后台阶气固流动的双流体大涡模拟和二阶矩两相湍流模型的验证  

Two-fluid large-eddy simulation of backward-facing step gas-particle flows and validation of second-order-moment two-phase turbulence model

作　　者：刘阳[1] 周力行[1] 许春晓[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：《化工学报》2008年第10期2485-2489,共5页CIESC Journal

基　　金：国家自然科学基金项目(50606026,50736006)~~

摘　　要：用基于气体Smagorinsky亚网格应力模型和颗粒动理学模型的双流体大涡模拟(LES)和统一二阶矩两相湍流模型的RANS模拟(USM-RANS),对后台阶气固流动进行了数值模拟。瞬态模拟结果给出各向异性两相湍流结构和颗粒弥散的发展过程。LES经过统计平均得到的颗粒速度及颗粒均方根脉动速度和USM-RANS的模拟结果与实验结果的对照表明,两种模拟结果和实验结果在定量上吻合较好。因此USM模型基本上得到了LES的验证。但是在剪切流区域中,LES得到的颗粒-气体纵向脉动速度关联的峰值大于USM-RANS模拟的结果,这就表明LES和USM-RANS模拟还需要进一步验证和改进。A two-fluid large-eddy simulation （LES）, based on the Smagorinsky SGS stress model and particle kinetic theory, and unified second-order-moment two-phase turbulence Reynolds averaged Navier Stokes modeling （USM-RANS） were used to study backward-facing step gas-particle flows. The instantaneous results gave the evolution of anisotropic two-phase turbulence structures and particle dispersion processes. The IrES statistical results and USM-RANS modeling results of particle averaged velocity and RMS particle fluctuation velocity were in good quantitative agreement with the experimental results. Hence, the USM-RANS modeling was basically validated by IRES. However, in the shear flow region, the peak values of the two-phase velocity correlation predicted by IrES were larger than those predicted by USM-RANS modeling. It implied that the IrES and USM RANS modeling remained to be further validated and improved.

关 键 词：后台阶流动 气固流动 大涡模拟 二阶矩两相湍流模型 

分 类 号：TK223.2[动力工程及工程热物理—动力机械及工程]