采用大涡模拟（LES）对气体羽流分层特性进行数值模拟，分析了基于LES的气体羽流模型、控制方程和数值计算方法，探讨了LES在多组分气体羽流模拟中的应用；以文献[1]中氦气在空气中形成羽流的实验数据为参考，对所建模型进行验证。利用该模型对密闭空间油气泄漏过程进行数值模拟，计算结果表明油气在泄漏发生的240 s之内，不同组分表现出显著不同的分层规律：相对于空气，密度较大的组分聚集在空间下部20%的范围内；密度较小的组分主要分散在空间上部80%的范围内。研究结果为油库油气危险源安全监测与预警、火灾预防与扑救等提供了关键参数参考和工程设计理论依据。%Numerical simulation of gas plume was conducted by the method of large eddy simulation (LES). The gas plume model based on LES, the governing equations and the numerical methods were analyzed and the application of LES in multicomponent gas plume simulation was discussed. The model was first validated by comparing simulation results with existing experimental data of the helium leakage in a confined room. Then the model was used to study the stratification behavior of gasoline vapor plumes in a leakage accident. Results show that components in gasoline vapor may show different stratifying rules:in relation to air, the denser components tend to stay at the 20%lower part of the room while the lighter ones prefer to disperse in the 80%upper part of the room. This study may provide key parameters and serve as a reference to related engineering design for oil depot hazard monitoring and early warning.
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