Environmental Engineering Reference
In-Depth Information
2.4 Landing
Takeoff (LTO) NO x
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The
rst ICAO NO x regulatory standard (viz. ICAO Committee on Aviation Engine
Emissions, CAEE) was adopted in 1981 followed by the second (viz. ICAO
Committee on Aviation Environment Protection, CAEP/2) with additional 20 %
reduction for newly certi
ed engines produced after December 31, 1999. The
CAEE also
takeoff cycle for commercial subsonic aviation
engines as depicted in Fig. 12 . It comprises of four engine operating modes for the
sea-level, static, standard-day (1) takeoff duration of 0.7 min at the rated thrust F 00 ,
followed by (2) 2.5 min of climbout at constant thrust of 85 % F 00 . On the other
hand, the
finalized the landing
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final approach of the aircraft descending from 3,000 ft. to the runway
touchdown is simulated by assuming that it takes (3) 4 min at 30 % F 00 . The aircraft
taxi-in and taxi-out to the takeoff location is simulated by assuming engine (4) run
time of 26 min at 7 % F 00 .
Therefore, the gaseous pollutant during the LTO cycle and its normalized value
by F 00 (viz. DP/F 00 ) can be calculated by using the following two equations:
LTO cycle pollutant ; P i ½g of pollutant ¼ X
j
EIP ij W Fj tj ; LTO Pollutant ð NO x ; CO ; HC Þ
¼ DP
F 00 ;
g
=
kN ¼ P i = F 00
Here the pollutant Pi i
is in EI units, namely gm of pollutant/kg fuel. Even though
OEM
achievements in terms of
LTO NO x regulatory levels which have become progressively more stringent
through the years, CAEP2, CAEP4, CAEP6, and CAEP8 regulations need to be
discussed later; combustion technologists perhaps get more insight by plotting rich
domes
'
s marketing of
ces campaign about their engines
'
takeoff NO x as a function of takeoff pressure ratio (viz. Mongia 2013a , b , c )
or stoichiometric
'
fl
flame temperature (viz. Mongia 2010a , b ); idle CO as a function of
Fig. 12 ICAO Landing
Takeoff Cycle for commercial aviation engines comprised of idle,
takeoff, climbout, and approach
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