The Research On Smoke Current Laws And Simulation Research Of Tunnel Fire

With the development of the long highway tunnels, the fire hazard of tunnel fire accident become more and more on account of friction hit of vehicles and the burning of flammable and explosive substances or other sorts of reasons. Once the tunnel fire is broken out, because the tunnel space is narrow, the vehicles are hard to turn round, fire is hard to control in time and consequences are inestimable. These lead to tunnel collapsed, disrupted traffic, significant casualties and property losses. How to prevent the fire and make safety management is the urgent problem to solve in safety operation of tunnel. This paper does mainly research of critical wind speed and roof temperature field distribution.This paper introduces fire cause, characteristics, and damages of tunnel and current research at home and abroad. On the basis of this, this paper put forward the research content. Firstly, the author analyzes the smoke airflow, critical wind speed, roof temperature field distribution of the tunnel fire and establishes the mathematical model by the means of continuity equations, momentum equations, energy equations and component equations. Secondly, this paper presents numerical simulation of the critical wind speed and roof temperature field on fire smoke flow. Analysis results show that critical wind speed is different under the different scales of fire. The ventilation speed should not be less than critical wind speed, this can prevent gas counter-current phenomenon. The simulation results of the temperature field indicate that changes of roof temperature field distribution is influenced by the fire scale and ventilation speed. At last, the paper dose the research of the tunnel fire control through two aspects, these are high temperature hazard and toxic hazard of gas flow and put forward the preventive measures of tunnel fire. Figure 31 table 1 reference 55...