Three-Dimensional Numerical Simulation Study On Fir By Effect Of Shaft In Highway Tunnel

In this paper, the focus is placed on the highway tunnel. It presents numerical simulation on temperature field, pressure field and smoke distribution in the pressure-suction ventilation of highway tunnels.Firstly, the paper has introduced anti-disaster characteristic of vary ventilation model, and suggested the calculating model in pressure-suction ventilation of highway tunnels. Then, based on the conservation law, a three-dimensional mathematical model of the smoke movement in tunnel fire was established. The finite volume method was used to discrete the governing equations and the SIMPLE algorithm was employed to solve the discretized equations.Numerical results coincided well with those of scale model fire experiment of Qingling Zhongnanshan King-size Highway Tunnel, which indicated the proposed fire model was reasonable and valid. So it can be applied in depth research.The paper presented a thorough calculation and analysis on fire smoke flows in tunnel and summarized their characters, which included velocity, temperature, pressure and the affect of ventilation condition on them.It also discussed the affect of fire by the height variation of shaft. we have generalized that the stack effect of shaft is very limited in a special tunnel fire. it is not useful to raise the height to improve the ventilation ability of shaft. So, we must determine the height of shaft with the scale of fire and condition of ventilation in the design of organization of ventilation on tunnel fire.