Book 2 - Exhaust System Flashcards
the _________ and _________ of the exhaust gases create the ___ the thrust in the turbo-___ engine, but in the turbo-prop, only a _____ amount of energy is contributed by the exhaust gases, because most of the energy has been absorbed by the _______ for driving the __________
the VELOCITY and PRESSURE of the exhaust gases create the ALL the thrust in the turbo-JET engine, but in the turbo-prop, only a SMALL amount of energy is contributed by the exhaust gases, because most of the energy has been absorbed by the TURBINE for driving the PROPELLER
the temperature of the gas entering the exhaust system is between ___ and ___ celsius. turbo prop and by-pass engines have the _______ exhausts. with the use of after-burn (reheat) the temperature in the jet pipe can be ____ celsius
the temperature of the gas entering the exhaust system is between 550 and 850 celsius. turbo prop and by-pass engines have the COOLEST exhausts. with the use of after-burn (reheat) the temperature in the jet pipe can be 1700 celsius
gas enters the exhaust system at speeds of ___-____ ft/sec but to reduce the effect of high _______ losses, the speed of flow is ________ by diffusion. this is done by creating a __________ passage between an exhaust ____ and the outer wall. it is usual to hold outlet gas velocity at ___ ft/sec
gas enters the exhaust system at speeds of 750-1200 ft/sec but to reduce the effect of high FRICTION losses, the speed of flow is REDUCED by diffusion. this is done by creating a DIVERGENT passage between an exhaust CONE and the outer wall. it is usual to hold outlet gas velocity at 950 ft/sec
the exhaust gases pass to atmosphere through the propelling ______, which forms a __________ duct, thus increasing gas velocity
exhaust gases pass to atmosphere through the propelling NOZZLE, which forms a CONVERGENT duct, thus increasing gas velocity
during most operating conditions, the ____ velocity reaches the speed of sound. the propelling nozzle is then said to be in the _______ condition and no further increase in ________ can be obtained unless temperature is __________,
________ then builds up inside the exhaust, causing exhaust pressure to rise. the gases then escape to atmosphere, trying to __________ the pressure. this creates an additional forward reaction known as ________ thrust which acts on top of ___________ thrust. exhaust gas velocity will remain _____ but a higher volume of air squeezing its way through the propelling nozzle
during most operating conditions, the EXIT velocity reaches the speed of sound. the propelling nozzle is then said to be in the CHOKED condition and no further increase in VELOCITY can be obtained unless temperature is INCREASED,
PRESSURE then builds up inside the exhaust, causing exhaust pressure to rise. the gases then escape to atmosphere, trying to EQUALISE the pressure. this creates an additional forward reaction known as PRESSURE thrust which acts on top of MOMENTUM thrust. exhaust gas velocity will remain SONIC but a higher volume of air squeezing its way through the propelling nozzle
propelling nozzle size is extremely important. too small, pressure, temperature and thrust all ________ but increase possibility of engine _______. too large nozzle and pressure, temperature and thrust too ______
propelling nozzle size is extremely important. too small, pressure, temperature and thrust all INCREASE but increase possibility of engine SURGING. too large nozzle and pressure, temperature and thrust too SMALL
exhaust system manufactured from heat resisting ______ and heat prevented from transfer to surrounding components by passing ventilating ___ around the jet pipe, and by covering in insulating ________.
exhaust system manufactured from heat resisting STEELS and heat prevented from transfer to surrounding components by passing ventilating AIR around the jet pipe, and by covering in insulating BLANKETS.
bypass air and exhaust gases are mixed in a ______ unit which consists of a number of _______ through which the bypass air flows into the exhaust gases
bypass air and exhaust gases are mixed in a MIXER unit which consists of a number of CHUTES through which the bypass air flows into the exhaust gases
the exhaust system must be mounted and joined in such a way as to allow for ________ expansion and contraction without distortion or damage
the exhaust system must be mounted and joined in such a way as to allow for THERMAL expansion and contraction without distortion or damage
the cone and streamlined fairings in the exhaust are provided with ____ holes to obtain a pressure balance and prevent distortion
the cone and streamlined fairings in the exhaust are provided with VENT holes to obtain a pressure balance and prevent distortion
in cases of extreme temperature, the entire ___ pipe is usually double-walled. exhaust gases leaving the propelling nozzle induce, by ________ action, a flow of air through the ________ space of the engine nacelle. this flow of air _____ the inner wall of the jet pipe and acts as an __________ blanket to the outer wall
in cases of extreme temperature, the entire JET pipe is usually double-walled. exhaust gases leaving the propelling nozzle induce, by EJECTOR action, a flow of air through the ANNULAR space of the engine nacelle. this flow of air COOLS the inner wall of the jet pipe and acts as an INSULATING blanket to the outer wall
