Assessment of Fire Engineering Design Correlations Used to Describe the Geometry and Thermal Characteristics of Externally Venting Flames

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• 作者：Eleni K. Asimakopoulou ; Dionysios I. Kolaitis ; Maria A. Founti
• 关键词：Externally venting flames ; Fire plume ; Façade fire ; Large ; scale fire tests ; Centreline temperature ; Heat flux ; Fire engineering design ; Flame height ; Flame width ; Flame projection
• 刊名：Fire Technology
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：53
• 期：2
• 页码：709-739
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Civil Engineering; Classical Mechanics; Characterization and Evaluation of Materials; Physics, general;
• 出版者：Springer US
• ISSN：1572-8099
• 卷排序：53

文摘

Externally venting flames (EVF) may emerge through openings in fully developed under-ventilated compartment fires, significantly increasing the risk of fire spreading to higher floors or adjacent buildings. Several fire engineering correlations have been developed, aiming to describe the main characteristics of EVF that affect the fire safety design aspects of a building, such as EVF geometry, EVF centreline temperature and EVF-induced heat flux to the façade elements. This work is motivated by recent literature reports suggesting that existing correlations, proposed in fire safety design guidelines (e.g. Eurocodes), cannot describe with sufficient accuracy the characteristics of EVF under realistic fire conditions. In this context, a wide range of EVF correlations are comparatively assessed and evaluated. Quantification of their predictive capabilities is achieved by means of comparison with measurements obtained in 30 different large-scale compartment-façade fire experiments, covering a broad range of heat release rates (2.8 MW to 10.3 MW), ventilation factor values (2.6 m5/2 to 11.53 m5/2) and ventilation conditions (no forced draught, forced draught). A detailed analysis of the obtained results and the respective errors corroborates the fact that many correlations significantly under-predict critical physical parameters, thus resulting in reduced (non-conservative) fire safety levels. The effect of commonly used assumptions (e.g. EVF envelope shape or model parameters for convective and radiative heat transfer calculations) on the accuracy of the predicted values is determined, aiming to highlight the potential to improve the fire engineering design correlations currently available.