The effect of numerical diffusion and the influence of computational grid over gas–solid two-phase flow in a bubbling fluidized bed

2D CFD-PBM simulation of hydrodynamic and particle growth in an industrial gas phase fluidized bed polymerization reactor

“…Kinetic theory of granular flow (KTGF) was employed to describe the rheology and characterize the motion of particles. In addition, constitutive equations derived by Chen et al (2011a) were extensively utilized (Ahuja and Patwardhan, 2008;Chen et al, 2011a;de Souza Braun et al, 2010;Esmaili and Mahinpey, 2011;Sun et al, 2011;Wei et al, 2011). The radial distribution function between two solid phases was modelled according to (Syamlal et al, 1993).…”

“…The impact of first order upwind and second order upwind discretization scheme on numerical diffusion was investigated by Cooper and Coronella (2005) and Braun et al (2010).…”

A CFD Assessment of Drag Models Performance on Gas-Solid Flow Hydrodynamics in a Fluidized Bed

“…This parameter allows determining the momentum transfer between the gas and solid phases. The description of the gas-solid flow moment transfer through the drag model is very important, since fluidization is a result of the drag exerted by the interfacial gas flow in the gap between the solid particles (Ahuja & Patwardhan, 2008;de Souza Braun et al, 2010). Gidaspow (1994)…”

“…The simulations are performed for a time period of 25 seconds, in order to eliminate the large temporal fluctuation of all variables, thereby the time-averaging was done between 5 -25 seconds in real-time simulation. (Taghipour, Ellis, & Wong, 2005) For the convective terms discretization, SUPERBEE scheme can be used to simulate a gassolid fluidized bed in a course grid in order to avoid numerical diffusion effects (de Souza Braun et al, 2010;Hosseini, Ahmadi, Saeedi Razavi, & Zhong, 2010). The vertical sidewalls were treated with no-slip boundary conditions, while the base and top had fixed velocity inflow and pressure outflow boundary conditions.…”

“…In Eulerian-Eulerian approach, the drag model is responsible for the hydrodynamic description, which have a strong influence on the spatial distribution of solid particles in fluidized bed, being very important in determining properties such as heat and mass transfer rates, thereby, the predictive accuracy of a CFD model depends on the drag model used to describe the drag force (Du, Bao, Xu, & Wei, 2006;Sobieski, 2009;de Souza Braun et al 2010;Esmaili and Mahinpey 2011).…”