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Turbojet Engine
Applied Thermodynamics
A jet engine having a turbine-drivencompressor and developing thrust from theexhaust of hot gases is a turbojet engine.
This topic illustrates the working of aturbojet engine.
Turbojet Engine
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Turbojet Engine
Applied Thermodynamics
Thermodynamic Cycles
Two Isothermal processes and two adiabaticprocesses constitute a carnot cycle.
Two Adiabatic processes and two Constantpressure processes constitute a Brayton cycle.
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Turbojet Engine
Applied Thermodynamics
Brayton cycle is represented in P-v and T-s diagrams
Thermodynamic Cycles
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Turbojet Engine
Applied Thermodynamics
Working of a Turbojet Engine
In a turbojet engine, air enters axially into the rotor at state 1 and leaves the stator rotor assembly inAxial direction at state 2.
Axial Flow Compressor (process 1-2)
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Turbojet Engine
Applied Thermodynamics
Working of a Turbojet Engine
Then, air enters the combustion chamber in which fuel is mixed with air.
High energy igniter supplies necessary spark at the starting of the cycle.
Combustion Chamber (process 2-3)
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Turbojet Engine
Applied Thermodynamics
Working of a Turbojet Engine
The burnt Air fuel mixture is expanded in an Axial flow turbine.
The work output of turbine is equal to work input of compressor.
So, net work done by the Turbojet engine is Zero.
Axial Flow Turbine (process 3-4)
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Turbojet Engine
Applied Thermodynamics
Working of a Turbojet Engine
High pressure gases expand through nozzle which converts all pressure energy to Kinetic Energy.
Nozzle (process 4-5)
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Turbojet Engine
Applied Thermodynamics
Working of a Turbojet Engine
High Velocity jet of gases coming out of Nozzle gives the necessary thrust to move the engine forward.(Newtons Third law of motion).
Pressure Velocity variation in nozzle
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Turbojet Engine
Applied Thermodynamics
Resources
Books:
1. Gas Turbines by Cohen and Rogers2. IC Engines and Gas Turbines by Gill Smith
Reference Links:
1. www.asme.org
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Turbojet Engine
Applied Thermodynamics
What is the difference between Rockets and jetengines?
Jet engines work on Newtons III law of motion
Turbojet is an external combustion engine
Rockets operate at higher mach number than jetengines
Jet engines are self breathing engines
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Turbojet Engine
Applied Thermodynamics
Net Work Output of Turbojet engine is
Same as Compressor Work
Same as turbine Work
Zero
Equal to Wc- Wt
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Turbojet Engine
Applied Thermodynamics
Inlet temperature of air entering Turbojet depends on
Altitude of operation of flight
Monsoon conditions
Climatic conditions
It is always constant
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Turbojet Engine
Applied Thermodynamics
Where do we see the application of Turbojet engine?
Civil Aircrafts
Submarine
Helicopters
Rockets
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Turbojet Engine
Applied Thermodynamics
Answer Key
14
13
32
31
Answer(s)Question No.