气固流动大涡模拟和两相湍流模型的评价  

Large-eddy simulation of gas-particle flows and validation of a two-phase turbulence model

作　　者：刘阳[1] 许春晓[1] 周力行[1] 胡瓅元[2] 

机构地区：[1]清华大学工程力学系,北京100084 [2]上海交通大学机械与动力工程学院,上海200240

出　　处：《清华大学学报（自然科学版）》2009年第2期297-300,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50606026);国家自然科学基金重点资助项目(50736006)

摘　　要：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(LES)以及统一二阶矩两相湍流模型(USM-RANS),对轴对称突扩气固流动进行了数值模拟。结果表明:LES模拟的颗粒轴向平均速度和均方根脉动速度,以及USM-RANS计算得到的模拟结果都与实验结果吻合较好。LES得到的颗粒-气体轴向脉动速度关联值比USM-RANS模拟值更接近实验值,这表明USM-RANS模拟还有改进余地,并基本上得到了LES的验证。LES的瞬态模拟能显示气固湍流流动的各向异性两相湍流结构和颗粒弥散的发展过程,而USM-RANS无法实现。A two-fluid large-eddy simulation （LES） based on the Smagorinsky SGS stress model and particle kinetic theory was combined with a unified second-order-moment two-phase turbulence modeling （USM-RANS） to study axisymmetric sudden expansion gas-particle flows. The calculational results show that LES statistical results and the USM-RANS modeling results for the axial particle time-averaged velocity and the RMS particle fluctuation velocity are in good agreement with. experimental data. The predicted two-phase fluctuation velocity correlation from the LES method is in better agreement with the experimental results than that predicted by the USM-RANS model. Thus the USM-RANS model needs further improvements. Furthermore, the LES results give the instantaneous evolution of the anisotropic two-phase turbulence structures and the particle dispersion processes, which the USM-RANS model cannot obtain.

关 键 词：两相湍流 大涡模拟 二阶矩模型 

分 类 号：O359[理学—流体力学]