Abstract:
In this paper, the problem of unsteady natural convective flow of nanofluids inside a semicircular shaped enclosure using the newly developed nonhomogeneous dynamic model has been investigated numerically. The Galerkin weighted residual finite element technique has been employed to solve the governing nonlinear and coupled dimensionless partial differential equations. The streamlines, the isotherms, and the isoconcentrations are displayed graphically to show the flow and thermal fields as well as concentration levels of nanofluid. The average Nusselt numbers at the heated wall of the enclosure for 16 types of nanofluids are calculated for different flow parameters. Comparisons are made with the numerical as well as the experimental data available in the literature. The results show that nanoparticles uniformly suspend in a base fluid when the particle diameter ranges from 1 to 10 nm. The average Nusselt number increases significantly with the increase of the nanoparticle volume fraction as well as with different shapes of nanoparticles, whereas it decreases remarkably with the increase of nanoparticles diameter. It is noted that -water and -water nanofluids are the best performer to enhance heat transfer rates compared to the other nanofluids considered in the analysis.
Full Text Link: https://doi.org/10.1016/j.tsep.2017.02.001
