BGT Flashcards
Expansion would be in reference to what sort of duct?
Convergent
In axial flow compressor, reduction in annulus area between rotor shaft and stator causing would do what ?
Reduce area where compressed air held
Manintain constant air stream velocity
In turbo prop power plant, what is the proportion of prop to jet exhaust thrust contribution?
Prop 90%
J.E.T 10%
What is the main purpose of the compressor?
Supply large mass of compressed air to combustion chambers
What is the purpose of water or water methanol injection?
Increase mass flow through engine to increase thrust at takeoff
What is the purpose of variable inlet nozzle guide vanes?
Reduce chance of HIGH pressure compressor surging, especially during engine start
On a two spool turbofan engine, the fan and low pressure compressor are drive by what?
The last stage turbine
Which spins faster, N1 or N2 blades? Why?
N2 blades rotate at higher speeds
They are shorter than N1 and operate in higher temp air
What is high output igniters used for and how often do they discharge compared to low output?
Starting and in-flight re-lighting
Discharge less that low output
What is low output igniters used for and how often do they discharge compared to high output?
Flying in rain, turbulence, icing conditions and take off
Discharge more often then high
What happens to N1 rpm and N2 rpm as twin spool gas turbine aircraft gains height?
Both increase
What would you expect engine compressor rpm to be on a hotter day
Higher
EPR is measured between which two point?
First stage compressor inlet and Last stage TURBINE outlet
During take off run, what happens to EPR?
Drops
Thermo-dynamic rating of an engine describes what ratio?
Power output delivered at max turbine limit temperature
