Numerical and experimental investigation of heat transfer enhancement in a microtube using nanofluids

Forced convective laminar flow of different types of nanofluids such as Al2O3 and SiO2, with a nanoparticle size of 30 nm, and different volume fractions ranging from 0.5% to 1% using water as base fluids were investigated numerically and experimentally. This investigation covers the Reynolds number in the range of 90 to 160. The results have shown that SiO2-water nanofluid has the highest Nusselt number, followed by Al2O3-water, and lastly pure water. The maximum heat transfer enhancement was about 22% when using the nanofluids and the numerical and experimental results agree well with the conventional theory. (C) 2014 Elsevier Ltd. All rights reserved.