Abstract The effect of surface roughness peaks (SRP) on laminar air-flow and heat transfer performances in rough micro- and mini-channels is analyzed by 3D computational fluid dynamics (CFD) simulation method. The variations of channel height, SRP height, pitch and width, aligned and off-set SRP, and hybrid SRP in rectangular channels are studied. The parametric ranges of channel height, SRP height and constricted diameter of the channel are 150 μm to 400 μm, 15 μm to 45 μm, and 179 μm to 663 μm, respectively. The results showed that heat transfer performance of smooth micro- and mini-channels with low aspect ratio is higher than the conventional predictions. The maximum convective heat transfer depends on the optimum combination of channel size and roughness height. Furthermore, increasing SRP pitch has less impact on the heat transfer while increasing roughness width improves the performance index. Hybrid SRP in a channel is more effective than constant SRP at lower Reynolds number with the performance index improved up to 12%. Aligned peaks are more efficient than the off-set arrangement and the average rise of performance is 9% under present conditions. Relative roughness with varying parameters can be configured for practical purposes without compromising the compactness.

中文翻译：

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结构化表面粗糙度峰值对微通道和微型通道的流动和传热性能的影响

摘要 通过3D计算流体动力学(CFD)模拟方法分析了表面粗糙度峰值(SRP)对粗糙微通道和微通道层流气流和传热性能的影响。研究了矩形通道中通道高度、SRP高度、间距和宽度、对齐和偏移SRP以及混合SRP的变化。通道高度、SRP高度和通道收缩直径的参数范围分别为150μm至400μm、15μm至45μm和179μm至663μm。结果表明，具有低纵横比的光滑微通道和微型通道的传热性能高于常规预测。最大对流传热取决于通道尺寸和粗糙度高度的最佳组合。此外，增加 SRP 节距对传热的影响较小，而增加粗糙度宽度可提高性能指标。在较低雷诺数下，通道中的混合 SRP 比恒定 SRP 更有效，性能指标提高了 12%。对齐峰值比偏移排列更有效，在当前条件下性能的平均提升为 9%。可以根据实际目的配置具有不同参数的相对粗糙度，而不会影响紧凑性。