Direct Simulations of Mixing of Liquids with Density and Viscosity Differences

J. J. Derksen*

*Corresponding author for this work

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000-12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0-0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time.

Original languageEnglish
Pages (from-to)6948-6957
Number of pages10
JournalIndustrial & Engineering Chemistry Research
Volume51
Issue number19
Early online date23 Apr 2012
DOIs
Publication statusPublished - 2012

Keywords

  • LARGE-EDDY SIMULATIONS
  • STIRRED-TANK
  • FLUID-FLOW
  • TURBULENCE
  • IMPELLER
  • AUTOMATA
  • EQUATION
  • TURBINE
  • LDA

Cite this

Direct Simulations of Mixing of Liquids with Density and Viscosity Differences. / Derksen, J. J.

In: Industrial & Engineering Chemistry Research, Vol. 51, No. 19, 2012, p. 6948-6957.

Research output: Contribution to journalArticle

@article{852581f57a95492bb1786ed7d5ec6ac0,
title = "Direct Simulations of Mixing of Liquids with Density and Viscosity Differences",
abstract = "Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000-12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0-0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time.",
keywords = "LARGE-EDDY SIMULATIONS, STIRRED-TANK, FLUID-FLOW, TURBULENCE, IMPELLER, AUTOMATA, EQUATION, TURBINE, LDA",
author = "Derksen, {J. J.}",
year = "2012",
doi = "10.1021/ie3000419",
language = "English",
volume = "51",
pages = "6948--6957",
journal = "Industrial & Engineering Chemistry Research",
issn = "0888-5885",
publisher = "American Chemical Society",
number = "19",

}

TY - JOUR

T1 - Direct Simulations of Mixing of Liquids with Density and Viscosity Differences

AU - Derksen, J. J.

PY - 2012

Y1 - 2012

N2 - Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000-12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0-0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time.

AB - Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000-12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0-0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time.

KW - LARGE-EDDY SIMULATIONS

KW - STIRRED-TANK

KW - FLUID-FLOW

KW - TURBULENCE

KW - IMPELLER

KW - AUTOMATA

KW - EQUATION

KW - TURBINE

KW - LDA

U2 - 10.1021/ie3000419

DO - 10.1021/ie3000419

M3 - Article

VL - 51

SP - 6948

EP - 6957

JO - Industrial & Engineering Chemistry Research

JF - Industrial & Engineering Chemistry Research

SN - 0888-5885

IS - 19

ER -