Thermodynamic Irreversibility and Exergy Analysis of Jet-Impinged Microchannel Heat Sinks

This study evaluates the thermal-hydraulic and thermodynamic performance of three microchannel heat sink (MCHS) configurations—baseline microchannel heat sink (MCFHS), Microchannel V-profiled heat sink (MCVHS), and Microchannel Jet impinged V-profiled heat sink (MCJVHS)—using water and nanofluids (CuO, ZnO, [Formula: see text]) at flow rates of [Formula: see text]. Numerical predictions, validated against experiments ([Formula: see text] temperature and 3–8% pressure drop deviations), identified geometry as the dominant factor. MCJVHS achieved the highest heat transfer coefficient ([Formula: see text]), the lowest hotspot temperature ([Formula: see text]), and the minimum thermal resistance ([Formula: see text]), reducing resistance by up to 55% and temperature by [Formula: see text] compared to the weakest case. Nanofluids enhanced performance by 5–20%, with CuO and ZnO nearly overlapping and superior to [Formula: see text]. Exergy analysis showed that MCJVHS with CuO/ZnO reduced entropy generation by 25–55% and reached maximum efficiency (25.9%), [Formula: see text] higher than [Formula: see text]. Although high pumping penalties lowered Performance enhancement criteria below unity, MCJVHS with CuO/ZnO at higher flow rates provided the most effective high-heat-flux cooling solution.