Boundary Layer Control

Air particles flow in two directions over a wing, one at right angles to the leading edge, other follows leading edge
1. Produces spanwise flow
Spanwise flow thickens boundary layer towards the wing tip, especially during low speed flight with high angle of attack
1. Wing fences reduce effects of spanwise flow
Flow separation risk is increased with spanwise flow
Vortex Generator
1. Improves boundary layer control
2. Small and low aspect ratio wing placed vertically on surface of a large wing
3. Produces lift and has associated tip vortex which is comparable to induced drag
4. Vortex is large relative to generator because of small aspect ratio
5. Takes high energy air from outside boundary layer and mixes it with low energy air in boundary layer
6. Generator must be right size and right location to go through boundary layer
Stall Strips (Wedges)
1. TYpically consist of small piece of aluminium triangular cross section, often 6 - 12 inches long
2. Initiates flow separation earlier than at other positions along the wing
  1. Causes wing root to stall before outer portions, ensuring a progressive outward stall
    1. Minimizes risk of spinning and giving maximum aileron control throughout stall

Resource summary

	Created by Kenzie Evans about 7 years ago