Numerical investigation of traveling wave-induced flow control on a NACA0018 airfoil at Reynolds number of 20,000

The application of traveling wave morphing surfaces has emerged as an effective approach to reduce drag and prevent stall on airfoils at low Reynolds numbers. This study specifically examines the influence of wave parameters on flow control and stall mitigation over a NACA0018 airfoil at a Reynolds number of 20,000. Numerical simulations were performed to explore how traveling waves interact with the boundary layer, focusing on their ability to modify the flow dynamics and influence coherent flow structures. The results demonstrate that traveling waves can reduce turbulent kinetic energy in the region near the suction surface, promoting flow re-laminarization under certain conditions, particularly with low-speed, high-amplitude waves. At the same time, faster waves enhance turbulence, aiding separation control by generating coherent structures such as quasi-streamwise vortices and horseshoe-shaped vortices. This dual mechanism, combining relaminarization and enhanced turbulence, contributes to drag reduction and lift enhancement by preventing flow separation. Overall, this study highlights the effectiveness of traveling wave-induced flow control in improving aerodynamic performance and offers new insights into the interaction between the traveling waves and boundary layer dynamics.