Effect of Shock Wave Interference on Aeroelasticity of Hypersonic Airfoils

Shock wave interference is a common phenomenon in hypersonic vehicles. It modifies the load distribution across the wing surface, thereby affecting the aeroelastic characteristics. This paper investigates the influence of shock wave interference location and intensity on the flutter characteristics of a hypersonic airfoil using a method based on a reduced-order model. The flutter mechanism under shock wave interference is revealed through root locus analysis and the unsteady aerodynamic work method. When the shock wave interference moves from the leading edge to the midpoint of the airfoil, the critical flutter velocity gradually increases but remains lower than the critical flutter velocity in the absence of shock wave interference. When the shock wave moves from the midpoint to the trailing edge, the critical flutter velocity reaches its maximum value and then gradually decreases. The influence of shock wave interference intensity on the flutter characteristics exhibits monotonic behavior. Finally, this paper finds that, in order to improve the aeroelastic stability of hypersonic airfoils, the first step is to move the shock wave interference location away from the front area of the airfoils. Second, the flutter mode can be changed to increase the critical flutter velocity.