Lattice Boltzmann simulation of nanofluid natural convection heat transfer in a channel with a sinusoidal obstacle

Abstract

The aim of this work is to conduct numerical study of fluid flow and natural convection heat transfer by utilizing the nanofluid in a two-dimensional horizontal channel consisting of a sinusoidal obstacle by lattice Boltzmann method (LBM). The fluid in the channel is a water-based nanofluid containing Cuo nanoparticles. Thermal conductivity and nanofluid’s viscosity are calculated by Patel and Brinkman models, respectively. A wide range of parameters such as the Reynolds number ([Formula: see text]–400) and the solid volume fraction ranging ([Formula: see text]–0.05) at different non-dimensional amplitude of the wavy wall of the sinusoidal obstacle ([Formula: see text]–20) on the streamlines and temperature contours are investigated in the present study. In addition, the local and average Nusselt numbers are illustrated on lower wall of the channel. The sensitivity to the resolution and representation of the sinusoidal obstacle’s shape on flow field and heat transfer by LBM simulations are the main interest and innovation of this study. The results showed that increasing the solid volume fraction [Formula: see text] and Reynolds number Re leads to increase the average Nusselt numbers. The maximum average Nusselt number occurs when the Reynolds number and solid volume fraction are maximum and amplitude of the wavy wall is minimum. Also, by decreasing the [Formula: see text], the vortex shedding forms up at higher Reynolds number in the wake region downstream of the obstacle.