000079697 001__ 79697 000079697 005__ 20200117221624.0 000079697 0247_ $$2doi$$a10.1016/j.proci.2018.07.031 000079697 0248_ $$2sideral$$a109842 000079697 037__ $$aART-2018-109842 000079697 041__ $$aeng 000079697 100__ $$aCifuentes, L. 000079697 245__ $$aLocal entrainment velocity in a premixed turbulent annular jet flame 000079697 260__ $$c2018 000079697 5060_ $$aAccess copy available to the general public$$fUnrestricted 000079697 5203_ $$aThe 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. 000079697 536__ $$9info:eu-repo/grantAgreement/EC/H2020/706672/EU/Interfaces in Turbulent Premixed Flames (ITPF)/ITPF$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 706672-ITPF 000079697 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000079697 590__ $$a3.299$$b2018 000079697 591__ $$aENGINEERING, MECHANICAL$$b22 / 129 = 0.171$$c2018$$dQ1$$eT1 000079697 591__ $$aTHERMODYNAMICS$$b11 / 60 = 0.183$$c2018$$dQ1$$eT1 000079697 591__ $$aENERGY & FUELS$$b45 / 103 = 0.437$$c2018$$dQ2$$eT2 000079697 591__ $$aENGINEERING, CHEMICAL$$b40 / 138 = 0.29$$c2018$$dQ2$$eT1 000079697 592__ $$a1.035$$b2018 000079697 593__ $$aChemical Engineering (miscellaneous)$$c2018$$dQ1 000079697 593__ $$aPhysical and Theoretical Chemistry$$c2018$$dQ1 000079697 593__ $$aMechanical Engineering$$c2018$$dQ1 000079697 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000079697 700__ $$aKempf, A. 000079697 700__ $$0(orcid)0000-0002-2267-8598$$aDopazo, C.$$uUniversidad de Zaragoza 000079697 7102_ $$15001$$2600$$aUniversidad de Zaragoza$$bDpto. Ciencia Tecnol.Mater.Fl.$$cÁrea Mecánica de Fluidos 000079697 773__ $$g37, 2 (2018), 2493-2501$$pProc. Combust. Inst.$$tPROCEEDINGS OF THE COMBUSTION INSTITUTE$$x1540-7489 000079697 8564_ $$s425337$$uhttps://zaguan.unizar.es/record/79697/files/texto_completo.pdf$$yPostprint 000079697 8564_ $$s70228$$uhttps://zaguan.unizar.es/record/79697/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000079697 909CO $$ooai:zaguan.unizar.es:79697$$particulos$$pdriver 000079697 951__ $$a2020-01-17-21:55:39 000079697 980__ $$aARTICLE