ANALISA NUMERIK PENINGKATAN TRANSFER KALOR ALIRAN TURBULEN FLUIDA NANO TiO₂/AIR PADA CIRCULAR MINICHANNEL

Abstract

Conventional heat transfer fluids such as water, ethylene glycol and oil are limited by their poor thermal properties therefore it is needed the advanced heat transfer fluids that be able to improve their thermal performance. Nanofluids is a colloidal dispersion of nano-sized particles which are a breakthrough of thermal system. This numerical study using the multi-phase mixture model method  investigated the convective heat transfer of TiO2/water nanofluids flowing through a circular mini channel with a 1.09 mm diameter and 306 mm length under turbulent flow regime. TiO2 nanoparticles with a diameter of 21 nm were dispersed into water with volume concentrations of 1.0, 2.0, 3.5, and 5.0 vol.%. The Reynolds number was varied from 4000-20,000 and a constant heat flux of 6500 W/m2. The results showed that the addition of nanoparticles and the variation of the Reynolds number increased the convective heat transfer coefficient of TiO2/water nanofluid by 5.18%, 7.4%, 12.4%, and 14.3%, respectively, with increasing in nanoparticles concentrations.