Environmental Engineering Reference
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Fig. 44 EINO
x
/P
0.5
versus adiabatic
fl
flame temperature for the LDI-2
fl
at and recessed domes;
refer to Tacina et al. (
2014
) for more details
here is more than 99.9 %. Several important observations can be made including: (1)
NO
x
increases slowly from
1.0 EI/atm
0.5
at 1,500 K to
2.0 EI/atm
0.5
at 1
900 K
T
flame
; (2) no noticeable difference between the recessed and domes, except the latter
shows
-
*
*
slightly bigger data scatter band;
(3)
rapid increase in NO
x
for
T
flame
> 1,900 K; (4) and
finally the simple correlation (viz. NO
x
as a function of
T
flame
) needs further enhancements to take into account other secondary effects of the
fl
flat dome LDI-2. The development of good and useful engineering correlation is a
long process which will be shared for these designs in future publications. The
Woodward/NASA LDI-2 team should be very pleased to see that their relevant data
(viz. right part of Fig.
44
) is pretty competitive with the GE N + 2 technology point
(Fig.
37
) which the author feels is a proud milestone for the TAPS team that has
worked hard continuously since 1995, and spent more than $500 million in devel-
oping the TAPS technology and GEnx products.
7 Modeling and Correlations
It should be obvious from Figs.
41
,
42
, and
43
, and Table
6
that both LDI-2
con
cant departures from the baseline LDI-1 design and that
no use was made of the CFD models in making the LDI-2 design selections. The
LDI-1 empirical correlation was not applicable either and therefore the selection
process was driven by combustion fundamentals tempered by the guidelines pro-
vided by the LDI-1 design experience. The author is a strong believer in using CFD
in the design process (Mongia and Smith
1978
, Mongia et al.
1986
,
2004a
,
b
,
c
,
d
,
e
,
f
; Mongia
1993
,
2001a
,
b
,
2008
). His teams have spent 10
gurations were signi
25 % of their
resources in the development and calibration of CFD-based combustion models
applicable in the design process since the middle 1970s. Subsequently, many
publications have been shared by his former team members contributing signifi-
-
-
cantly toward the usefulness of CFD in the design process. The author has shared in
several of these publications the applications and limitations of the models in the
design process; the latter is covered by complimenting with simpler models as
explained brie
fl
y. The author is also a strong believer in the formulation and
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