134909 20260217205516.0 doi 10.1007/s10494-023-00494-3 sideral 138414 ART-2024-138414 eng Chakraborty, Nilanjan Evolution of flame displacement speed within flame front in different regimes of premixed turbulent combustion 2024 Access copy available to the general public Unrestricted A transport equation for the flame displacement speed evolution in premixed flames is derived from first principles, and the mean behaviours of the terms of this equation are analysed based on a Direct Numerical Simulation database of statistically planar turbulent premixed flames with a range of different Karlovitz numbers. It is found that the regime of combustion (or Karlovitz number) affects the statistical behaviour of the mean contributions of the terms of the displacement speed transport equation which are associated with the normal strain rate and curvature dependence of displacement speed. The contributions arising from molecular diffusion and flame curvature play leading order roles in all combustion regimes, whereas the terms arising from the flame normal straining and reactive scalar gradient become leading order contributors only for the flames with high Karlovitz number values representing the thin reaction zones regime. The mean behaviours of the terms of the displacement speed transport equation indicate that the effects arising from fluid-dynamic normal straining, reactive scalar gradient and flame curvature play key roles in the evolution of displacement speed. The mean characteristics of the various terms of the displacement speed transport equation are explained in detail and their qualitative behaviours can be expounded based on the behaviours of the corresponding terms in the case of 1D steady laminar premixed flames. This implies that the flamelet assumption has the potential to be utilised for the purpose of any future modelling of the unclosed terms of the displacement speed transport equation even in the thin reaction zones regime for moderate values of Karlovitz number. info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es 2.4 2024 THERMODYNAMICS 32 / 79 = 0.405 2024 Q2 T2 MECHANICS 79 / 171 = 0.462 2024 Q2 T2 0.6 2024 Chemical Engineering (miscellaneous) 2024 Q2 Physics and Astronomy (miscellaneous) 2024 Q2 Physical and Theoretical Chemistry 2024 Q2 5.0 2024 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Dopazo, Cesar Universidad de Zaragoza (orcid)0000-0002-2267-8598 Dunn, Harry Ahmed, Umair 5001 600 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Mecánica de Fluidos 112, 3 (2024), 793-809 Flow turbul. combust. Flow, Turbulence and Combustion 1386-6184 2002544 http://zaguan.unizar.es/record/134909/files/texto_completo.pdf Versión publicada 1671229 http://zaguan.unizar.es/record/134909/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:134909 articulos driver 2026-02-17-20:26:57 ARTICLE