Investigation of The Means of Regulating The Spread of Fire Harmful Factors in Metro Tunnels Based on Numerical Simulation.
One of the fastest growing sectors of modern transport infrastructure is the underground transport network of cities. Underground transport is characterized by several advantages, but at the same time, due to space constraints, security problems are more acute. Fire safety is a major concern for metro safety. In subway tunnels, fires can bring disastrous results primarily in terms of the loss of people's lives. In the article, on the basis of numerical modeling, the problem of the propagation and regulation of harmful factors caused by fires in the metro is studied. To solve the problem, a basic model with typical metro tunnel geometry has been compiled. The boundary condition between the portals is given by the difference in dynamic pressure on one of the portals. To regulate the flow of harmful gases and air temperature, it is proposed to install a soft flexible wall of refractory material in tunnels, which will block the cross-section of the tunnel with different degrees of filling. The effect of changing the degree of filling of the tunnel cross section on the distribution of toxic and asphyxiating gases along the tunnel for different boundary conditions at the portals was investigated. The effectiveness of this method is shown when the direction of propagation of harmful factors of a person coincides with the direction of evacuation of people. A quantitative assessment of the harmful factors from both sides of the soft flexible wall is given. Estimated time of self-evacuation of people with and without a soft flexible wall.