Flow and heat transfer characteristics in laminar flow through random rough microchannels
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摘要: 对水在随机粗糙微通道中的单相液体层流流动和传热特性进行了数值模拟研究.构造了两条随机粗糙微通道和一条规则粗糙微通道,计算Re范围100~2 000.结果发现:3条计算通道的Poiseuille数(Po)和Nusselt数(Nu)均大于光滑通道的分析解,并随Re缓慢增大.规则粗糙微通道中的Po和Nu都明显大于随机粗糙微通道的结果.最后,认为粗糙度对当地Nusselt数的影响,是粗糙元引起的流速变化与协同角变化共同决定的.Abstract: The flow and heat transfer characteristics of water in laminar flow through random roughness microchannels were investigated numerically. Two random rough microchannels were modeled by a simple method. And another microchannel was designed with periodically distributed roughness for compare. The Re range was 100~2 000. Results show that the Poiseuille number (Po) and the Nusselt number (Nu) in three rough microchannels are all larger than that in smooth channels significantly, and increase slightly with Re. In addition, Po and Nu in random roughness microchannels are all smaller than that in regular roughness microchannel. It could be concluded that the effect of roughness on local Nusselt number is attributed to the variation of velocity and the intersection angle between velocity and temperature gradient together.
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Key words:
- microchannel heat sink /
- liquid cooling /
- heat transfer enhancement /
- random roughness
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