Numerical study of heat transfer and entropy generation in ribbed microchannel with nanofluid and multiple jet impingement

Due to the high miniaturization of electronic devices, there is an urgent need to eliminate high heat flux in electronic devices and improve their heat transfer characteristics. This article simulated the single-phase flow to study the effects of five different arrangements of column ribs and different volume concentration (1 %–5%) of nanofluids on the convective heat transfer coefficient, pressure drop, and the irreversibility of flow heat transfer in ribbed microchannel heat sinks with multiple jets impingement (MJI) within the Re range of 200–1000. The working coolants is deionized water and water - Al₂O₃ nanofluid. Different important parameters, such as the characteristic of heat transfer and flow, Performance Evaluation Criterion (PEC), and entropy generation are investigated. The results indicated that MJI III can effectively improve the convective heat transfer coefficient while the increase in pressure drop is not obvious. The PEC of MJI III is 1.408 at Re = 600, which is much higher than the other MJIs. Additionally, the cooling performance and irreversibility of water-Al₂O₃ nanofluid are superior to those of deionized water within the research scope. With the concentration, the irreversibility of flow and heat transfer of water-Al₂O₃ nanofluid increasing increases. The data shows that, the overall performance is optimal when $\phi$ = 1 %, and its highest PEC is 1.75 at Re = 400.