Experimental evaluation of heat transfer characteristics of silica nanofluid

Abstract

The laminar convective heat transfer characteristics were investigated for silica nanofluid. An experimental loop was built to obtain heat transfer coefficients for single-phase nanofluids in a circular conduit in laminar flow regime. Thermal conductivity and viscosity measurements were conducted on the silica nanofluid to determine the thermophysical properties needed for analysis. Qualitative tests showed that the silica nanofluid was a stable colloidal suspension under the temperature range expected in the heated flow loop up to 80°C. Experiments were performed in the flow loop for the silica nanofluid at 0.2 Vol.%, 1 Vol.%, and 5 Vol.% concentrations. It was found that the heat transfer coefficient increased only slightly, but the heat transfer increase is within the experimental uncertainty of ±10%. The experiment results were in agreement with correlations using the as-measured thermal conductivity and viscosity of the nanofluid. It is concluded that silica nanofluid tested in this study showed no abnormal heat transfer enhancement in the laminar flow regime.