Aircraft Lift, Thrust, Weight and Drag
Introduction to Aeronautical Science, ASCI 202
Embry-Riddle Aeronautical University
This brief paper is designed to give the reader a basic understanding of the principles of Aircraft Lift, Thrust, Weight and Drag. It will cover the basic wing airflow design; aircraft thrust and engine development and technologies employed today on large modern aircraft. This paper will discuss basic aircraft weight and center of gravity, and drag reduction employed during aircraft hull designs and development. In conclusion a brief summary of the effects of these four elements and the course of aviation in the future.
Aircraft Lift, Thrust, Weight and Drag
The predecessor of the fixed wing aircraft is the kite. The kite was the first kind of aircraft to fly, and believed to have been invented in China somewhere around 500 BC. The first aircraft that was capable of controlled free-flight was a glider. The glider designed by Sir George Cayley (1773-1857) carried out the first true manned, controlled flight in 1853. (Encyclopedia, 2012) Practical, powered, fixed wing aircraft (the airplane) was invented by Alberto Santos-Dumont (1873-1932) (Concise, 2012). Besides the method of propulsion, fixed wing aircraft discussed here are in general characterized by their wing configuration.
Bernoulli’s Principle: states that "the pressure of a fluid, liquid or gas, decreases as the
speed of the fluid increases." Within the air, in the example of aircraft in flight, high speed flow
is associated with low pressure, and low speed flow is associated with high pressure (Annanberg, 2012).
Lift is generated by the movement of the air above and below the wing which will
increase as the speed of the air increases. Lift also increases due to the AOA (angle of attack)
of the wing. Past a certain point, however, increased AOA will cause the wing to suddenly
lose lifting capability and stall occurs.
Most airplane wings have a basic shape, their upper surfaces are curved and their lower surfaces flatter. This shape is what works with the air to create lift. As the air moves around the wing, some goes over the top and some goes beneath. Movement of air that goes over the upper surface is reduced in pressure and accelerated downward due to the curve of the upper wing. The wing is then is moved in the direction of the upper surface by increased air pressure below the wing. Also, downward acceleration of the air at the trailing edge forces the wing upward.
Rotary Wing Aircraft
Helicopter: An aircraft without wings that achieves vertical flight from spinning of the overhead
blades. Proof a thousand rivets will fly in formation.
The historical evolution of the rotary wing aircraft, the most versatile aircraft known to
man, exists due to great ideas and efforts of so many people from all around the world. The first
concept was envisioned by the ancient Chinese in the 1400’s (Gazzola, 1997). Children played
with toys that had flexible bands twisted tightly together and once released the toy would rise up.
Leonardo Da Vinci’s theoretical drawing of a rotary wing machine is what we now know as a
Through time many models were developed but lacked adequate engine power. The first
of countless discoveries came during the close of the 19th and beginning of the 20th centuries.
The invention of the internal combustion engine made the first giant leap possible. It improved
the functioning models with a suitable power source. The first of many problems was torque
reaction (Tennessee, 2012). Torque reaction is the effect produced by the rotor blades forcing the
fuselage to rotate in the opposite direction as the engine. Disproportion of lift would result in the
helicopter to flip over. The invention of the swashplate supported pitch control...
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