The onset of Brinkman convection induced by purely internal heating in a rotating porous medium layer saturated by a nanofluid is investigated for rigid-rigid boundary surfaces with two sets of thermal boundary conditions namely, Case (i) - both boundaries isothermal - and Case (ii) - lower insulated and upper isothermal. The zero nanoparticle flux condition under the thermophoretic effects is taken at the boundaries. The model used for nanofluid combines the effects of Brownian motion and thermophoresis, while for porous medium Brinkman model is considered. The effect of rotation parameter, porosity parameter, Darcy number, Lewis number, nanoparticle Rayleigh number, modified diffusivity ratio and modified specific heat increment on the onset of convection is shown graphically and analyzed in detail. It is found that the Lewis number, the nanoparticle Rayleigh number and the modified diffusivity ratio have destabilizing effect on the onset of convection, while modified specific heat increment has no significant effect on the stability of the system. The rotation parameter, the porosity parameter and the Darcy number delay the onset of convection. The system is found to be more stable when both boundaries are isothermal.
Bibliographical noteFunding Information:
This work was supported by the Yonsei University Research Fund of 2014–15. and the Korea Institute of Energy Technology Evaluation and Planning (KETEP, No. 20144030200560 ) grant funded by the Korea government Ministry of Trade, Industry and Energy.
© 2015 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)