, 22.66%, 26.05%, 19.15%, 16.72%, 6.91% as TSR=0.095, 0.191, 0.287, 0.383, 0.5, 1 respectively.The maximum average torque coefficient CQ enhancement of wavy wing with wave length variationare23.89%, 22.23%, 13.52%, 12.71%, 12.56%, -0.29% as TSR=0.095, 0.191, 0.287, 0.383, 0.5, 1 respectively.
The wind turbine power analysis also implemented with numerical simulation and wind tunnel measurement. Comparing with the smooth leading edge, the maximum power enhancement of wavy wing with amplitude variationare40.05%, 39.63%, 24.91%, 22.02% as TSR=0.05, 0.06, 0.07, 0.08 respectively with numericalsimulation; and the enhancements are40.31%, 44.65%, 37.34%, 48.88% as TSR=0.05, 0.06, 0.07, 0.08 respectivelywith wind tunnel measurement.
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