What does a boundary layer fence prevent on a swept-wing aircraft?

A boundary layer fence is designed to optimize the aerodynamics of a swept-wing aircraft by managing the airflow over the wing. Specifically, it helps prevent flow separation, which occurs when the airflow detaches from the surface of the wing.

In a swept-wing design, the airflow can behave differently due to the angle of the wing and the speeds at which the aircraft operates. When the boundary layer becomes too thick or encounters adverse pressure gradients, it may separate from the wing surface, which can lead to a significant loss of lift and an increase in drag. By directing the flow and maintaining its attachment to the wing, the boundary layer fence helps maintain better aerodynamic performance, enhancing both lift and stability during flight.

Understanding the importance of preventing flow separation is crucial for maintaining a swept-wing aircraft’s efficiency, particularly at higher speeds and in various flight conditions.