A numerical analysis was performed to study free convection in a stationary laminar regime in a partially heated cube filled with ionanofluid. To numerically solve the dimensionless equations, we applied the finite volume method using the SIMPLEC algorithm for pressure correction. All walls are adiabatic, except for the left and right side walls which are partially heated differently. At the end of this simulation, several results are given in the form of current lines, isotherms, and variations in the Nusselt number. These results are obtained by analyzing the effect of a set of factors such as Rayleigh number, particle volume fraction, cold and source position on the dynamic and thermal fields, and heat transfer. It has been shown that the percentage of nanoparticles and high Rayleigh numbers significantly increase heat transfer by ionanofluid. Two comparisons have been made, between ionic fluid and ionanofluid at isotherms and streamlines, and between nanofluid and ionanofluid at Nusselt number, which show the advantage of using ionanofluid in heat transfer.

This work focuses on the numerical study of natural convection fluid flow and heat transfer of (Cu, Al2O3 and TiO2)-water nanofluids in the annuli of two partially-heated square ducts. The left and right vertical walls of the outer duct have constant but different temperatures Th and Tc respectively, while the inner duct is maintained at the same and opposite temperatures. The ducts top and bottom walls are kept insulated. The governing equations are solved numerically using the finite-volume method. The SIMPLEC algorithm was employed to couple velocity and pressure fields. Using the developed in house code, the effects of pertinent parameters such as the Rayleigh number, volume fraction of nanoparticles and aspect ratio on the fluid flow and heat transfer inside the cavity were investigated. It is observed from the results that the average Nusselt number increases when both the Rayleigh number and the volume fraction of the nanoparticles increase. Moreover, heat transfer in nanofluid with Cu nanoparticles is much better than Al2O3 and TiO2 nanoparticles.

Convective heat transfer using nanofluids play an important role in thermal applications such as heat exchangers, automotive industries, and power generation. In this work, a numerical analysis is conducted to examine the heat transfer of nanofluid in three-dimensional differentially heated cavity. The finite volume method-based SIMPLEC algorithm is used to solve the system of the mass, momentum, and energy transfer governing equations. The left and the right vertical side walls of the cube are maintained at constant temperatures T C and T H , respectively. The remaining walls of the cube are insulated. Effective thermal conductivity and viscosity of the nanofluid are determined using Brinkman and Maxwell models, respectively. Studies are carried out for three types of nanoparticles and volume fractions of nanoparticles ( 0 – 5 % ). The effects of two binary liquid mixtures as a base fluid (propylene glycol-water and ethylene glycol-water) are also examined. Results show an enhancement of 13 % for Al2O3-EG in comparison to pure ethylene glycol in the case of Ra = 10 3 . In addition, heat transfer enhancement was increased with the rise of nanoparticle volume fractions.

The need for freshwater supply in different parts of the world has given great interest to the study of seawater desalination which has led to the development of various innovative techniques in this field. The present numerical study contributes to the improvement of the evaporative desalination operation by introducing nanoparticles into the base fluid. The desalination technique considered in this study consists of a saltwater film falling along the inner wall of a vertical channel heated uniformly by a constant heat flux. The equations governing the flow and the heat and mass transfer associated with the boundary and interface conditions are solved numerically using the finite difference method. We considered two values of salinity, 10 g.kg-1 and 39 g.kg-1 which correspond respectively to brackish water and sea water with different types and volume fractions of nanoparticles in order to study the effect of the combination of these parameters on the enhancement of desalination by evaporation. The results showed that the evaporation process by injecting nanoparticles into salt water improves due to its positive effect on thermophysical properties. In addition, Al2O3 is significantly better for evaporative desalination than TiO2 and copper. Moreover, we can achieve the same heat and mass transfer performance by using 2% alumina instead of 4% TiO2.

A numerical analysis was performed to study the influence of a magnetic field in free convection in a cube full with nanofluid. To solve the equation, we appeal to finite volume method. The SIMPLEC algorithm is used for pressure-velocity coupling. All walls are adiabatic, except for the left and right walls that are heated differently. The effects of the Rayleigh and Hartmann numbers, as well as the volume fraction of nanometric particles were studied. Results are conveyed in the form of isotherms, streamlines, velocity curves and Nusselt numbers. It has been shown that as the percentage of nanoparticles increases and the number of Rayleigh increases, heat transfer improves. Hartman number has considerable influence on hydrodynamic and thermal field.