The paper addresses the question if there exists a finite stopping time for an unforced motion of a yield stress fluid with free surface. A variational inequality formulation is deduced for the problem of yield stress fluid dynamics with a free surface. The free surface is assumed to evolve with a normal velocity of the flow. We also consider capillary forces acting along the free surface. Base...

We have studied the flow induced by a macroscopic spherical particle settling in a Laponite suspension that exhibits a yield-stress, thixotropy and shear-thinning. We show that the fluid thixotropy (or aging) induces an increase with time of both the apparent yield stress and shear-thinning properties but also a breaking of the flow fore-aft symmetry predicted in Hershel-Bulkley fluids (yield-s...

Abstract The presence of complex fluids in nature and industrial applications combined with the rapid growth computer power over past decades has led to an increasing number numerical studies non-Newtonian flows. In most cases, models can be implemented existing Newtonian solvers by relatively simple modifications viscosity. However, due scarcity analytical solutions for fluid flows widespread ...

We discuss the applicability of a unified hyperbolic model for continuum fluid and solid mechanics to modeling non-Newtonian flows in particular stress-driven solid-fluid transformations viscoplastic fluids, also called yield-stress fluids. In contrast conventional approaches relying on non-linear viscosity concept Navier-Stokes theory representation state as an infinitely rigid non-deformable ...

This study examines identification of rheological parameters for a constitutive model characterizing the rheological behavior of a ferrous nanoparticle-based magnetorheological (MR) fluid. Particle size is nominally 28 nm and the MR fluid has a weight fraction of 27.5% Fe. A constant shear rate rheometer is used to measure flow curves (shear stress vs. shear rate), as a function of applied magn...

The aim of the present work is to investigate flow rate/pressure gradient relationship for yield stress fluids through rectilinear capillaries non-circular cross-sections. These very often serve as basic elements in modeling porous media bundles or pore-network models. Based on notions shape coefficient and critical Bingham number, empirical relationships have been proposed both Herschel–Bulkle...

We present the results of displacement flows different Newtonian and Herschel–Bulkley non-Newtonian fluids in a new-developed eccentric Hele–Shaw cell with dynamic similarly to real field wellbore annulus during primary cementing. The possibility tracking interface between using particles intermediate or neutral buoyancy is studied. behaviors movements sizes densities against vertical flow stro...

The analysis of grease-lubricaled rolling element bearings i s presented. Exferimen tally determined flow curaes for grease are found to be well correlated by the Herschel-Bdkley model flow eqzration. A theory for predicting roller Jilm thickness based on the assumed flow model i s derived. Experimental results show that grease will deveIop a larger film lhickness lhan the grease base oil at ji...