TY - JOUR
T1 - Experimental study of the effects of geometrical parameters, Reynolds number, and equivalence ratio on methane-oxygen premixed flame dynamics in non-adiabatic cylinderical meso-scale reactors with the backward facing step
AU - Baigmohammadi, Mohammadreza
AU - Tabejamaat, Sadegh
AU - Farsiani, Yasaman
N1 - Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/8/18
Y1 - 2015/8/18
N2 - In this study, we experimentally investigated the effects of geometrical parameters (such as the reactor length (L) and the inner diameter (DR)), the step height (rin-rR), the Reynolds number (Re), and the equivalence ratio (ϕ)) of the inlet mixture on the behavior of the rich fuel methane-oxygen flames in non-adiabatic cylindrical meso-scale reactors with the backward facing step. During the experiments, seven different flame regimes were observed. These flame regimes were the blow-out, marginal, stationary (stable), RERI, stationary (stable)-flashback, RERI-flashback, and flashback, respectively. Also, the results showed that the length and diameter of reactors could strongly affect flame dynamics, especially the borders among the observed flame regimes in the meso-scale reactors. As a result, it was demonstrated that the reactor length and diameter obviously influenced the traveling speed and frequency of RERI flame regime. Also, it was shown that decreasing the step height from 1.4mm to 0.4mm suppressed RERI flame regime in the meso-scale reactors. Moreover, in the certain ranges of the equivalence ratio, increasing the Reynolds number decreased the flame presence range in the meso-scale reactors. Finally, it was concluded that RERI flame regime is a prevalent operational regime for applications in which an almost uniform temperature pattern on the outer surface of lengthy meso-scale reactors is required. However, it was shown that this privilege was not valid as compared to the temperature distribution patterns caused by the stationary flame regimes in the small length reactors.
AB - In this study, we experimentally investigated the effects of geometrical parameters (such as the reactor length (L) and the inner diameter (DR)), the step height (rin-rR), the Reynolds number (Re), and the equivalence ratio (ϕ)) of the inlet mixture on the behavior of the rich fuel methane-oxygen flames in non-adiabatic cylindrical meso-scale reactors with the backward facing step. During the experiments, seven different flame regimes were observed. These flame regimes were the blow-out, marginal, stationary (stable), RERI, stationary (stable)-flashback, RERI-flashback, and flashback, respectively. Also, the results showed that the length and diameter of reactors could strongly affect flame dynamics, especially the borders among the observed flame regimes in the meso-scale reactors. As a result, it was demonstrated that the reactor length and diameter obviously influenced the traveling speed and frequency of RERI flame regime. Also, it was shown that decreasing the step height from 1.4mm to 0.4mm suppressed RERI flame regime in the meso-scale reactors. Moreover, in the certain ranges of the equivalence ratio, increasing the Reynolds number decreased the flame presence range in the meso-scale reactors. Finally, it was concluded that RERI flame regime is a prevalent operational regime for applications in which an almost uniform temperature pattern on the outer surface of lengthy meso-scale reactors is required. However, it was shown that this privilege was not valid as compared to the temperature distribution patterns caused by the stationary flame regimes in the small length reactors.
KW - Methane
KW - Oxygen
KW - Reactor
KW - RERI
KW - Stable
KW - Step
UR - http://www.scopus.com/inward/record.url?scp=84928954877&partnerID=8YFLogxK
U2 - 10.1016/j.ces.2015.04.008
DO - 10.1016/j.ces.2015.04.008
M3 - Article
AN - SCOPUS:84928954877
SN - 0009-2509
VL - 132
SP - 215
EP - 233
JO - Chemical Engineering Science
JF - Chemical Engineering Science
ER -