Abstract Considered is the addition of special surface roughness patterns to impingement target surfaces to improve the effectiveness and surface heat transfer augmentation levels of impingement cooling. Three different impingement hole shapes are employed within a jet array: circle, racetrack, and triangle. These are designed so that all three hole shapes have the same hydraulic diameter. Different sizes, different shapes, and different distributions of surface roughness elements are utilized, including arrays of small triangle roughness, with different roughness heights, employed with and without the addition of large pin roughness elements. Data are presented for impingement jet Reynolds numbers of 900, 1500, 5000, and 11,000. Overall, the racetrack hole configuration generally provides approximately the same heat transfer augmentation as the circle hole configuration, with slightly better performance, under some conditions. The triangle hole configuration provides lower heat transfer augmentation, compared to both the circle hole and racetrack hole configurations. The addition of small triangle roughness to the target plates shows an increase in heat transfer augmentation, compared to the baseline target plate, for both the circle and racetrack hole configurations. For the triangle hole configuration, the addition of small triangle roughness generally shows negligible or negative improvement, compared to the baseline target plate. Also illustrated is significantly different Reynolds number dependence for impingement cooling, as hole shape changes from circle to racetrack, and triangle.

中文翻译：

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孔形状对具有小尺度目标表面三角形粗糙度的冲击射流阵列传热的影响

摘要 考虑将特殊的表面粗糙度图案添加到冲击目标表面，以提高冲击冷却的效率和表面传热增强水平。在射流阵列中采用三种不同的冲击孔形状：圆形、跑道和三角形。它们的设计使所有三个孔形状都具有相同的水力直径。使用不同尺寸、不同形状和不同分布的表面粗糙度元素，包括具有不同粗糙度高度的小三角形粗糙度阵列，在添加和不添加大销粗糙度元素的情况下使用。提供了 900、1500、5000 和 11,000 的撞击射流雷诺数的数据。全面的，在某些条件下，跑道孔配置通常提供与圆形孔配置大致相同的传热增强，但性能稍好一些。与圆形孔和跑道孔配置相比，三角形孔配置提供较低的传热增强。对于圆形和跑道孔配置，与基线目标板相比，向目标板添加小三角形粗糙度表明传热增强增加。对于三角形孔配置，与基线目标板相比，添加小三角形粗糙度通常显示出可忽略不计或负面的改进。还说明了冲击冷却的雷诺数依赖性显着不同，因为孔形状从圆形变为跑道，