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Jet engine
- 2. JET ENGINE PRESENTED BY:- K.AJITARAVIND S.ARAVIND KUMARAN K.ARAVINTH V.AJITH 2 GUIDED BY:- PROF.T.NITHYANANTHAM
- 3. JET ENGINE • Jetengine is nothing but a Gas turbine. • It works under the principle of Newton’s third law • It states that “For every acting force there is an equal and opposite force” • Gas turbine operates like toy balloon
- 4. HISTROY •The first jetengine was built by Egyptian scientists during 100 B.C •This device was known as Aeolipile. •It is also called as the Hero’s Engine
- 5. PARTS OF JETENGINE
- 6. HOW A JETENGINE WORKS ? Air Intake •Sucked in by the compressor Compressor •Series of vanes and stators •The vanes rotate, while the stator remains stationary •Compressor speed and temperature increases gradually Fuel Burner •Fuel is mixed with the air, and electric sparks light the air, causing it to combust Air intake
- 7. HOW A JETENGINE WORKS ? Combustion Chamber • The air is burnt Increase in the temperature of the air, thus increases the pressure inside the engine Turbine •The blades gain energy from the hot gases moving past them which is used to power the compressor Jet Pipe and Propelling Nozzle •The hot air rushes out of the nozzle •High pressure Hot air rushes out at very high speed
- 8. TYPES OF JET ENGINES •Gasturbine •Turbo jets •Turbo propeller •Turbofan •Ramjet •Pulse jet
- 9. GAS TURBINE • Typeof internal combustion engine. • Works on Brayton cycle with air as working fluid. • Mechanical energy is changed irreversibly into pressure and thermal engergy
- 10. THEORY OF OPERATION Undergoes four thermodynami c process •An isentropic compression • An isobaric combustion • An isentropic expansion • An isobaric heat rejection
- 11. ADVANTAGES DISADVANTAGES Very highpower to weight ratio compared to reciprocating engines Lower peak combustion pressures than reciprocating engines Low lubricating oil cost and consumption Core engine cost can be high Less efficient than reciprocating engines Less response to changes in power demands
- 12. TURBO JETS • Itsan Airbreathing Jet engine. • The turbojet engine is a reaction engine • Substantial increases in thrust can be obtained by employing an afterburner
- 13. CONSTUCTION AND WORKING Main Parts •Diffuser • Rotary Compressor • Combustion chamber • Turbine • Exhaust nozzle
- 14. Advantages • High exhaustspeed • Low frontal area • Relative simplicity Disadvantages • Noisy • Insufficient to use below mach number 2 Applications • Piloted Aircrafts • Military Aircrafts
- 15. TURBO PROPELLER • Aturboprop is a jet engine attached to a propeller. • Modern turboprop engine are equipped with propeller that have a smaller diameter but a large number of a blades for efficient operation at much higher flight speed.
- 16. CONSTUCTION AND WORKING Main Parts •Diffuser • Compressor • Combustion chamber • Turbine • Exhaust nozzle • Reduction gear • Propeller
- 17. Advantages • High take-offthrust • Reduced vibration and noise • Better fuel economy Disadvantages • Complex engine construction • Efficiency decreases rapidly at high speed Applications • Better suited for both commercial and military aircraft due to high flexibility and fuel economy
- 18. TURBOFAN • Combination ofturbo propeller and turbojet • The objective of the sort of bypass system is to increase thrust without increasing fuel consumption. • It achieves this by increasing the total air- mass flow and reducing the velocity within the same total energy supply
- 19. CONSTUCTION AND WORKING Main Parts •Fan • Compressor • Combustion chamber • Turbine • Fan Nozzle
- 20. Advantages • Thrust developedis higher than turbojet • Less noise • Weight per unit thrust is lower than turboprop Disadvantages • Increased frontal area • Fuel consumption is high • Lower speed limit Applications • Better suited for both commercial and military aircraft
- 21. RAMJET • It hasno moving parts. • Its compression ratio depend upon forward speed. • It has no static thrust. • Guided-missile system , space vehicle use this type of jet.
- 22. CONSTUCTION AND WORKING Main Parts •Inlet and supersonic diffuser • Subsonic diffuser • Combustion chamber • Nozzle
- 23. Advantages • Simple anddoes’nt moving part • Cost is low • Less maintance Disadvantages • Low thermal efficiency • Starting is impossible without external launching device Applications • Subsonic ramjet are used in target weapons • High speed aircrafts and missiles
- 24. PULSE JET • Combustionoccurs in pluses • Capable of running statically • Light
- 25. CONSTUCTION AND WORKING Main Parts •Diffuser • Valve grid with springs • Combustion chamber • Spark plug • Tail pipe
- 26. Advantages • Simple anddoes’nt moving part • Cost is low • Light weight Disadvantages • High fuel consumption • Low propulsive efficiency • High degree of vibration Applications • Subsonic flights, German V-I missiles, target aircraft missiles, etc
- 27. MERITS AND DEMERITS Merits ofjet engine over IC engine Mechanical efficiency of jet engine is high as compared to IC engine. Weight and speed of jet engine per HP developed is higher then IC engine. Ignition and lubricating system are much simpler in jet engine then IC engine. Demerits of jet engine over IC engine Thermal efficiency of jet engine is low compared to IC engine. Difficult to start. Turbine blades need a special cooling system due high temperature.
- 28. CONCLUSION • Normal typeof jet engine is used to domestic purpose i.e. Traveling , carrying goods etc. • Ram and scram type of jet engine used in only in defence sector. Because it travels at supersonic speed and generally high level of training is required. • Since it travels at such a speed it is can not used for travelling. • So that common type of jet engines are very common in use.
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