https://doi.org/10.1140/epjp/s13360-023-03717-8
Regular Article
Onset of LTNE anisotropic porous convection: effect of asymmetric temperature boundary conditions
1
Department of Mathematics, School of Applied Sciences, REVA University, 560064, Bengaluru, India
2
Department of Mathematics, Dr. G. Shankar Government Women’s First Grade College and Post Graduate Study Centre, 576101, Ajjarakadu, Udupi, India
3
Department of Mathematics, Government First Grade College and Centre for PG Studies, 576106, Thenkanidiyur, India
4
Department of Mathematics, Bangalore University, 560 056, Bengaluru, India
Received:
5
October
2022
Accepted:
18
January
2023
Published online:
31
January
2023
The onset of buoyancy-driven convection in a fluid-saturated anisotropic porous layer is studied by employing a local thermal non-equilibrium (LTNE) model. The porous layer is assumed to be bounded by impermeable boundaries with isoflux and isothermal conditions prescribed at the lower and upper boundaries, respectively. The anisotropy in permeability as well as fluid and solid thermal conductivities is considered. The linear instability analysis has been performed, and the eigenvalue problem is constituted using the procedure of normal mode analysis. The threshold values of the Darcy–Rayleigh number and the wave number for the onset of convection are extracted numerically using the shooting method. Increase in the mechanical anisotropy parameter and decrease in the thermal anisotropy parameters, scaled inter-phase heat transfer coefficient and the ratio of porosity-modified conductivities encourage a destabilizing influence on the onset of convection. For lower isoflux and upper isothermal boundaries case, small temperature differences are found to be sufficient to trigger the convective instability when compared to both boundaries isothermal.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
