Numerical simulations reveal the formation of singular structures in the polymer stress field of a viscoelastic fluid modeled by the Oldroyd-B equations driven by a simple body force. These singularities emerge exponentially in time at hyperbolic stagnation points in the flow and their algebraic structure depends critically on the Weissenberg number. Beyond a first critical Weissenberg number t...

We investigate the effects of helical swimmer shape (i.e., pitch angle and tail thickness) on swimming dynamics in a constant viscosity viscoelastic (Boger) fluid via combination particle tracking velocimetry, image velocimetry 3D simulations FENE-P model. The printed is actuated magnetic field using custom-built rotating Helmholtz coil. Our results indicate that increasing thickness enhances n...

Abstract A Taylor–Galerkin finite element time marching scheme is derived to numerically simulate the flow of a compressible and nonisothermal viscoelastic liquid between eccentrically rotating cylinders. Numerical approximations governing constitutive equations are computed over custom refined unstructured grid piecewise linear Galerkin elements. An original extension DEVSS formulation for flu...

The FENE dumbbell model consists of the incompressible NavierStokes equation for the solvent and the Fokker-Planck equation for the polymer distribution. In such a model, the polymer elongation cannot exceed a limit √ b which yields all interesting features of solutions near this limit. This work is concerned with the sharpness of boundary conditions in terms of the elongation parameter b. Thro...

We review recent analytical and computational results for macroscopic-microscopic beadspring models that arise from the kinetic theory of dilute solutions of incompressible polymeric fluids with noninteracting polymer chains, involving the coupling of the unsteady Navier– Stokes system in a bounded domain Ω ⊂ Rd, d = 2 or 3, with an elastic extra-stress tensor as right-hand side in the momentum...

Recent numerical studies on pressure-drops in contraction flows have introduced a variety of constitutive models to compare and contrast the competing influences of extensional viscosity, normal stress and shear-thinning. Early work on pressure-drops employed the constant viscosity Oldroyd-B and Upper Convected Maxwell (UCM) models to represent the behavior of so-called Boger fluids in axisymme...

In this paper we will discuss several issues related to the moment-closure approximation of multiscale models for viscoelastic polymeric fluids. These moment-closure approaches are based on special ansatz for the probability density function (PDF) in the finite extensible nonlinear elastic (FENE) dumbbell micro-macro models which consists of the coupled incompressible Navier-Stokes equations an...