Laminar flame speed, Markstein length, and cellular instability for spherically propagating methane/ethylene–air premixed flames
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ArticleKAUST Department
Combustion and Laser Diagnostics LaboratoryMechanical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2020-02-04Online Publication Date
2020-02-04Print Publication Date
2020-04Embargo End Date
2022-02-04Submitted Date
2019-08-02Permanent link to this record
http://hdl.handle.net/10754/661491
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An experimental study on laminar flame speed, Markstein length, and the onset of cellular instability was conducted by varying the equivalence ratio and ethylene/methane mixing ratio in spherically propagating premixed flames at ambient temperature and elevated pressures up to 0.8 MPa. Unstretched laminar burning velocities were first validated for methane − air flames by optimizing the range of the flame radius in testing linear and non-linear extrapolation models, and subsequently comparing the results with those simulated using four kinetic mechanisms. Based on the results, unstretched laminar burning velocities were determined for premixed flames of methane/ethylene mixture fuels. The predictability of theoretical Markstein lengths was appreciated by adopting a composite solution of the heat-release-weighted Lewis number and the temperature-dependent Zel'dovich number. Measured Markstein lengths were compared with those predicted based on a composite model for laminar flame speeds against flame radius. Depending on the fuels (methane or methane/ethylene mixture), pressure, and equivalence ratio, the predictability of the model varied. For methane − air flames, cellular instabilities were not observed within the observation window at pressures up to 0.6 MPa. Cell formation, caused by hydrodynamic instability, was enhanced by an increase in the ethylene ratio and chamber pressure. Theoretical critical flame radii for the onset of cellular instability predicted by the composite model were consistent with the measured ones for both lean and rich mixtures.Citation
Kim, H. J., Van, K., Lee, D. K., Yoo, C. S., Park, J., & Chung, S. H. (2020). Laminar flame speed, Markstein length, and cellular instability for spherically propagating methane/ethylene–air premixed flames. Combustion and Flame, 214, 464–474. doi:10.1016/j.combustflame.2020.01.011Sponsors
This work was conducted under the framework of the Research and Development Program of the Korea Institute of Energy Research (B9-2431). CSY was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2018R1A2A2A05018901). SHC was supported by the King Abdullah University of Science and Technology (KAUST).Publisher
Elsevier BVJournal
Combustion and FlameAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S0010218020300146ae974a485f413a2113503eed53cd6c53
10.1016/j.combustflame.2020.01.011