Battery thermal management using nanofluid flow and phase change material

Microchannel heat sinks (MCHSs) are frequently employed in electronics and energy systems due to their excellent thermal efficiency and small size. This study presents novel microchannel heat sink (MCHS) designs, a base configuration, and four variants (Cases 1–4), to systematically evaluate how geometric parameters influence their performance evaluation criteria (PEC). Additionally, water-based ternary hybrid nanofluid (W-THNF) is utilized to improve the thermal performance. The results reveal that the base case achieves the poorest surface temperature uniformity (STU), while Case 4 exhibits the best performance. It is found that the average heat transfer coefficient (HTC) and Nusselt number ( Nu ), along with pressure drop (Δ p ), are enhanced with Reynolds number ( Re ), whereas thermal resistance (TR) and PEC are reduced as Re rises. The results reveal that Case 4 delivers optimal PEC, improving the base case by 57.47% ( Re = 600), 49.88% ( Re = 800), 43.77% ( Re = 1000), 38.54% ( Re = 1200), and 34.11% ( Re = 1400).