Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 2
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

In this study, the turbulent non-premixed methane-air flame is simulated to determine the effect of air velocity on the length of flame, temperature distribution and mole fraction of species. The computational fluid dynamics (CFD) technique is used to perform this simulation. To solve the turbulence flow, k-ε model is used. In contrast to the previous works, in this study, in each one of simulations the properties of materials are taken variable and then the results are compared. The results show that at a certain flow rate of fuel, by increasing the air velocity, similar to when the properties are constant, the width of the flame becomes thinner and the maximum temperature is higher; the penetration of oxygen into the fuel as well as fuel consumption is also increased. It is noteworthy that most of the pollutants produced are NOx, which are strongly temperature dependent. The amount of these pollutants rises when the temperature is increased. As a solution, decreasing the air velocity can decrease the amount of these pollutants. Finally, comparing the result of this study and the other work, which considers constant properties, shows that the variable properties assumption leads to obtaining more exact solution but the trends of both results are similar.

Go to article

Authors and Affiliations

Zafar Namazian
Heidar Hashemi
Farideh Namazian
Download PDF Download RIS Download Bibtex

Abstract

Biogas, a renewable fuel, has low operational stability range in burners due to its inherent carbon-dioxide content. In cross-flow configuration, biogas is injected from a horizontal injector and air is supplied in an orthogonal direction to the fuel flow. To increase the stable operating regime, backward facing steps are used. Systematic numerical simulations of these flames are reported here. The comprehensive numerical model incorporates a chemical kinetic mechanism having 25 species and 121 elementary reactions, multicomponent diffusion, variable thermo-physical properties, and optically thin approximation based volumetric radiation model. The model is able to predict different stable flame types formed behind the step under different air and fuel flow rates, comparable to experimental predictions. Predicted flow, species, and temperature fields in the flames within the stable operating regime, revealing their anchoring positions relative to the rear face of the backward facing step, which are difficult to be measured experimentally, have been presented in detail. Resultant flow field behind a backward facing step under chemically reactive condition is compared against the flow fields under isothermal and non-reactive conditions to reveal the significant change the chemical reaction produces. Effects of step height and step location relative to the fuel injector are also presented.
Go to article

