STUDY OF TURBULENT NATURAL CONVECTION OF A NANOFLUID IN A SOLAR WATER HEATER ENCLOSURE

Abstract

In this research we study the heat transfer by turbulent natural convection of a water-copper nanofluid in a solar water heater enclosure, the heating of enclosure is achieved by the solar collector wall at constant heat flux Q. The left vertical wall of the solar thermal storage tank is maintained at constant cold temperature Tc, the other parts of the enclosure are considered as adiabatic. The volume fractions of the nanoparticles are varied in the range of 0 to 0.20. The permanent forms of two-dimensional Reynolds-Averaged-Navier–Stokes equations and conservation equations of mass and energy are solved by the finite volume method with use of the SIMPLE algorithm for pressure-velocity coupling. The turbulence is modeled by the standard k-ε model. The Rayleigh number Ra is varied in the range of 108 to 1012. The streamlines and the isotherms and the variation of the average Nusselt number at the heated wall are shown for various combinations of the Rayleigh number Ra and different values of volume fraction of the nanoparticles