Effect of synthetic jet parameters on controlled flow over an airfoil

Flow control for performance enhancement over airfoils (both stall and load enhancement) has become an increasingly important topic. This numerical work describes the characteristics of flow control using synthetic jets over a NACA 0015 airfoil at a Reynolds number of 8.96 × 105 (based on the chord length and free-stream velocity) and at 20° angle of attack (wherein the flow is separated). A range of synthetic jet parameters were chosen to visualize their effects on the controlled flow. Analysis of key flow parameters indicate that the synthetic jet is efficient in increasing the lift coefficient while simultaneously reducing the drag coefficient, more so for larger jet amplitudes and at smaller angles of jet injection. A regression model for predicting the flow parameters is also specified. Toward the end of the study, a new parameter—the differential time of suction and blowing—was identified and its effect on the flow dynamics was observed. While the time modulation offers some benefits, it is the opinion of the authors that the benefits are too marginal to justify the implementation of such a system. This work serves as a platform to qualitatively and quantitatively understand the effects of the jet parameters on the separated flow over the airfoil, by understanding the flow parameters and structures. © 2017 by Begell House, Inc.