Ma Hao, Duan Zhipeng, Su Liangbin, Ning Xiaoru, Bai Jiao, Lv Xianghui
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
Entropy (Basel). 2019 Jul 28;21(8):739. doi: 10.3390/e21080739.
The flow in channels of microdevices is usually in the developing regime. Three-dimensional laminar flow characteristics of a nanofluid in microchannel plate fin heat sinks are investigated numerically in this paper. Deionized water and AlO-water nanofluid are employed as the cooling fluid in our work. The effects of the Reynolds number (100 < < 1000), channel aspect ratio (0 < < 1), and nanoparticle volume fraction (0.5% < < 5%) on pressure drop and entropy generation in microchannel plate fin heat sinks are examined in detail. Herein, the general expression of the entropy generation rate considering entrance effects is developed. The results revealed that the frictional entropy generation and pressure drop increase as nanoparticle volume fraction and Reynolds number increase, while decrease as the channel aspect ratio increases. When the nanoparticle volume fraction increases from 0 to 3% at = 500, the pressure drop of microchannel plate fin heat sinks with = 0.5 increases by 9%. It is demonstrated that the effect of the entrance region is crucial for evaluating the performance of microchannel plate fin heat sinks. The study may shed some light on the design and optimization of microchannel heat sinks.
微器件通道内的流动通常处于发展阶段。本文对微通道板翅式散热器中纳米流体的三维层流特性进行了数值研究。去离子水和氧化铝 - 水纳米流体被用作我们工作中的冷却流体。详细研究了雷诺数（100 < Re < 1000）、通道纵横比（0 < AR < 1）和纳米颗粒体积分数（0.5% < φ < 5%）对微通道板翅式散热器中压降和熵产生的影响。在此，推导了考虑入口效应的熵产生率的通用表达式。结果表明，摩擦熵产生和压降随着纳米颗粒体积分数和雷诺数的增加而增加，随着通道纵横比的增加而减小。当在Re = 500时纳米颗粒体积分数从0增加到3%时，AR = 0.5的微通道板翅式散热器的压降增加了9%。结果表明入口区域的影响对于评估微通道板翅式散热器的性能至关重要。该研究可能为微通道散热器的设计和优化提供一些启示。
