Effects of Composition Heterogeneities on Flame Kernel Propagation: A DNS Study
Type
ArticleKAUST Department
King Abdullah University of Science and Technology (KAUST), Computer Electrical and Mathematical Science and Engineering Division (CEMSE), Thuwal 23955, Saudi Arabia.Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Applied Mathematics and Computational Science Program
Extreme Computing Research Center
Date
2020-09-04Submitted Date
2020-08-04Permanent link to this record
http://hdl.handle.net/10754/665061
Metadata
Show full item recordAbstract
In this study, a new set of direct numerical simulations is generated and used to examine the influence of mixture composition heterogeneities on the propagation of a premixed iso-octane/air spherical turbulent flame, with a representative chemical description. The dynamic effects of both turbulence and combustion heterogeneities are considered, and their competition is assessed. The results of the turbulent homogeneous case are compared with those of heterogeneous cases which are characterized by multiple stratification length scales and segregation rates in the regime of a wrinkled flame. The comparison reveals that stratification does not alter turbulent flame behaviors such as the preferential alignment of the convex flame front with the direction of the compression. However, we find that the overall flame front propagation is slower in the presence of heterogeneities because of the differential on speed propagation. Furthermore, analysis of different displacement speed components is performed by taking multi-species formalism into account. This analysis shows that the global flame propagation front slows down due to the heterogeneities caused by the reaction mechanism and the differential diffusion accompanied by flame surface density variations. Quantification of the effects of each of these mechanisms shows that their intensity increases with the increase in stratification’s length scale and segregation rate.Citation
Er-raiy, A., Boukharfane, R., & Parsani, M. (2020). Effects of Composition Heterogeneities on Flame Kernel Propagation: A DNS Study. Fluids, 5(3), 152. doi:10.3390/fluids5030152Publisher
MDPI AGJournal
FluidsAdditional Links
https://www.mdpi.com/2311-5521/5/3/152ae974a485f413a2113503eed53cd6c53
10.3390/fluids5030152
Scopus Count
Except where otherwise noted, this item's license is described as This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.