Experimental Investigation of Nanofluid-Based Heat Transfer Enhancement in a Triangular Microchannel Heat Exchanger

Abstract

Microchannel heat exchangers (MCHEs) play a critical role in miniature-scale thermal management systems, particularly in cooling applications such as microelectronics, refrigeration, biomedical devices, and electric vehicle battery systems, where efficient heat removal is essential. This study experimentally investigates the influence of channel geometry and nanofluid concentration on the thermal and hydraulic performance of MCHEs featuring triangular microchannels. Three types of nanofluids, CuO, Al₂O₃, and carbon nanotubes (CNT), were examined at concentrations of 0.01%, 0.03%, and 0.05% under laminar flow conditions (Re = 100–500). The results revealed that increasing nanoparticle concentration significantly enhanced heat transfer for all nanofluids. At 0.05% concentration and Re = 500, the triangular microchannel achieved Nusselt number enhancements of 24.55% for CuO, 28.65% for Al₂O₃, and 43.06% for CNT, accompanied by pressure drop increases of 22.03% (CuO), 27.46% (Al₂O₃), and 249.49% (CNT), respectively. Overall, CNT-based nanofluids in triangular microchannels exhibited the highest thermal performance, demonstrating the strong synergistic effect of geometry and nanoparticle type on MCHE efficiency.