Abstract This investigation used laser-processed 25-μm-thick stainless steel foils as heaters in pool boiling experiments under subcooled and saturated conditions at atmospheric pressure. Boling surfaces were modified by a nanosecond fiber laser. In most cases, laser-textured parts on boiling surfaces were spaced apart by a capillary length of water (2.5 mm) and had different shapes and arrangements. Multi-scale micro-cavities (with diameters ranging from 0.2 to 10 μm) on the laser-textured areas of the surfaces provided potential active nucleation sites. The highest heat flux measured before the burnout was observed on the fully treated sample; this heat flux was a factor of 3.7 greater than that of the untreated sample. The sample with hexagonally arranged textured circular shapes with a diameter of 2.0 mm provided a more than 4-fold higher heat transfer coefficient compared to the untreated sample. All of the laser-textured boiling surfaces showed enhanced pool boiling heat transfer performance in comparison to the untreated surface. The optimal spacing between the laser-textured regions was experimentally found to be equal to the capillary length of the working fluid. Our results demonstrate that laser texturing has strong potential for producing patterned surfaces for engineering applications of boiling heat transfer.

中文翻译：

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具有毛细管长度间隔的一维和二维激光纹理图案的表面的沸腾性能

摘要 本研究使用激光加工的 25 微米厚不锈钢箔作为加热器，在大气压过冷和饱和条件下进行池沸腾实验。Boling 表面由纳秒光纤激光器改性。在大多数情况下，沸腾表面上的激光纹理部件被水的毛细管长度（2.5 毫米）隔开，并具有不同的形状和排列。表面激光纹理区域上的多尺度微腔（直径范围为 0.2 至 10 μm）提供了潜在的活性成核位点。在完全处理过的样品上观察到在燃尽前测得的最高热通量；该热通量比未处理样品的热通量大 3.7 倍。具有六边形排列的纹理圆形的样品，直径为 2。与未处理的样品相比，0 mm 的传热系数提高了 4 倍以上。与未经处理的表面相比，所有激光纹理沸腾表面都显示出增强的池沸腾传热性能。实验发现激光纹理区域之间的最佳间距等于工作流体的毛细管长度。我们的结果表明，激光纹理具有为沸腾传热工程应用生产图案化表面的巨大潜力。