Influence of Tangential Synthetic Jet Location on Flow Control

A numerical study of separation control has been made to investigate aerodynamic characteristics of a NACA0012 airfoil with a tangential synthetic jet. Simulations are carried out at the chord Reynolds number of Re=1,000,000. The present approach relies on solving the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. The turbulence model used in the present computation is the K-ω SST equations. All computations are performed with a finite volume based code. We have varied the synthetic jet position on the suction side of the airfoil at various locations from 4% of the chord all the way up to 60% of the airfoil chord. The jet oscillating frequency of f_j = 15 Hz, (which corresponds to the non-dimensional oscillating frequency of $Fjet+$ = 1 when the jet is placed at the 12% chord location), and the blowing ratio of V_j/U_∞ = 2 are used during the control cycle. All the cases considered here are for the airfoil at the constant angle of attack of α = 19°, where the airfoil stalls in the uncontrolled base flow. We found that stall characteristics are significantly improved by controlling the formation of separation vortices in the flow. The airfoil lift is more than doubled by placing the tangential synthetic jet anywhere between 20% chord to 50% chord location. This corresponds to a 25% improvement over the best cases reported by Chapin and Benard (2015) for a cross flow synthetic jet.