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Flashcards in Axial Flow Turbines Deck (7)
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1

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

2

What is the flow accelerated by in the absolute frame?

The stator

3

What is the flow accelerated by in the relative frame?

The rotor

4

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

The flow leaves the rotor slower than it left the stator

5

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

6

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

7

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