Analysis of the Temporal Evolution of Thermal Conductivity in Alumina-Water Nanofluid

Abstract

In this effort, the temporal behavior of a manufactured alumina (Al2O3) – water nanofluid was evaluated. Measurements of nanofluid effective thermal conductivity were acquired over an extended time period. Analysis of acquired measurements elucidated the degradation of nanofluid effective thermal conductivity with respect to time. Specifically, the measured thermal conductivity of nanofluid decreased from an initial value of 0.6365 W/m-ºC to a final value of 0.6130 W/m-ºC over a period of several months. This corresponded to a change in the thermal conductivity enhancement realized due to the suspension of nanoparticles in fluid from an initial value of 11.2% to a final value of 7.2%. Temporal evolution of the nanofluid’s thermal conductivity is attributed to changes in the stability of the colloidal suspension. Future work is planned to investigate the physical mechanisms controlling this phenomenon.