What are the main types of turbine engine?
Turboshaft, Turboprop, Turbojet and Turbofan
Turboprop and Turbofan
Turboprop, Turbojet and Turbofan
Turboshaft, Turboprop, Ramjet and Turbofan
What is the definition of the bypass ratio of a turbofan engine?
The ratio of the mass of air bypassing the engine core, to the mass of the air passing through the engine core.
The ratio of the mass of air bypassing the engine core, to the mass of the air passing into the engine core.
The ratio of the mass of air bypassing the engine case, to the mass of the air passing through the engine core.
The ratio of the pressure of air bypassing the engine core, to the pressure of the air passing through the engine core.
What is the main similarity between a turbine engine and a reciprocating engine?
Both the turbine and reciprocating engine are internal combustion
Both the turbine and reciprocating engine are external combustion
Both the turbine and reciprocating engine are continuous cycle
Both the turbine and reciprocating engine produce similar thrust
How does the combustion cycle of a turbine engine compare with that of a reciprocating engine?
A turbine engine combustion takes place at a near constant pressure, while in a reciprocating engine combustion takes place at near constant volume.
A turbine engine combustion takes place at a near constant volume, while in a reciprocating engine combustion takes place at near constant pressure.
A turbine engine combustion takes place at a near constant pressure, while in a reciprocating engine combustion takes place at near constant temperature.
A turbine engine combustion takes place at a near constant pressure, while in a reciprocating engine combustion takes place at near constant pressure.
What is the functional difference between a turboprop and a turbo shaft?
A turboprop engine has an output shaft which drives a gearbox for a propeller while a turboshaft engine has an output shaft which drives a gearbox for something other than a propeller
A turboshaft engine has an output shaft which drives a gearbox for a propeller while a turbprop engine has an output shaft which drives a gearbox for something other than a propeller
How is a free power turbine characterised?
It is mechanically completely independent of the other spools in the engine
It is mechanically completely dependent of the other spools in the engine
It is mechanically partially independent of the other spools in the engine
It is mechanically partially dependent of the other spools in the engine
What are the advantages of a free turbine propulsion system?
The design flexibility of the layout, easier to start, the spools can run at their optimum speeds independent of each other and the ability to stop the propeller while the engine is still running
Easier to start, the spools can run at their optimum speeds independent of each other and the ability to stop the propeller while the engine is still running
The design flexibility of the layout, easier to start and the ability to stop the propeller while the engine is still running
The design flexibility of the layout, the spools can run at their optimum speeds independent of each other and the ability to stop the propeller while the engine is still running
Why does a free turbine turboprop engine require a smaller starter motor than direct-drive and compound turboprops?
Because only the high pressure turbine and compressor need to be rotated on start
Because only the low pressure turbine and compressor need to be rotated on start
Because only the low pressure turbine and ignitor need to be rotated on start
Because only the high pressure turbine and ignitor need to be rotated on start
Which part of a turboprop engine usually powers the accessory gearbox?
The high pressure compressor (N2) section.
The high pressure compressor (N1) section.
The low pressure compressor (N1) section.
The low pressure compressor (N2) section.
What drives the main drive gearbox in a free turbine turboprop or turboshaft?
The low pressure turbine(s)
The high pressure turbine(s)
What is the meaning of the term 'Spool'
An independent compressor, shaft, turbine combination
An dependent compressor, shaft, turbine combination
An dependent compressor and turbine combination
An independent compressor and turbine combination
What is a compressor/turbine combination called?
A free turbine
A spool
A continuous cycle
A geared turbine
Why do turbine engines have multiple spools?
So that each can operate closer to their design rpm
So that each can operate closer to their design egt
So that each can operate closer to their design limits
So that each can operate closer to their design features
In a twin spool turbine engine, which are the high pressure and low pressure stages of the compressor and turbine?
The first stage(s) of the compressor and the last stage(s) of the turbine are low pressure, while the last stage(s) of the compressor and the first stages of the turbine are high pressure
The first stage(s) of the compressor and the last stage(s) of the turbine are high pressure, while the last stage(s) of the compressor and the first stages of the turbine are low pressure
Within an engine's spools, what drives the intermediate pressure compressor?
The intermediate pressure turbine
The low pressure turbine
The high pressure turbine
Within an engine's spools, what drives the low pressure compressor?
What is the 'core' of a turbofan engine comprised of?
The compressor, combustion chamber, turbine and exhaust sections
Intake, the compressor, the combustion chamber, turbine and the exhaust nozzle
The compressor, combustion chamber, turbine and exhaust nozzle
What is the bypass ratio if 20% of the intake air passes through the engine core?
4:1
2:1
3:1
5:1
In terms of bypass ratio, how does a pure turbojet compare to a turbofan?
A pure turbojet has no bypass air
A pure turbofan has no bypass air
What percentage of bypass air passes through the compressor of a turbofan engine?
0%
40%
80%
22%
What are the advantages of a twin spool over a triple spool bypass engine?
Lower cost, easier maintenance
Shorter and lighter, better range/fuel consumption
Shorter and lighter, lower cost, easier maintenance
Lower cost, easier maintenance, better range/fuel consumption
What are the advantages of a triple spool over a twin spool bypass engine?
Lower cost, better range/fuel consumption
Shorter and lighter, easier maintenance
What output is provided by an APU?
AC electrical power and bleed air
DC electrical power
AC electrical power
DC electrical power and bleed air
What is the primary purpose of an APU?
To provide AC electrical power and pneumatic bleed on the ground, and in flight in the event of a main engine failure.
To provide DC electrical power and pneumatic bleed on the ground, and in flight in the event of a main engine failure.
To provide DC electrical power and pneumatic bleed on the ground, and in flight in the event of a main battery/generator failure.
To provide AC electrical power and pneumatic bleed on the ground, and in flight in the event of a battery/generator failure.
What section of an APU provides pneumatic bleed air for engine start?
The driveshaft
The turbine
The compressor
The spools
