POWERPLANT - GAS TURBINE ENGINE

Question 1

What is the primary difference between the Brayton cycle and the Otto cycle in terms of process?

Answer 1

Brayton cycle is a constant pressure process

Question 2

Which component is essential for the Brayton cycle in jet engines but not present in reciprocating engines?

Answer 2

Compressor

Question 3

In the Brayton cycle, what happens during the compression phase?

Answer 3

Air is compressed, raising its pressure and temperature

Question 4

During which part of the Brayton cycle is energy extracted to perform work?

Answer 4

Expansion

Question 5

In a typical jet engine operating on the Brayton cycle, where does the combustion process occur?

Answer 5

In the combustion chamber

Question 6

How does the Brayton cycle improve the efficiency of jet engines compared to piston engines using the Otto cycle?

Answer 6

By continuously compressing and expanding air

Question 7

Whch of the following best describes the sequence of processes in a Brayton cycle?

Answer 7

Intake, Compression, Combustion, Expansion, Exhaust

Question 8

Which component in a turbojet engine compresses the air?

Answer 8

Compressor

Question 9

What is the purpose of an air intake in a jet engine?

Answer 9

Supply air to the compressor

Question 10

What is the function of the compressor in a jet engine?

Answer 10

Increase the pressure of the incoming air

Question 11

How is fuel typically ignited in a jet engine?

Answer 11

Combustion chamber igniters

Question 12

What is the purpose of the combustor in a jet engine?

Answer 12

To burn the fuel-air mixture

Question 13

What is the purpose of the turbine in a jet engine?

Answer 13

. Increase air pressure

Question 14

What is the primary function of the turbine in a jet engine?

Answer 14

To extract energy from the combustion gases

Question 15

In a turbine engine, what is the function of the compressor section?

Answer 15

To increase the pressure of the air before combustion

Question 16

Which component in a jet engine extracts energy from the high-speed exhaust gases?

Answer 16

Turbine

Question 17

What is the primary purpose of the afterburner in some jet engines?

Answer 17

To increase thrust by burning additional fuel in the exhaust stream

Question 18

How is the speed of a turbojet engine primarily controlled?

Answer 18

Adjusting the fuel flow

Question 19

Which type of ignition system is commonly used in jet engines?

Answer 19

Electric spark ignition

Question 20

What is the primary purpose of the reduction gear in a turboprop engine?

Answer 20

Decrease propeller RPM

Question 21

How is the thrust generated in a turbofan engine?

Answer 21

By the bypassed air and exhaust gases

Question 22

What is the function of the accessory gearbox in a jet engine?

Answer 22

Power auxiliary components

Question 23

Which type of lubrication system is commonly used in jet engines?

Answer 23

Pressure lubrication

Question 24

What is the purpose of the diffuser in a jet engine?

Answer 24

Decrease air velocity and increase pressure

Question 25

What is the main function of the turbine blades in a jet engine?

Answer 25

Extract energy from the exhaust gases

Question 26

Which type of cooling system is typically used in jet engines?

Answer 26

Air cooling

Question 27

How is the speed of a turboprop engine controlled?

Answer 27

Changing the propeller pitch

Question 28

Which type of turbine is used to drive the fan in a high-bypass turbofan engine?

Answer 28

Low-pressure turbine

Question 29

Which type of turbine blade is used in the high-temperature section of a jet engine?

Answer 29

Ceramic-coated blades

Question 30

What does the term 'compressor pressure ratio' refer to in a jet engine?

Answer 30

c. Ratio of compressor outlet pressure to inlet pressure

Question 31

What is the purpose of a bypass duct in a turbofan engine?

Answer 31

Allow air to bypass the engine core

Question 32

What is 'hot section' maintenance in a jet engine?

Answer 32

Maintenance of the combustor, turbine, and exhaust sections

Question 33

What is the purpose of a turbine blade shroud in a jet engine?

Answer 33

To reduce vibration and blade tip leakage

Question 34

What is the primary function of a fuel control unit in a jet engine?

Answer 34

To manage the fuel flow to maintain the desired engine speed and power output

Question 35

What is a 'choked' nozzle in a jet engine?

Answer 35

A nozzle that limits the maximum airflow

Question 36

What is the purpose of an igniter in a jet engine?

Answer 36

To ignite the fuel-air mixture during start-up

Question 37

What is the primary advantage of using a turbofan engine over a turbojet engine?

Answer 37

Higher fuel efficiency

Question 38

What is the function of an aftercooler in a reciprocating engine?

Answer 38

To cool the compressed air before it enters the combustion chamber

Question 39

What is the purpose of a 'variable stator vane' in a jet engine compressor?

Answer 39

To adjust the airflow through the compressor for optimal performance

Question 40

What type of bearing is commonly used in the turbine section of a jet engine?

Answer 40

Ball bearing

Question 41

What is the purpose of a 'bleed valve' in a jet engine?

Answer 41

To control airflow through the compressor

Question 42

What is the function of a 'surge tank' in an aircraft fuel system?

Answer 42

To collect overflow fuel

Question 43

What is the purpose of a 'turbine nozzle' in a jet engine?

Answer 43

To direct the flow of hot gases onto the turbine blades

Question 44

What is the purpose of a 'thrust reverser' in a jet engine?

Answer 44

To reverse the direction of thrust to help slow the aircraft during landing

Question 45

What is a 'hot start' in a jet engine?

Answer 45

A start in which the engine's EGT exceeds safe limits

Question 46

The main purpose of engine oil in a turbine engine is to:

Answer 46

Lubricate and cool bearings

Question 47

What is the function of a fuel flow transmitter in a turbine engine?

Answer 47

To measure the rate of fuel consumption

Question 48

The term "hot section inspection" in turbine engine maintenance refers to inspecting:

Answer 48

The combustion chamber and turbine section

Question 49

What is the purpose of a fire detection system in a turbine engine?

Answer 49

To detect and alert of any fire in the engine compartment

Question 50

Which type of fuel filter are used in turbine engines?

Answer 50

Metal mesh filter

Question 51

What does 'N2' indicate in a dual-spool jet engine?

Answer 51

The speed of the high-pressure compressor