An Experimental Study of Natural Convection of Nanofluid in a Rectangular Cavity

Abstract

The concept of nanofluids refers to a new kind of heat transport fluids by suspending nano scaled metallic or nonmetallic particles in base fluids. The experimental results showed that the suspended nanoparticles increased convective heat transfer coefficient of the fluid. The properties and behavior of a nanofluid depend on a number of parameters including the properties of the base liquid and the dispersed phases, particle concentration, particle size and morphology, as well as the presence of dispersants and/or surfactants. From a macroscopic view, the properties of homogenous nanofluids that affect the heat transfer behavior include heat capacity, thermal conductivity, density and viscosity. Natural convective heat transfer is affected by a number of processes in parallel and/or series, including unsteady state heat conduction through the heating wall, conduction within the boundary layer and its development, as well as convection due to the variation of liquid density and the density difference between the nanoparticles and the liquid. In this experimental study, natural heat transfer of Nanofluid will be investigated. Nanofluid with different volume percentage will be put between walls of the cavity, and the natural heat transfer will be observed. As a result of the experimental readings, Nusselt number as a function of Rayleigh number (i.e. Nu= c Raⁿ) will be obtained.