Some important fundamental aspects of fluid mechanics and rheology are discussed. First, we examine the basis for the continuum approximation of fluids, and the formulation of equations in the continuum description. Then, we look at stress-strain rate relationships for simple shear flows of both viscous and viscoelastic fluids. The extension of the description to complex flows, which involves t...

We present molecular dynamics simulations on the structural relaxation of a simple bead-spring model for polymer blends. The introduction of a different monomer size induces a large time scale separation for the dynamics of the two components. Simulation results for a large set of observables probing density correlations, Rouse modes, and orientations of bond and chain end-to-end vectors, are a...

To study the swimming of the multi-flagellated bacterium Escherichia coli, we deploy a bead-spring hydrodynamic model (Watari and Larson 2010), whose body and flagellar geometry, motor torques, and motor reversals are adjusted to match the experimental observations of the Berg group (Turner et al. 2000; Darnton et al. 2007) during both running and tumbling of the bacterium. In this model, hydro...

A reasonably accurate representation of a polymer chain is provided by beads connected with rods, or stiff, inextensible springs that mimic single Kuhn step. Due to high computational cost, coarse-grained bead–spring models are used in typical applications, where each spring supposed replace several steps. Earlier investigations indicate the BD simulation predictions steady state different flow...

due to the fact that many application processes take place at different temperature, better examining and understanding of swelling properties as a function of temperature is essential for such application. the temperature effect on the swelling properties of commercial polyacrylic acid (paa) hydrogel beads was investigated as a function of time and temperature. gel bead size, swelling equilibr...