Velocity and Lift
In
the same way increasing the angle of attack creates more lift, increasing the
velocity of the plane can also produce more lift. This is because the amount of energy transferred
from the wing to the air is greater if the plane’s speed is faster, resulting
in a greater downward velocity of the downwash air. As you now know, momentum is quantified by velocity and
mass. If the angle of attack
remained the same, then ideally the same mass of air would be diverted, but
the final velocity of the air would be greater, resulting in a greater
overall momentum of the air and opposing lift force. As
you can now see, lift is proportional to the angle of attack and the plane
velocity. If the velocity of the
plane is decreased, then the angle of attack must increase to maintain the
same lift. The airline industry
is big business, and over the years engineers have found new ways to make the
generation of lift more efficient.
Anyone who has flown on a commercial jet has seen the flaps and slats
that move out during takeoff and landing. These devices help the airfoil shape to be much more
curved, generating more lift on the wing despite the slower speeds associated
with landings and takeoffs.
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