Viscoplastic Couette Flow in the Presence of Wall Slip with Non-Zero Slip Yield Stress

Abstract

The steady-state Couette flow of a yield-stress material obeying the Bingham-plastic constitutive equation is analyzed assuming that slip occurs when the wall shear stress exceeds a threshold value, the slip (or sliding) yield stress. The case of Navier slip (zero slip yield stress) is studied first in order to facilitate the analysis and the discussion of the results. The different flow regimes that arise depending on the relative values of the yield stress and the slip yield stress are identified and the various critical angular velocities defining those regimes are determined. Analytical solutions for all the regimes are presented and the implications for this important rheometric flow are discussed.

A review on multi-physics numerical modelling in different applications of magnetorheological fluids

“…Therefore, the presented numerical model in that study couples the electromagnetic and fluid flow solvers in the same two-way scheme illustrated earlier for COMSOL/Multiphysics in section ‘Coupling between magnetic and fluid flow solvers’. Another study for the flow of MR fluids in a concentric annulus was presented by Damianou et al (2019), in which the flow was modelled analytically.…”

Sliding flows of yield-stress fluids

“…In the present study, the objective is to systematically address the effect of slip on yield-stress fluid flows and its consequences on the yield limit; not only by conducting numerical simulations, but also by forming a theoretical framework for analysing this type of problem. Although some attempts have been made to solve simple rheometric flows in previous years (Philippou, Kountouriotis & Georgiou 2016; Panaseti & Georgiou 2017; Damianou, Panaseti & Georgiou 2019), still the lack of generic numerical implementation frameworks (especially non-regularized methods) and the absence of adequate theoretical frameworks to attack sliding yield-stress fluid flows are discernible. Hence, in what follows, we aim to partially fill this gap in the literature.…”

Formation and Topology of vortices in Couette Flow over open cavities

“…Couette flow is driven by virtue of viscous drag force acting on the fluid, but it may additionally be motivated by an applied pressure gradient in the flow direction. The classical Couette flow problem under various conditions has been widely investigated [1][2][3][4][5][6].…”