Compressors

Question 1

What are the two main types of compressors

Answer 1

Centrifugal flow and axial flow

Question 2

What are the two main types of compressors driven by and are connected to what?

Answer 2

Driven by engine turbine and coupled direct to turbine shaft

Question 3

What two components does a centrifugal flow compressor have

Answer 3

Impeller (accelerate the air) & diffuser (pressure rise)

Question 4

Why is an axial flow compressor better than centrifugal

Answer 4

Axial flow gives more thrust for same frontal area (more air)

Question 5

How does the centrifugal compressor operate

Answer 5

Impeller rotates at high speed by the turbine and air is induced into the centre of the impeller.

Question 6

At what tip speed do impellers operate at?

Answer 6

Up to 1,600 ft per second

Question 7

The gap between the impeller and casing must be small as possible why?

Answer 7

To prevent excessive air leaking

Question 8

Which type of bearings does the impeller shaft rotate in

Answer 8

Ball and roller bearings

Question 9

Why are the vanes of the centre of the impeller curved?

Answer 9

Ease the air from axial flow In the entry duct.