Abstract We present a novel methodology to enhance the capillarity and thus the heat transfer capacity of a polygonal micro heat pipe by axially varying the apex angle of grooves. To analyse the effect of axial variation of apex angle on thermal performance of micro heat pipes, we use a quasi-one-dimensional mathematical model that takes into account the axial variation of apex angle. We analyse micro heat pipes with linear variation of apex angle and uniform apex angle. Numerical results of our model show that a linear increase in the apex angle from the evaporator to the condenser section can increase the heat transport capacity of the micro heat pipe by more than 55% compared to micro heat pipe with uniform apex angle. We describe how the axial variation in apex angle leads to enhanced capillarity in a micro heat pipe. We show that axial variation of apex angle redistributes the liquid mass from the condenser section of the micro heat pipe to the evaporator section resulting in a reduction of liquid pressure drop. Lastly, we mathematically optimise the axial variation of apex angle to obtain 100% enhancement in the maximum heat transport capacity in comparison to micro heat pipe with uniform apex angle.

中文翻译：

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使用可变顶角凹槽增强微热管的毛细作用

摘要 我们提出了一种新的方法，通过轴向改变凹槽的顶角来增强毛细管作用，从而提高多边形微热管的传热能力。为了分析顶角轴向变化对微型热管热性能的影响，我们使用了一个考虑了顶角轴向变化的准一维数学模型。我们分析了顶角线性变化和均匀顶角的微型热管。我们模型的数值结果表明，从蒸发器到冷凝器段的顶角线性增加，与具有均匀顶角的微热管相比，微热管的传热能力可提高55%以上。我们描述了顶角的轴向变化如何导致微热管中的毛细管作用增强。我们表明，顶角的轴向变化将液体质量从微热管的冷凝器部分重新分配到蒸发器部分，从而降低了液体压降。最后，我们在数学上优化了顶角的轴向变化，与具有均匀顶角的微型热管相比，最大传热能力提高了 100%。