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.