Fundamental Study of CH4-Air Combustion under an Axisymmetric Small-scale Rectangular Combustor using Computational Modeling

Karan Gaglani; Md. Amzad Hossain

doi:10.38032/jea.2022.01.005

Authors

Karan Gaglani Department of Aerospace Engineering, Embry-Riddle Aeronautical University, Prescott, AZ-86301, USA
Md. Amzad Hossain Department of Mechanical Engineering, Embry-Riddle Aeronautical University, Prescott, AZ-86301, USA

DOI:

https://doi.org/10.38032/jea.2022.01.005

Keywords:

Axisymmetric Combustor, Parallel Flow Injection, Species Transport Model, Flame Temperature, Heat of Reaction, Emission

Abstract

The optimization of the design and operating conditions of industrial combustors depends on the fundamental study of combustion dynamics and flow behaviors. Complete combustion increases the thermal efficiency as well as reduces the emission significantly. A study of this kind also allows exploring alternative fuels that would increase the combustion efficiency thus the life cycle of the systems. To develop a highly-performed combustion system for rocket engines or power plants, fundamental research under an axisymmetric small-scale combustor is considered in this study. The k-Ɛ (2 Eqn.) and species transport model (STM) are used to study the flow turbulence and combustion behavior, respectively. A Parallel flow injection configuration of fuel and air is considered. In this study, combustion behavior is investigated at a wide range of fuel and air flowrate conditions while keeping the air slot dimension (240 mm) and fuel injection slot diameter (10 mm) constant. The fuel velocity (FV) and air velocity (AV) are changed from 2 m/s to 30 m/s so that a better test matrix could be proposed. At each run, turbulence, the flame temperature, reaction heat release rate, mass fraction of CO₂, etc are studied. It is seen that the combustion temperature increases with the increase in fuel injection velocity. The static flame temperature reaches its maximum (2177 K-2287 K) and falls within the standard limits of CH₄-Air combustion. The mass fraction of CO₂ is found to be within the acceptable limit (0.121-0.153). The heat of the reaction is found to be high at variable Re_air and Re_CH4 conditions. It is observed that the computational models used in this study are capable of predicting the flow and combustion behaviors accurately.

References

CO2 Emissions from Fuel Combustion (2020 Edition) by International Energy Agency (IEA), Accessed: 2021, Available: http://energyatlas.iea.org/#!/tellmap/1378539487

Hossain, M.A., 2020. Laser Diagnostics of Compressible and High-intensity Premixed Methane-air Combustion Inside a Backward Facing Step Combustor Using High-repetition Rate CH-PLIF and PIV (Doctoral dissertation, The University of Texas at El Paso).

Islam, M.N.A., Hossain, M.A., De la Torre, M., Acosta-Zamora, A. and Choudhuri, A.R., 2019. Laser Diagnostics of Highly Turbulent Premixed Methane-Air Flow Over a Backward Facing Step Using PIV and OH-PLIF. In AIAA Propulsion and Energy 2019 Forum (p. 4323). DOI: https://doi.org/10.2514/6.2019-4323

Hossain, M.A., Islam, M.N.A. and Choudhuri, A., 2019, July. Flame Imaging of Highly Turbulent Premixed Methane-Air Combustion Using Planar Laser Induced Fluorescence (PLIF) of CH (CX). In ASME Power Conference (Vol. 59100, p. V001T01A008). American Society of Mechanical Engineers. DOI: https://doi.org/10.1115/POWER2019-1894

Hossain, M.A., Islam, M.N.A., Hossain, W. and Choudhuri, A.R., 2020. CH-PLIF Diagnostics of High Intensity Turbulent Premixed Methane-Air Combustion. In AIAA Scitech 2020 Forum (p. 1705). DOI: https://doi.org/10.2514/6.2020-1705

Hamzah, D.A., 2015. Theory Comparison between Propane and Methane Combustion inside the Furnace. International Journal of Current Engineering and Technology, 5(4), pp.2429-2434.

Ibrahim, I.A., Gad, H.M. and Shabaan, M.M., 2014. Numerical simulation of combustion characteristics of methane flame in an axisymmetric combustor model. Global Journal of Engineering Science, pp.2349-4506.

Pitsch, H. and Peters, N., 1998. A consistent flamelet formulation for non-premixed combustion considering differential diffusion effects. Combustion and flame, 114(1-2), pp.26-40. DOI: https://doi.org/10.1016/S0010-2180(97)00278-2

Matalon, M., 2007. Intrinsic flame instabilities in premixed and nonpremixed combustion. Annu. Rev. Fluid Mech., 39, pp.163-191. DOI: https://doi.org/10.1146/annurev.fluid.38.050304.092153

Lacaze, G. and Oefelein, J.C., 2012. A non-premixed combustion model based on flame structure analysis at supercritical pressures. Combustion and Flame, 159(6), pp.2087-2103. DOI: https://doi.org/10.1016/j.combustflame.2012.02.003

Barths, H., Hasse, C. and Peters, N., 2000. Computational fluid dynamics modelling of non-premixed combustion in direct injection diesel engines. International Journal of Engine Research, 1(3), pp.249-267. DOI: https://doi.org/10.1243/1468087001545164

Hossain, M.A., December 2021. Study of Ultra Low-swirl Burner (LSB) for Non-Premixed Methane-Air Combustion Using Computational Analysis. Proceedings of the International Conference on Mechanical Engineering and Renewable Energy 2021 (ICMERE 2021), 12 – 14, Chattogram, Bangladesh.

Kassem, H.I., Saqr, K.M., Aly, H.S., Sies, M.M. and Wahid, M.A., 2011. Implementation of the eddy dissipation model of turbulent non-premixed combustion in OpenFOAM. International Communications in Heat and Mass Transfer, 38(3), pp.363-367. DOI: https://doi.org/10.1016/j.icheatmasstransfer.2010.12.012

Kongre, U.V. and Sunnapwar, V.K., 2010. CFD modeling and experimental validation of combustion in direct ignition engine fueled with diesel. International Journal of Applied Engineering Research, 1(3), p.508.

Enagi, I.I., Al-Attab, K.A. and Zainal, Z.A., 2017. Combustion chamber design and performance for micro gas turbine application. Fuel Processing Technology, 166, pp.258-268. DOI: https://doi.org/10.1016/j.fuproc.2017.05.037

Davis, S.G., Joshi, A.V., Wang, H. and Egolfopoulos, F., 2005. An optimized kinetic model of H2/CO combustion. Proceedings of the combustion Institute, 30(1), pp.1283-1292. DOI: https://doi.org/10.1016/j.proci.2004.08.252

D’Errico, G., Lucchini, T., Onorati, A. and Hardy, G., 2015. Computational fluid dynamics modeling of combustion in heavy-duty diesel engines. International Journal of Engine Research, 16(1), pp.112-124. DOI: https://doi.org/10.1177/1468087414561276

Hossain, M.A., 2022. Computational Study of Methane-air Combustion Using the Species Transport Model. In AIAA SCITECH 2022 Forum (p. 1102). DOI: https://doi.org/10.2514/6.2022-1102

Ge, H.W. and Gutheil, E., Modeling and Simulation of Turbulent Spray Flows Using RANS and PDF Transport Equations.

Urzica, D. and Gutheil, E., 2008. Counterflow combustion modeling of CH4/air and CH4/O2 including detailed chemistry. Italy: ILASS.