Avik Sarkar, Fernando E. Milioli, Shailesh Ozarkar, Tingwen Li, Xin Sun, Sankaran Sundaresan, Filtered sub-grid constitutive models for fluidized gas-particle flows constructed from 3-D simulations, Chemical Engineering Science, Volume 152, 2 October 2016, Pages 443-456, ISSN 0009-2509, http://dx.doi.org/10.1016/j.ces.2016.06.023.
Abstract: The accuracy of fluidized-bed CFD predictions using the two-fluid model can be improved significantly, even when using coarse grids, by replacing the microscopic kinetic-theory-based closures with coarse-grained constitutive models. These coarse-grained constitutive relationships, called filtered models, account for the unresolved gas-particle structures (clusters and bubbles) via sub-grid corrections. Following the previous 2-D approaches of Igci et al. [AIChE J., 54(6), 1431–1448, 2008] and Milioli et al. [AIChE J., 59(9), 3265–3275, 2013], new closures for the filtered inter-phase drag and stresses in the gas and particle phases are constructed from highly-resolved 3-D simulations of gas-particle flows. These new closure relations are then validated through the bubbling-fluidized-bed challenge problem presented by National Energy Technology Laboratory and Particulate Solids Research Inc.
Keywords: Computational fluid dynamics (CFD); Constitutive models; Fluidization; Multiphase flow; Scale-up; Two-fluid model