M15.1

Question 1

What is average acceleration of gravity?

Answer 1

9.8 meters per second

Question 2

What is the equation for force?

Answer 2

Force x distance

Question 3

What is the equation for power?

Answer 3

Work / time

Question 4

1j = nm

Answer 4

1

Question 5

1w = nm/s

Answer 5

1nm/s

Question 6

Newtons 1st law?

Answer 6

A body at rest and a body in motion moves at a constant velocity unless acted upon by a un balanced external force

Question 7

Newtons 2nd law?

Answer 7

Force = mass x acceleration

Question 8

Newtons 3rd law?

Answer 8

Every action has a equal and opposite reaction

Question 9

What’s the working cycle of engines?

Answer 9

Induction
Compression
Combustion
Exhaust

Question 10

What is the cycle in a piston engine and a GTE

Answer 10

Piston = intermittent
GTE = continuous

Question 11

What happens to pressure and volume in a GTE

Answer 11

Pressure stays the same
Volume increases

Question 12

Why does pressure not rise in a GTE engine during combustion? And what is this called?

Answer 12

Because it’s not in an enclosed space

Heating at constant pressure or isobaric heating

Question 13

What octane fuel does GTE use?

Answer 13

Low octane

Question 14

The GTE is essentially what?

Answer 14

A heat engine that uses air as a working fluid to produce thrust

Question 15

How is velocity of air increased in a GTE?

Answer 15

Increase pressure energy
Increase heat energy
A final conversion back to kinetic energy in form of a high velocity jet efflux

Question 16

What are the functions of a a/c engine?

Answer 16

Generate thrust
Hydraulic power
Electrical power bleed air

Question 17

What are the advantages of piston engines?

Answer 17

More fuel efficient

Question 18

What’s the disadvantage of piston engines?

Answer 18

Decrease in performance
Lower altitudes
Too large for a/c
Weight to power ratio decreased

Question 19

What are the 4 types of GTE

Answer 19

Turbojet engine
Turbofan engine
Turboprop engine
APU

Question 20

What is the basic principle of jet propulsion?

Answer 20

Jet propulsion is the propelling force which is generated in the opposite direction to the flow of mass through the jet nozzle

Question 21

A jet engine that uses propulsion is called what?

Answer 21

Reaction engine

Question 22

What happens to un used gasses in a turbojet engine?

Answer 22

Used to drive the compressor and the accessories is converted into thrust

Question 23

What’s the negatives of turbojet engines?

Answer 23

Extremely loud
Not very efficient

Question 24

How do turboprop engines provide thrust?

Answer 24

By small acceleration of large quantities of air with a propeller

Question 25

How is the propeller driven in turboprop engines?

Answer 25

By the compressor shaft or by free turbine and long centre drive shaft

Question 26

Why does a turboprop engine have a reduction gear?

Answer 26

To reduce the high gas turbine engine rotation to speeds that can be managed by the propeller

Question 27

What does a turbofan engine combine?

Answer 27

Turbojet and turboprop engine

Question 28

How many spools does a turbofan engine have?

Answer 28

Twin or triple

Question 29

What is the fan driven by?

Answer 29

A turbine via drive shaft

Question 30

Does a turbofan engine have reduction gears?

Answer 30

No

Question 31

How much total thrust is produced by turbofan engine?

Answer 31

80%

Question 32

What is a bypass ratio?

Answer 32

Ratio of air that passes through fan duct compared to air passing through core

Question 33

What is the bypass ratio on modern a/c?

Answer 33

4:1 or 9:1

Question 34

What does the GTE power?

Answer 34

Either a single fan or set of counter rotating fans via a gearbox

Question 35

Why are propfan engines not commonly found on a/c?

Answer 35

Because of mounting difficulties

Question 36

What is a non modular engine?

Answer 36

The engine is designed in a way where it is hard to remove components from the engine

Question 37

What is a modular construction on engines?

Answer 37

Used on modern a/c where engine is set into major modules so components are easy to remove and replace

Question 38

Where are aluminium alloys mainly used on engines?

Answer 38

Used on gearbox housing Fan stator castings Other low loaded parts of fan module

Question 39

Where are ceramic coatings used?

Answer 39

In the combustor and high pressure turbine The coatings serve as heat and corrosion protection

Question 40

Where are steel alloys used?

Answer 40

On the N1 drive shaft Engine bearings Main structural frames

Question 41

Where is cobalt used?

Answer 41

Highly heat resistant Found in stator of first stage of the hp turbine

Question 42

Where are titanium alloys used?

Answer 42

Where there are high centrifugal forces

Question 43

Where are nickel alloys used?

Answer 43

Hp compressor Combustion section for lp/ hp turbine