Question | Answer |
how can you tell if a turbofan or turbojet engine is out of trim? | there will be high exhaust gas temperature at target engine pressure ratio for takeoff power. |
what prevents the combustion chamber from burning? | cooling air along the inside of the liner. |
what is a split compressor system? | also called dual or twin spool compressors, these are connected to the turbine section with two rotor shafts, one inside the other. |
what are carbon seals used for in turbine engines? | they are used as oil seals for the rotor shaft bearings. |
how does relative humidity affect turbine engines? | negligible effect. |
name two(3) different methods for attaching turbine engine rotor blades to the rotor disk. | dovetail-type root, bulb-type root, fir tree-type root. |
what are the possible causes(2) for a turbojet or turbofan engine having high exhaust gas temperatures, low r.p.m., and high fuel flow at all engine pressure ratios? | turbine damage or loss of turbine efficiency due to wear. |
explain the main difference and advantage of turbofan over turbo jet engines. | a turbofan engine uses a fan to bypass some air around the engine core and to provide thrust. the advantage is that this provides additional thrust without increasing fuel flow. |
name the major components in a gas turbine engine.(7) | air inlet, compressor section, combustion section, turbine section, exhaust section, gearbox and accessory section. |
what determines the amount of airflow through a turbine engine?(3) | the forward speed of the aircraft, compressor speed, and air density. |
why are compressor washes performed(2) and what methods are commonly used(2)? | to remove any contaminates from the compressor section and improve engine performance. the fluid wash and abrasive grit wash are commonly used. |
name the two types of compressors commonly used in turbine engines. | axial and centrifugal flow compressors. |
what is the purpose of the interconnecting tubes attached between can-type combustion chambers? | for flame propagation during start. |
name the different types of compressor blade damage that may be found during inspection(8). | dents, cracks, galling, pitting, scratches, burrs, burns, gouges. |
what kind of markers can be used to mark the parts in hot and cold sections during repair(3)? | layout dye, felt tip marker, chalk. |
what are the different types of combustion chambers(4) used in turbine engines? | can, annular, can-annular, and reverse flow annular. |
what function do axial flow turbine nozzles perform? | they direct the mass airflow to drive the turbine rotor at a specific angle. |
how is thermal stress relieved on a turbine disk? | by directing bleed air onto the face of the disk, or by grooves being cut into the disk. |