Drag Part 2 Flashcards
What type of drag occurs when air meets at a junction?
Interference drag.
What type of drag does fillets remove/reduce?
Interference drag.
How do you reduce form drag?
Streamline.
How do you reduce skin friction drag?
Smooth the surface.
How do you reduce interference drag?
Fillets.
How do you reduce induced drag?
Winglets.
How induced drag proportional to velocity?
Id & 1/v^2
What does the Coefficient of drag consist of?
Coefficient of parasite + coefficient of induced.
How is coefficient of induced drag proportional to coefficient of lift?
CID & CL^2
What type of speed characteristics are improved by winglets?
Low speed.
Although tip tanks can reduce wingtip vortices, what type of drag is increased when they’re used?
Form drag.
How do fences reduce trailing edge vortices?
Prevent spanwise flow.
What do vortilons and strakes do?
The promote vortices, preventing spanwise flow.
How does a vortex generator delay separation?
It induces energy from the free stream layer into the boundary layer.
How is parasite drag and speed proportional?
Pd & v^2
How do flaps effect induced drag?
It doesn’t.
How do flaps affect trailing edge and wing tip vortices?
Increases trailing edge but decreases wing tip vortices.
Whats it called where parasite drag and induced drag meet on a drag,speed graph.
Minimum drag speed.
What number of minimum drag speed is the best for drag to speed ratio?
1.32.
At speed stable, which is greater : drag or thrust?
Thrust.
At speed unstable, which is greater : drag or thrust?
Drag.
As mass increases, what happens to the VMD? (Minimum drag speed)
It gets faster.
As flaps are extended what happens to the VMD?
It slows.
As TAS increases, what happens to the mean drag curves’ position as altitude increase?
It moves to the right.
