Blending of miscible liquids with different densities starting from a stratified state

J. J. Derksen*

*Corresponding author for this work

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Homogenization of initially segregated and stably stratified systems consisting of two miscible liquids with different density and the same kinematic viscosity in an agitated tank was studied computationally. Reynolds numbers were in the range of 3000-12,000 so that it was possible to solve the flow equations without explicitly modeling turbulence. The Richardson number that characterizes buoyancy was varied between 0 and 1. The stratification clearly lengthens the homogenization process. Two flow regimes could be identified. At low Richardson numbers large, three-dimensional flow structures dominate mixing, as is the case in non-buoyant systems. At high Richardson numbers the interface between the two liquids largely stays intact. It rises due to turbulent erosion, gradually drawing down and mixing up the lighter liquid. (C) 2011 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)35-45
Number of pages11
JournalComputers & Fluids
Volume50
Issue number1
DOIs
Publication statusPublished - Nov 2011

Keywords

  • Mixing
  • Blending
  • Buoyancy
  • Stratified liquids
  • Simulations
  • Turbulent flow
  • Active scalar
  • LATTICE-BOLTZMANN-EQUATION
  • LARGE-EDDY SIMULATIONS
  • FLOW
  • FLUID
  • TURBULENCE
  • AUTOMATA
  • TURBINE

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