1. Gas Turbines
By: Katie Steddenbenz

2. How they work Energy is added to the gas stream
Combustion increases the temperature, velocity, and volume of the gas flow
Turbine rotates, powering the compressor
Energy is then extracted in the form of shaft power, compressed air and thrust

3. Brayton Cycle
Gas turbines are described thermodynamically by the Brayton cycle
In this cycle:
air is compressed isentropically
combustion occurs at constant pressure
heated air expands through the turbine
heat is rejected into the atmosphere

4. Advantages of gas turbine engines
Very high power-to-weight ratio
More size efficient
Moves in one direction only, with fewer moving parts
Low operating pressures
High operation speeds
Low lubricating oil cost and consumption

5. Disadvantages of gas turbine engines
More expensive compared to a similar-sized reciprocating engine
More complex machining operations
Usually less efficient than reciprocating engines, especially at idle
Delayed response to changes in power settings

6. Questions?