A Model to Improve Granular Temperature in CFD-DEM Simulations
Open Access
- 11 September 2020
- Vol. 13 (18) , 4730
Abstract
CFD-DEM (computational fluid dynamic-discrete element method) is a promising approach for simulating fluid–solid flows in fluidized beds. This approach generally under-predicts the granular temperature due to the use of drag models for the average drag force. This work develops a simple model to improve the granular temperature through increasing the drag force fluctuations on the particles. The increased drag force fluctuations are designed to match those obtained from PR-DNSs (particle-resolved direct numerical simulations). The impacts of the present model on the granular temperatures are demonstrated by posteriori tests. The posteriori tests of tri-periodic gas–solid flows show that simulations with the present model can obtain transient as well as steady-state granular temperature correctly. Moreover, the posteriori tests of fluidized beds indicated that the present model could significantly improve the granular temperature for the homogenous or slightly inhomogeneous systems, while it showed negligible improvement on the granular temperature for the significantly inhomogeneous systems.Keywords
Funding Information
- National Natural Science Foundation of China (21978228; 51906196)
- Shaanxi Provincial Natural Science Basic Research Program-Youth Fund Project (2020JQ-050)
- Shaanxi Creative Talents Promotion Plan-Technological Innovation Team (2019TD-039)
- Fundamental Research Funds for the Central Universities (cxtd2017004)
This publication has 22 references indexed in Scilit:
- Effects of granular temperature on inter-phase drag in gas-solid flowsPowder Technology, 2017
- Micro/meso simulation of a fluidized bed in a homogeneous bubbling regimeInternational Journal of Multiphase Flow, 2017
- Force variation within arrays of monodisperse spherical particlesPhysical Review Fluids, 2016
- Direct numerical simulation of moderate-Reynolds-number flow past arrays of rotating spheresPhysics of Fluids, 2015
- A new drag correlation from fully resolved simulations of flow past monodisperse static arrays of spheresAIChE Journal, 2014
- Drag law for monodisperse gas–solid systems using particle-resolved direct numerical simulation of flow past fixed assemblies of spheresInternational Journal of Multiphase Flow, 2011
- Discrete particle simulation of particulate systems: Theoretical developmentsChemical Engineering Science, 2007
- Drag force of intermediate Reynolds number flow past mono‐ and bidisperse arrays of spheresAIChE Journal, 2007
- Discrete particle simulation of two-dimensional fluidized bedPowder Technology, 1993
- Kinetic theories for granular flow: inelastic particles in Couette flow and slightly inelastic particles in a general flowfieldJournal of Fluid Mechanics, 1984