Effects of blowing and suction jets on the aerodynamic performance of wind turbine airfoil

This work experimentally investigates the effects of blowing and suction jets on the aerodynamic performance of a NACA0012 airfoil at a moderate Reynolds number Re = 1.0 × 105. The performance of a single blowing jet is only examined first, and then combinations of blowing and suction are implemented. The loadcell and surface oil flow visualization techniques are respectively used to measure the aerodynamic forces and flow structures on the uncontrolled and controlled airfoil. Effects of momentum coefficient and location of blowing and suction jets on the lift, drag, stall angle, cut-in speed, flow separation, and flow reattachment are studied to find an optimum control case. The results prove that the single blowing jet located at 0.2c from the leading edge has the best performance in the lift enhancement, where c is the airfoil chord length. The maximum enhancements of peak lift force coefficient CL and lift-to-drag ratio CL/CD are achieved as 18.4% and 804%, respectively. The underlying physics of aerodynamic performance enhancement relies on suppression of the flow separation and formation of separation bubbles.