A numerical investigation of synthetic jet effect on dynamic stall control of oscillating airfoil

At high angles of attack, the dynamic stall phenomenon can arise from the vortex shedding, particularly in an oscillating airfoil. As a result of this phenomenon, a considerable decrease in the lift and an increase in the drag and pitching moment coefficients are observed. This study aims to investigate the flow control of an NACA 0015 airfoil using a Synthetic Jet (SJ). The flow was assumed to be unsteady and turbulent at the Mach number of 0.2 and Reynolds number of 1 million. This research was conducted at the angle of attack of 15 degrees +/- 10 degrees. In order to carry out the numerical analysis of the problem, the 2D compressible turbulent Navier-Stokes equations based on "Roe" scheme with the second-order accuracy were solved. Turbulence modeling was carried out using the three-equation k - k(L) - omega model. According to the obtained results, this flow control method could significantly control or eliminate the dynamic stall of the airfoil. In addition, the phase difference between the jet and airfoil oscillations was mostly affected by the dynamic stall decrement. In these changes, using SJ with a momentum coefficient of 0.1 brought about the amplitude of maximum lift at phi = -30 degrees, and the multiplication of the coefficients of drag and moment amplitudes at phi = -10 degrees ensured the best performance. (C) 2021 Sharif University of Technology. All rights reserved.