Turbine Test 2

Question 1

Two sections of a turbine engine:

Answer 1

Cold section

Hot section

Question 2

3 components of the cold section of a turbine engine:

Answer 2

Inlet
Compressor
Diffuser

Question 3

3 components of the hot section of a turbine engine:

Answer 3

Combustors.
Turbine.
Exhaust.

Question 4

N =

Answer 4

Compressor speed in RPM

Question 5

N1=

Answer 5

Speed of LOW PRESSURE compressor.

Question 6

N2=

Answer 6

Speed of HIGH PRESSURE compressor

Question 7

N3=

Answer 7

Speed of the free turbine

Question 8

P or psia =

Answer 8

Absolute pressure

Question 9

T =

Answer 9

Abosolute temperature in Kelvin or Rankine

Question 10

t =

Answer 10

Temperature in Fahrenheit or Celsius.

Question 11

s (modifier) =

Answer 11

Static

Question 12

t (modifier) =

Answer 12

Total or turbine

Question 13

3 typical ducts for turboprop engines:

Answer 13

1) Ducted spinner inlet
2) Conical spinner inlet
3) Underscoop inlet

Question 14

Most subsonic inlet ducts are what type?

Answer 14

Divergent.

To slow the air and convert its velocity into pressure.

Question 15

Supersonic inlet ducts are what type?

Answer 15

Convergent-Divergent duct.

Used to create a shock wave to slow the supersonic air.

Question 16

The _______ inlet has almost no duct losses and is used when calibrating gas turbine engines.

Answer 16

Bell mouth.

Question 17

______ may be installed to prevent debris from being sucked into the engine of aircrafts while on the ground.

Answer 17

Vortex dissipaters.

Question 18

3 types of compressors:

Answer 18

1) Centrifugal compressors.
2) Axial-Flow compressors.
3) Hybrid compressors.

Question 19

3 typical parts of a centrifugal compressor:

Answer 19

1) Impeller
2) Diffuser
3) Manifold

Question 20

Axial-Flow compressors use _____, _____ and _____ to move air and build pressure.

Answer 20

Inlet Guide Vanes.
Rotor Blades.
Stator Vanes.

Question 21

T/F

A compressor’s rotor blades rotate to force air between the inlet guide vanes.

Answer 21

False.

Between the stator vanes

Question 22

If the ______ becomes excessive, the air foils are subject to stalls.

Answer 22

Angle of attack.

Question 23

The angle of attack of an air foil is the angle formed between its _____ and the _____.

Answer 23

Chord line.

Relative wind.

Question 24

Angle of attack is determined by 2 factors:

Answer 24

1) Velocity of airflow.

2) Rotational speed of the compressor.

Question 25

5 causes of compressor stall and surge:

Answer 25

1) Abrupt flight maneuvers.
2) Choking of engine airflow.
3) High crosswind.
4) Excessive pressure in burner section.
5) Obstruction to inlet airflow.

Question 26

2 Types of axial-flow compressors:

Answer 26

1) Single spool.

2) Dual spool.

Question 27

The first-stage compressor in a dual spool gas turbine engine:

Answer 27

Low-pressure compressor.

Question 28

The second-stage compressor in a dual-spool gas turbine engine:

Answer 28

High pressure compressor.

Question 29

The high pressure compressor is called the ______.

Answer 29

N2 Compressor.

Question 30

The low pressure compressor is called the _______.

Answer 30

N1 compressor.

Question 31

T/F

The N1 compressor is rotated by the starter.

Answer 31

False.

N2 compressor. (Due to its lighter weight.)

Question 32

T/F

The N1 compressor is driven by the rearmost stages of the turbines.

Answer 32

True.

Question 33

T/F

The speed of the N1 compressor is held steady by the governor in the fuel control.

Answer 33

False.

The N2 is governed while N1 changes its RPM according to atmospheric changes.

Question 34

A gas turbine engine consisting of both centrifugal and axial-flow compressors:

Answer 34

Hybrid compressor engine.

Question 35

_______ combustors make the most of limited space in axial-flow compressor engines.

Answer 35

Annular.

Question 36

___________ combustors are used in engines where overall length is critical.

Answer 36

Reverse-flow annular.

Question 37

2 types of turbines used in aircraft engines.

Answer 37

1) Axial.

2) Radial inflow.

Question 38

What section operates in the most hostile environment of the engine?

Answer 38

Turbine section.

Question 39

The turbine section consists of a ring of ______ and one or more stages of ______.

Answer 39

Inlet guide vanes.

Turbines.

Question 40

Each stage of a turbine consists of a set of _____ followed by a _____.

Answer 40

Guide vanes.

Turbine.

Question 41

Holes on the turbine blades are called _____.

Answer 41

Gill holes.

Question 42

Holes on the turbine blades are for ______.

Answer 42

Transforation cooling

Or film cooling

Question 43

3 types of turbine blades:

Answer 43

1) Reaction.
2) Impulse.
3) Reaction-impulse blade.

Question 44

3 main causes of turbine failure:

Answer 44

1) Creep.
2) Metal fatigue.
3) Corrosion.

Question 45

The deformation of a metal part that is continually exposed to high centrifugal loads at high temperatures is called _____.

Answer 45

Creep.

Question 46

A process in which cool air is blown around the turbine case, shrinking the case to minimize turbine blade tip loss.

Answer 46

Active Clearance Control.

ACC

Question 47

T-shaped turbine blades used to reduce vibration and minimize tip loss.

Answer 47

Shrouded turbine blades.

Question 48

TIT =

Answer 48

Turbine inlet temperature

Question 49

TOT =

Answer 49

Turbine outlet temperature

Question 50

ITT =

Answer 50

Interstage turbine temperature.

Question 51

TGT =

Answer 51

Turbine gas temperature

Question 52

4 EGT readings:

Answer 52

1) TIT
2) ITT
3) TOT
4) TGT

Question 53

4 accessories powered by gas turbine engines:

Answer 53

1) Fuel pumps.
2) Oil pumps.
3) Hydraulic pumps.
4 Air conditioning.

Question 54

To produce more thrust with exhaust gases, the exhaust system components must _____ and _____the stream of gases.

Answer 54

Straighten and accelerate

Question 55

4 exhaust system components:

Answer 55

1) Exhaust collector.
2) Exhaust cone.
3) Exhaust pipe.
4) Exhaust nozzel.

Question 56

3 types of combustors:

Answer 56

1) Multiple can
2) Can-Annular
3) Annular