Hydrodynamic field around a Brownian particle

Abstract

We use molecular dynamics simulations of a solid Brownian particle in an explicit solvent to analyze the velocity field generated by a stochastic motion of a particle. The simulation data demonstrate that the amplitude of the velocity field around a Brownian particle decays much faster than the velocity field around a particle moving with a constant velocity. However, the time-integrated response of the velocity field around a Brownian particle has exactly the same distance dependence as the velocity field around a particle moving with a constant velocity. This finding elucidates the validity of an assumption used in theoretical descriptions of Brownian particles dynamics in confined geometries and in colloids; namely, that viscous drag forces can be computed as if the particles move with constant velocities.

A comprehensive review of thermo-physical properties and convective heat transfer to nanofluids

“…The high surface energy of nanoparticles allows for easy coagulation and difficult dispersion in the base fluid. This condition changes the morphology and volume fraction of the nanoparticles, which cause low fluidity [146,147,220]. Therefore, controlling the coagulation of nanoparticles in the nanofluid is a primary issue to exploit their potential benefits and applications.…”

The Classical Nature of Thermal Conduction in Nanofluids

“…Am important observation we made was that a nanofluid under equilibrium conditions, will not support any convection regardless of Brownian motion of the nanoparticles. We note that the mixing of fluid currents around a nanoparticle, a concept which is borrowed from the macroscopic fluid flow, is not appropriate at microscales because the dragging of fluid around nanoparticles can occur at equilibrium conditions [85] in a nanofluid while macroscopic fluid flow is always under non-equilibrium conditions. To put it differently, the dragging of the bulk fluid in a nanofluid is thermally driven while at macroscopic scales, it is gradient driven.…”

Hot Brownian Motion

“…Strictly speaking, in view of how it deals with long-ranged and long-lived correlations arising from conservation laws governing the solvent hydrodynamics, this practical and commonplace Markovian description applies only asymptotically for late times [5,6]. Corresponding corrections to Eqs.…”