Fluidization XVI
Development of a Refined Grid Model for an Industrial Gas-Solid Flow System
The DEM-CFD method is often employed in a simulation of a gas-solid flow. In the DEM-CFD method, local volume average technique is employed in the governing equations, and hence the CFD grid size must be sufficiently larger than particle size. In the DEM-CFD method, structure grids are often used in the calculation of a gas flow. The local volume average technique makes it difficult to create a narrow path or thin wall in a fluid system by structure grids, though these gas flows are often encountered in industrial systems. Therefore, the DEM-CFD has been applied to simple systems so far. In order to overcome the difficulty, refined grid model is developed, where fine grid is flexibly used in the DEM-CFD method. Several verification tests are performed to show adequacy of the refined grid. The DEM-CFD method introducing the refined grid model is applied to a fluidized bed inserted thin wall and a fluidized bed inserted a rotating screw. It is shown that not only adequacy of the gas flow is proven, but also qualitatively excellent behavior of solid phase can be simulated by the DEM-CFD method introducing the refined grid model.
This study was financially supported by JSPS KAKENHI (17H02825) and by Grant-in-Aid for JSPS Research Fellow from the Japan Society for the Promotion of Science (18J12267).