Future Trends in Commercial Aviation Engines’ Combustion - Novel Combustion Concepts for Sustainable Energy Development - page 109

Fig. 1 The Pratt and Whitney PW1000G engine cross-section highlighting important technologies;
Modified a picture grabbed from http://grabcad.com/library/pratt-and-whitney-turbofan-engine-
pure-power-1000g on July 13, 2014. 1 Advanced 3-D aerodynamics for improved efficiency.
2 Advanced technology. 3 Higher speed

GTF provides reasonable engine architecture for future 14 BPR engines without
increasing LPC and LPT stage count, with moderate increase in the LP spool torque
(from 29.3 to 32.8kN-m), and LPT stage loading from 1.05 to 1.29 with additional
fuel burn reduction of 6 %. In summary, GTF has invigorated competitive

ghts
among the engine original equipment manufacturers (OEM) for the next generation
of propulsion engines, so-called N + 1 and N + 2 generation engines with operating
overall pressure ratios (OPR) approaching or exceeding 60 (Kumar et al. 2012a , b ,
c ; Panda et al. 2012a , b ). It is therefore interesting to note that the

rst GTF product,

-

the PW1000G, will be used on the 130 180-seat A320neo family with 12 BPR,

replacing the IAE V2500; the 70 - 90-seat Mitsubishi Regional Jet with 9 BPR; the

110 212-seat Irkut MS-21

family. The projected 12.2 BPR for the A320neo has forced the LEAP-X with
conventional turbofan architecture to 11 BPR, both claiming 16 % reduction in
mission fuel burn (Arvai 2011 ).
The medium-size GTFs and competing high BPR and OPR engines have to use
smaller size high-pressure cores requiring a new set of fuel/air mixing devices for
high combustor inlet temperature (T 3 ) and temperature rise (

- 130-seat Bombardier CSeries with 12 BPR; and the 150 -

Δ T) (Mongia 2011a , b ).
Moreover, TALON-X as highlighted in Fig. 1 claims to take the rich-quench-lean
(RQL) combustion technology developed progressively since the early 1980s (viz.
Mongia 2013a , b , c , d ) to yet another lower level (McKinney et al. 2007 ), leading to
reassessing the combustion mixers technology path taken in the last 40 years
(Mongia 2011c , d , e ). If the statements made by AirInsight ( 2011 ) turn out true in
regard to the PW1000G and LEAP-X operating pressure and HPT gas path tem-
perature levels (viz. The LEAP will need to run at hotter temperatures and have

higher pressure ratios than the GTF

“

— LEAP is expected to have gas path