Effect of microtube length on heat transfer enhancement of an water/Al2O3 nanofluid at high Reynolds numbers

Water-Al2O3 nanofluids with different volume fractions ranged from 1% to 4% were used. This investigation covers Reynolds number in the range of 104-105. The results have shown that convective heat transfer coefficient for a nanofluid is enhanced than that of the base liquid. Wall heat transfer flux is increasing with the particle volume concentration and Reynolds number. Moreover, a study on microtube length influence on heat transfer was attempted and few correlations were established.