Variable

Description

Explanation

Angle of attack

A straight line at less than a
45^{o} angle through 0,0. The lift and angle show +
and  numbers.

The straight line shows a steady
increase. If you double the angle, then you double the
lift.

Thickness of airfoil

A slight upward
curve.

The curve shows that as the
thickness increases the lift also increases, but to a lesser
degree.


At angle = 0.0, there is no line on the
graph.

For a symmetric airfoil, a change in thickness
will not change the lift.

Camber

A straight line at less than a
45^{o} angle through 0,0 with lift being both + and
.

The straight line shows a steady
increase.

Airspeed

An upward curve where the slope
of the line increases with increased speed.

The upward curve shows that lift
increases at a greater rate than the speed
increases.


At angle = 0.0, there is no line.

For a symmetric airfoil, a change in airspeed
does not create lift.

Altitude (density)

A downward curving line where
the slope decreases with altitude.

As altitude increases the lift
that results decreases; but the decrease lessens with
altitude. ( As the altitude increases, the density of the
air decreases. So lift decreases as density
decreases.)

Area of airfoil surface

A straight line at a
45^{o} angle through 0,0.

The lift increases at the same
rate as the area.
