20.500.12556/DiRROS-31241 Development and application of a dynamic flame extinction and re-ignition model in FDS A new dynamic flame extinction and re-ignition model that considers the local properties of the flow has been developed. The extinction model is based on the default enthalpy balance used by the Fire Dynamics Simulator (FDS) and employs a dynamic calculation of the critical flame temperature, T CFT, derived from well-stirred reactor simulations with different diluent concentrations, which depends on the local mixing time and species concentrations. On the other hand, re-ignition is allowed to occur if the cell temperature is above a threshold re-ignition temperature, T ign, derived from counterflow simulations considering hot fuel and oxidizers, which depends on the local strain rate magnitude. The model has been implemented in FDS and validated against two well-characterized scenarios with different fuels (i.e., UMD line burner and FM burner cases) involving flame extinction due to dilution. Overall, improved predictions with respect to the reduction of the combustion efficiency, when compared to the original extinction and re-ignition model of FDS, are obtained. The predicted T CFT and T ign were (significantly) higher and lower, respectively, compared to the default value of FDS. In addition, lower O2 concentrations were qualitatively observed within the flame region with the new model. flame extinction flame re-ignition critical flame temperature strain rate CFD modelling FDS ugasnitev plamena ponovno vžiganje plamena kritična temperatura plamena hitrost deformacije CFD-modeliranje FDS true false true Elsevier Angleški jezik Slovenski jezik Neznano 2026-07-23 06:40:49 2026-07-23 06:54:14 2026-07-24 03:52:00 0000-00-00 00:00:00 2026 0 0 str. 1-19 [article no.] 104927 Vol. 165 Nov. 2026 0000-00-00 PostprintKoncna Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-07-15 2028-07-15 614.84 1873-7226 10.1016/j.firesaf.2026.104927 285621507 https://doi.org/10.1016/j.firesaf.2026.104927 0 ae9487bc-8650-11f1-a96a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=48230 RAZ_Floyd_Jason_2026.pdf RAZ_Floyd_Jason_2026.pdf 1 4919BB55B8333A3D96334CFE10E0F2C2 5d9506a5758489b98c0e810e5e72a51e2d9abef14c64a898be3f59cde65a8311 4f4279e3-8652-11f1-a96a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=48231 Zavod za gradbeništvo Slovenije 0 0 0