Abstract: The tests on several rates of flow of gas were carried out.Based on the tests,distribution of gas mole fraction in utility tunnel was calculated using numerial simulation.In comparison with the experimental results,it is found that the gas mole fraction can be simulated by standard κ－ε  turbulent model and the numerical accuracy nearby gas leakage point is almost good according to the demand of engineering.The results show that three-dimensional tuberlence in engineering can be simulated.

Key words: fluid dynamics；utility tunnel；numerical simulation；experiment；gas；three-dimensional turbulence；κ－&epsilon, model