Understanding Lift Force on Airplanes

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SUMMARY

The force of lift on an airplane is calculated using the formula F = Lc * D * v^2 * A, where Lc is the lift coefficient, D is air density, v is velocity, and A is the lift area of the wing. For example, using Lc = 1.0, D = 1.225, v = 100, and A = 21 results in a lift force of 257,250 N. This force can be interpreted in relation to the weight of the aircraft, where the resultant force is calculated as F_total = F_lift - mg. In level flight, lift must equal the weight of the aircraft, and understanding the balance of forces is crucial for practical applications.

PREREQUISITES
  • Understanding of basic physics principles, particularly Newton's laws of motion.
  • Familiarity with aerodynamics, specifically the concept of lift and drag.
  • Knowledge of SI units, particularly Newtons for force measurement.
  • Basic understanding of aircraft weight and gravitational force calculations.
NEXT STEPS
  • Research the principles of aerodynamics, focusing on lift and drag forces.
  • Learn about the lift coefficient and its impact on aircraft performance.
  • Study the relationship between thrust, drag, and lift in various flight conditions.
  • Explore the effects of different wing designs on lift generation.
USEFUL FOR

Aerospace engineers, aviation students, and anyone interested in the physics of flight and aircraft performance optimization.

Poposhka
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the force of lift excerted on an airplane is defined as
F = Lc * D * v^2 * A
where Lc is the lift coefficient, D is the air density, v velocity, and A the lift area of the wing structure. If i use SI units, the Force is expressed in Newtons.

What I'm trying to grasp here, is how does this apply in practicality?
If i use the numbers Lc = 1.0, D = 1.225, v = 100, A = 21, (not random values) the result is 257,250 N ... now ... what does that MEAN? that the wings on that airplane produces enough lift to accelerate a 2000 kg airframe upwards at 128.6 m/s^2 ? Or, am i not calculating in gravitation? should the correct formula be 257250 / (2000 * 9.8) = 13.1 m/s^2 ? That just seems like an awfully high number... Or is it impossible to determine accurate lift unless you account for drag?

Thanks for any help
-- Pops
 
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Remember that lift is not the only force acting, don't forget gravity. The resultant force would be something like;

F_{total} = F_{lift} - mg

~H
 
The thrust pushes the plain forward and drag pushes/pulls against the aircraft.

In level flight, the lift balances the weight of the aircraft.

The forward velocity of the aircraft cause the lift as the air passes above and below the wing. The pressure over the wing is slightly less than the air pressure under the wing. In fact, the average differential pressure across the wing of a Boeing 747 is about 1 psi, and there is about 1 in2 of surface area for each lbm (weight of 1 lbf) of plane + load.
 

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