Examining of nanofluid natural convection heat transfer in a Gamma-shaped enclosure including a rectangular hot obstacle using the lattice Boltzmann method

摘要

The present investigation is set to evaluate the nanofluid thermogravitational convection within a Gamma-shaped enclosure that consists of a local heater by the lattice Boltzmann method (LBM). In this study the Rayleigh number (10(3)-10(6)), cavity's aspect ratio (0.2-0.6), nanofluid solid volume fraction (0-0.05), height and location of the heater on the liquid circulation and heat transfer parameters examined with respect to the Gamma-shaped enclosure. The study is innovated in nature as it combines the nanofluid and the hot obstacle within the same Gamma-shaped enclosure. The results of the conducted analyses indicate that the mean Nusselt number would increase as the Rayleigh number and nanoparticles concentration increased. This resulted in a reduction in the enclosure aspect ratio and increment in the obstacle's height. The thermal transmission rate is highly affected by the obstacle's position. Also, it is found that, when the heater is situated on the left border, the mean Nusselt number would be maximized. (C) 2019 Elsevier B.V. All rights reserved.