This article addresses the issue of reproducing quantitative pressure-drop predictions for constant shear-viscosity fluids in contraction and contraction/expansion flow geometries. Experimental observations on pressure-drop for severe strain-hardening Boger fluids reveal significant enhancement above Newtonian fluids in axisymmetric but not planar configurations. This discrepancy has eluded pre...

This article addresses the issue of reproducing quantitative pressure-drop predictions for constant shear-viscosity fluids in contraction and contraction/expansion flow geometries. Experimental observations on pressure-drop for severe strain hardening Boger fluids reveal significant enhancement above Newtonian fluids in axisymmetric but not planar configurations. This discrepancy has eluded pre...

Because of their various applications during the past several years, generalizations of the Navier-Stokes model to highly nonlinear constitutive laws have been proposed and studied (see [4, 5, 7]). Several different models have been introduced to explain such nonstandard features, as normal stress effect, rod climbing, shear thinning, and shear thickening. Among the differential-typemodels, Old...

This paper presents a numerical evaluation of two different artificial stress diffusion techniques for the stabilization viscoelastic Oldroyd-B fluid flows at high Weissenberg numbers. The standard in form Laplacian extra tensor is compared with newly proposed approach using discrete time derivative tensor. Both methods are implemented finite element code and demonstrated solution flow two-dime...

We investigate finite amplitude stability of spatially inhomogeneous steady state an incompressible viscoelastic fluid which occupies a mechanically isolated vessel with walls kept at non-uniform temperature. For wide class models including the Oldroyd-B model, Giesekus FENE-P Johnson–Segalman and Phan–Thien–Tanner model we prove that is stable subject to any perturbation.

We investigate some critical models for visco-elastic flows of Oldroyd-B type in dimension two. We use a transformation which exploits the Oldroyd-B structure to prove an L∞ bound on the vorticity which allows us to prove global regularity for our systems.

Cross stream migration and stable orientations of elliptic particles falling in an Oldroyd-B fluid in a channel are studied. We show that the normal component of the extra stress on a rigid body vanishes; lateral forces and torques are determined by the pressure. Inertia turns the longside of the ellipse across the stream and elasticity turns it along the stream; tilted off-center falling is un...

We analyze the steady non-Newtonian fluid–structure interaction between flow of an Oldroyd-B fluid and a deformable channel. Specifically, we provide theoretical framework for calculating leading-order effect fluid’s viscoelasticity on rate–pressure drop relation deformation channel’s elastic wall. first identify characteristic scales dimensionless parameters governing in slender shallow channe...