Turbine Engine Part 3

Question 1

A gas turbine engine turbine section may employ active clearance control:

Answer 1

To provide enhanced clearances between the blade tips and the casing

Question 2

About a twin-spool compressor:

Answer 2

The low pressure spools runs at a lower RPM than the high pressure spool

Question 3

During low axial speeds and high RPM the compressor angle of attack will be -

Answer 3

high

Question 4

When a gas turbine engine is fitted with can-type combustion chambers:

Answer 4

A total of only two igniters are usually fitted since the chambers are inter-connected

Question 5

A gas turbine engine is run at ground idle for a period of time prior to shut-down to:

Answer 5

Prevent seizure of the rotor blades in their seals

Question 6

For a subsonic airflow, in a divergent duct:

Answer 6

Pressure increases, velocity decreases and temperature increases

Question 7

After a successful start of a high-bypass turbofan engine, the air starter:

Answer 7

Is disengaged by the coupling between engine N2 spool and starter by the use of centrifugal forces

Question 8

The indications of a hung start is:

Answer 8

Low and stagnating RPM, low fuel flow, high EGT.