Numerical investigation of air suction and blow mechanism for passive control flow over a wind turbine airfoil

Flow separation phenomena near root regions of wind turbine blades is one of the main factors of energy loss in these machines, and preventing it from taking place is considered impactful in efficiency increase for these systems. In this study, through utilization of a 2d incompressible CFD solver, 2D flow around the airfoils used near rout regions of a wind turbine has been analyzed. The governing equations have been considered to be solved through pressure-based and transient form. The RANS approach with k-ω SST turbulence model have been employed in order to solve the turbulence equations. Good agreement was observed with numerical results and experimental data. In the next step 11 different flow controlling designs have been devised and investigated; eventually, the final design meets the needs for flow separation control and lift to drag ratio increase. Then, the optimum design was tested with different angles of attack and the result demonstrated that the performance of the base airfoil has been ameliorated significantly. In comparison with the base case, 38% and 36% increases in lift and drag coefficients has been achieved respectively while the separation phenomena have been absolutely diminished.