Flashcard Set Preview
Side ASide B
at what point in an axial flow turbojet engine will the highest gas press. occur?
at the compressor outlet(burner inltet.
what does a nozzle diaphragm in a turbine engine do?
directs the flow of gases to strike the turbine blades at the desired angle.
the fan rotational speed of a dual axial compressor forward fan engine is the same as the..?
low pressure compressor.
the abbreviation Pt17 used in turbine engine term means..?
the total pressure at station number 17.
how should the blending of blades and vanes in a turbine engine be performed?
parallel to the length of the blades using smooth contours to minimize stress points.
what turbine engine section provides for proper mixing of the fuel and air?
in a gas turbine engine, combustion occurs at a constant..?
what is the relationship between thrust and RPM in jet engines?
at higher engine speeds, thrust increases rapidly with small increases in RPM.
some high volume turboprop and turbojet engines are equipped w/ two-spool or split compressors. what happens to these engines when operated at high altitudes?
the low press. rotor will increase in speed as the compressor load decreases in the lower density air.
turbine nozzle diaphragms located on the upstream side of each turbine wheel, are used in the gas turbine engine to..?
increase the velocity of the heated gases flowing past this point.
where is the ighest gas pressure in a turbojet engine?
in the entrance of the burner section.
an exhaust cone placed aft of te turbine in a jet engine will cause the pressure in the first part of the exhaust duct to..?
increase and the velocity to decrease.
what is the function of the stator vane assembly at the discharge end of a typical axial flow compressor?
to straighten airflow to eliminate turbulence.
the turbine section of a jet engine drives the..?
when starting a turbine engine a hot start is indicated..?
if the exhaust gas temp. exceeds specified limits.
in the dual axial flow or twin spool compressor system, the first stage turbine drives the..?
when starting a turbine engine, a hung start is indicated..?
when the engine fails to reach idle RPM.
what are the two basic elemts of the turbine section in a turbine engine?
stator and rotor.
the function of the exhaust cone assembly of a turbine engine is to..?
straighten and collect the exhaust gases into a solid exhaust jet.
what are the two elements in a centrifugal compressor?
impeller and diffuser.
what must be done after the fuel control unit has been replaced on an aircraft gas turbine engine?
retrim te engine.
a turbine engine compressor which containes vanes on both sides of the impeller is a..?
double entry centrifugal compressor.
what is the first engine instrument indication of a succesful start of a turbine engine?
a rise in the exhaust gas temp.
who establises the recommended operating time between overhauls(TBO) of a turbine engine used in general aviation?
the engine manufacturer.
turbine engine components exposed to high temp, generally may NOT be marked w/..?
wax, grease, or graphite pencil.
who establishes mandatory replacement times for critical components of turbine engines?
the engine manufacturer.
main bearing oil seals used with turbine engines are usually what type?
labyrinth and/or carbon rubbing.
how does a dual axial flow compressor improve the efficiency of a turbojet engine?
higher compression ratios can be obtained.
three types of turbine blades are..?
impulse, reaction, and impulse-reaction.
an advantage of the axial flow compressor is its..?
high peak efficiency.
what is one purpose of the stator blades in the compressor section of a turbine engine?
controls the direction of the airflow.
what is the purpose of the diffuser section in a turbine engine?
to increase pressure and reduce velocity.
where do stress rupture cracks usually appear on turbine blades?
across the leading or trailing edge at a right angle to the edge length.
in which type of turbine enging combustion chamber is the case and liner removed and installed as one unit during maintenance?
the diffuser section of a jet engine is located between..?
the compressor and the burner section.
when the leading edge of a first stage turbine blade is found to have stress rupture cracks, which of the following should be suspected?
turbine blades are generally more susceptible to perating damage than compressor blades because of..?
exposure to high temp.
which is the ultimate limiting factor of turbine engine operation?
turbine inlet temp (TIT).
the recurrent ingestion of dust or other fine airborne particulates into a turbine engine can result in..?
erosion damage to the compressor and turbine sections.
whic of the following engine variables is the most critical during turbine engine operation?
reduced blade vibration and improved airflow characteristics in gas turbines are brought about by..?
