Numerical simulation of smoke behavior in fire conditions in a short urban tunnel

Along with the increasing development of countries, the daily need to transport various goods and equipment and travel in general for many reasons is increasing and for this reason, the number of different types of cars has significantly increased in recent years. In this way, this issue has caused heavy traffic on highways and various roads in big cities. Various actions and approaches, including public transportation, have been taken into consideration to facilitate the traffic. However, in some cases the solution to facilitate traffic jams, especially in big cities, is to build urban tunnels. Therefore, in recent years, urban tunnels have been considered as a solution to facilitate traffic. In this regard, the study of safety in tunnels becomes very important. The aim of this article is to simulate a fire in a short tunnel with natural ventilation to consider the behavior of smoke in different scenarios of natural air flow in the tunnel. The results of CFD simulation showed that limited fire (usual small passenger cars) will not cause problems for people as well as rescue team, especially fire extinguishing.