ON THE PERFORMANCE OF DIFFERENT RANS BASED MODELS TO DESCRIBE THE TURBULENT FLOW IN AN AGITATED VESSEL USING NON-STRUCTURED GRIDS AND PIV VALIDATION

• Main Authors: Alejandro Alonzo-Garcia, Víctor X. Mendoza-Escamilla, Sergio A. Martinez-Delgadillo, Israel Gonzalez-Neria, Claudia del C. Gutiérrez-Torres, José A. Jiménez-Bernal
• Format: Article
• Language: English
• Published: Brazilian Society of Chemical Engineering
• Series: Brazilian Journal of Chemical Engineering
• Subjects: Agitated tank; Pitched blade turbine, Cut-Cell; RANS; Tetrahedral cells; PIV
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322019000100361&lng=en&tlng=en

ABSTRACT The performances of the Standard κ-ε, RNG, Realizable, κ-ω and RSM turbulence models to describe the behavior of the flow in agitated tank reactors were evaluated. Because most of these tanks have complex geometries, structured meshing schemes are not a practical alternative in engineering. Two particular unstructured meshing schemes composed of either Cartesian Cut-Cell (CC) or Tetrahedral elements were tested in domains larger than 3 million cells. In this work, the blade thickness, which is usually disregarded, was accounted for. The performance of the turbulence models was validated by PIV measurements. A strong dependence on the grid size and the power number was found, with CC grids having good agreement with grids > 3.6 Million. The pumping number was independent of the cell number and the values agree with experimental data. The Realizable model resolved with a tetrahedral grid presented the overall best performance.