Low-Reynolds-Number Aeroelastic Coupling of NACA 0012 with Upper Surface Membrane

This paper numerically investigates the aeroelastic coupling characteristics of a NACA 0012 flexible airfoil at a low Reynolds number, focusing on the effects of elastic modulus and angle of attack. Results show that the aeroelastic coupling effect exhibits strong parameter sensitivity. At low elastic modulus, time-averaged camber deformation increases airfoil camber and expands the laminar separation bubble, which is the dominant cause of aerodynamic efficiency degradation. Dynamic vibration presents a dual effect strictly correlated with separation bubble position: it suppresses the bubble and improves aerodynamic performance when the bubble lies at midchord but aggravates trailing-edge secondary separation and degrades performance when the bubble is at the trailing edge. Angle of attack governs the transition of this vibration effect by altering the separation bubble position. An optimal elastic modulus range exists, where appropriately increased structural stiffness mitigates adverse deformation effects, and strong fluid–structure frequency lock-in is observed across the full parameter range. This study clarifies the core mechanism that time-averaged deformation has a predominantly adverse effect, while dynamic vibration’s effect is determined by the laminar separation bubble position, providing key theoretical guidance for flexible flight vehicle design.