| 1. |
- Baigmohammadi, Mohammadreza, et al.
(author)
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Experimental study on the effect of external thermal pattern on the dynamics of methane-oxygen and methane-oxygen-carbon dioxide premixed flames in non-adiabatic meso-scale reactors
- 2019
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In: International journal of thermal sciences. - : Elsevier. - 1290-0729 .- 1778-4166. ; 137, s. 242-252
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Journal article (peer-reviewed)abstract
- In the current study, the effect of external thermal pattern on the dynamics and characteristics of methane oxygen and methane-oxygen-carbon dioxide premixed flames in non-adiabatic meso-scale cylindrical reactors is investigated experimentally. In this regard, two different external thermal patterns were imposed on the outer surface of the reactors. The results showed that imposing method/direction and also temperature level of the external thermal pattern have impressive effect on flame dynamics and chemiluminescence in the non-adiabatic meso-scale reactors. Also, it was shown that increasing the temperature level of the external thermal pattern could significantly extend the flame stability and its presence range in the meso-scale reactors, especially for the vitiated mixtures (methane-oxygen-carbon dioxide). Moreover, the results demonstrated that decreasing the inner diameter of a meso-scale reactor, which was subjected to an external thermal pattern, could increase the flame controllability and its presence range in the non-adiabatic meso-scale reactors.
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| 2. |
- Baigmohammadi, Mohammadreza, et al.
(author)
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Experimental study on the effects of mixture flow rate, equivalence ratio, oxygen enhancement, and geometrical parameters on propane air premixed flame dynamics in non-adiabatic meso-scale reactors
- 2017
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In: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 121, s. 657-675
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Journal article (peer-reviewed)abstract
- In the present study, the effects of reactive mixture flow rate, adding oxygen to propane-air mixture, geometrical parameters, and equivalence ratio on propane-air/oxygen premixed flame dynamics in non adiabatic meso-scale reactors were experimentally investigated. During the experiments, seven flame regimes of blow-off, blow-out, asymmetric stationary, stationary-repetitive extinction and re-ignition (RERI), forced/self-RERI, RERI-flash-back, and flash-back were observed. The results showed that increasing the reactive mixture flow rate could generally promote variety of the flame regimes and also improve flame stability in the non-adiabatic meso-scale reactors, especially in 40% and 80% oxygen enhanced cases. Also, the results demonstrated that increasing the reactor inner diameter and equivalence ratio generally extended propane-air- oxygen flame stability and its presence range in the non adiabatic meso-scale reactors. Moreover, it was shown that increasing the reactor length and also increasing the added oxygen to propane-air mixture more than 40% promoted flame instability and consequently restricted propane-air-oxygen flame presence range in the non-adiabatic meso-scale reactors. Also, it was shown that variations in the mixture flow rate, the reactor length and inner diameter, equivalence ratio, and oxygen concentration in propane-air mixture could significantly influence the flame average propagation speed, acoustic, and chemiluminescence in the non-adiabatic meso-scale reactors.
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| 3. |
- Baigmohammadi, Mohammadreza, et al.
(author)
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Numerical Study of Methane-Oxygen Premixed Flame Characteristics in Non-adiabatic Cylindrical Meso-Scale Reactors with the Backward-Facing Step
- 2019
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In: Iranian Journal of Science and Technology, Transactions of Mechanical Engineering. - : Springer. - 2228-6187 .- 2364-1835. ; 43, s. 117-140
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Journal article (peer-reviewed)abstract
- In the present study, the effects of reactor diameter, inlet velocity, velocity profile, equivalence ratio (Phi, Ф), and outer wall convective and radiative heat transfer coefficients on flame characteristics in cylindrical non-adiabatic meso-scale reactors with the backward-facing step were investigated numerically. The results showed that these parameters could strongly affect the mole fraction of radical species within the flame zone. Also, it was shown that as compared to the reactor with 3 mm inner diameter, increasing the inlet velocity in the reactor with 5 mm inner diameter may lead to the opposite effect on the flame location. In addition, it was observed that the velocity profile could sensibly affect the flame location, temperature, and the species mole fractions in the meso-scale reactors. Moreover, it was demonstrated that the effect of equivalence ratio on the flame characteristics was more crucial for the reactors with smaller diameters. Furthermore, it was maintained that the outer wall convective and radiative heat transfer coefficients could cause the flame instability in the meso-scale reactors because of decreasing the mole fraction of important species such as O, H, and OH in the vicinity of the reactor inner wall.
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