Investigations into flow and heat transfer performance of bifurcated-divergent micro-channels

• Hydrothermal performance of bifurcated-divergent micro-channel is studied. • Effects of bifurcation plate width and height on hydrothermal performance are studied. • Bifurcated-divergent design reduces flow resistance and enhances heat transfer sharply. • Bottom wall temperature can be reduced by 7.1 K in bifurcated-divergent micro-channel. • Pressure drop in bifurcated-divergent design is lower than parallel design by 63.7 %. The flow and heat transfer characteristics of the bifurcated-divergent micro-channels were investigated through numerical simulations. The average heat transfer coefficients ( h ave ), average bottom wall temperatures ( T w,ave ), and pressure drop penalties (Δ P ) in the baseline bifurcated-divergent micro-channel (BBDMC) were obtained and compared with those in the parallel (PMC) and divergent (DMC) micro-channels over a Reynolds number ( Re ) range of 300–1100. The performance index ( PI ) and entropy generation ( S ) were employed to evaluate the overall flow and heat transfer performance of the micro-channels. Additionally, the effects of the width and height of the bifurcation plate on the flow and heat transfer performance of the bifurcated-divergent micro-channels were systematically analyzed. The results show that the bifurcation plate disrupts the thermal boundary layer within the micro-channel and promotes fluid mixing, thereby significantly enhancing the heat transfer performance of the bifurcated-divergent micro-channel. Meanwhile, the divergent structure improves the flow performance of the bifurcated-divergent micro-channel by expanding the flow area. The PI values for the bifurcated-divergent micro-channels consistently exceed 1.0 under all operating conditions, indicating superior overall performance compared to the parallel micro-channel. The results also reveal that increasing the width of the bifurcation plate enhances the heat transfer performance but deteriorates the flow performance of the bifurcated-divergent micro-channel. Implementing a bifurcation plate with a larger leading edge and a smaller trailing edge is beneficial for improving the flow and heat transfer performance of the bifurcated-divergent micro-channels. A moderate reduction in the height of the bifurcation plate enhances the overall performance of the bifurcated-divergent micro-channel. The bifurcated-divergent micro-channels achieve a maximum reduction of 7.1 K in the average bottom wall temperature compared to the parallel micro-channel. The numerical results demonstrate that the bifurcated-divergent structures significantly reduce the flow resistance while enhancing the heat transfer performance, thereby providing both a theoretical foundation and practical guidance for the design of high-performance micro-channels.