ISSN 0010-5082, Combustion, Explosion, and Shock Waves, 2018, Vol. 54, No. 3, pp. 294–300.
Pleiades Publishing, Ltd., 2018.
Original Russian Text
D.K. Sharaborin, D.M. Markovich, V.M. Dulin.
Spatial Structure of a Reacting Turbulent
Swirling Jet Flow with Combustion
of a Propane–Air Mixture
D. K. Sharaborin
and V. M. Dulin
Published in Fizika Goreniya i Vzryva, Vol. 54, No. 3, pp. 47–54, May–June, 2018.
Original article submitted September 1, 2017.
Abstract: Results of an experimental study of the spatial structure of a reacting ﬂow during
combustion of a propane–air mixture in a turbulent swirling jet escaping into atmospheric air are
presented. The fuel-to-air equivalence ratio is φ = 0.7, and the Reynolds number of the jet is
Re = 5 · 10
. The time-averaged spatial distributions of velocity, local density, and concentrations
of the main species of the gas mixture are measured in low-swirl and high-swirl ﬂows. In both
cases, the ﬂame front is stabilized in the internal mixing layer formed by the axial region of jet
retardation, where hot combustion products are concentrated. In a high-swirl ﬂow, the temperature
distributions in the cross section y/d = 0.5 show that the region with the maximum temperature
of the gas is located at the periphery of the central recirculation zone. Moreover, in the case of a
high-swirl ﬂow, there exists a recirculation zone at the axis, and the CO
concentration is twice
higher than in a low-swirl jet. The opposite situation is observed for O
Keywords: ﬂame in a swirling ﬂow, spontaneous Raman scattering, particle image velocimetry.
The ﬂame in many burners and combustion cham-
bers is stabilized by means of formation of swirling jets,
which ensure successful ignition and stable combustion
of the fuel in a compact volume within wide ranges of
the fuel and oxidizer ﬂow rates [1–3]. By using low-swirl
jets (see [4–6]), it is possible to ensure signiﬁcant reduc-
tion of NO
concentrations in combustion products of
fuel-lean mixtures as compared to a high-swirl jet un-
der similar conditions . The eﬀect is achieved owing
to reduction of the residence time of hot combustion
products containing nitrogen and oxygen molecules in
the combustion chamber caused by the absence of the
central zone of ﬂow recirculation because nitrogen ox-
Kutateladze Institute of Thermophysics, Siberian Branch,
Russian Academy of Sciences, Novosibirsk, 630090 Russia;
Novosibirsk State University, Novosibirsk, 630090 Russia.
idation mainly occurs in hot combustion products be-
hind the ﬂame front . In particular, ﬂow swirling
allows ﬂame stabilization in the case of fuel-lean mix-
tures, which is an eﬀective way of decreasing NO
sions . However, fuel-lean mixtures are usually highly
sensitive to ﬂow disturbances and to ﬂuctuations of the
fuel-to-oxidizer equivalence ratio, which, in particular,
can lead to the emergence of a thermoacoustic resonance
in the combustion chamber . Thus, investigations
of the spatial structure and the inﬂuence of combustion
processes in fuel-lean turbulent swirling jet ﬂows is an
important issue in optimization of burners and combus-
tion chambers of gas-turbine facilities.
Detailed information on the turbulent ﬂow struc-
ture can be obtained by using contactless optical meth-
ods, such as laser Doppler anemometry (LDA) [4, 11]
and particle image velocimetry (PIV) [7, 12–14]. PIV
allows one to measure the spatial distribution of velocity
in a chosen cross section of the ﬂow. To estimate the dis-
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