This paper establishes a lattice Boltzmann equation-discrete element method (LBE-DEM) coupled simulation method under the Eulerian-Lagrangian framework at first, and applies it to simulating a two-dimensional gas-soli...This paper establishes a lattice Boltzmann equation-discrete element method (LBE-DEM) coupled simulation method under the Eulerian-Lagrangian framework at first, and applies it to simulating a two-dimensional gas-solid two-phase cross jet. The gas phase is simulated by the lattice-Boltzmann method via the TD2G9 model; the solid phase is traced by the Lagrangian method and the inter-particle collision is calculated by the DEM method. Three values of the Stokes number St=10, 25, and 50 are simulated under the same mass loading. This paper focuses on the characteristics of vortex structure, particle distribution, and the reverse-flow/rebounding rate in cross jets. We analyze the characteristics of fluid vortex motion, particle cluster distribution, rebounding rate of particles and the influencing factors for them. The results show the existence of joint distribution of discrete clusters and discrete particles in cross jets. Meanwhile, it shows that a larger concentration of particles in the early stage of jet evolution or a smaller Stokes number under the same mass loading can produce a larger rebounding rate. However, the rebounding rate of particles at the late stage, in general, is stable.展开更多
The stochastic simulation method, based on the concept of control window and the numerical solution of the Langevin equation, is applied to solve the deposition problem of particles from the flowing suspensions onto a...The stochastic simulation method, based on the concept of control window and the numerical solution of the Langevin equation, is applied to solve the deposition problem of particles from the flowing suspensions onto a fiber collector. Using the Kuwabara model to characterize the flow field, the effects of Stokes number, interception parameter, packing density, particle size distribution on the collection efficioncy, and the deposition morphology of particles onto a collector are i examined. The morphology of deposit obtained in the simulated results agrees Well with experimental observations. The estimation of the initial coUection efficiency through the simulations considers that the deposited particles are in good agreement with published experimental data. In addition, the collection efficiency of particles increases in a wider particle size distribution region.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51106180)the research funds of China University of Petroleum, Beijing (Grant No. BJ-2010-03)
文摘This paper establishes a lattice Boltzmann equation-discrete element method (LBE-DEM) coupled simulation method under the Eulerian-Lagrangian framework at first, and applies it to simulating a two-dimensional gas-solid two-phase cross jet. The gas phase is simulated by the lattice-Boltzmann method via the TD2G9 model; the solid phase is traced by the Lagrangian method and the inter-particle collision is calculated by the DEM method. Three values of the Stokes number St=10, 25, and 50 are simulated under the same mass loading. This paper focuses on the characteristics of vortex structure, particle distribution, and the reverse-flow/rebounding rate in cross jets. We analyze the characteristics of fluid vortex motion, particle cluster distribution, rebounding rate of particles and the influencing factors for them. The results show the existence of joint distribution of discrete clusters and discrete particles in cross jets. Meanwhile, it shows that a larger concentration of particles in the early stage of jet evolution or a smaller Stokes number under the same mass loading can produce a larger rebounding rate. However, the rebounding rate of particles at the late stage, in general, is stable.
基金Shanghai Leading Academic Discipline Project,China(No.B604)
文摘The stochastic simulation method, based on the concept of control window and the numerical solution of the Langevin equation, is applied to solve the deposition problem of particles from the flowing suspensions onto a fiber collector. Using the Kuwabara model to characterize the flow field, the effects of Stokes number, interception parameter, packing density, particle size distribution on the collection efficioncy, and the deposition morphology of particles onto a collector are i examined. The morphology of deposit obtained in the simulated results agrees Well with experimental observations. The estimation of the initial coUection efficiency through the simulations considers that the deposited particles are in good agreement with published experimental data. In addition, the collection efficiency of particles increases in a wider particle size distribution region.
