15.12 AIR SYSTEMS 👌🏼

Question 1

What component is the most critical lubricating point

Answer 1

Exhaust turbine bearing

Question 2

Secondary airflow for cooling is provided by

Answer 2

Bleed air (early stages)

Question 3

Explain zone 1

Answer 3

• area around fan case that contains accessory case and EEC

Question 4

Explain zone 2?

Answer 4

• cooled by fan air from upper part of fan duct and exhausted to lower end back into fan air stream

Question 5

Explain zone 3?

Answer 5

• area around HP compressor to turbine cases
• also contains fuel and oil lines and other accessories

Question 6

What is the temperature of rear stages of compressor

Answer 6

350c - 450c

Question 7

What percentage of incoming air is directed inside liner

Answer 7

20% - 30%

Question 8

What is the secondary airflow acting as

Answer 8

Cooling air blanket

Question 9

Cooling takes place in 2 ways

Answer 9

• cooling air removes heat from combustion liner
• cooling air creates film which acts as thermal barrier

Question 10

What is the common method to cool turbine section

Answer 10

Engine bleed air

Question 11

What is necessary to increase life expectancy of turbine nozzle guide vanes and turbine blades

Answer 11

• cooling by compressed air

Question 12

Which compressor bleed air is used for the sealing of the engine bearing chambers

Answer 12

LP compressor

Question 13

What does it mean by bowed rotor

Answer 13

Engine can bend due to different expansions between upper and lower engine zones

Question 14

What does it mean by bowed rotor

Answer 14

Engine can bend due to different expansions between upper and lower engine zones