نوع مقاله : علمی - پژوهشی
نویسندگان
1 مهندسی معدن، دانشکده مهندسی معدن، نفت و ژئوفیزیک
2 مهندسی معدن - دانشکده مهندسی معدن، نفت و ژئوفیزیک- ایران
3 دانشکده مهندسی معدن، نفت و ژئوفیزیک، شاهرود
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In terms of longitudinal ventilation design, airflow velocity and the reverse flow of smoke are the two most important parameters in a tunnel fire. Because critical velocity should not be more or less than the actual value, it is difficult to estimate. In fire study, computer simulation is very important. This study is focused on fires in curved tunnels using a small-scale model (in a 1/20 scale) experiments and Computational Fluid Dynamics (CFD) simulations. At first, grid sensitivity analysis and its impact on HRR estimation were investigated. The result of this is a significant effect of gridding dimensions on the correct estimation of HRR and the necessity of accuracy in its selection. Then, the effect of the pool edge was investigated. The absence of the pool edge decreased by about 30 % estimated value. In the third section, the results of HRR for two pool fire were compared and it has been found that the software is able to properly estimate HRR. After construction curved tunnel and using physical equipment, critical velocity in the tunnel was determined. The results of numerical and physical study were compared and the results show good accuracy in the critical velocity estimation. Du to critical velocity in curved tunnel (0.92 m/s) and in straight tunnel (0.82 m/s), it can be understood that if there is a curvature in the tunnel, then critical velocity is higher.
کلیدواژهها [English]
)
