Collaborative Studies on Flow Separation Control

This paper presents the wind tunnel test results concerning the effects of deploying steady and synthetic jets on a NACA0015 airfoil and describes the design of a multi-orifice-single-chamber synthetic jet actuator. Three steady jets with different configurations were tested. The orifice diameter, orientation and spacing were the varying parameters. Synthetic jets were deployed through a single row of orifices that were orientated normal to the airfoil surface. A single row of each type was positioned at 30% of chord from the leading edge. These jets exhibited varying degree of control authority over the lift and drag coefficients. The timescales of attachment and separation were estimated for the test cases of angled steady and synthetic jets. In view of controlling the flow separation in a dynamic manner, a multi-orifice-single-chamber actuator with a typical response time smaller than that of the afore-mentioned time scales was designed, fabricated and tested in quiescent condition.