In this paper, the entropy generation (ENT) in two novel micro heatsinks (MHSs) is investigated numerically. The HSs are two types of octagonal ones with circular and rectangular fins. Water/alumina boehmite nanofluid (NF) is used as a cooling fluid for HSs, which enters from the middle of the heatsink (HS) and exits from four side outputs. The Reynolds number (Re) varies from 300 to 1700 and the concentration of nanoparticles (NPs) changes from 0 to 6%. The shapes of NPs include platelet brick, blade, cylinder, and Oblate Spheroid (OS). A heat flux due to the operation of a microprocessor is applied to the bottom of the HSs made of copper. The finite element method is used for the simulations. The variables include pumping power (PP), ENT, ENT due to fluid friction, thermal ENT, temperature gradient contours, etc. The results of this study show that less ENT occurs in the HS with rectangular fins and less PP occurs in the HS with circular ones. Increasing the Re reduces the amount of ENT and increases the PP. The results demonstrate that the addition of NPs with high volume percentages is not suitable in terms of ENT and PP.

本文对两种新型微型散热器 (MHS) 中的熵生成 (ENT) 进行了数值研究。HS 有两种类型的八角形，带有圆形和矩形翅片。水/氧化铝勃姆石纳米流体 (NF) 用作 HSs 的冷却液，它从散热器 (HS) 的中间进入并从四个侧面输出端排出。雷诺数 (Re) 从 300 变化到 1700，纳米粒子 (NP) 的浓度从 0 变化到 6%。NPs 的形状包括片状砖、刀片、圆柱体和扁球体 (OS)。由于微处理器的操作而产生的热通量被施加到由铜制成的 HS 的底部。有限元法用于模拟。变量包括泵送功率 (PP)、ENT、由于流体摩擦引起的 ENT、热 ENT、温度梯度等值线等。这项研究的结果表明，在具有矩形翅片的HS中，ENT较少出现，而在具有圆形翅片的HS中出现的PP较少。增加 Re 会减少 ENT 的量并增加 PP。结果表明，在 ENT 和 PP 方面，添加高体积百分比的 NPs 是不合适的。