79697 20200117221624.0 doi 10.1016/j.proci.2018.07.031 sideral 109842 ART-2018-109842 eng Cifuentes, L. Local entrainment velocity in a premixed turbulent annular jet flame 2018 Access copy available to the general public Unrestricted The local entrainment velocity of the enstrophy interfaces of a methane-air turbulent premixed turbulent annular jet flame stabilized on a bluff-body burner has been investigated using a high-fidelity flame-resolved three-dimensional simulation. The enstrophy (inner and outer) and the scalar interfaces have been defined and characterized by their propagation speeds, VE and Sd , relative to the fluid flow. Mean values (<. Sd |. c> and <. VE |. c>) conditioned on the reaction progress variable c have been obtained. A thin layer (near the enstrophy interfaces) has been used to compute mean values (<. VE |. E>, <. Sd |. E>, and its different contributions) conditional upon enstrophy E. At the inner interface, results indicate that <. Sd |. c< > 0 and >. Sd |. E> > 0 (entrainment of fresh reactants into the flame front and hot products), while <. VE |. c> < 0 and <. VE |. E> < 0 (entrainment of hot products into the reacting jet across the inner enstrophy interface). The outer enstrophy interface displays <. VE |. E> > 0 (ambient gases are predominantly entrained into the jet of reactants), which implies a lean mixture in its neighborhood. These preliminary results aim at understanding the physical mechanisms of flame anchoring, in terms of entrainments of either hot products or fresh reactants into the diffusive-reactive region. Local geometries of the inner and outer interfaces have also been examined, through the computation of joint probability density functions of the mean curvature km and Gauss curvature kg of the iso-enstrophy surfaces, and through <. VE >|. km, kg at the inner and outer interfaces. This information has subsequently been used to discuss the physics of how the turbulent entrainment process affects premixed flames. info:eu-repo/grantAgreement/EC/H2020/706672/EU/Interfaces in Turbulent Premixed Flames (ITPF)/ITPF This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 706672-ITPF info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 3.299 2018 ENGINEERING, MECHANICAL 22 / 129 = 0.171 2018 Q1 T1 THERMODYNAMICS 11 / 60 = 0.183 2018 Q1 T1 ENERGY & FUELS 45 / 103 = 0.437 2018 Q2 T2 ENGINEERING, CHEMICAL 40 / 138 = 0.29 2018 Q2 T1 1.035 2018 Chemical Engineering (miscellaneous) 2018 Q1 Physical and Theoretical Chemistry 2018 Q1 Mechanical Engineering 2018 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Kempf, A. (orcid)0000-0002-2267-8598 Dopazo, C. Universidad de Zaragoza 5001 600 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Mecánica de Fluidos 37, 2 (2018), 2493-2501 Proc. Combust. Inst. PROCEEDINGS OF THE COMBUSTION INSTITUTE 1540-7489 425337 http://zaguan.unizar.es/record/79697/files/texto_completo.pdf Postprint 70228 http://zaguan.unizar.es/record/79697/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:79697 articulos driver 2020-01-17-21:55:39 ARTICLE