15.1

Question 1

Potential energy

Answer 1

Energy due to virtue of position

Question 2

Kinetic energy

Answer 2

Energy due to virtue of motion

Question 3

Newton 1st law

Answer 3

Law of inertia

Question 4

Newton’s second law

Answer 4

Force = mass x acceleration

Question 5

Newton third law

Answer 5

Every action has an opposite and equal reaction

Question 6

How many changes of state

Answer 6

4

Isobaric
Isochoric
Isothermal
Isentropic

Question 7

What is the Brayton cycle

Answer 7

Thermodynamic cycle of a gas turbine engine that produces thrust

Question 8

What’s the difference between piston engine working cycle and GTE working cycle

Answer 8

Piston is intermittent whereas GTE is continuous

Question 9

What is isobaric heating

Answer 9

Heating at a constant pressure

Question 10

Piston engine peak pressure

Answer 10

Excess of 1000psi

Question 11

During combustion does pressure of the air increase

Answer 11

Pressure of air doesn’t increase

Question 12

What happens to air during suck

Answer 12

An increase of pressure and decrease in volume

Question 13

What happens to air in the compressor

Answer 13

Compressed which gives large increase in pressure and decrease in volume

Question 14

What happens to air during expansion

Answer 14

Pressure is constant but increase in volume

Velocity energy is converted into mechanical energy by a turbine

Question 15

What happens to air in the exhaust section

Answer 15

Converts expanding volume and decreasing pressure of gases to a final high velocity

Question 16

2 important changes of state in GTE

Answer 16

Isobaric and isentropic

Question 17

What’s the main function of an aircraft engine

Answer 17

Create necessary movement of the aircraft (thrust)

Question 18

Advantage of piston engine

Answer 18

More fuel efficient

Question 19

Disadvantage to piston engine

Answer 19

Performance decreases as altitude does

Too large for aircraft

Question 20

What’s another name for a turbo shaft engine

Answer 20

APU

Question 21

What is the bypass ratio

Answer 21

Air coming into engine vs coming out

Question 22

Advantage of turbojet

Answer 22

Very high speed

Question 23

Disadvantage of turbojet

Answer 23

Very loud

Question 24

How does turbofan work better then turbojet

Answer 24

Fans at front of engine produce 80% off thrust

Quieter and better fuel consumption

Question 25

What is a spool

Answer 25

Turbine driving a compressor through a shaft

Question 26

What does an twin spool arrangement have

Answer 26

HP compressor and turbine & LP compressor and turbine

Question 27

What does triple spool arrangement have

Answer 27

HP , IP , LP Compressors and turbines

Question 28

Difference between turboprop and turbojet

Answer 28

Turboprop has additional turbines , power shaft , and reduction gearbox

Question 29

Turboprop most efficient mid-range speed and altitude

Answer 29

Speed - 250-400 knots Altitude - 18000-30000 ft

Question 30

What parts are in the cold section

Answer 30

Parts of the engine from inlets to compressors/diffuser

Question 31

What parts are in the hot section

Answer 31

Areas past compressors from the combustion chamber to the exhaust

Question 32

What construction does a GTE consist of

Answer 32

Modular construction

Question 33

Advantages to modular construction

Answer 33

Modules easily removed and replaced and no rebalancing

Question 34

What area is 0-2 isentropic

Answer 34

Compression stage pressure increases volume decreeses

Question 35

3-5 isentropic

Answer 35

Expansion process

Question 36

What process is 2-3

Answer 36

Isobaric heating in combustion chamber

Question 37

What is 3-4 stage

Answer 37

Expanded gases into mechanical power by turbine and jet pipe

Question 38

What kind of materials do we need for the engine

Answer 38

Light and cheap as possible