Contribution à l’étude numérique de la convection naturelle thermosolutale dans un espace annulaire rempli de nanofluides.

Abstract

The present work is a contribution to the study of thermosolutal magnetohydrodynamic natural convection and entropy generation in a horizontal annular space between two concentric circular cylinders filled with nanofluids and subjected to a uniform vertical magnetic field. The inner wall is maintained at a high temperature and concentration, while the outer wall is kept cold and at a low concentration. Within the scope of the Boussinesq approximation, the governing equations (continuity, momentum, energy and concentration) are numerically solved using the finite volume method and applying the SIMPLE algorithm for Pressure-Velocity coupling, based on the commercial software FLUENT. The study focuses on the combined effect of control parameters expressed as dimensionless numbers, such as Rayleigh number (102≤Ra≤105), buoyancy ratio (-4≤N≤4), Lewis number (0.01≤Le≤10), Hartmann number (0≤Ha≤50) and nanoparticles volume fraction (ϕ=0, 0.02 and 0.04) for two conductive nanofluids. The acquired results are presented as streamlines, isotherms, isoconcentrations and isentropics, along with profiles of heat and mass transfer rates, all discussed in detail in accordance with the control parameters. Furthermore, a thermal and mass performance criterion, representing the interaction between irreversibility and heat and mass transfer within the system, is also introduced and discussed.