Filtered and heterogeneity‐based subgrid modifications for gas–solid drag and solid stresses in bubbling fluidized beds

摘要: Two different approaches to constitutive relations for filtered two-fluid models (TFM) of gas–solid flows are deduced. The first model (Model A) is derived using systematically results obtained from a highly resolved simulation bubbling fluidized bed. second B) stems the assumption formation subgrid heterogeneities inside suspension phase beds. These unresolved terms appearing in TFM are, then, substantiated by corresponding data. Furthermore, presented verified case bed used generate fine grid numerical on coarse grids demonstrate that computed hydrodynamics fairly good agreement with simulation. further show contribution frictional stresses required correctly predict bubble rise velocity grids. © 2013 American Institute Chemical Engineers AIChE J, 60: 839–854, 2014