Assessment of hindered diffusion in arbitrary geometries using a multiphase DNS framework
Artikel i vetenskaplig tidskrift, 2021

The hydrodynamics around a Brownian particle has a noticeable impact on its hindered diffusion in arbitrary geometries (such as channels/pores) due to reduced mobility close to walls. These effects are difficult to describe at sub-pore scales, wherein a complete analytical solution of the underlying hydrodynamics is challenging to obtain. Here, we propose a coupled Langevin-multiphase direct numerical simulation (DNS) framework, that fully resolves the hydrodynamics in such systems and consequently provides an on-the-fly capability to probe local instantaneous particle diffusivities.

We validate and establish the capabilities of this framework in square micro-channels (under varying degrees of hydrodynamic confinement) and in an arbitrary pore. Our results show that directional variations in mean-squared displacements, velocity auto-correlation functions and diffusivities of the Brownian particle, due to inherent asymmetries in the geometry are adequately captured. Further, a local anisotropy in the hydrodynamic resistances along the co-axial direction of the channel is also noted.

Micro-channel and Mobility

Immersed boundary method

Hydrodynamic resistance

CFD

Brownian diffusion

Hindered diffusion

Författare

Ananda Subramani Kannan

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Andreas Mark

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Dario Maggiolo

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Gaetano Sardina

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Srdjan Sasic

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Henrik Ström

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Chemical Engineering Sciences

0009-2509 (ISSN)

Vol. 230 116074

En kontinuummodell för Brownsk rörelse i förtunnande gas-partikelflöden

Vetenskapsrådet (VR), 2016-01-01 -- 2019-12-31.

Styrkeområden

Transport

Produktion

Energi

Ämneskategorier

Farmaceutisk vetenskap

Energiteknik

Strömningsmekanik och akustik

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1016/j.ces.2020.116074

Mer information

Senast uppdaterat

2021-01-11