Gas Turbine Exhaust Systems

Question 1

Gas velocity from the Turbine exits at around 370m/s; maintaining this velocity would cause friction losses
– To reduce and prevent this an exhaust cone is fitted within the exhaust; the exhaust forms a convergent/divergent duct

Answer 1

Divergent

Question 2

At the exhaust : The static pressure within the exhaust is now above blank and ‘pressure thrust’ will be increased.

Answer 2

Atmospheric pressure

Question 3

Where dies the most noise come from in an engine?

Answer 3

Compressor

Question 4

What are chevrons for on boeing?

Answer 4

Noise compression.

Question 5

Reverse thrust reduces blank

Answer 5

Wear on the engines.

Question 6

What airflow do blocker doors move?

Answer 6

Bypass

Question 7

To prevent inadvertent operation there must be a number of blank protections regarding the Reverse Thrust system

Answer 7

Interlock

Question 8

Blocker doors, clamshells and buckets are all actuated hydraulically/pneumatically.

Answer 8

Hydraulically.

Question 9

Within the Turbine engine temperatures are measured and monitored for engine health and monitoring conditions
• Due to the high temperatures involved, blanks are employed around the aircraft

Answer 9

Thermocouples

Question 10

EGT – Exhaust Gas Temperature – typically measured after the blank

Answer 10

Turbine

Question 11

JPT – Jet Pipe Temperature – measured further forward/back in the Jet Pipe

Answer 11

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