Experimental Study of Sidewall Interference Control on Large Thickness Airfoil

High-performance large-thickness airfoils with blunt trailing edge are important for the development of multi-megawatt large-scale wind turbines. Currently, serious sidewall interference problems are encountered in obtaining performance data of such airfoils in wind tunnel experiment. In this paper, a new idea of sidewall interference control for large thickness airfoil wind tunnel experiment based on tandem vortex generators was proposed, and the experimental verification was carried out in NF-3 wind tunnel of Northwestern Polytechnical University. An airfoil with a maximum thickness of x/c = 55% was experimented at a chord based Reynolds number of 1 × 106. The experiment results were analyzed thoroughly from three aspects including the aerodynamic performance, the pressure distribution and the flow visualization based on fluorescent filament. It is shown that appropriate tandem vortex generators configuration can effectively suppress the flow separation at the junction of the sidewall and the airfoil model over a wide range of angles of attack, thus effectively controlling sidewall interference. And the proposed method provides a basis for the accurate acquisition of wind tunnel experimental data for large-thickness airfoils with blunt trailing edge.