On continuum modeling using kinetic–frictional models in high shear granulation

•The use of kinetic–frictional models in high shear granulation (HSG) was evaluated.•Dense sheared granular flow in a Couette shear cell was studied.•Effect of the lack of scale separation was investigated.•A significant resolution dependence of the stresses was found.•Results showed that conventional kinetic–frictional models were not adequate for describing HSG.

This short communication demonstrates why extreme caution has to be taken when applying conventional kinetic–frictional closures to continuum modeling of high shear granulation (HSG). Conventional models refer to closure laws where the kinetic and frictional stresses are summed up to obtain the total stress field. In the simple, dense, and sheared system of a Couette shear cell, the effect of the lack of scale separation on the model predictions is examined, both quantitatively and qualitatively. It is observed that the spatial resolution has a significant effect on the magnitude of the kinetic and frictional contributions to the solid phase stresses. With this new investigation and previous studies of HSG, it is concluded that conventional kinetic–frictional models are inadequate for continuum modeling of HSG.

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