Numerical study using a double grid to model the effect of the grooves of a vertical wall in a heated cavity on the natural convection of a nanofluid

Abstract

In this work we study numerically the natural convection of a carbon-based nanofluid (water + C60) in a differentially heated square cavity. One of the vertical walls of the cavity is grooved and maintained at a high temperature. The purpose of this work is to compare the effect of the macrostructural aspect of the grooves and the effect of the addition of fullerene nanoparticles (C60) to pure water on the heat exchange by natural convection in this type of geometry. To better quantify the convective heat exchange numerically near the grooves we used a refined grid with two non-conforming blocks at the hot wall level. The governing equations were discretized by the finite volume method using a power law scheme which offers a good stability characteristic in this type of flow. A numerical code was designed and produced in this context to use numerical simulation as an investigative tool. The results are represented in the form of streamlines and isothermal fields. The variation in the mean Nusselt number of the cold wall to the right of the cavity is calculated as a function of the volume fractions of the nanoparticles (0???0.06) for different numbers and sizes of the grooves and for different Rayleigh numbers (103 ? Ra ? 106).