The steady ow of viscoplastic uids through brous porous media is studied numerically and theoretically. We consider uids with a plastic yield stress and a rate-dependent viscosity that can be described by the HerschelBulkley model. We rst investigate the pore-scale ow characteristics through numerical simulations for ow transverse to a square array of bers with comprehensive parametric studies ...

Plastic liquids, also known as Bingham liquids, retain their shape when loads are small, but flow when loads exceed a threshold. We discovered that plastic liquid films coated on elastomers develop wavy patterns under cyclic loads. As the number of cycles increases, the wavelength of the patterns remains unchanged, but the amplitude of the patterns increases and then saturates. Because the patt...

High performance is the most important expectation from concrete which is commonly used in today’s construction technology. To form a high performance concrete “HPC”, two fundamental properties are required. These properties are optimization of the materials used to form the concrete and the workability of fresh concrete during shaping. Many scientists have used rheological properties in conjun...

We investigate the performance of the finite volume method in solving viscoplastic flows. The creeping square lid-driven cavity flow of a Bingham plastic is chosen as the test case and the constitutive equation is regularised as proposed by Papanastasiou [J. Rheology 31 (1987) 385-404]. It is shown that the convergence rate of the standard SIMPLE pressure-correction algorithm, which is used to ...

Additives were tested for their ability to modify the rheology of lignocellulosic biomass. Additive types included water-soluble polymers (WSPs), surfactants, and fine particles. WSPs were the most effective rheological modifiers, reducing yield stresses of concentrated biomass by 60–80% for additive concentrations of 1–2 wt. % (based on mass of dry biomass solids). Yield stress and plastic vis...

A closed-form analytical solution to rheological phenomena is obtained based on Hoek-Brown (HB) yield criterion and the generalized Bingham model. Once circular tunnel excavated, an initial plastic region formed. When total stresses fulfil condition, steps into viscoplastic region, in which displacement develops with time. The one-dimensional constitutive equation of model transformed a three-d...