| The complex flow condition around wind turbine become stronger with the increasing of the wind turbine utility scale.Blade flow control on plays an important role in the research about the increase of the wind turbine operation efficiency and decrease of the wind turbine fatigue loads.The blade aerodynamic performance depends on the airfoils performance.Adding the attach equipment on the airfoil surface,take good control of the surrounding flow,and improve the airfoil performance.Hence,the paper researched on the vortex generator、transition band and gurney gap flow control mechanism on the DU97-W-300 airfoil by the wind tunnel experiment method.Through the analysis of the airfoil lift and drag coefficient and pressure coefficient distribution,obtain the flow control effect of the different attach equipment.The content of the research is arranged below:(1)The effect of vortex generators(VGs)airfoil on the airfoil uppers surface flow.The effects of the installation position,geometry,height,pitch,spacing and angle of the VGs on the surface flow of the airfoil are studied step by step.In terms of increasing lift,the installation position of VGs is 20%chord length,and 30%chord length is the best in delaying flow separation.The shape of triangle is better.The step has little effect on the aerodynamic performance of the airfoil.The effect of spacing of the VGs is different under the different Reynolds number.The effect is better when the spacing is small,the effect of 5 times and 7 times of the spacing is better,and the effect of angle 15°is relatively better.In addition,the double-row VGs installed on the airfoil upper surface is not as good as the single-row VGs.and the front row plays a leading role in the arrangement of the double-row VGs case.(2)The effect of the transient tape stick on the airfoil surface.Firstly,the transition tape are respectively attached to different positions of the upper and lower airfoil surfaces.The influence of the position of the transition tape on the lift coefficient is studied.The results show that the effect become more obvious with the closer to leading edge of the lower airfoil,and the farther it is.the less obvious.The effect is not obvious when the position reaches the lower airfoil 2%chord length.The effect of the upper wing surface become best at the 5%chord length.The transient tape adhered on the lower airfoil causes flow separation at a negative angle of attack.Secondly,the influence of the width and thickness of the transient tape is compared.The effect of the width is not obvious.The increase of the thickness has a greater influence on the maximum lift coefficient,and the high thickness will have a sharp drag increase at a small angle of attack.The comparison found that the sharp drag increase is the result of a combination of width and thickness.Finally,the transient tape is combined with VGs to study the coupled effect.The results show that the combination of the transient tape and the VGs can both reduce the lift and delay the stall angle of attack.(3)The effect of the gurney flap installed the airfoil trailing edge.Firstly,five different height of gurney flaps on the trailing edge of the airfoil is investigated.The higher of the gunnery height,the increase of lift become better.Secondly,the experiment of combining the gurney flap with the VGs is studied,and the result show that lift can be increased and the stall angle of attack are delayed,but the lift-to-drag ratio is lower than that of only VGs. |
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