How Does Engine Work ?

Part one

Why do we need Engines ?

● Mechanical Power.

● Bleed air.

● Thrust force.

Aircraft Engines Types

● Turbojet

● Turbfan

● Turboprop

Working Cycle

The principles of Engine are the same whatever

old or very modern engine.

Pressurization.

Adding Heat.

Expansion.

Brayton Cycle

Pressurization

● Here the engine does work on gas " air flow "

● It converts the kinetic energy " Velocity " into

pressure energy " static pressure".

● Also , the wok of compressor increases the total

pressure of flow.

● Compressors in this stag are to be assumed

adiabatic.

● Most of civil aircraft compressors are axial

compressors.

Pressurization Cont'd

● Now most of airplanes engines are turbofan

because of its efficiency in this flight regime for

civil big airplanes.

● The airflow is to be pressurized due to ram

effect and this is done by intake.

● Then it passes through fan which is the major

part for thrust.

● After this , flow is to be divided according to

bypass ratio=Fan secondary flow / core primary

flow by passing over splitter

Pressurization Cont'd

● The air flow is to be compressed over two

stages of compressors.

● Low pressure compressor and High pressure

compressor.

● The reason of using two compressors is to

avoid stall or surge during starting the engine.

● Now there is three spool (compressors) working

engines such as Trent series.

800Trent

Combustors

● Types of Combustion chambers

● Annular

Combustors Cont'd

● Can

Combustors Cont'd

● Can Annular

Combustors Cont'd

The benefits of can combustor is maintainability.

But the disadvantage is that if one can is to stop

working properly during flight how much the

damage will be on turbine blade because of

change of temeprature.