Revision Questions Flashcards
A compressor stage is?
One set of rotor blades followed by one set of stator vanes.
During the compression stage of the gas turbine working cycle, air pressure is?
Increase, volume decrease,s, and temperature increases.
THE AIR PASSING THROUGH THE GAS TURBINE ENGINE IS?
Used to support combustion and to cool the engine.
At what location on an impulse reaction turbine blade can the impulse design be seen?
Bottom of the blade
At which point on an axial-flow turbojet will the highest gas pressure occur?
At the compressor outlet
State the claimed advantage of the axial flow type compressor?
Consumes more air, so can attain higher pressure ratios and more thrust for the same frontal area, the increase pressure ratio by addition of stage will all lead to improved efficiency, SFC and thrust
Explain the function of an inlet guide van?
To direct airflow onto the rotor at the most desirable angle of attack.
Describe two methods of controlling airflow through an axial flow compressor?
Variable inlet guide vanes and stator vanes
Explain the function of a variable stator vane?
Vanes adjusted accordingly to engine speed at temperature to match airflow angle to rotor speed can increase the stall margin to prevent compressor stall.
What are two types of thrust reversers that are used with turbojet engines?
Aerodynamic Blockage
Mechanical Blockage
At what point in a turbine engine is the temperature the highest?
Combustion chamber
What is the function of the nozzle guide vanes?
To direct the flow of gases to strike the turbine buckets at the desired angle
What is the comparison of the Brayton cycle with that of the otto engine cycle?
That is both cycles there is an induction, compression, combustion, and exhaust.
In a turbine engine what type of pumps are oil pressure and scavenge type pumps?
Spur gear type.
Gas turbine oil synthetic because?
It has to operate over a wide temperature range and has a low evaporation point.
