What occurs when airflow breaks away from the airfoil and forms a turbulent wake?

When airflow breaks away from the airfoil, it leads to boundary layer separation. This phenomenon occurs when the smooth flow of air over the surface of the airfoil loses its momentum, typically due to adverse pressure gradients or increased surface curvature. As a result, the airflow detaches from the surface, creating a turbulent wake behind the airfoil.

Boundary layer separation is significant because it affects the overall performance of the aircraft, particularly in terms of lift. When the boundary layer separates, it disrupts the smooth flow over the airfoil, resulting in an increase in drag and a potential loss of lift. This can lead to a stall if the angle of attack is further increased.

Understanding boundary layer separation is crucial in aerodynamics, as it influences design considerations for airfoils, wing shapes, and control surfaces to optimize aircraft performance and stability.