4 forces of flight

A detailed Summary of 4 forces of flight

Have you ever looked up at an airplane and given any thought to the forces that keep it moving and in the air? There are four forces that keep an airplane in the air; they are lift, weight, thrust, and drag. The combination of these helps an airplane sustain flight.

The most important of these aerodynamic forces is lift. Without lift, the airplane could not stay in the air. Lift is created when the camber (curvature) of an airfoil's upper surface makes the air flowing over it moves faster than the air flowing under the wing. This increase in velocity reduces the pressure on the top of the wing so lift is produced. This is known as Bernoulli's Principle. This principle is so named because Daniel Bernoulli, a Swiss scientist, discovered it (Jeppesen). Every airfoil, no matter what its camber or chord, will lose its smooth flow at some point along the upper surface. The regular airfoil has turbulence somewhere forward of the trailing edge even though level flight is maintained. With every increase in the angle of attack, this turbulent flow moves closer forward to the leading edge. This is true up to a point because one must also consider the power need to move the aircraft through the air. With unl

Streamlining the aircraft prevents parasite drag. Parts of an aircraft that cannot be streamlined are covered with fairings that have a streamlined shape (Levy).

Parasite drag is a form of skin friction drag that occurs around rough edges of an aircraft. The friction between outer surfaces of the aircraft and the air that it moves causes skin friction drag. It is found on all surfaces of the aircraft.

Dynamic drag is dependent on the angle of attack. Depending on the angle of attack, there will be a force backward (induced drag) and a force upward (lift). The ammount of force in each direction will depend on the angle of attack. If the angle of attack is small, the drag and lift is also small. Any increase in angle of attack will increase the amount of drag and lift. However, at high angles of attack, lift will decrease and drag will overcome lift and thrust with loss of airspeed and attitude. If the wing were completely vertical to the relative wind, the only force would be backward, therefore all dynamic drag and no lift (Levy).

The next aerodynamic force is thrust. Thrust, also know as velocity, is the forward-acting force that opposes drag and propels the aircraft. In most aircraft, this is performed when the engine turns a propeller. As is the case with lift, differential pressures produce thrust. The shape and angle of attack of the propeller produces reduced pressure in front of the propeller and increased behind it. This produces a reaction force in the direction of the lesser pressure therefore moving the aircraft forward. Increasing the power of the engine increases thrust. During straight and level flight thrust and drag are equal, therefore, there is no increase or decrease in speed is done. Using a throttle to increase engine power increases thrust. Whe

Some common words found in the essay are:
Bernoulli Swiss, Levy Parasite, Levy Dynamic, , Levy Pressure, angle attack, induced drag, Bernoulli's Principle, pressure drag, angle attack means, aerodynamic forces, level flight, drag lift, upper surface, aircraft air, drag aircraft, turbulent flow, attack means wing, increase angle attack, newton's third law, third law motion,

Approximate Word count = 1217
Approximate Pages = 5 (250 words per page double spaced)

Category: Science