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Flashcards in Axial Flow Turbines Deck (7)
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What are 5 summary points of turbine blade design?

Turns flow away from engine axis
Flow area decreases (to a minimum at the throat)
Average velocity increases
Average pressure decreases
Extracts energy from the hot gases and drives the compressor


What is the flow accelerated by in the absolute frame?

The stator


What is the flow accelerated by in the relative frame?

The rotor


In the absolute frame, where does the flow leave slower?

The flow leaves the rotor slower than it left the stator


What's the difference between an Impulse Turbine and a Reaction Turbine?

Impulse turbine - all pressure drop is in the nozzle effect on the blades is momentum only
Reaction turbines - pressure drop in both rotor and stator


What does the Stage Loading (Temperature Drop) coefficient do?

Defines how much work can be obtained from a stage - the higher the better, but usually at the cost of efficiency


What's the definition of the Degree of Reaction?

How much of the expansion takes place in the rotor verses how much across the stage