【摘要】 对气粒两相后台阶流动,利用大涡模拟方法模拟气相场,用轨道法模拟颗粒相运动.计算中气相亚格子模式(SGS)采用了标准的Smagorinsky模式,研究了气相场大涡演变规律,并给出了速度时均统计值与实验结果的比较,吻合很好.在此基础上深入研究了不同Stokes数下颗粒的运动规律以及不同入口滑移条件下的颗粒运动规律,进一步对直径为150μm的玻璃微珠进行了模拟,得到了颗粒相速度时均统计结果,并与实验结果进行比较,吻合良好.这为细观框架下研究气粒两相相互作用规律提供了依据.更多还原

【Abstract】 The twodimensional gaspartick twophase turbulent twodimeasional backworkfacing step flow was studied by numerical method. Gas field was simulated by large eddy simulation (LES) and solid particle motion was traced by particle track model. The standard Smagorinsky subgrid model was used to model motions of smallscale structures. The simulation attained the large eddy coherent structures evolving spatially and temporally. The time average mean velocity agreed well with the experiment data. Then, the particle motions with various particle Stokes numbers and different initial twophase velocity slip conditions were discussed deeply. The research shows that the initial twophase velocity slip plays an important role in enforcing particles dispersion when the particle stokes numbers are larger. The particle phase temporal statistic velocity fields of glass bead in diameter of 150 μm were also attained, which agreed well with the experiment results. The present research paves a way for the further study of turbulence modification of twophase flow.更多还原