Thermosolutal convection in a horizontal nanofluid layer: Introduction of oscillatory motions

Micro and Nano Syst Lett

2020

Self Cite

The extraordinary enhancement in heat transfer efficiency of nanofluids at extremely low volume fractions has attracted a lot of attention in identifying the governing mechanisms. The nanoscale effects, Brownian motion (random motion of particles inside the base fluid) and thermophoresis (diffusion of particles due to temperature gradient) are found to be important slip mechanisms in nanofluids. Based on these findings, a set of partial differential equations for conservation laws for nanofluids was formed. Since then, a large number of mathematical studies on convective heat transfer in nanofluids became feasible. The present paper summarizes the studies pertaining to instability of a horizontal nanofluid layer under the impact of various parameters such as rotation, magnetic field, Hall currents and LTNE effects in both porous and non-porous medium. Initially, investigations were made using the model considering fixed initial and boundary conditions on the layer, gradually the model was revised in the light of more practical boundary conditions and recently it has been modified to get new and more interesting results. The exhaustive analysis of instability problems is presented in the paper and prospects for future research are also identified.

Section: Thermosolutal Instabilitymentioning

confidence: 99%

Rayleigh–Bénard instability in nanofluids: a comprehensive review

Ahuja¹,

Micro and Nano Syst Lett

2020

Self Cite

“…The thermosolutal and thermal instability problems for Walters` (model B`) with elastico-viscous fluid in a porous medium studied by Rana and Sharma [9]. Gupta et al studied the effect of horizontal magnetic field on nanofluid convection [5]. Pundir et al studied on the onset of thermosolutal convection of an elastico-viscous nanofluid in porous medium in presence of magnetic field [8].…”

Section: Introductionmentioning

confidence: 99%

Effect of Rotation on Thermosolutal Convection in Visco-elastic Nanofluid with Porous Medium

Pundir¹,

Kumar²,

Pundir³

2021

JUSST

In this paper, we studied the rotation effect on the thermosolutal convection in visco-elastic nanofluid in the presence of porous medium using Walters` (model B`). To solve the conservation equation, we used the normal mode technique and Galerkin weighted residual method. For stationary convection, the onset criterion derived analytically and experiential that visco-elastic nanofluid behaves as a regular Newtonian nanofluid. The effect of rotation, thermo-nanofluid Lewis number, thermosolutal Lewis number and solutal Rayleigh number analyze analytically and graphically.

“…Their work is extended by Gupta et al (2014) and Yadav et al (2012) by investigating the convection in a binary nanofluid layer for alumina-water nanofluid. The influence of magnetic field and rotation on double diffusive nanofluid convection was studied in non-porous and porous medium by Gupta et al (2015) and Sharma et al (2016) respectively, using different nanofluid parameter values.…”

Section: Introductionmentioning

confidence: 99%

Modified Model for Binary Nanofluid Convection with Initial Constant Nanoparticle Volume Fraction

Gupta

2017

JAFM

A modified model considering effects of density as well as conductivity of nanoparticles is used to investigate the instability of a binary nanofluid layer. It is assumed that volume fraction of nanoparticles is small and remains constant at the initial state which leads to very interesting and useful results. The perturbed equations so found are analyzed using normal modes and weighted residual method. It is found that oscillatory motions are not possible and instability is invariably through stationary mode. After solving the problem analytically, numerical solutions are found for metallic (aluminium, copper, silver, iron) and non-metallic (alumina, silica, titanium oxide, copper oxide) nanoparticles using the software Mathematica. The effects of size of nanoparticles, difference in solute concentration, volume fraction of nanoparticles, difference in temperature, conductivity and density of nanoparticles are studied on the onset of convection. The increase in density of nanoparticles destabilizes the fluid layer system where as increase in conductivity stabilizes the same. Lower density of aluminium makes it more stable than other nanoparticles in spite of having its lower conductivity. Metals are largely more stable than non-metals.