Abstract:Based on Fluent software, a physical and mathematical model of airflow diffusion was established for the proliferation of leakage when the vehicle was traveling in the tunnel and carrying dangerous goods (e.g., natural gas). By using the theories of accidental leakage dynamics and fluid dynamics, the propagation characteristics of the leakage airflow have been investigated. Reynolds time-averaged equations and standard k-equation were adopted in this paper and SIMPLEC algorithm was used to solve the N-S equation. The component transport was used to solve the problem of multicomponent fluid diffusion. By using transient model, the airflow diffusion phenomena were simulated at different leakage time in the actual situation. The diffusion of leaked natural gas was simulated at different locations with or without obstacles, and the influence of inlet gas velocity was considered as well. Based on the simulation results, some reference data could be provided to minimize the loss and take effective rescue measures in a real leakage accident of dangerous goods in the tunnel.