An experimental and numerical comparison of new full-scale atrium fire tests in the 20 m cubic atrium with four different heat release rates (1.7 MW, 2.3 MW, 3.9 MW and 5.3 MW) is presented. Different exhaust conditions (steady and transient extraction rates) and different make-up air configurations (symmetric and asymmetric) are assessed. Temperature measurements in the near (fire plume) and far field (close to the walls) have been recorded by means of 59 thermocouples. The smoke layer interface is also estimated by means of a thermocouple tree with 28 measurements using the least-square and the n-percent methods. The simulations have been conducted using FDS (version 6, Release Candidate 3). The comparison with the simulations shows average discrepancies lower than 32% and 11%, for the near and far field temperatures, respectively. A discrepancy lower than 5% (1 m) is obtained by both methods for the smoke layer height when the steady state is reached. Finally, a slower response to an increment on the exhaust rate is predicted on the smoke layer, being more perceptible for high heat release rates.

The design of smoke management systems in large-volume enclosures is of utter importance for life safety, property protection, and business continuity in case of fire. Despite the recent international trend in smoke control design towards the use of advanced fire models, simple plume entrainment correlations are the basis of the discipline and are still a common practice since they are often incorporated in technical documents for the design of smoke control systems. Different plume entrainment correlations have been developed over the years and are cited in different national codes and design guides. These correlations have been widely investigated for fires in small enclosures, but their applicability and accuracy in large enclosures is not clear. The present work studies the suitability and applicability of these approaches to properly predict the fire induced conditions within large volumes. The results obtained from the plume entrainment correlations have been compared with full scale experimental data in an 8.000 m³ enclosure. Based on the results obtained by this analysis performed in a large-volume enclosure, the current methods available of modelling fire and determining the smoke produced by the fire might not be suitable. It was observed that for the steady state, the McCaffrey correlation gave results closest to the experiments, and for the transient evolution of the smoke layer, the Zukoski correlation. On the contrary, the popular Thomas method underpredicted smoke production and entrainment, giving the highest smoke layer interface heights and leading to estimations that are not conservative (with errors between 36.5% and 101%). The authors analyze the reasons for the discrepancies and give some practical recommendations for the design of smoke control in large volume buildings, such as that the use of such models to predict the smoke production of a given fire shall be only a first approximation and not a design tool, especially when using those models that have not shown a good match to the experimental data.

En muchas ocasiones las superficies finales de los túneles de carretera (tanto los hastiales, como la bóveda) resultan no solo con rugosidades uniformes importantes, también con huecos más o menos numerosos y más o menos considerables: generalmente en túneles sin revestir es donde más se presentan las irregularidades uniformes importantes, y en túneles en roca excavados con voladuras es donde más se manifiestan los huecos. Esto da lugar a coeficientes de fricción con las paredes del túnel que pueden ser muy elevados. La fricción que se produce al paso del aire en la ventilación puede dar lugar a necesidades de empujes aerodinámicos (con ventilación con jet-fan) muy importantes, esto es, a consumos de energía eléctrica significativos. Para túneles de carretera con ventilación longitudinal con jet-fan se analizan las pérdidas de carga de túneles rugosos y con cavidades, y se evalúan los empujes aerodinámicos necesarios para contrarrestar las correspondientes pérdidas de carga.

La adición de pisos(levantes) en edificios existentes de viviendas ha sido una práctica habitual en Europa desde mediados del siglo XX. Los desarrollos urbanos en los ensanches, ocupados por bloques de viviendas en la segunda mitad del siglo XIX y en la primera del XX, encuentran en los levantes una oportunidad para cubrir los costes de renovación y para limitar la dispersión urbana. Sin embargo, las obras para llevarlos a cabo enfrentan a promotores, diseñadores y reguladores a muchos retos, constituyendo la seguridad de incendio (SCI) uno de los más confusos. Los Códigos prescriptivos de SCI están redactados para edificios nuevos y su uso en edificios existentes puede tener resultados impredecibles, llegando incluso a imposibilitar determinadas intervenciones. Este artículo analiza la problemática que la aplicación de la regulación prescriptiva española de SCI genera en los levantes, proponiendo soluciones basadas en prestaciones que no disminuyan el nivel de seguridad requerido.