What is one primary function of boundary layer fences in aviation design?

Boundary layer fences are aerodynamic devices strategically placed on the wings of aircraft to manage the airflow over their surfaces. Their primary function is to prevent airflow separation, which can occur when the boundary layer—a thin layer of air close to the wing surface—loses its adhesion to the wing. This loss of attachment can lead to a significant decrease in lift and an increase in drag, potentially resulting in stall conditions.

When boundary layer fences are used, they disrupt the smooth flow of air in a way that energizes the boundary layer, helping it to stay attached to the wing for a longer span of its surface. This effectively enhances the overall performance of the wing at various angles of attack, allowing the aircraft to maintain lift and stability during flight. Thus, the function of boundary layer fences is crucial for ensuring that the wing can operate efficiently and safely, particularly during critical phases of flight such as takeoff and landing.