Lift and Drag Flashcards
Define Lift in relation to the airflow
Lift is force that acts Perpendicular to the airflow
Define Drag in relation to the airflow
Drag is force that acts Parallel to the airflow
Total Air Reaction (TAR) is the result of which two forces?
Lift and Drag
Name the aerofoil shape that doesn’t produce Lift at zero degrees Angle of Attack
Symmetrical
Name the aerofoil shape that produces Lift at zero degrees Angle of Attack
Cambered
What happens to Lift when the aerofoil goes past the Stall Angle?
There’s a dramatic reduction in Lift
What happens to the Centre of Pressure (CoP) when an aerofoil stalls?
It moves backwards on the upper surface towards the middle of the aerofoil
State the Lift equation
L = ½ ρ v² S Cʟ
(Lift = Half x Density x Velocity Squared x Wing Area x Coefficient of Lift)
State the Drag equation
D = ½ ρ v² S Dʟ
(Drag = Half x Density x Velocity Squared x Wing Area x Coefficient of Drag)
Name the two main types of Drag
Profile Drag and Induced Drag
Define Profile Drag and Induced Drag
Profile Drag is the result of the movement of an object through the air.
Induced Drag is the result of an object producing Lift
Name three components of Profile Drag
Pressure (Form) Drag, Skin Friction Drag and Interference Drag
Define the three components of Profile Drag
Pressure (Form) Drag is caused when a viscous fluid flows past a body.
Skin Friction Drag is caused by the viscous dragging nature of the Boundary Layer.
Interference Drag is caused when the shape of an object causes airflow patterns to mix as they flow around protruding objects
Name three methods of reducing Pressure Drag
Streamlining, a reduction in in the frontal area and Boundary Layer control
Name three methods of reducing Skin Friction Drag
Keep the Total Surface Area to a minimum, smooth surface finish and maintain the Laminar Boundary Flow (delay the Transition Point)
