Numerical study of mixed convection heat transfer in lid-driven cavity utilizing nanofluid: Effect of type and model of nanofluid

Abstract

Numerical investigation of the laminar mixed convection in two-dimensional lid driven cavity filled with water-Al2O3, water-Cu or water-TiO2 nanofluids is done in this work. In the present study, the top and bottom horizontal walls are thermally insulated while the vertical walls are kept at constant but different temperatures. The governing equations are given in term of the stream function-vorticity formulation in the non-dimensionalized form and then solved numerically by second-order central difference scheme. The thermal conductivity and effective viscosity of nanofluid have been calculated by Maxwell-Garnett and Brinkman models, respectively. An excellent agreement between the current work and previously published data on the basis of special cases are found. The governing parameters are Rayleigh number 103 ? Ra ? 106 and solid concentration 0 ? ? ?0.2 at constant Reynolds and Prandtl numbers. An increase in mean Nusselt number is found as the volume fraction of nanoparticles increases for the whole range of Rayleigh numbers. In addition, it is found that significant heat transfer enhancement can be obtained by increasing thermal conductivity coefficient of additive particles. At Ra=1.75?105, the Nusselt number increases by about 21% for TiO2-Water, and almost 25% for Al2O3-Water, and finally around 40% for Cu-Water nanofluid. Therefore, the highest values are obtained when using Cu nanoparticles. The result obtained using variable thermal conductivity and variable viscosity models are also compared to the results acquired by the Maxwell-Garnett and the Brinkman model.

A new approach for the analysis of the nanoparticles effects on Cu-water nanofluid mixed convection heat transfer and required power in a lid-driven cavity

“…3 and ∆Τ = T h -T c from this table are substituted into eq. (19) to calculate total vertical wall heat transfer. The results are presented in tab.…”

“…Some researchers have also studied nanofluid mixed convection heat transfer in a cavity with moving walls [11][12][13][14][15][16][17][18][19]. Among them, Tiwari and Kumar Das [15] studied the effects of nanoparticles volume fraction and Richardson number for three different moving conditions of the walls and showed that with the increase of nanoparticles volume fraction average Nusselt number of moving walls increases, and from this result they concluded that heat transfer from the walls increases.…”

Numerical comparison of viscosity models on mixed convection in double lid-driven cavity utilized CuO-water nanofluid

“…Several studies of convective heat transfer in lid-driven cavities filled with nanofluids have been reported in recent years [9][10][11][12][13]. What is prevalent in most of the mentioned numerical study on nanofluid combined convection problems is the use of the Brinkman [14] viscosity model for a nanofluid and hence, predict enhancement of heat transfer because of the presence of nanoparticles.…”

Effects of uncertainties of conductivity models on mixed convection for Al2O3-water nano fluid

“…However, for small Richardson number, the Pak and Cho model shows a reduction in the average Nusselt number in the single-lid driven cavity con guration. Pourmamoud et al [36] presented a numerical study on mixed convection uid ow and heat transfer inside a cavity lled with nano uid. They examined the e ect of type and used model in their investigation.…”