Book 2 - Engine Air Flow Control Flashcards
most engines will have a set of IGV’s (_____ _____ _____) immediately in front of the first _____ of compressor rotor blades
most engines will have a set of IGV’s (INLET GUIDE VANES) immediately in front of the first STAGE of compressor rotor blades
the purpose of the IGV’s is to give _____ to the air entering the front of the compressor, ensuring that it is presented at the correct _____ of attack
the purpose of the IGV’s is to give WHIRL to the air entering the front of the compressor, ensuring that it is presented at the correct ANGLE of attack
_________ IGV’s (VIGV’s) are fitted to many engines. they mechanically adjust their _____ to allow for changes in engine ___ and _______ conditions
the angle is adjusted mechanically by an ________ and suitable linkage, with the actuator control sensitive to engine ___ and intake ___________
VARIABLE IGV’s (VIGV’s) are fitted to many engines. they mechanically adjust their ANGLE to allow for changes in engine RPM and AMBIENT conditions
the angle is adjusted mechanically by an ACTUATOR and suitable linkage, with the actuator control sensitive to engine RPM and intake TEMPERATURE
some recent engine designs include VSV’s (________ ______ _____) which, like IGV’s, will present air at the correct angle to the following stage of _______. VSV’s however, are usually controlled by more complex computer based systems such as _____ (full authority digital engine control)
some recent engine designs include VSV’s (VARIABLE STATOR VANES) which, like IGV’s, will present air at the correct angle to the following stage of ROTORS. VSV’s however, are usually controlled by more complex computer based systems such as FADEC (full authority digital engine control)
VIGV’s and VSV’s may control angle of air within compressor, however, there is still risk of stall/surge due to ____ pressure from the combustion system. a method of overcoming such a problem is to ______ off excess pressure towards to ____ of the compressor
VIGV’s and VSV’s may control angle of air within compressor, however, there is still risk of stall/surge due to BACK pressure from the combustion system. a method of overcoming such a problem is to BLEED off excess pressure towards to REAR of the compressor
the amount of air bled from the compressor is controlled by ______ valves that are ____ at idle RPM and low ________ ratios, and automatically ______ at _______ RPM when the airflow conditions are more stable
the conditions most likely to bring about compressor stall and engine surge are those encountered when the engine is _______ in flight or during _________ ____________
the amount of air bled from the compressor is controlled by BLEED valves that are OPEN at idle RPM and low PRESSURE ratios, and automatically CLOSED at HIGHER RPM when the airflow conditions are more stable
the conditions most likely to bring about compressor stall and engine surge are those encountered when the engine is IDLING in flight or during MAXIMUM ACCELERATION
the bleed valves ____ at the critical periods to dump excess airflow from the _____ stages, to reduce airflow over the rear stages. this prevents _______ of the rear stages and subsequent stall
the bleed valves OPEN at the critical periods to dump excess airflow from the EARLY stages, to reduce airflow over the rear stages. this prevents CHOKING of the rear stages and subsequent stall
in FADEC engines, the V__’s, V___’s and the ______ valves will be controlled entirely by the computer in the FADEC
in FADEC engines, the VSV’s, VIGV’s and the BLEED valves will be controlled entirely by the computer in the FADEC
the VSV system contains a LVDT (______ ________ __________ __________/__________) which provides feedback to the computer regarding vane position. the computer will then ______ the angle depending on the steady or _________ state of the engine and _______ conditions
the VSV system contains a LVDT (LINEAR VARIABLE DIFFERENTIAL TRANSFORMER/TRANSDUCER) which provides feedback to the computer regarding vane position. the computer will then ADJUST the angle depending on the steady or TRANSIENT state of the engine and AMBIENT conditions
most FADEC equipped engines have _________ bleed valves (VBV’s), which means that they will operate over a limited range of RPM’s. position is computer controlled, however, also programmed to allow for differences in N_ (LP speed)
most FADEC equipped engines have VARIABLE bleed valves (VBV’s), which means that they will operate over a limited range of RPM’s. position is computer controlled, however, also programmed to allow for differences in N1 (LP speed)
