Natural Convection of Nanofluids in a Square Enclosure with a Protruding Heater

Abstract EN

This paper reports a numerical study on natural convection from a protruding heater located at the bottom of a square cavity filled with a copper-water nanofluid.

The vertical walls of the cavity are cooled isothermally; the horizontal ones are adiabatic, and the heater is attached to the bottom wall.

The heat source is assumed either to be isothermal or to have a constant heat flux.

The effective viscosity and thermal conductivity of the nanofluid are modeled according to Brinkman and Patel, respectively.

Numerical solutions of the full-governing equations, based on the lattice Boltzmann method, are obtained for a wide range of the governing parameters: the Rayleigh number, Ra; the Prandtl number,Pr; the geometrical parameters specifying the heater; the volume fraction of nanoparticles, Φ.

For a particular geometry, it has been found that, for a given Ra, heat transfer is enhanced with increasing Φ, independently of the thermal boundary condition applied on the heater.