Bibliography

[1] D. Andriani, A. Wresta, T.D. Atmaja, and A. Saepudin. A review on optimization production and upgrading biogas through CO 2 removal using various techniques. Applied Biochemistry and Biotechnology, 172(4):1909–1928, 2014. doi: 10.1007/s12010-013-0652-x.
[2] I.U. Khan, Mohd H.D. Othman, H. Hashim, T. Matsuura, A.F. Ismail, M. Rezaei-DashtArzhandi, and I. Wan Azelee. Biogas as a renewable energy fuel – A review of biogas upgrading utilization and storage. Energy Conversion and Management, 150:277–294, 2017. doi: 10.1016/j.enconman.2017.08.035.
[3] S. Rasi, A. Veijanen, and J. Rintala. Trace compounds of biogas from different biogas production plants. Energy, 32(8):1375–1380, 2007. doi: 10.1016/j.energy.2006.10.018.
[4] E. Ryckebosh, M. Drouillon, and H. Vervaeren. Techniques for transformation of biogas to biomethane. Biomass and Bioenergy, 35(5):1633–1645, 2011. doi: 10.1016/j.biombioe.2011.02.033.
[5] R.J. Spiegel, and J.L. Preston. Test results for fuel cell operation on anaerobic digester gas. Journal of Power Sources, 86(1-2):283–288, 2000. doi: 10.1016/S0378-7753(99)00461-9.
[6] H.-C. Shin, J.-W. Park, K. Park, and H.-C. Song. Removal characteristics of trace compounds of landfill gas by activated carbon adsorption. Environmental Pollution, 119(2):227–236, 2002. doi: 10.1016/s0269-7491(01)00331-1.
[7] R.J. Spiegel and J.L. Preston. Technical assessment of fuel cell operation on anaerobic digester gas at the Yonkers, NY, wastewater treatment plant. Waste Management, 23(8):709–717, 2003. doi: 10.1016/S0956-053X(02)00165-4.
[8] A. Lock, S.K. Aggarwal, I.K. Puri, and U. Hegde. Suppression of fuel and air stream diluted methane-air partially premixed flames in normal and microgravity. Fire Safety Journal, 43(1):24–35, 2008. doi: 10.1016/j.firesaf.2007.02.004.
[9] T. Leung and I. Wierzba. The effect of hydrogen addition on biogas non-premixed jet flame stability in a co-flowing air stream. International Journal of Hydrogen Energy, 33(14):3856–3862, 2008. doi: 10.1016/j.ijhydene.2008.04.030.
[10] A.M. Briones, S.K. Aggarwal, and V. Katta. A numerical investigation of flame liftoff, stabilization, and blowout. Physics of Fluids, 18(4):043603, 2006. doi: 10.1063/1.2191851.
[11] C.-E. Lee and C.-H. Hwang. An experimental study on the flame stability of LFG and LFG-mixed fuels. Fuel, 86(5-6):649–655, 2007. doi: 10.1016/j.fuel.2006.08.033.
[12] L. Xiang, H. Chu, F. Ren, and M. Gu. Numerical analysis of the effect of CO 2 on combustion characteristics of laminar premixed methane/air flames. Journal of the Energy Institute, 92(5):1487–1501, 2019. doi: 10.1016/j.joei.2018.06.018.
[13] N. Hinton and R. Stone. Laminar burning velocity measurements of methane and carbon dioxide mixtures (biogas) over wide ranging temperatures and pressures. Fuel, 116:743–750, 2014. doi: 10.1016/j.fuel.2013.08.069.
[14] S. Jahangirian, A. Engeda, and I.S. Wichman. Thermal and chemical structure of biogas counterflow diffusion flames. Energy and Fuels, 23(11):5312–5321, 2009. doi: 10.1021/ef9002044.
[15] A. Mameri and F. Tabet. Numerical investigation of counter-flow diffusion flame of biogas-hydrogen blends: Effects of biogas composition, hydrogen enrichment and scalar dissipation rate on flame structure and emissions. International Journal of Hydrogen Energy, 41(3):2011–2022, 2016. doi: 10.1016/j.ijhydene.2015.11.035.
[16] J.I. Erete, K.J. Hughes, L. Ma, M. Fairweather, M. Pourkashanian, and A. Williams. Effect of CO 2 dilution on the structure and emissions from turbulent, non-premixed methane-air jet flames. Journal of the Energy Institute, 90(2):191–200, 2017. doi: 10.1016/j.joei.2016.02.004.
[17] M.R.J. Charest, Ö.L. Gülder, and C.P.T. Groth. Numerical and experimental study of soot formation in laminar diffusion flames burning simulated biogas fuels at elevated pressures. Combustion and Flame, 161(10):2678–2691, 2014. doi: 10.1016/j.combustflame.2014.04.012.
[18] H.M. Nicholson and J.P. Field. Some experimental techniques for the investigation of the mechanism of the flame stabilization in the wakes of bluff bodies. Symposium on Combustion and Flame, and Explosion Phenomena, 3(1):44–68, 1948. doi: 10.1016/S1062-2896(49)0008-0.
[19] G.C. Williams and C.W. Shipman. Some properties of rod-stabilized flames C homogenous gas mixtures. Symposium (International) on Combustion, 4(1):733-742, 1953. doi: 10.1016/S0082-0784(53)80096-2.
[20] G.C. Williams, P.T. Woo, and C.W. Shipman. Boundary layer effects on stability characteristics of bluff-body flame holders. Symposium (International) on Combustion, 6(1):427–438, 1957. doi: 10.1016/S0082-0784(57)80058-7.
[21] E.E. Zukoski, and F.E. Marble. Experimental concerning the mechanism of flame blowoff from bluff bodies. Proceedings of the Gas Dynamics Symposium on Aerothermochemistry, 205-210, 1956.
[22] E.E. Zukoski. Flame stabilization on bluff bodies at low and intermediate Reynolds numbers. Ph.D Thesis, California Institute of Technology, Pasadena, United States of America, 1954. doi: 10.7907/E9V0-GM76.
[23] T. Maxworthy. On the mechanism of bluff body flame stabilization at low velocities. Combustion and Flame, 6:233–244, 1962. doi: 10.1016/0010-2180(62)90101-3.
[24] S.I. Cheng and A.A. Kovitz. Theory of flame stabilization by a bluff body. Symposium (International) on Combustion, 7(1):681–691, 1958. doi: 10.1016/S0082-0784(58)80109-5.
[25] A.A. Kovitz and H.-M Fu. On bluff body flame stabilization. Applied Scientific Research, 10:315–334, 1961. doi: 10.1007/BF00411927.
[26] C.-H. Chen and J.S. T’ien. Diffusion flame stabilization at the leading edge of fuel plate. Combustion Science and Technology, 50(4-6):283–306, 1986. doi: 10.1080/00102208608923938.
[27] T. Rohmat, H. Katoh, T. Obara, T. Yoshihashi, and S. Ohyagi. Diffusion flame stabilized on a porous plate in a parallel airstream. AIAA Journal, 36(11):1945–1952, 1998. doi: 10.2514/2.300.
[28] E.D. Gopalakrishnan and V. Raghavan. Numerical investigation of laminar diffusion flames established on a horizontal flat plate in a parallel air stream. International Journal of Spray and Combustion Dynamics, 3(2):161–190, 2011. doi: 10.1260/1756-8277.3.2.161.
[29] P.K. Shijin, S. Soma Sundaram, V. Raghavan, and V. Babu. Numerical investigation of laminar cross flow non-premixed flames in the presence of a bluff-body. Combustion Theory and Modelling, 18(6):692–710, 2014. doi: 10.1080/13647830.2014.967725.
[30] P.K. Shijin, V. Raghavan, and V. Babu. Numerical investigation of flame-vortex interactions in cross flow non-premixed flames in the presence of bluff bodies. Combustion Theory and Modelling, 20(4):683–706, 2016. doi: 10.1080/13647830.2016.1168942.
[31] P.K. Shijin, A. Babu, and V. Raghavan. Experimental study of bluff body stabilized laminar reactive boundary layers. International Journal of Heat and Mass Transfer, 102:219–225, 2016. doi: 10.1016/j.ijheatmasstransfer.2016.06.028.
[32] A. Harish, H.R. Rakesh Ranga, A. Babu, and V. Raghavan. Experimental study of the flame characteristics and stability regimes of biogas-air cross flow non-premixed flames. Fuel, 223:334–343, 2018. doi: 10.1016/j.fuel.2018.03.055.
[33] R.A. Barlow, A.N. Karpetis, J.H. Frank, and J.-Y Chen. Scalar profiles and NO formation in laminar opposed-flow partially premixed methane/air flames. Combustion and Flame, 127(3):2102–2118, 2001. doi: 10.1016/S0010-2180(01)00313-3.
[34] T. Hirano and Y. Kanno. Aerodynamics and thermal structures of the laminar boundary layer over a flat plate with a diffusion flame. Symposium (International) on Combustion, 14(1):391–398, 1973. doi: 10.1016/S0082-0784(73)80038-4.
Go to article

Authors and Affiliations

Alagani Harish
1
ORCID: ORCID
Vasudevan Raghavan
1

  1. Indian Institute of Technology Madras, Chennai, India

This page uses 'cookies'. Learn more