Publication detail

CFD analysis of free surface vortex shape in an unbaffled stirred tank

ILLÍK, J. ŠTIGLER, J.

English title

CFD analysis of free surface vortex shape in an unbaffled stirred tank

Type

article in a collection out of WoS and Scopus

Language

en

Original abstract

Stirred tanks are widely used in the chemical industry. There is plentiful research on the fluid flow characteristics within such vessels, mainly aimed at mixing optimization. This work focuses on the shape of the free surface formed into a vortex due to centrifugal effects. The two-phase simulation is performed with the Volume of Fluid (VOF) method and solely uses the Reynolds Stress Model (RSM) turbulence model. The accuracy of two RSM submodels is evaluated. The computational grid is stationary, and the rotation of the impeller is simulated using the Multiple Reference Frame (MRF) method. The calculation process is compared to the previous work, where also k-e turbulence model had to be used before switching to the RSM model. Further evaluation of the vortex shape is conducted on geometry without the impeller. The method of fitting the free surface with a curve based on the Cauchy probability density function is presented. The tangential velocity profile can be derived from the fitted curve – mainly for the deep vortex since the accuracy is limited.

English abstract

Stirred tanks are widely used in the chemical industry. There is plentiful research on the fluid flow characteristics within such vessels, mainly aimed at mixing optimization. This work focuses on the shape of the free surface formed into a vortex due to centrifugal effects. The two-phase simulation is performed with the Volume of Fluid (VOF) method and solely uses the Reynolds Stress Model (RSM) turbulence model. The accuracy of two RSM submodels is evaluated. The computational grid is stationary, and the rotation of the impeller is simulated using the Multiple Reference Frame (MRF) method. The calculation process is compared to the previous work, where also k-e turbulence model had to be used before switching to the RSM model. Further evaluation of the vortex shape is conducted on geometry without the impeller. The method of fitting the free surface with a curve based on the Cauchy probability density function is presented. The tangential velocity profile can be derived from the fitted curve – mainly for the deep vortex since the accuracy is limited.

Keywords in English

Stirred tank, Multiphase flow, Reynolds Stress Model, Vortex shape, Cauchy distribution

Released

09.05.2022

Publisher

Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences

Location

Prague

ISBN

978-80-86246-48-2

ISSN

1805-8248

Book

Engineering Mechanics 2022

Edition number

1

Pages from–to

165–168

Pages count

4

BIBTEX


@inproceedings{BUT182493,
  author="Jakub {Illík} and Jaroslav {Štigler},
  title="CFD analysis of free surface vortex shape in an unbaffled stirred tank",
  booktitle="Engineering Mechanics 2022",
  year="2022",
  month="May",
  pages="165--168",
  publisher="Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences",
  address="Prague",
  isbn="978-80-86246-48-2",
  issn="1805-8248"
}