EXPERIMENTAL HEAT TRANSFER STUDY OF ALUMINUM OXIDE NANOFLUID FLOW IN TUBES FOR LAMINAR THERMAL ENTRY REGION

Experiments have been conducted to characterize the viscosity, thermal conductivity, and Nusselt number of aluminum oxide (Al2O3) nanoparticle dispersions at 6% vol. in liquid water flowing through circular tubes. Rheological characterization of the Al2O3-water nanofluid has shown that it exhibits a Newtonian fluid behavior for the shear rate range of 6 to 122 s(-1) between 6 and 75 degrees C. Measurements of the nanofluid thermal conductivity have been performed for temperatures between 6 and 55 degrees C, and were found to be 8 to 17% higher than that of water. Heat transfer measurements for nanofluid flow in laminar thermal entry region have been conducted for three different test sections with LID of 155, 194, and 299. The experimental results within this study indicate that the heat transfer characteristics of the Al2O3-water nanofluid flow are largely in agreement with conventional theory for single-phase flow.