Abstract: 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.

Key words: 仿生, 微通道, 分形网络, 流动, 传热

摘要： 受自然界中蜂巢结构分形特征的启发，设计和加工了仿蜂巢分形微管道网络，并进行了参数优化.在微管道截面参数、对流传热系数、传热温差均相同的条件下，对流动与换热特性的理论分析表明：加热底面积相同时，仿蜂巢分形微管道网络所能带走的热量可达平行阵列微管道网络的5倍以上;不计分流、合流效应，总换热量一定时，仿蜂巢分形微管道网络所需的泵送功率约为传统平行阵列微管道网络的1/10.恒定热流条件下的去离子水层流对流换热实验也证明：仿蜂巢分形微管道网络比传统的平行阵列微管道网络具有更高的Nusselt数和更低的流动压降.这种分形微管道网络除用于电子器件冷却，还可用于微燃料电池极板、微混合器、微生化反应器等微化工系统结构设计.

关键词: 仿生, 微通道, 分形网络, 流动, 传热