Large-amplitude oscillatory shear flow (LAOS) is a popular for studying the nonlinear physics of complex fluids. Specifically, the strain rate sweep (also called the strain sweep) is used routinely to identify the onset of nonlinearity. In this paper, we give exact expressions for the nonlinear complex viscosity and the corresponding nonlinear complex normal stress coefficients for the Oldroyd ...

in this work, for the first time, the rheological properties of nanofluids of lanthania nanoparticles (nps) in ethylene glycol (eg) as functions of shear rate, volume fraction, and temperature were measured. the results showed that both eg and the nanofluids behave as non-newtonian fluids at lower shear rates and transform to newtonian fluids at higher shear rates. the values of viscosity for b...

Erupting magma often contains crystals over a wide range of sizes and shapes, potentially affecting magma viscosity over many orders of magnitude. A robust relation between viscosity and the modality of crystal sizes and shapes remains lacking, principally because of the dimensional complexity and size of the governing parameter space. We have performed a suite of shear viscosity measurements o...

In this paper, we investigate computationally the oscillatory tank-treading motion of healthy swollen human erythrocytes (owing to lower than physiological plasma osmolarity) in shear flows with capillary number Ca=O(1) and small to moderate viscosity ratios 0.01≤λ≤2.75. Swollen cells show similar shear flow dynamics with normal cells but with significantly higher inclination and tank-treading ...

Discontinuous shear thickening (DST) observed in many dense athermal suspensions has proven difficult to understand and to reproduce by numerical simulation. By introducing a numerical scheme including both relevant hydrodynamic interactions and granularlike contacts, we show that contact friction is essential for having DST. Above a critical volume fraction, we observe the existence of two sta...

The shear viscosity of a two-dimensional (2D) liquid was calculated using equilibrium molecular dynamics simulations with a Yukawa potential. The shear viscosity has a minimum, at a Coulomb coupling parameter Γ of about 17, arising from the temperature dependence of the kinetic and potential contributions. Previous calculations of 2D viscosity were less extensive, and for a different potential....

It is well known that the viscosity of a liquid is a measure of its resistance to shear. Upon the introduction of small solid objects into a viscous medium, the internal motion of the liquid when caused to flow is made more complicated than it would be otherwise and the resistance to shear is thereby increased. Einstein (4) has derived the following formula relating the viscosity of a suspensio...

Using molecular dynamics simulations, we study the lubricating properties of neutral and charged bottle-brush coatings as a function of the compression and shear stresses and brush grafting density. Our simulations have shown that in charged bottle-brush systems under shear there is a layer with excess counterions located in the middle between brush-bearing surfaces. The main deformation mode o...

We investigated experimentally the rheological behavior of whole human blood subjected to large amplitude oscillatory shear under strain control to assess its nonlinear viscoelastic response. In these rheological tests, the shear stress response presented higher harmonic contributions, revealing the nonlinear behavior of human blood that is associated with changes in its internal microstructure...