Drag and Coefficient Flashcards
What are the two main types of drag?
Induced drag
Parasite drag
What is induced drag?
A by product of lift production, caused by the generation of wing tip vortices. Higher CL = higher induced drag.
What is parasite drag?
Parasite drag is a combination of:
Skin friction (the friction of the air Aragon’s the the airframe which in turn generates boundary layers)
Profile drag (the inherent drag produced by the airframe moving through a mass and the air molecules stagnating against it)
Interference drag (the disrupted airflow between different sections of the airframe)
What happens to parasite drag with speed?
Parasite drag is inherently related to the shape and design of the aircraft and so will INCREASE with speed.
What happens to induced drag with speed?
Induced drag is inherently related to lift production. With increased speed we require less lift and so induced drag DECREASES with speed.
What is the minimum drag speed?
It is the point on the total drag curve where drag production is at its lowest. (Induced goes down as parasite goes up)
It is at this point we want to fly our aircraft for best efficiency.
What is the drag equation?
D = Q x S x Cd
What is the Cd equation?
Cd = D/QxS
