Constitutive Models for Filtered Two-Fluid Models of Fluidized Gas–Particle Flows

Abstract

presented a methodology where computational results obtained through highly resolved simulations of a given microscopic two-fluid model (TFM) for gas-particle flows are filtered to deduce models for the residual correlations appearing in the corresponding filtered TFM equations that are appropriate for coarsegrid simulations of gas-particle flows. In the present study, we have performed a large number of highly resolved simulations of a kinetic theory based TFM in two-and three-dimensional periodic domains using this methodology and filtered the results to generate computational data on the filtered drag coefficient, the filtered particle phase pressure, and the filtered particle phase viscosity. These results have been captured in the form of correlations that can readily be employed in coarse-grid simulations of gasparticle flows.

Evaluation of a filtered model for the simulation of large scale bubbling and turbulent fluidized beds

“…The equation setup used in this paper was receive through personal communication directly from Sundaresan and co-workers and represents the latest and most accurate formulations according to the filtering methodology outlined in two recent publications [5,6]. While a previous study [7] validated these formulations in riser flows, this study aims to carry out validation studies in the bubbling and turbulent fluidization regimes, thereby fully assessing the generality of the modelling approach.…”

“…Such an approach allows for computational speedups of several orders of magnitude, but additional closure relations are required to close the filtered conservation equations. This work is based on filtered two-fluid models of gas-particle flows as formulated by Sundaresan and co-workers [5,6]. The models were developed in two stages.…”

Computational characterisation of intermittent hydrodynamic behaviours in a riser with Geldart A particles

“…particle clusters) in the CFBs with Geldart A particles range from several particle diameters to the riser diameter, adequate sub-grid models are required to take the effects of the unresolved mesoscale structures on the constitutive laws into account [21,22]. One approach is the adoption of the socalled filtered models developed to describe the sub-grid closures of drag force [23][24][25].…”

The effect of frictional pressure, geometry and wall friction on the modelling of a pseudo-2D bubbling fluidised bed reactor

“…In terms of model development, the majority of recent research activity has been focussed on large scale simulations through a filtered approach (e.g. [4]), but room for improvement still exists in the smaller scale resolved simulations on which these filtered models are based, especially in reactive flows (e.g. [5]).…”