Prediction of CO Concentration and Maximum Smoke Temperature beneath Ceiling in Tunnel Fire with Different Aspect Ratio
عنوان مقاله: Prediction of CO Concentration and Maximum Smoke Temperature beneath Ceiling in Tunnel Fire with Different Aspect Ratio
شناسه ملی مقاله: JR_JAFM-9-4_036
منتشر شده در در سال 1395
شناسه ملی مقاله: JR_JAFM-9-4_036
منتشر شده در در سال 1395
مشخصات نویسندگان مقاله:
S. Gannouni - Faculty of Sciences of Tunis, Department of Physics, Laboratory of Energizing and Thermal and Mass Transfer, ۲۰۹۲ ElManar, Tunis, Tunisia
R. Ben Maad - Faculty of Sciences of Tunis, Department of Physics, Laboratory of Energizing and Thermal and Mass Transfer, ۲۰۹۲ ElManar, Tunis, Tunisia
خلاصه مقاله:
S. Gannouni - Faculty of Sciences of Tunis, Department of Physics, Laboratory of Energizing and Thermal and Mass Transfer, ۲۰۹۲ ElManar, Tunis, Tunisia
R. Ben Maad - Faculty of Sciences of Tunis, Department of Physics, Laboratory of Energizing and Thermal and Mass Transfer, ۲۰۹۲ ElManar, Tunis, Tunisia
In a tunnel fire, the production of smoke and toxic gases remains the principal prejudicial factors to users. The heat is not considered as a major direct danger to users since temperatures up to man level do not reach tenable situations that after a relatively long time except near the fire source. However, the temperatures under ceiling can exceed the thresholds conditions and can thus cause structural collapse of infrastructure. This paper presents a numerical analysis of smoke hazard in tunnel fires with different aspect ratio by large eddy simulation. Results show that the CO concentration increases as the aspect ratio decreases and decreases with the longitudinal ventilation velocity. CFD predicted maximum smoke temperatures are compared to the calculated values using the model of Li et al. and then compared with those given by the empirical equation proposed by kurioka et al. A reasonable good agreement has been obtained. The backlayering length decreases as the ventilation velocity increases and this decrease fell into good exponential decay. The dimensionless interface height and the region of bad visibility increases with the aspect ratio of the tunnel cross-sectional geometry.
کلمات کلیدی: Smoke hazard, Tunnel fire, CO concentration, Maximum smoke temperature, Aspect ratio, CFD
صفحه اختصاصی مقاله و دریافت فایل کامل: https://civilica.com/doc/1383564/