Gas Turbine Components: Closed Cycle

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Gas Turbine Components Closed Cycle
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Ideal Model of Compressor

1. Steady-state
2. Isentropic Adiabatic and reversible
3. One stream in and one stream out
4. Changes in KE and PE are small compared to
   enthalpy change

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Turbojet Thrust
Drag Force
Va
Vj
Assume ideal case where Pa Pj assume that
Areaa Areaj
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Turbojet Thrust

• Conservation of momentum
• Apply in x-direction

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Propulsion efficiency

• Propulsion efficiency in this idealized case is
  then

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• The propulsion efficiency goes to __ as Vj?Va.

• This is why turbofans were created, they provide
  thrust with a low velocity jet to get high
  efficiency!

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Turbofan