11.1 Wing Fences & Saw Tooth Flashcards
Why is boundary layer control important ?
To stop span-wise flow from creating strong vortecies from creating drag
What is there a particular danger with swept wing aircraft ?
Stalling tip first
What happens if both wings stall at the same time ?
The CofP moves closer towards the CofG. If the CofP overtakes the CofG, it can cause a nose up pitch moment which could worsen the stall
What do wing fences do ?
Reduce the effects of span-wise flow and helps reduce the risk of swept wing aircraft from stalling
How do wing fences work ?
Limit the boundary layer outflow before it begins to stagnate. They will then redirect this boundary layer back along the aerofoil
What are saw tooth leading edges?
There is an extension of the leading edge or a zig zag cut out. It helps reduce wing tip stall on swept wing aircraft
How do saw tooth leading edges work ?
The saw tooth creates a small vortex that limits the boundary layer outflow and redirects the spanwise flow.
What is the main difference between saw tooth leading edges and wing fences?
They work similarly, however they reinvigorate the airflow, increasing momentum and delaying stall
