Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Module 15 GTE's > Module 15.7 Exhaust > Flashcards

Module 15.7 Exhaust Flashcards

1
Q

What is the main task of the exhaust system on a jet engine?

A

Accelerate airflow from the turbine to generate thrust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the main task of the exhaust on a turboprop and APU?

A

Exhaust gases overboard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an additional feature of an APU exhaust?

A

Mufflers, for noise reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the components of the exhaust section?

A
  • Exhaust cone
  • Tailpipe
  • Exhaust nozzle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The exhaust cone is what, to decrease velocity and increase the static pressure?

A

Diverging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the exhaust cone assembly consist of?

A
  • Outer shell
  • Inner cone
  • Hollow struts (sole support for the inner cone)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the purposes of the radial struts in the exhaust?

A
  • Support the inner cone by connecting it to the outer shell
  • Straighten out airflow from the low pressure turbine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How is the tail pipe usually constructed?

A

Semi-flexible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the bellow arrangement allow for?

A

Movement in installation, maintenance and thermal expansion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two methods for protecting the fuselage structure?

A
  • Insulation blankets
  • Shrouds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the two types of exhaust nozzle design?

A
  • Converging (Subsonic)
  • Converging-diverging (Supersonic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What effect does a converging nozzle have on exhaust gases?

A

Increase in velocity, causing an increase in thrust (15-20%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two types of exhaust nozzle?

A
  • Fixed
  • Variable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When is a variable area nozzle used?

A

When there is an augmenter or afterburner.

Supersonic aircraft, making it divergent allows for supersonic airflow. As after mach 1 divergent ducts increase velocity and decrease static pressure, convergent have the opposite effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What effect does changing the area/diameter of the exhaust nozzle have?

A
  • Engine performance
  • Exhaust Gas Temperature (EGT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What section of a convergent-divergent exhaust handles air at subsonic speed?

A

Convergent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

GTE’s require what for operations in airports or high population areas?

A

Noise suppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 sources of GTE noise?

A
  • Air intake
  • Engine housing vibration
  • Engine exhaust (by far the most)
19
Q

Noise levels vary with what?

A

Engine thrust

20
Q

Why is a turbofan engine quieter than a turbojet?

A
  • Slower moving cooler air
  • Greater mass flow of air
21
Q

What are the two types of noise suppressor?

A
  • Corrugated perimeter
  • Multitube
22
Q

What does the noise absorbing lining convert acoustic energy into?

23
Q

What does the noise absorbing lining consist of?

A

Porous skin supported by honeycomb backing

24
Q

What do thrust reversers do once operated?

A

Reduce braking distance

25
How does a thrust reverser provide braking force?
Deflecting exhaust gas stream in the opposite direction
26
What airflow is reversed in a high-bypass turbofan engine?
Fan air
27
When would a bucket type reverser be used?
Low-bypass engines
28
What do turbofans with a low-bypass ratio usually have?
A common exhaust nozzle
29
Where are clamshell reversers located on a low-bypass engine?
In front of the exhaust nozzle
30
Where are the bucket-type reversers located?
After the exhaust nozzle
31
In clamshell reversers, what do exit ducts have?
Cascade vanes
32
How are clamshell reversers operated?
Pneumatically
33
What are fan reversers?
Cascade type reversers with translating sleeves
34
How may fan reversers be operated?
- Hydraulically - Pneumatically
35
What moves rearwards when the thrust reversers are activated in the cockpit?
Translating sleeve
36
What closes off the fan discharge duct?
Blocker doors
37
How are pivoting door type reversers activated?
Hydraulically
38
Where are pivot doors reversers when they are not activated?
Flush with the cowling
39
How are the disadvantages of reversers minimised?
Reversed airflow is matched to the engine position
40
On four engine aircraft, why is the angle of reverse stream more important?
Airflow from inner engines can be ingested by outer engines
41
How is thrust vectoring accomplished?
Relocating/moving the exhaust nozzle
42
The inward-pointing airflow is directed at such an angle that it cannot blow into what? (Reverse thrust)
Main wheel well
43
If the engines are far enough apart that the reverse flow does not effect the adjacent engines, what is an advantage of this configuration?
All engines can have the same cowlings, meaning fewer parts
44
What are some negative effects of reversers?
- Engine compressor can surge and stall - At very low aircraft speeds the engine can ingest its own reversed airflow - FOD ingestion

Module 15 GTE's (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions