Exploration of newer geometrical structures for microsinks stems from the desire to achieve better cooling at a lower pressure drop for more compact electronic devices. In this study, a three-dimensional conjugate heat transfer analysis is performed for a novel microchannel heat sink (MCHS) with disruptive structures in an otherwise rectangular channel. Each of these structural units has a pair of triangular cavities (TCs) on the opposite side walls and one in between the rib positioned symmetrically about the vertical mid-plane. Different units with diamond rib, rectangular rib (RR), backward triangular rib (BTR), and forward triangular rib (FTR) are analyzed. A notable finding of this work is identifying a rib as a disruption leading to thinning of the boundary layer on the side walls in the channel behind the rib. Another important contribution of a rib in both TC-RR and TC-BTR units is shown to promote chaotic advection due to having a longitudinal downstream vortex in each quadrant. The benefit of the lowest wall temperature is evident from the predicted results. Simple thermodynamic models are developed to establish that the minimization of entropy generation number (EGN) leads to the lowest temperature of the channel material for removing a given heat flux by the MCHS, and the maximization of the thermal performance (TP) implies achievement of the lowest pumping power. The corresponding numerical results are exploited for identifying the geometrical parameters over Reynolds number ranging from 197 to 595 that maximize the TP and closely minimize the EGN. The TC-FTR configuration is seen to yield the highest TP of about 1.78 at an intermediate value of Re around 400 along with low EGN of nearly 0.45. Results show that a microchannel with TC-BTR combination yields the highest heat transfer rate with a maximum pressure drop penalty leading to its poor TP. Thus, TC-RR turns out to be the choice in case a low wall temperature happens to be a critical requirement. A small sacrifice in it makes TC-FTR the choice for having the highest TP leading to a compact design.

中文翻译：

---

通过评估热性能和熵生成数来识别具有三角形腔和不同肋结构的改进微通道配置

对微型散热器的新型几何结构的探索源于对更紧凑的电子设备以更低的压降实现更好的冷却的愿望。在这项研究中，对在其他矩形通道中具有破坏性结构的新型微通道散热器 (MCHS) 进行了三维共轭传热分析。这些结构单元中的每一个都在相对的侧壁上有一对三角形腔 (TC)，在肋之间有一个，位于关于垂直中平面对称的位置。分析了具有菱形肋、矩形肋 (RR)、后三角肋 (BTR) 和前三角肋 (FTR) 的不同单元。这项工作的一个显着发现是将肋识别为导致肋后面通道侧壁上边界层变薄的破坏。TC-RR 和 TC-BTR 装置中肋的另一个重要贡献显示，由于每个象限中都有纵向下游涡流，因此可以促进混沌平流。从预测结果中可以明显看出最低壁温的好处。开发了简单的热力学模型来确定熵生成数 (EGN) 的最小化导致用于通过 MCHS 去除给定热通量的通道材料的最低温度，并且热性能 (TP) 的最大化意味着实现最低泵送功率。相应的数值结果被用于识别雷诺数范围从 197 到 595 的几何参数，这些参数使 TP 最大化并密切最小化 EGN。可以看到 TC-FTR 配置产生了大约 1 的最高 TP。78 的中间值 Re 约为 400，同时 EGN 接近 0.45。结果表明，具有 TC-BTR 组合的微通道产生最高的传热速率和最大的压降损失，导致其 TP 较差。因此，如果低壁温恰好是一个关键要求，则 TC-RR 是一种选择。它的一个小牺牲使 TC-FTR 成为具有最高 TP 导致紧凑设计的选择。