11.1 Boundary Layer Control

Question 1

What is a vortex generator ?

Answer 1

A device used to re-energise a slow moving boundary layer. It’s a small aerofoil placed vertically on the wing

Question 2

How does a vortex generator work ?

Answer 2

Tales high energy air from outside the boundary layer and mixed it with low energy air to re-energise the boundary later

Question 3

How are vortex generators placed ?

Answer 3

They are placed in opposing pairs so that the vortices mix

Question 4

What are stall wedges ?

Answer 4

Small metal wedges that sit on the leading edge by the root of the wing which causes the wing to stall at the root before the tip.

Question 5

Why are stall wedges beneficial?

Answer 5

Stall wedges cause the root to stall before the tip. The root stalling causes a noticeable vibration which the pilot can feel and correct the plane before the tip stalls

Question 6

How do stall wedges work ?

Answer 6

At high angles of attack, it encourages airflow separation at the tip of the wing. Turbulence at the tail will give the pilot some physical warning for an impending stall

Question 7

What are the most common lift devices ?

Answer 7

-slots,
-slats,
-flaps,
-flaperons