化工学报 ›› 2008, Vol. 59 ›› Issue (10): 2485-2489.

• 多相流和计算流体力学 • 上一篇    下一篇

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

刘阳;周力行;许春晓;胡瓅元   

  1. 清华大学工程力学系;上海交通大学机械与动力工程学院
  • 出版日期:2008-10-05 发布日期:2008-10-05

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

LIU Yang;ZHOU Lixing;XU Chunxiao;HU Liyuan   

  • Online:2008-10-05 Published:2008-10-05

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。

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

Abstract:

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 LES 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 LESHowever,in the shear flow region,the peak values of the twophase velocity correlation predicted by LES were larger than those predicted by USM-RANS modelingIt implied that the LES and USM-RANS modeling remained to be further validated and improved.

Key words:

后台阶流动, 气固流动, 大涡模拟, 二阶矩两相湍流模型