PRESENTED BY:
SHAIK IBRAHIM

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What is air propulsion ?
Air propulsion is the act of moving an object through the air.
A propulsion system is a machine that produces thrust to push an object forward.
On airplanes, thrust is usually generated through some application of Newton's third law of action and reaction.
Aerodynamic forces
thrust
Drag
Self weight of plane
lift
In order for an airplane to fly straight and level, the following relationships must be true:
Thrust = Drag
Lift = Weight
Thrust
Thrust is an aerodynamic force that must be created by an airplane in order to overcome the drag.
Airplanes create thrust using propellers, jet engines or rockets
Drag
Drag is an aerodynamic force that resists the motion of an object moving through a fluid.
The factors that affect the magnitude of the drag force are
shape of the airplane.
stickiness of the air.
speed of the aircraft .
Weight and lift
Weight is amount of gravitational pull exerted by the earth on the plane.
Lift- A fluid flowing past the surface of a body exerts a surface force on it.
Lift is defined to be the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is defined to be the component of the surface force parallel to the flow direction.
How lift is created ?
Air particles that approach the leading edge of the wing must travel either over or under the wing.
Let's assume that two nearby particles split up at the leading edge, and then come back together at the trailing edge of the wing.
Since the particle traveling over the top goes a longer distance in the same amount of time, it must be traveling faster.
As the speed of air particles increases, pressure decreases , and due to this difference in pressure lift is created.
Types of propulsion systems
Internal combustion engines
Limitation of I.C engine in aircrafts
Since the mass of air inducted into the engine depends on density, their performance drops at higher altitudes.
The engine becomes heavy.
Hence it is used only for small and low speed aircrafts flying at lower altitudes
Introduction of Gas turbine engine
Simpler in construction
Bigger and faster aircrafts operating at higher altitudes employ gas turbine engines.
The gas turbine engine operates on simple joules or brayton cycle.
Gas turbine engine
Ram jet engines
Other types of engines
Turbo prop engine
turbo jet engine
Turbo fan engine
pulse jet engine
Areas of use
Military.
Civil.
Commercial.
General aviation.
Experimental.
Model.
conclusion