Oxygen
-
enhanced oxy
-
fuel flame structure in a co
-
flow non
-
premixed jet burner
has been
investigated.
The
effect of
varying j
et Reynolds number and O
2
concentration
on
temperature and
key
species
OH and CH
2
O was
analysed
.
Temperature was measured
using polarised/ depolarised
(P/D)
Rayleigh scattering and
the
OH/ CH
2
O
species using
planar laser induced fluorescence (PLIF)
, collec
ted simultaneously
. ‘Traditional Rayleigh’ requires a constant
Rayleigh cross
-
section throughout the combustion process, which
is
impossible in high temperature oxy
-
fuel flames
due to thermal decomposition
leading
to inaccuracy.
However, a
carefully
-
chosen
combination of fuel and oxidiser
can be exploited
so the relative signal difference of
P/D
can be
utilised
.
M
ixture fraction can
thereby
be determined
and temperature accurately
recovered
.
This joint measurement enables combustion evolution in preheat (re
presented
by CH
2
O) and oxidation (represented by OH) zones to be analysed.
Detail
ed analysis of
localised extinction was also
performed