Influence of current direction in longitudinal ventilated road tunnels on the backflow of combustion Produits
| Autor: | Lanchava Omar, Ilias Nicolae, Javakhishvili Giorgi, Radu Sorin Mihai, Makharadze Leon |
|---|---|
| Jazyk: | English<br />French |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | MATEC Web of Conferences, Vol 373, p 00076 (2022) |
| Druh dokumentu: | article |
| ISSN: | 2261-236X 20223730 |
| DOI: | 10.1051/matecconf/202237300076 |
| Popis: | The results of numerical modeling in longitudinal ventilated sloping road tunnels are given. The slope of the tunnels varies in the range of 0-6%. The geometry of the tunnel is as follows: length: 100 m; width: 8 m; height: 6 m; area of the seat of fire: 16 m2. The seat of fire sized: 2.75x5.8x1.5 m is in the central part of the tunnel. The scenarios of development of 5, 10, 20, 30, 50 MW fires are studied in the case of positive and negative directional ventilation flows. The time of modelling was 120 seconds. The numerical problems were modelled with a volumetric grid method. The grid cell dimensions were: 0.5*0.5*0.5 m. Virtual point and volumetric measuring equipment was used to record the modeling results. The modelling used 4 groups of measuring devices that measured and recorded air velocity, temperature, and air and smoke densities. The paper discusses cases of algebraically summarizing the ventilation and fire-induced flows. Based on the results of numerical modeling, we can point out that the widely accepted indices of critical velocity and back-layering length in inclined road tunnels often give erroneous results. Therefore, in strategies for emergency ventilation, indicators such are critical velocity and back-separation should be used with caution. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|