Laminar Natural Convection of Non-Newtonian Nanofluids in a Square Enclosure with Differentially Heated Side Walls

Abstract

The present work deals with the laminar natural convection in a square cavity with differentially heated side walls subjected to constant temperatures and filled with homogenous 0,4 wt. % aqueous solution of carboxymethyl cellulose (CMC) based Au, Al 2 O 3 , Cu and TiO 2 nanofluids obeying the Power law rheological model. The governing differential equations have been solved by the standard finite volume method and the hydrodynamic and thermal fields are coupled together using the Boussinesq approximation.The main objective of this study is to investigate the influence of the nanoparticles' volume fraction (0 % ≤ φ ≤ 10 %) on the heat transfer characteristics of CMC based nanofluids over a wide range of nanofluid Rayleigh number (10 3 ≤ Ra nf ≤ 10 6 ). Accurate numerical results are presented in the form of dimensionless temperature and velocity variations, isotherms, mean Nusselt number and heat transfer enhancement. The results indicate clearly that the heat and momentum transfer characteristics are affected only by the nanofluid Rayleigh number, while the type of nanoparticles (i.e. thermo-phyisical properties) and their volume fraction have effect only on the heat transfer enhancement.

Conduction and convection heat transfer characteristics of water-based au nanofluids in a square cavity with differentially heated side walls subjected to constant temperatures

“…compact heat exchangers [8] and cooling systems [9,10], selective laser melting process [11]). Although quite some various different configurations of the enclosure problem are possible [12][13][14][15][16][17][18], one of the most studied cases involves the two-dimensional square enclosure with differentially heated isothermal vertical walls and adiabatic horizontal walls [19,20]. When the vertical walls are insulated to ensure adiabatic conditions and the lower horizontal wall held at the higher temperature then one has the Rayleigh-Bénard configuration [21,22].…”

Simulation of Sheet and Cloud Cavitation with Homogenous Transport Models

“…It should be noted, that, due to the non-uniform grid refinement, this is an iterative procedure, which, in the case of uniform grid refinement (mainly encountered in 2-dimensional numerical analyses of fluid [16,18] and heat [19,20] flow), simplifies to a straightforward numerical accuracy assessment.…”

Laminar Forced Convection Heat Transfer Characteristics from a Heated Cylinder in Water Based Nanofluids

“…Such a procedure is useful and encountered in many numerical studies [25][26][27][28] for applying the Richardson's extrapolation technique which is a method for obtaining a higher-order estimate of the flow value (value at infinite grid) from a series of lower-order discrete values. …”