中文摘要：

采用基于气体Smagorinsky亚网格应力模型和颗粒动力论模型的双流体大涡模拟（two fluidlarge eddy simulation，TWF—LES）对轴对称突扩稀疏气固流动进行了数值模拟。瞬态模拟结果给出了各向异性两相湍流结构和颗粒弥散的发展过程。TWF—LES得到的统计平均的颗粒体积分数和颗粒相的轴向平均速度，以及脉动速度与实验结果相当接近，但在剪切流区域中，TWF—LES得到的颗粒相轴向脉动速度及颗粒一气体轴向脉动速度关联量与实验结果略有出入，表明模型还需要进一步验证和改进。

英文摘要：

A two--fluid large--eddy simulation （TWF--LES）, based on the Smagorinsky SGS stress model with particle kinetic theory was used to study axi--symmetric sudden expansion dilute gas--particle flows. The instantaneous results give the evolution of anisotropic two--phase turbulence structures and particle dispersion processes. The TWF--LES statistical results of particle averaged velocity and RMS particle fluctuation velocity are in good quantitative agreement with the experimental ones. But, in the shear flow region,the value of particle phase fluctuation velocity and in the axial direction of particle fluctuation velocity correlation of difference with those experiments a little. It implies ther validated and improved. particle--gas phase predicted by TWF--LES are that the TWF--LES modeling remains to be further validated and improved.