Scalar mixing by granular particles

J. J. Derksen*

*Corresponding author for this work

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

We study by direct numerical simulation the role of spherical, solid, uniformly sized, moving particles immersed in a fluid in spreading a passive scalar with high Schmidt number dissolved in the fluid. The solid particles are one-way coupled to the fluid: they agitate the fluid but they do not feel the presence of the fluid (they move as a granular gas). The two independent variables in the simulations are the solids volume fraction that we vary in the range of 10-45%, and the granular Reynolds number, based on the particle diameter and the granular temperature, which has been varied from 2.8 to 280. It is shown that the scalar spreading rate strongly decreases with increasing solids volume fraction; the spreading appears to scale quite well with the mean free path of the particles. At increasing granular Reynolds number the fluid flow develops more small scale structures that enhance scalar spreading. We propose a relation for an effective diffusion coefficient that describes the scalar spreading in terms of the independent variables. (C) 2008 American Institute of Chemical Engineers.

Original languageEnglish
Pages (from-to)1741-1747
Number of pages7
JournalAIChE Journal
Volume54
Issue number7
DOIs
Publication statusPublished - Jul 2008

Keywords

  • computational fluid dynamics (CFD)
  • multi-phase flow
  • mixing
  • HYPERBOLIC CONSERVATION-LAWS
  • HIGH-RESOLUTION SCHEMES
  • FLUIDIZED-BEDS
  • NUMERICAL SIMULATIONS
  • BOLTZMANN-EQUATION
  • FLOW
  • SUSPENSIONS
  • BOUNDARY

Cite this

Scalar mixing by granular particles. / Derksen, J. J.

In: AIChE Journal, Vol. 54, No. 7, 07.2008, p. 1741-1747.

Research output: Contribution to journalArticle

Derksen, J. J. / Scalar mixing by granular particles. In: AIChE Journal. 2008 ; Vol. 54, No. 7. pp. 1741-1747.
@article{d6fd2a4fa7484afcae129f9d4dbb69ed,
title = "Scalar mixing by granular particles",
abstract = "We study by direct numerical simulation the role of spherical, solid, uniformly sized, moving particles immersed in a fluid in spreading a passive scalar with high Schmidt number dissolved in the fluid. The solid particles are one-way coupled to the fluid: they agitate the fluid but they do not feel the presence of the fluid (they move as a granular gas). The two independent variables in the simulations are the solids volume fraction that we vary in the range of 10-45{\%}, and the granular Reynolds number, based on the particle diameter and the granular temperature, which has been varied from 2.8 to 280. It is shown that the scalar spreading rate strongly decreases with increasing solids volume fraction; the spreading appears to scale quite well with the mean free path of the particles. At increasing granular Reynolds number the fluid flow develops more small scale structures that enhance scalar spreading. We propose a relation for an effective diffusion coefficient that describes the scalar spreading in terms of the independent variables. (C) 2008 American Institute of Chemical Engineers.",
keywords = "computational fluid dynamics (CFD), multi-phase flow, mixing, HYPERBOLIC CONSERVATION-LAWS, HIGH-RESOLUTION SCHEMES, FLUIDIZED-BEDS, NUMERICAL SIMULATIONS, BOLTZMANN-EQUATION, FLOW, SUSPENSIONS, BOUNDARY",
author = "Derksen, {J. J.}",
year = "2008",
month = "7",
doi = "10.1002/aic.11519",
language = "English",
volume = "54",
pages = "1741--1747",
journal = "AIChE Journal",
issn = "0001-1541",
publisher = "Wiley-Blackwell",
number = "7",

}

TY - JOUR

T1 - Scalar mixing by granular particles

AU - Derksen, J. J.

PY - 2008/7

Y1 - 2008/7

N2 - We study by direct numerical simulation the role of spherical, solid, uniformly sized, moving particles immersed in a fluid in spreading a passive scalar with high Schmidt number dissolved in the fluid. The solid particles are one-way coupled to the fluid: they agitate the fluid but they do not feel the presence of the fluid (they move as a granular gas). The two independent variables in the simulations are the solids volume fraction that we vary in the range of 10-45%, and the granular Reynolds number, based on the particle diameter and the granular temperature, which has been varied from 2.8 to 280. It is shown that the scalar spreading rate strongly decreases with increasing solids volume fraction; the spreading appears to scale quite well with the mean free path of the particles. At increasing granular Reynolds number the fluid flow develops more small scale structures that enhance scalar spreading. We propose a relation for an effective diffusion coefficient that describes the scalar spreading in terms of the independent variables. (C) 2008 American Institute of Chemical Engineers.

AB - We study by direct numerical simulation the role of spherical, solid, uniformly sized, moving particles immersed in a fluid in spreading a passive scalar with high Schmidt number dissolved in the fluid. The solid particles are one-way coupled to the fluid: they agitate the fluid but they do not feel the presence of the fluid (they move as a granular gas). The two independent variables in the simulations are the solids volume fraction that we vary in the range of 10-45%, and the granular Reynolds number, based on the particle diameter and the granular temperature, which has been varied from 2.8 to 280. It is shown that the scalar spreading rate strongly decreases with increasing solids volume fraction; the spreading appears to scale quite well with the mean free path of the particles. At increasing granular Reynolds number the fluid flow develops more small scale structures that enhance scalar spreading. We propose a relation for an effective diffusion coefficient that describes the scalar spreading in terms of the independent variables. (C) 2008 American Institute of Chemical Engineers.

KW - computational fluid dynamics (CFD)

KW - multi-phase flow

KW - mixing

KW - HYPERBOLIC CONSERVATION-LAWS

KW - HIGH-RESOLUTION SCHEMES

KW - FLUIDIZED-BEDS

KW - NUMERICAL SIMULATIONS

KW - BOLTZMANN-EQUATION

KW - FLOW

KW - SUSPENSIONS

KW - BOUNDARY

U2 - 10.1002/aic.11519

DO - 10.1002/aic.11519

M3 - Article

VL - 54

SP - 1741

EP - 1747

JO - AIChE Journal

JF - AIChE Journal

SN - 0001-1541

IS - 7

ER -