How the Turboprop engine works ?

Operating Principle | Advantages | Disadvantages|Applications

how the turboprop engine works

Operating Principle:

Turboprop engine is an intermediate between a pure jet engine and a propeller engine.

Turboprop engine provides high thrust per unit mass flow of fuel burnt by increasing mass flow of air. It offers better fuel economy. Propeller displaces a large mass of air rearwards, thereby increasing the net thrust.
Schematic-diagram-of-turboprop-with-station-numberingTurbine extracts more power from the combustion gasses to drive the propeller. A small remaining energy is extracted by expansion in the jet nozzle.
Propeller and the compressor may be mounted on a single shaft or on separate shafts with a free turbine driving the propeller.

  • Turboprop engines have a higher thrust at take-off and better fuel economy.
  • Turboprop Engine can operate economically over a wide range of speeds ranging from low speeds where turbojet is uneconomical to high speeds of about 800 km/hr where piston-prop engine cannot operate efficiently
  • It is to maintain and has lower vibration level than piston-prop engine. The frontal area is much less than corresponding piston-prop engine.


  • Main disadvantage is that the propeller efficiency decreases greatly at high speeds due flow separation and shocks. The maximum speed is thus limited.
  • Turbine speeds need to be reduced through a suitable reduction gearing which adds to weight.

Turboprop engine is widely used in commercial and military aircraft due to its flexibility of operation and good fuel economy.

Posted by insideaero

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