M15.1 Flashcards
What are the units of force in all technical manuals?
Decanewton
What is the unit for weight?
Newtons
How is work measured?
Force multiplied by distance
How is power measured?
Work over time
What is Newton’s first law?
A body at rest will stay at rest unless acted upon
What is Newton’s third law?
Every action has an equal and opposite reaction
What is the working cycle of a gas turbine?
- induction (suck)
- compression (squeeze)
- combustion (bang)
- exhaust (blow)
What are the different types of gas turbine engines on an aircraft?
- turbojet
- turboprop
- turbofan
- APU
What is the APU used for?
Electrical and pneumatic power
What is an engine that uses jet propulsion called?
A reaction engine (they use newtons law of motion)
What year did Hans Von Ohain build a gas turbine engine with a radial turbine?
1937
What year did Frank Whittle build a engine with an axial turbine?
1941
Why aren’t turbojet engines used commonly anymore?
They’re very loud and not very efficient
What is special about the turboprop combine to the turbojet and turbofan?
It can be driven directly by the compressor shaft or by a free turbine and a long centre drive shaft
What is used to reduce the high gas turbine engine rotation to speeds the propeller can handle?
A reduction gear
How much gas energy is converted into torque on a turboprop engine?
All of it
A turbofan engine converts a large part of the gas energy into torque to drive the fan and the engine compressor. Where does the rest go?
It is directly converted into thrust
The total thrust of the turbofan engine is what?
The sum of thrust from the core and fan
What is the bypass ratio?
It is the ratio of air that flows through the fan duct compared to the core engine
Why aren’t prop-fan engines used commonly?
They’re difficult to mount to the wings
How much fuel percentage do prop-fan engines save combined to turbofan engines?
20%
What are the two types of engine design?
Modular and non-modular
What’s the difference between modular and non-modular?
Modular is split into sub modules and non modular is one whole piece
What is aluminium alloy manly used for?
Gearbox housings, fan stator casing and low loaded parts of the fan module
Where is ceramic used?
In the combustion chamber and the high pressure turbine
Why is ceramic used?
It is a good heat and corrosion protection system
What are steel alloys used for?
The N1 drive shaft, bearing, and main structural frames on some engines
Where is cobalt found in an engine?
They’re found in the first stage of the high pressure turbine
Where is titanium mainly used?
In the fan, low pressure compressor and front stages of the high pressure compressor
Where is nickel used in an engine?
The high pressure compressor, the combustion section and. For the turbines
