The Effect of Steady and Pulsed Air Jet Vortex Generator Blowing on an Airfoil Section Model Undergoing Sinusoidal Pitching

Abstract

Experimental results are reported on the assessment of steady and pulsed air jet vortex generators (AJVGs) for the suppression of dynamic stall on a sinusoidal pitching RAE9645 airfoil model. Tests at Rec of 1 million, at reduced pitching frequencies between 0.01 and 0.10 were performed with and without steady and pulsed AJVG blowing. The effect of jet momentum coefficient (0.0003< Cμ< 0.0046), jet duty cycle (0.25< DC< 1) and jet pulsing frequency (0.29< F+< 2.93) were investigated. Pulsed air jet blowing with F+ in the range 0.5–1.0 and with a duty cycle in the range 0.4–0.5, was found to be the most effective to achieve full suppression of dynamic stall vortex formation.