THE FORCE OF FLIGHT
* A Force is defined most simply as a push or a pull
* There are two components to a force: magnitude (or the amount of force applied) and direction.
* thus we say that " a force of a creation magnitude is applied in a particular direction.
FOUR FORCES
* it is the inter play between these four forces that result in an airplane's motion.
WEIGHT
* All object in the universe exert an attractive force on each other that is called gravity.
* The magnitude of this force is development on the mass of the object.
* The earths gravitational pull weakens as object move further away from it.
* Thus we say that objects that are far from the Earth " weigh less " than when they are
on the earth .
* Thus we say that objects that are far from the earth " weight less " than when they are on the earth
LIFT
* for objects "on" and "close" to the earth ( we will assume that airplane fly at altitudes "close " to the earth ) the weight of an object can be considered constant .
* Weight is the force that measure the effects of gravity.
* In order for an airplane to fly , a force must be generated that is stronger than the weight force.
* That force is called lift.
* The lift force is generated by air flowing over an object called wing .
* The direction of the lift force will always be perpendicular to the direction that the air is flowing
* As an airplane is flying , air is flowing over its wing , from the front ( or leading edge ) to the back ( or trailing edge ) .
* This generates a lift force perpendicular to the direction of the airflow.
* It is easy to understand that the shapes of wing will have a direct influence on " how " the air flows from front to back .
* " How " the air flows will have a direct influence on how much lift the wing can
generate.
* An object that is shaped to generate maximum lift is called and " airfoil "
THRUST
* when an airplane in on the ground not moving , there is not enough air flowing around it to create lift
* Another force is needed to get the airplane moving through the air , so that the airflow can do its job of creating lift.
* This force is called thrust .
* Thrust propels an object in an particular direction
* the arm of baseball pitcher generates thrust and applies it to baseball ( that is , throws it )
towards a batter .
* likewise , a jet engine generates thrust and , because it is is attached to the wing of an airplane , its thrust will be applied to the airplane .
* So , as the engine thrust the airplane in the direction that they are pointed , air flows over and
* If enough lift is generated , the airplane will fly.
DRAG
* The fourth primary force is drag .
* Drag is the force that result any object traying to move through a fluid .
* The drag on an airplane is the result of , among other things , the energy needed to move the air out of the way of the airplane .
* obviously drag is hard at works when massive object , like an airplane , tries to fly
through a fluid like air .
* Any motion or movement by the airplane will always be resisted by a drag force .
* The direction of the drag force is opposite to the direction of flight .
* The thrust force is aligned to counter the drag force.
* Reducing drag is one of the main concerns of aeronautical engineers when designing aircraft
* Drag can stress different parts of an which can lead to structural failure during creation
maneuvers .
* The less Drag an aircraft has ,the faster an aircraft can go , or the less power is needed from the engine.
* Less powerful engines are generally lighter ( that is , have less weight ) and need less fuel ( that is , cost less to fly)
* A light aircraft means that less lift is needed to fly and the airplane can be more maneuverable.
* If less lift is needed, a smaller wing is required which decrease weight and drag.
* All of this , taken together , reduces the cost of building and flying the airplane.
* when an airplane in on the ground not moving , there is not enough air flowing around it to create lift
* Another force is needed to get the airplane moving through the air , so that the airflow can do its job of creating lift.
* This force is called thrust .
* Thrust propels an object in an particular direction
* the arm of baseball pitcher generates thrust and applies it to baseball ( that is , throws it )
towards a batter .
* likewise , a jet engine generates thrust and , because it is is attached to the wing of an airplane , its thrust will be applied to the airplane .
* So , as the engine thrust the airplane in the direction that they are pointed , air flows over and
* If enough lift is generated , the airplane will fly.
DRAG
* The fourth primary force is drag .
* Drag is the force that result any object traying to move through a fluid .
* The drag on an airplane is the result of , among other things , the energy needed to move the air out of the way of the airplane .
* obviously drag is hard at works when massive object , like an airplane , tries to fly
through a fluid like air .
* Any motion or movement by the airplane will always be resisted by a drag force .
* The direction of the drag force is opposite to the direction of flight .
* The thrust force is aligned to counter the drag force.
* Reducing drag is one of the main concerns of aeronautical engineers when designing aircraft
* Drag can stress different parts of an which can lead to structural failure during creation
maneuvers .
* The less Drag an aircraft has ,the faster an aircraft can go , or the less power is needed from the engine.
* Less powerful engines are generally lighter ( that is , have less weight ) and need less fuel ( that is , cost less to fly)
* A light aircraft means that less lift is needed to fly and the airplane can be more maneuverable.
* If less lift is needed, a smaller wing is required which decrease weight and drag.
* All of this , taken together , reduces the cost of building and flying the airplane.
0 Comments