Abstract In order to provide a basis for the design and optimization of the aspect ratio of the manifold microchannel, the effect of channel aspect ratio on the heat transfer performance of manifold microchannel heat sinks at fixed mass flow rate is numerically investigated in this present work. The results show that the heat transfer performance of the manifold microchannel heat sink reaches the peaks at one specific channel aspect ratio, which is defined as optimal aspect ratio αo. It is found that the optimal aspect ratio is different at various working fluids and solid materials. The optimal aspect rises with the increase of thermal conductivity of the channel wall and dynamic viscosity of working fluid, or the decrease of specific heat capacity of working fluid and thermal conductivity of working fluid. Further numerical simulations are conducted to quantitatively analyze the influence of each thermophysical parameter on αo. Finally, a criterion formula is given to describe the optimal aspect ratio as a function of Re number, Pr number, and the ratio of thermal conductivity between working fluid and channel wall.

中文翻译：

---

不同通道纵横比对歧管微通道散热器传热性能影响的研究

摘要 为了为歧管微通道纵横比的设计和优化提供依据，本文数值研究了通道纵横比对固定质量流量下歧管微通道散热器传热性能的影响。结果表明，歧管微通道散热器的传热性能在某一特定通道纵横比处达到峰值，定义为最佳纵横比αo。发现不同的工作流体和固体材料的最佳纵横比是不同的。最佳方面随着通道壁热导率和工质动力粘度的增加而升高，或随着工质比热容和工质热导率的降低而升高。进一步进行数值模拟以定量分析每个热物理参数对αo的影响。最后，给出了一个准则公式来描述作为 Re 数、Pr 数以及工作流体与通道壁之间热导率比的函数的最佳纵横比。