We investigate the flow patterns of Newtonian and viscoelastic fluids in microchannels containing bifurcations. The Newtonian fluid used as a reference is de-ionized water, while the non-Newtonian fluid used in the experiments has a shear rheology similar to that of human blood. The geometrical shape of the channels used reproduce bifurcating vessels, typically encountered in microcirculation n...

Complex fluids exist in nature and are continually engineered for specific applications involving the addition of macromolecules to a solvent, among other means. This imparts viscoelasticity fluid, property responsible various flow instabilities major modifications fluid dynamics. Recent developments numerical methods simulation viscoelastic flows, described by continuum-level differential cons...

In real systems, the phenomena, such as pipe-wall viscoelasticity, unsteady friction or fluid structure interaction induce additional damping and dispersion of transient pressure waves than that defined by classical waterhammer. In this paper, unsteady friction models and viscoelastic damping models will be presented and a theoretical formulation of the viscoelastic damping in piping systems wi...

in this paper, we present an analytical method for solving a well-posed boundary value problem of mathematical physics governing the vibration characteristics of an internal flow propelled fluid-structure interaction where the pipeline segment is idealized as an elastic hollow beam conveying an incompressible fluid on a viscoelastic foundation. the effect of coriolis and damping forces on the o...

Abstract The effective thermal expansion coefficient β∗ of a binary viscoelastic composite is shown to be frequency dependent even if the thermal expansion coefficients βA and βB of both constituents are themselves frequency independent. Exact calculations for binary viscoelastic systems show that β∗ is related to constituent values βA, βB , volume fractions, and bulk moduli KA, KB , as well as...

We study theoretically the viscoelastic properties of sheared binary fluids that have strong dynamical asymmetry between the two components. The dynamical asymmetry arises due to asymmetry between the viscoelastic stresses, particularly the bulk stress. Our calculations are based on the two-fluid model that incorporates the asymmetric stress distribution. We simulate the phase separation proces...

We study a defect correction method for the approximation of viscoelastic fluid flow. In the defect step, the constitutive equation is computed with an artificially reduced Weissenberg parameter for stability, and the resulting residual is corrected in the correction step. We prove the convergence of the defect correction method and derive an error estimate for the Oseen-viscoelastic model prob...

We study a nonlinear, unsteady, moving boundary, fluid-structure interaction (FSI) problem arising in modeling blood flow through elastic and viscoelastic arteries. The fluid flow, which is driven by the time-dependent pressure data, is governed by 2D incompressible Navier-Stokes equations, while the elastodynamics of the cylindrical wall is modeled by the 1D cylindrical Koiter shell model. Two...

Many small organisms self-propel in viscous fluids using travelling wave-like deformations of their bodies or appendages. Examples include small nematodes moving through soil using whole-body undulations or spermatozoa swimming through mucus using flagellar waves. When self-propulsion occurs in a non-Newtonian fluid, one fundamental question is whether locomotion will occur faster or slower tha...