Aerodynamic performance improvement of a pitching airfoil via a synthetic jet

Abstract

The aim of the present work is to control the dynamic stall of a pitching NACA0012 airfoil and improve its aerodynamic performance by using a synthetic jet in a low Reynolds number compressible flow for use in prospective applications, such as flights on Mars and in the stratosphere. A recently developed variable correction-based immersed boundary method is employed to predict the complex flow fields. A sinusoidal function is selected to fulfill the periodic jet. Compared with the situation without control, the use of a synthetic jet can obtain a significant improvement of the aerodynamic performance of the pitching airfoil. Based on the numerical results, adjusting the phase angle to trigger the suction time of the synthetic jet at a large angle of attack can obtain the best lift increment and drag reduction. Additionally, in a small variation range, a larger jet momentum coefficient can produce better aerodynamic performance. However, when the jet momentum coefficient increases up to some fixed value, the enhancement is weakened. Furthermore, placing the jet at the leading edge is more conducive to improving the aerodynamic performance. Finally, the higher the Mach number, the worse the control effect of the synthetic jet.