ABSTRACT Nucleate pool boiling experiments were performed on plain and five laser-textured stainless-steel foils using saturated pure water, 100% ethanol, 0.4% and 4.2% mole fraction ethanol – water mixtures. All laser-textured samples contained untreated, smooth 0.5 mm wide regions and intermediate textured surfaces, that differ in the width of the laser patterned regions (from 0.5 mm to 2.5 mm). For smooth surfaces, we measured significant decreases in average heat transfer coefficients (HTC) and increases in bubble activation temperatures in comparison with the laser-textured surfaces for all the tested working fluids. Significant enhancement in HTC (280%) on a textured heating surface with 2.5-mm-wide laser pattern was recorded using pure water. For pure ethanol, the highest enhancement of 268% was achieved on a heating surface with 1.5-mm-wide laser pattern. The highest enhancement of HTC for the tested binary mixtures was obtained using 2.0-mm wide-laser-textured regions (HTC improved by 235% and 279% for the 0.4% and 4.2% mixtures, respectively). Our results indicate that laser texturing can significantly improve boiling performance when the intervals of the laser-textured patterns are close to the capillary lengths of the tested fluids.

中文翻译：

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饱和纯液体和乙醇-水混合物在光滑和激光纹理表面上核池沸腾的研究

摘要 使用饱和纯水、100% 乙醇、0.4% 和 4.2% 摩尔分数乙醇 - 水混合物在普通和五个激光纹理不锈钢箔上进行核池沸腾实验。所有激光纹理样品都包含未经处理的 0.5 毫米宽的光滑区域和中间纹理表面，激光图案区域的宽度不同（从 0.5 毫米到 2.5 毫米）。对于光滑表面，与所有测试工作流体的激光纹理表面相比，我们测量了平均传热系数 (HTC) 的显着降低和气泡活化温度的升高。使用纯水记录了具有 2.5 毫米宽激光图案的纹理加热表面上 HTC (280%) 的显着增强。对于纯乙醇，在 1 的加热表面上实现了 268% 的最高增强。5 毫米宽的激光图案。使用 2.0 毫米宽的激光纹理区域获得了测试二元混合物的 HTC 的最高增强（对于 0.4% 和 4.2% 的混合物，HTC 分别提高了 235% 和 279%）。我们的结果表明，当激光纹理图案的间隔接近测试流体的毛细管长度时，激光纹理可以显着提高沸腾性能。