Heat Transfer Analysis of Aqueous Suspensions of CNTs in Microchannel Radiators

ABSTRACT With advances in technology and the increasing use of nanomaterials, ongoing research is focused on improving the performance of thermal systems. This study investigates the thermal conductance (UA) of a radiator using aqueous suspensions of carbon nanotubes (CNTs), which are among the nanomaterials with the highest heat transfer coefficient. For this purpose, three different nanofluids were prepared, each with varying concentrations of single‐walled carbon nanotubes (SWCNTs) and multi‐walled carbon nanotubes (MWCNTs). The heat transfer performance of three hybrid nanocoolant fluids (NF), namely, NF1 (0.8 wt% MWCNT + 0.4 wt% SWCNT), NF2 (0.4 wt% MWCNT + 0.4 wt% SWCNT), and NF3 (0.4 wt% MWCNT + 0.8 wt% SWCNT), was experimentally examined and compared with water. The results show that CNT suspensions can enhance heat transfer by up to 16.9% compared with the base fluid, and SWCNTs were observed to have better thermophysical qualities than MWCNTs.