Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Module 15 - Gas Turbine Engines > 15.3 Inlet > Flashcards

15.3 Inlet Flashcards

1
Q

What is the purpose of the inlet?

A

It must furnish a uniform supply of air to the compressor to ensure it performs a stall-free compressor performance.

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

What is the inlet duct on a commercial airliner known as?

A

Pitot type

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

What does the pitot type engine inlet maximise?

A

The ram effect; suffering only a minimum loss of ram pressure as the aircraft altitude changes

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

What can cause pressure losses in an aircraft engine inlet?

A

Friction (along the walls)
Turbulence
Mach number related shockwaves

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

What is a vortex dissipater?

A

A blow away jet (linked to weight on wheels, so only operates on the ground)

It is compressor bleed air

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

What happens to the air when total ram recovery has been achieved?

A

The airflow will be faster than the compressor is capable of tolerating. The engine benefits by expanding less mechanical energy for compressor.
It produces a ‘nose suction’ effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where would you see a bell-mouth air inlet?

A

Engine testing and helicopter turboshaft engines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why aren’t inlet screens used in modern gas turbine powered aircraft?

A

They cause more maintenance problems and icing, so have been avoided.

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

What are the 3 types of turboprop inlet?

A

Ducted spinner
Conical spinner
Under scoop

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

What is installed in an APU air intake, incase of a flap actuator failure?

A

A manual override device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to the conical surface (Mach cone) as an aircraft increases in supersonic speed?

A

It’s angle gets smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens in a normal shockwave?

A

Airflow becomes subsonic. The shockwave is perpendicular to the flow direction.
It’s the strongest of all shockwaves

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

What happens in an oblique shockwave?

A

Air speed increases

Slight angle change

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

What speed is needed for airflow in a jet engine ?

A

Subsonic, around Mach 0.4

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

Where would you find a plug intake?

A

High supersonic speed aircraft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where would you find an inlet filter?

A

Helicopters for prevention of FOD

17
Q

What is EAPS?

A

Engine advanced protection system.

Small fans on intake, prevent FOD, ice, less erosion, all weather protection

18
Q

When are anti-icing conditions deemed to exist?

A

Below +10°C with visible moisture.

19
Q

What is a disadvantage of ducted air anti-ice systems?

A

A slight power loss when in use

20
Q

Where would you find an electrical heating element system on an engine intake?

A

Turbo-prop intakes.

21
Q

How are the electrical heating elements (pads) attached to the engine intake?

A

Bonded to the outer skin

22
Q

How are electrical ice protection systems different in operation to a bleed air anti-ice system?

A

They are intermittently heated, allowing ice to form in the “heat-off” period.

23
Q

In terms of pressure and kinetic energy, how does the intake take advantage of the Ram Effect?

A

It converts kinetic energy of the air into pressure energy

24
Q

What is the purpose of the nose cone on the N1 Fan?

A

Streamlined fairing only

25
Q

How much can EGT increase by with using the bleed air anti-ice system?

A

10 degrees C

26
Q

When is the inlet door of a variable geometry intake open?

A

Subsonic speeds. Closed at supersonic speeds

27
Q

What happens to pressure and velocity in a bellmouth intake?

A

Velocity increases and pressure decreases

28
Q

What does increasing ram effect do to the efficiency?

A

It increases the overall propulsive efficiency

29
Q

What happens to the aerodynamic efficiency of a pitot type intake when it approaches the transonic range?

A

Decreases due to the shock waves produced

30
Q

How does a turboprop engine INLET anti-ice system operate?

A

Continuously (The propeller blades are intermittent)

31
Q

What is the Ram Recovery point?

A

The intake total pressure equals the ambient pressure

32
Q

What does an increase in the Ram Ratio of an intake do to temperature?

A

Increases the temperature

33
Q

What happens to the efficiency of a Pitot inlet as an aircraft approaches the transonic range?

A

It decreases due to shockwaves in the transonic region

34
Q

What does intake momentum drag cause?

A

A decrease in thrust at low airspeeds

Module 15 - Gas Turbine Engines (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions