풍차날개의 공력 성능 향상과 유동 박리 감소를 위한 수동 유동 제어에 대한 DES 해석 = Detached Eddy Simulation of a Passive Flow Control for Aerodynamic Performance Enhancement and Separation Reduction of a Wind Turbine Blade

다국어 초록 (Multilingual Abstract)

Power generation of a horizontal axis wind turbine is severely dependent upon aerodynamic phenomena over the blade, especially the flow separation. Since, usually the local AoA (Angle of Attack) in the inner and middle parts of a blade is much greater than the separation onset, the blade section encounters a highly separated flow or even stall condition. Hence, flow control methods can be employed in order to reduce or weaken the negative effects of the separation. This paper investigates the effects of a recently verified passive flow control method for HAWTs via a validated three dimensional DES(Detached Eddy Simulation) of split versions of the S809 airfoil. In this research, two different airfoil families with four various split width values of 0.5, 1, 2 and 4 percent of chord length are simulated at a range of angle of attack from 0 to 25 degrees. As a result of existence of the split, flow from the high-pressure zone at the lower surfaces gets injected into the separated area over the suction surfaces. The positive or negative effect of this method is mainly dependent upon split end location on the suction surface. Direction of the jet flow with respect to the free stream and also the width of split are the other important parameters. Also, the findings reveal that in each family there exists one optimal split width for which the airfoil aerodynamic performance is enhanced remarkably.

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