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Thermal instability of a Rivlin-Ericksen nanofluid saturated by a Darcy-Brinkman porous medium: a more realistic model

Rana G. C., Chand R., Sharma V.

Engineering Transactions

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2016

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Vol. 64, iss. 3

271--286

EN

In this paper, we study thermal instability in a horizontal layer of Rivlin-Ericksen elasticoviscous nanofluid in porous medium. Brinkman model is used as a porous medium and RivlinEricksen fluid model is used to describe the rheological behavior of nanofluid. In the earlier model (Chand and Rana [18]), we constrained both temperature and nanoparticle volume fractions at the boundaries of Rivlin-Ericksen nanofluid layer. In this paper, we assume that the value of temperature can be constrained on the boundaries, while the nanoparticle flux is zero on the boundaries. The considered boundary condition neutralizes the possibility of oscillatory convection due to the absence of two opposing forces, and only stationary convection occurs, in which Rivlin-Ericksen elastico-viscous nanofluid behaves like an ordinary nanofluid. The effects of Lewis number, medium porosity, modified diffusivity ratio, Darcy-Brinkman number and concentration Rayleigh number in stationary convection are discussed analytically and numerically. The results of this study are in good agreement with the results published earlier.

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Effect of the magnetic field and suspended particles on thermosolutal instability of a rotating Rivlin-Ericksen fluid with varying gravity field in a porous medium

Singh V., Dixit S.

International Journal of Applied Mechanics and Engineering

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2012

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Vol. 17, no. 2

559-570

EN

In the paper we consider thermal instability of a rotating Rivlin-Ericksen viscoelastic fluid in the presence of suspended particles in a porous medium, the effect of magnetic field with varying gravity field are also studied. It is found that for stationary convection, a Rivlin-Ericksen fluid behaves like an ordinary Newtonian fluid while the magnetic field has both stabilizing and destabilizing effect on the system. Other different aspects affecting stability are also considered.

3

Effect of time - periodic modulation on convection in solutions of dilute polymeric liquids in a porous medium

Siddheshwar P. G., Srikrishna C. V.

International Journal of Applied Mechanics and Engineering

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2008

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Vol. 13, no 3

753-780

EN

The thermal instability in a layer of dilute polymeric liquid when boundaries are subjected to imposed time - periodic boundary temperatures (ITBT) is investigated. The critical Rayleigh and wave numbers for small amplitudes of ITBT are obtained for synchronous and asynchronous cases by following the Venezian approach. For small frequency modulation the Floquet theory adopted by Rosenblat and Herbert is employed and the periodicity and amplitude criterion is determined for thermal stability. The qualitative effects of various governing parameters on convective system are discussed. The problem has applications in solidification process of polymeric solutions and melts.