Prediction of flame speed and exergy analysis of premixed flame in a heat recirculating cylindrical micro combustor

Energy ◽  
2017 ◽  
Vol 126 ◽  
pp. 658-670 ◽  
Author(s):  
Uttam Rana ◽  
Suman Chakraborty ◽  
S.K. Som
Keyword(s):  
Exergy Analysis ◽  
Flame Speed ◽  
Premixed Flame ◽  
Micro Combustor

Quantifying the role of Darrieus–Landau instability in turbulent premixed flame speed determination at various burner sizes

2021 ◽  
Vol 33 (2) ◽  
pp. 025104
Author(s):  
Xin Wang ◽  
Xiaobei Cheng ◽  
Hao Lu ◽  
Yishu Xu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Flame Speed ◽  
Premixed Flame ◽  
Turbulent Premixed Flame ◽  
Landau Instability ◽  
Turbulent Premixed

Negative flame speed in an unsteady 2-D premixed flame: A computational study

1996 ◽  
Vol 26 (1) ◽  
pp. 323-329 ◽  
Author(s):  
Inge R. Gran ◽  
Tarek Echekki ◽  
Jacqueline H. Chen
Keyword(s):  
Computational Study ◽  
Flame Speed ◽  
Premixed Flame

scholarly journals Structure and Laminar Flame Speed of an Ammonia/Methane/Air Premixed Flame under Varying Pressure and Equivalence Ratio

2021 ◽  
Author(s):  
Rodolfo C. Rocha ◽  
Shenghui Zhong ◽  
Leilei Xu ◽  
Xue-Song Bai ◽  
Mário Costa ◽  
...  
Keyword(s):  
Equivalence Ratio ◽  
Laminar Flame ◽  
Flame Speed ◽  
Premixed Flame ◽  
Laminar Flame Speed

Experimental Study On Premixed Flame Acceleration In Closed Pipe

2013 ◽  
Vol 62 (1) ◽  
Author(s):  
M. H. Mat Kiah ◽  
R. M. Kasmani
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Equivalence Ratio ◽  
Flame Speed ◽  
The Other ◽  
Premixed Flame ◽  
High Mass ◽  
Mass Burning Rate ◽  
Straight Pipe ◽  
Flame Acceleration

An experimental study has been carried out to investigate the flame acceleration in closed pipe. A horizontal steel pipe, with 2 m long and 0.1 m diameter, giving L/D ratio of 20 was used in this project. For test with 90 degree bends, the bend has a radius of 0.1 m and added a further 1 m to the length of the pipe (based on the centerline length of the segment). Ignition was affected at one end of the vessel while the other end was closed. Natural gas/oxygen mixtures were studied with equivalence ratio, Ф ranges from 0.5 to 1.8. It was demonstrated that bending pipe gave three times higher in overpressure (5.5 bars) compared to 2.0 bars of straight pipe. It is also shown that the flame speed is 63 m s-1, greater by factor of ~ 3 for explosion in bending pipe in comparison with straight pipe (23 m s-1). This is due to bending acting similar to obstacles. This mechanism could induce and create more turbulence, initiating the combustion of unburned pocket at the corner region, causing high mass burning rate and hence, increasing the flame speed.

The analytical investigation of premixed combustion in cylindrical micro-combustor

2011 ◽  
Vol 225 (4) ◽  
pp. 931-938 ◽  
Author(s):  
M Bidabadi ◽  
A Rahbari ◽  
M Alizadehheidari
Keyword(s):  
Heat Conduction ◽  
Volume Ratio ◽  
Analytical Investigation ◽  
Flame Speed ◽  
Premixed Combustion ◽  
Adiabatic Condition ◽  
Product Gas ◽  
Heat Recirculation ◽  
Flame Region ◽  
Micro Combustor

In this study, an analytical model for heat recirculation in cylindrical micro-combustors is presented, including the effects of heat transfer from the product gas stream in the reaction zone and post-flame region to the reactant in the preheat zone, structural heat conduction through the combustor walls and heat loss to ambient. Eventually, the explicit expression for the flame speed in non-adiabatic condition and the implicit expression for adiabatic condition are obtained in this research. In addition, comparison is made between adiabatic and non-adiabatic flame speeds. It is demonstrated that the streamwise heat conduction through the structure of combustor plays an important role in the flame broadening in both adiabatic and non-adiabatic conditions. Moreover, it is shown that reducing the size of the combustor to a submillimetre scale extremely increases the surface-to-volume ratio, leading to the decrease in the flame speed and flame quenching.

scholarly journals Influence of Turbulent Scalar Mixing Physics on Premixed Flame Propagation

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
H. Kolla ◽  
N. Swaminathan
Keyword(s):  
Direct Effect ◽  
Flame Propagation ◽  
Indirect Effect ◽  
Turbulent Flame ◽  
Quantitative Difference ◽  
Flame Speed ◽  
Premixed Flame ◽  
Scalar Mixing ◽  
Turbulent Flame Speed ◽  
Reactive Scalar

The influence of reactive scalar mixing physics on turbulent premixed flame propagation is studied, within the framework of turbulent flame speed modelling, by comparing predictive ability of two algebraic flame speed models: one that includes all relevant physics and the other ignoring dilatation effects on reactive scalar mixing. This study is an extension of a previous work analysing and validating the former model. The latter is obtained by neglecting modelling terms that include dilatation effects: a direct effect because of density change across the flame front and an indirect effect due to dilatation on turbulence-scalar interaction. An analysis of the limiting behaviour shows that neglecting the indirect effect alters the flame speed scaling considerably when is small and the scaling remains unaffected when is large. This is evident from comparisons of the two models with experimental data which show that the quantitative difference between the two models is as high as 66% at but only 4% at . Furthermore, neglecting the direct effect results in a poor prediction of turbulent flame speed for all values of , and both effects are important for practically relevant values of this velocity ratio.

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