What is the primary function of vortex generators on an aircraft wing?

• A. Delays stall and boundary layer separation by energizing the boundary layer.
• B. Increases wing camber to generate more lift.
• C. Reduces drag by smoothing laminar flow.
• D. Acts as additional ailerons.

Answer: (A)

Vortex generators energize the boundary layer by drawing higher-energy air from the outer flow into the slower air near the wing surface. This creates small vortices that mix momentum into the boundary layer, increasing its shear and resistance to separation. With a more energetic boundary layer, the flow stays attached longer under high angles of attack or disturbed conditions, delaying stall and improving controllability.

They don’t change the wing’s camber, and their job isn’t to smooth laminar flow to reduce drag. They also aren’t control surfaces like ailerons. The effect is to keep the wing’s lift going longer by preventing premature flow separation.