Open AccessNumerical simulation of a low Prandtl number flow with a four-parameters turbulence model through an explicit algebraic definition of Reynolds stress and turbulent heat flux
Author(s) -
Giacomo Barbi,
Andrea Chierici,
Leonardo Chirco,
Valentina Giovacchini,
Sandro Manservisi,
L Sirotti
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2177/1/012005
Subject(s) - turbulent prandtl number , turbulence , reynolds stress equation model , reynolds stress , prandtl number , turbulence modeling , mechanics , k epsilon turbulence model , reynolds number , k omega turbulence model , physics , statistical physics , classical mechanics , heat transfer , nusselt number
Computational Fluid Dynamics codes usually adopt the Reynolds analogy in order to simulate dynamic and thermal flow fields for ordinary fluids like water and air. On the other hand, in low Prandtl fluids, such as heavy liquid metals like Lead-Bismuth Eutectic (LBE), the time scales of temperature and velocity fields are rather different and therefore similarity hypothesis cannot be used. Furthermore, to properly predict a complex flow field characterized by anisotropic behavior, it is necessary to overcome eddy-viscosity models and move to more advanced turbulence models. In the present work, we propose a nonlinear method for the computation of the Reynolds stress tensor and of the turbulent heat flux. Explicit algebraic models (EAM) and new time scales have been implemented using a logarithmic four parameters turbulence model (i.e. K-Ω-K θ -Ω θ ). This new model is validated through the simulation of plane channel and cylinder flows and results are compared with DNS data.