Abstract Airfoil slots, as a passive flow control technique-based wing improvement structure, may successfully delay the stall angle and increase the lift coefficient in situations with a high angle of attack. But when the angle of attack is minimal, it drastically reduces the airfoil’s initial aerodynamic performance. The NACA4412 airfoil is used as the research object in this study, which uses Computational Fluid Dynamics (CFD) techniques to examine how various slot configurations affect the airfoil’s aerodynamic properties. Based on the optimal slot configuration, a scheme for dynamically adjusting the slot angle is proposed. The research results demonstrate the following: 1) Compared to previous configurations, Slot Configuration III may greatly enhance the airfoil’s stall characteristics by postponing the stall angle to 24° and raising the maximum lift coefficient by 27.6% to 1.57; 2) Through the rotation of the leading edge, the study achieved changes in slot configuration and inlet/outlet parameters, resulting in two slot configurations capable of maintaining aerodynamic performance under small angles of attack; 3) Utilizing the geometric relationship between Slot Configurations III and IV (5°, 8°), a variable-angle slot scheme is proposed, which enhances small angle of attack lift while effectively suppressing stall phenomena.
Zhang et al. (Fri,) studied this question.