shrouded turbine rotor blades.
which turbine engine compressor offers the greatest advantages for both starting flexibility and improved high altitude performance?
split spool, axial flow.
an advantage of the centrifugal flow compressor is its high..?
pressure rise per stage.
the highest heat to metal contact in a jet engine is the..?
turbine inlet guide vanes.
which two elements make up the axial flow compressor assembly?
rotor and stator.
the two types of centrifugal compressor impellers are..?
single entry and double entry.
between each row of rotating blades in a turbine engine compressor, there is a row of stationary blades which act to diffuse the air. they are called..?
when turbine blades are subjected to excessive heat stress, what type of failures would you expect?
in an axial flow compressor, one purpose of the stator vanes is to..?
straighten the airflow and eliminate turbulence.
the purpose of the shrouds on the turbine blades of an axial flow engine is to..?
in a dual axial flow compressor, the first stage turbine drives..?
what should be done initially if a turbine engine catches fire when starting?
turn off the fuel and continue engine roation w/ the starter.
what is the proper starting sequence for a turbojet engine?
starter, ignition, fuel.
a weak fuel to air mixture along with normal airflow through a turbine engine may result in..?
a lean die out.
what is used in turbine engines to aid in stabilization of compressor airflow during low thrust engine operation?
variable guide vanes and compressor bleed valves.
in a turbine engine with a dual spool compressor, the low speed compressor..?
seeks its own best operating speed.
what is the function of the inlet guide vane assembly on an axial flow compressor?
directs the air into the first stage rotor blades at the proper angle.
the stator vanes in an axial flow compressor..?
convert velocity energy into pressure energy.
anti icing of jet engine air inlet is commonly accomplished by..?
engine bleed air ducts.
when starting a turbine engine, the starter should be disengaged..?
after the engine has reached self accelerating speed
what is the primary advantage of an axial flow compressor over a centrifugal one?
greater pressure ratio.
the purpose of a bleed air valve in an aircraft gas turbine engine is to..
vent some of the air overboard.
what is meant by a double entry centrifugal compressor?
a compressor with vanes on both sides of the impeller.
whats te function of the turbine assembly in a turbojet engine?
supplies power to turn the compressor.
stator blades in the compressor section of an axial flow turbine engine..?
decreases the air velocity and prevent swirling.
a gas turbine engine comprises which three main sections?
turbine, compressor, combustion.
what type of turbine blade is most commonly used in aircraft jet engines?
what is the primary factor which controls the pressure ratio of an axial flow compressor?
the number of stages in the compressor.
the non rotating axial flow compressor airfoils in an aircraft gas turbine engine are called..
the air passing trough the combustion chamber of a turbine engine is used to..?
support combustion and to cool the engine.
the stators in the turbine section of a gas turbine engine..?
increase the velocity of the gas flow.
the compressor stators in a gas turbine engine act as diffusers to..?
decrease the velocity of the gas flow/
what is the possible cause when a turbine engine indicates no change in power setting parameters, but oil temperature is high?
engine main bearing distress.
a turbine engine hot section is susptible to what kind of damage?
what influences the operation of an automatic fuel control unit on a turbojet engine?
the compression ratio of an axial flow compressor is a function of the..?
number of compressor stages.
why do some turbine engines have more than one turbine wheel?
to extract more power from the exhaust gases.
the exhaust section of a turbine engine is designed to..?
impart a high exit velocity to the exhaust gases.
which of the following types of combustion sections are used in aircraft turbine engines?
multiple-can, annular, and can-annular.
a cool off period prior to shutdown of a turbine engine is accomplished in order to..?
allow the turbine wheel to cool before the case contracts around it.
what term is used to describe permanent deformation of the turbine blades of a turbojet engine?
what is the purpose of the dump valve used on aircraft gas turbine engine?
dumps the fuel from the fuel manifold when the engine is shut down.
at what stage ina turbine engine are gas pressures the greatest?
in waht section of a turbojet engine is the jet nozzle located?
compressor stall is caused by..?
a high angle of attack airflow through the first stages of compression.
hotspots are possible indicators of..?
malfunctioning fuel nozzles.