150663 20260419074239.0 doi 10.1016/j.ijhydene.2025.01.253 sideral 142770 ART-2025-142770 eng (orcid)0000-0001-9446-8461 Remacha, P. Universidad de Zaragoza Impact of hydrogen blending on the formation of flammable atmospheres in enclosed spaces due to gas leaks 2025 Access copy available to the general public Unrestricted This study addresses the potential impact of hydrogen addition to natural gas (NG) on the formation of flammable atmospheres due to small gas leaks. First, the effect of hydrogen blending on leak rate in realistic situations is estimated with an alternative flow model validated with experimental data for a wide range of gases and pressures on real and manufactured leaking coupons. Second, the temporal evolution of gas concentration in ventilated rooms and the time to reach flammable conditions is predicted for NG/hydrogen blends, showing that hydrogen addition leads to faster gas build-up. This may have practical consequences, for example, on required response times to attend emergency calls due to gas leakages. In general, hydrogen addition results in a faster formation of flammable atmospheres, but differences with respect to natural gas are less severe than expected from the usual ideal flow model, which tends to overestimate leak rates and may lead to a too conservative assessment of actual behaviors in most practical situations. info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Tizné, E. Universidad de Zaragoza Pina, A. (orcid)0000-0002-0063-1318 Barroso, J. Universidad de Zaragoza (orcid)0000-0003-1337-0310 Muelas, Á. Universidad de Zaragoza (orcid)0000-0003-2863-4681 Ballester, J. Universidad de Zaragoza 5001 600 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Mecánica de Fluidos 142 (2025), 685-696 Int. j. hydrogen energy International Journal of Hydrogen Energy 0360-3199 730583 http://zaguan.unizar.es/record/150663/files/texto_completo.pdf Postprint info:eu-repo/date/embargoEnd/2026-01-25 1358955 http://zaguan.unizar.es/record/150663/files/texto_completo.jpg?subformat=icon icon Postprint info:eu-repo/date/embargoEnd/2026-01-25 oai:zaguan.unizar.es:150663 articulos driver 2026-04-18-11:05:07 ARTICLE