Combined effects of thermo-diffusion, diffusion-thermo and internal heat generation on the stabilization/destabilization of the flow in a cavity differentially heated and salted

Abstract

Lattice Boltzmann simulations of double-diffusive convection in a rectangular cavity differentially heated and salted are conducted in the presence of internal heat generation and Dufour and Soret effects. The study is performed for an aspect ratio $A=2,$ an external Rayleigh number ${Ra}_E={10}^5,$ a Lewis number $Le=2,$ a buoyancy ratio $N=-1,$ and a Prandtl number $Pr=0.71.$ The study focuses mainly on the effect of Dufour number ($Du=0$ and 0.5) to measure its impact on the ranges of steady/unsteady solutions reported in a previous study for the Soret parameter ranging from −0.5 to 0.5 and internal to external Rayleigh numbers ratio ranging from 0 to 80. Compared to $Du=0,$ the results obtained show that the presence of Dufour mechanism with a positive value leads to a destabilizing effect by widening the ranges of instability observed for the considered values of $Sr.$ The combinations ($Sr, Du$) the most stabilizing/destabilizing are identified and discussed in this study.

Keywords:

• Soret and Dufour effects
• internal heat generation
• multi relaxation time lattice Boltzmann method
• stabilizing and destabilizing effects
• thermosolutal convection

Disclosure statement

No potential conflict of interest was reported by the author(s).