This study investigates the aerodynamic performance of switchable vortex generators (SVGs) operated in spoiler configuration for load alleviation at transonic speeds. Using three-dimensional computational fluid dynamics (CFD) simulations, the effects of design parameters - including the height, aspect ratio, and spacing between the vortex vanes - are analysed on a simplified wing geometry, modelled as a straight extrusion of a supercritical airfoil. The analysis demonstrates that finite-span spoiler devices such as SVGs can effectively reduce the generated lift in cruise conditions, but their performance is strongly affected by geometric properties. Distinct aerodynamic regimes can be determined by placing a SVG of varying height and aspect ratio on the wing upper surface, characterised by different degrees of flow separation downstream of the device. Lift reduction becomes significant only when the size of the vortex vane is such to trigger full flow separation. The aerodynamic behaviour induced by a single SVG is further examined under high-speed off-design conditions, showing that larger vortex vanes induce full flow separation at lower angles of attack, while smaller SVGs can lead to sharp lift variations at higher incidence. The interaction between multiple SVGs is found to be significantly influenced by their spacing and aspect ratio, with the wall ratio emerging as a critical parameter. Smaller SVGs are most effective at high wall ratios, where they can generate a more uniform flow separation across the upper surface. In contrast, larger devices perform better at low wall ratios, where they can trigger full flow separation independently of their mutual interaction.

This paper investigates the impact of introducing a switchable vortex generator (SVG), acting as a minitab, on the aerodynamic performance of a high-aspect-ratio wing’s outer section in transonic regime. A parametric study is conducted employing computational fluid dynamics two-dimensional simulations, focusing on the aerodynamic effects of changing the chordwise position and height of the vane of a SVG located on the airfoil upper surface in both nominal cruise conditions and for varying angles of attack. The analysis reveals that minitabs can strongly affect the aerodynamic forces produced by the wing section, showing great potential for load alleviation and control, but also emphasizing the need for a careful parameter selection to reduce undesirable effects such as the generation of shock waves. In cruise conditions, lift reduction increases with the vane height and has its maximum for chordwise positions at 60% of the chord length. However, SVGs located in the first half of the chord length yield more robust performance for varying angle of attack, without sharp lift variations or generated shock waves, and a delayed stall onset. High SVGs (greater than or equal to 3% chord length) can also lead to strong shock waves on the airfoil lower surface at small or negative angle of attack, while small SVGs (less than 1% chord length) can generate normal shock waves on the upper surface, with limited lift reduction in cruise conditions and at higher incidence.

This paper investigates the impact of introducing a switchable vortex generator (SVG), acting as a mini-tab, on the aerodynamic performance of a high-aspect-ratio wing's outer section in transonic regime. A parametric study is conducted employing computational fluid dynamics 2D simulations, focusing on the aerodynamic effects of changing the chord-wise position and height of the vane of a SVG located on the airfoil upper surface in both nominal cruise conditions and for varying angles of attack. The analysis reveals that mini-tabs can strongly affect the aerodynamic forces produced by the wing section, showing great potential for load alleviation and control, but also emphasising the need for a careful parameter selection to reduce undesirable effects such as the generation of shock waves. In cruise conditions, lift reduction increases with the vane height and has its maximum for chord-wise positions at 60% of the chord-length. However, SVGs located in the first half of the chord-length yield more robust performance for varying angle of attack, without sharp lift variations or generated shock waves, and a delayed stall onset. High SVGs (≥3% chord-length) can also lead to strong shock waves on the airfoil lower surface at small or negative angle of attack, while small SVGs (