To understand aircraft propulsion it is important to understand the term propulsion first.
Propulsion is a means of producing force required for movement of object. The propulsion system has some source of mechanical power and some means of using this power to generate force such as wheels, propellers, legs, etc.
Nobody can precisely tell the origin of mankind’s desire to fly as it is lost in the distant past. There are legends of people strapping birdlike wings and jumping of a tower. People even tried to strap themselves to a kit in order to try flying.
Some primitive designs include the Chinese rotor wings, hot air balloon and Leonardo Da Vinci’s ornithopter. The hot air balloons made up of paper were …show more content…
I studied the material from various sources and collected notes.
4. Then I planned an outline of the paper.
5. Wrote the first draft.
6. Then finally edited and prepared the final paper. AIR PROPULSION
An aircraft propulsion system consists of an aircraft engine and propellers or propulsive nozzle for producing thrust.
An aircraft propulsion system must achieve two things. First, the system should be able to produce enough thrust that it must be equivalent to the drag on cruising airplane. Secondly its thrust should be able to exceed the drag on the airplane so that it can accelerate. The greater the excess thrust the faster will plan accelerate.
Some aircrafts like airliners or cargo planes use high bypass fans or turboprops as they require higher fuel efficiency which is achieved by accelerating large mass of gas by a small amount. On the other hand the fighter jets require very high thrust and not high fuel efficiency so the employ afterburners on a low turbofan bypass core.
Working principle
The basic working of aircraft propulsion system is based on Newton’s third law according to which ‘every action have equal and opposite …show more content…
The whole process is depicted in (fig2).
Fig2
Types of reciprocating engines:
In line engines: This type of engines have cylinder lined up in a row. Normally these engines have even number of cylinders. Its advantages include low frontal area which minimizes drag. Other advantages are improved visibility and lower center gravity. Main disadvantage is poor power to weight ratio. These engines have become rare in modern aviation.
V-type engines: Cylinders in this type of engines are arranged in two inline banks at 60-90 degrees apart joined to a common crankshaft and are generally water cooled. These have higher power to weight ratio as compared to the former.
Flat engine: Here there are two banks of cylinders on opposite sides of a common crankshaft. The engine is liquid or air cooled. These have a low centre of gravity. Refer to (fig3).