Flow and heat transfer in comby fractal microchannel network

Enlightened by the fractal character of natural honeycomb, a novel biomimetic comby fractal microchannel (BCFM) network was designed and fabricated by micromachining. Optimized parameters were presented by the use of the microchannel heat sinks porous medium model. Provided the channel cross-section, convection heat transfer coefficient, and temperature difference were same, the heat removal capacity of BCFM was over 5 times as that of traditional parallel microchannels. Given the total quantity of heat transfer, the pump power required in BCFM network was as low as one tenth of that in traditional parallel microchannels, neglecting the bifurcate and confluent flow effects. Experimental results of deionized water laminar convective heat transfer showed that, the BCFM network had higher mean Nusselt number and lower pressure drop than traditional parallel microchannels. The BCFM network could be used not only in electronics cooling, but also in micro structure designs, e.g., polar plate of micro PEM, micro mixer, and micro chemical reactor.