Transonic shock buffeting poses a significant threat to aircraft safety and performance. This paper presents a novel approach utilizing a zero-net-mass-flux (ZNMF) jet method, implemented through trailing edge blowing/suction on the NASA SC(2)-0714 airfoil, to tackle the critical issue of transonic shock buffeting control. The fundamental characteristics of transonic shock buffeting were obtained through wind tunnel experiments. Numerical simulations, validated against experimental data, were carried out to investigate the control effects by the unsteady Reynolds-averaged Navier-Stokes equations based on the Reynolds stress model. Key parameters including jet intervention timing, angle of attack, free stream Mach number, and the jet strength, were analyzed to optimize the suppression of transonic shock buffeting. Results show that the ZNMF jet can completely suppress the airfoil transonic shock buffeting, independent of the specific jet intervention timing. This suppression is maintained across a range of angles of attack and free stream Mach numbers, yielding significant improvement in aerodynamic characteristics. Specifically, the standard deviation of the pitching moment coefficient is reduced by more than an order of magnitude, and the lift-drag ratio is increased by more than 10% on average. Furthermore, the study identifies a critical threshold for the jet strength in suppressing the transonic shock buffeting. Sub-critical jet strengths result in reduced shock wave oscillation, while application of jet strengths above this threshold completely suppresses shock wave oscillation, offering valuable insights for pratical implementation in aircraft design and operation.

Aiming at the problem of dynamic stall of helicopter rotors under variable free stream during forward flight, a dynamic stall control method of airfoils based on the co-flow jet (CFJ) is developed. Taking NACA0012 airfoil as the research object, the unsteady Reynolds-averaged Navier-Stokes equations are solved based on the transition SST turbulence model, and numerical simulations of the dynamic stall of airfoils controlled by CFJ under different parameters are carried out. The results show that CFJ can effectively suppress the dynamic stall of airfoils. Under the condition of variable free stream, the jet channel has a negative impact on the original aerodynamic characteristics of the airfoil, and the power coefficient increases much faster than the jet momentum coefficient. There is an optimal working condition for CFJ to achieve the best control effect. CFJ accelerates the evolution of multi-vortex by mixing with the mainstream to suppress the dynamic stall, and enhances the kinetic energy of the chordwise flow to overcome the adverse pressure gradient to suppress flow separation and promote flow reattachment. Under the condition of Mach number 0.283, reducing frequency 0.151 and advance ratio 0.25, CFJ can increase the lift of the airfoil, reduce the drag and the negative pitching moment peak, and advance the reattachment of the flow. The overall aerodynamic characteristics of the airfoil are obviously improved by the CFJ control.