Thermo-Hydraulic and Flow Distribution Characteristics of Bionic Fractal Y-Shaped Bifurcation Microchannel Heat Sink

Limited by their intrinsic structures, traditional microchannel heat sinks easily cause flow maldistribution among microchannels. To achieve uniform flow distribution and improve thermo-hydraulic performance, a Y-shaped bifurcation (YSB) structure is proposed based on the biomimetic fractal theory. By integrating this YSB structure with straight microchannel arrays, a Y-shaped bifurcation straight microchannel heat sink (YSB-SMHS) is put forward. Four key parameters are chosen for simulation: fractal angle α, fractal stage number s, the number of microchannels nch and inlet flow velocity vin. The variation rules of hydraulic performance (flow-uniformity coefficient β, pressure drop Δp, pumping-power consumption Ω), thermal performance (average heat-transfer coefficient have, thermal resistance R) and comprehensive thermo-hydraulic performance evaluation criterion PEC are quantitatively analyzed. Finally, a smooth-plate heat sink (SPHS) is set as the baseline for comparison. The results show that β increases with the increase in α and vin, but decreases with the increase in s and nch. For hydraulic performance, both Δp and Ω grow gradually as α, s, nch and vin increase. For thermal performance, have increases with the increase in s, nch and vin and first increases and then decreases with the increase in α; R shows the opposite trend, decreasing with the increase in s, nch and vin and first decreasing and then increasing with the increase in α. PEC first increases and then decreases with the increase in α, s and vin and keeps increasing with the increase in nch. Compared with SPHS, the YSB-SMHS achieves a 167.42% improvement in have and 17.25% improvement in PEC, and thermal resistance is reduced by 49.73%. Overall, improvement in the thermal performance of YSB-SMHS outweighs the increment in pumping-power consumption. The proposed YSB-SMHS provides structural design guidance for high-efficiency liquid-cooling heat sinks.