Forced convection cooling of a parallel plate channel populated with heated blocks is encountered in a large number of important engineering applications, such as industrial heat exchangers, biomedical devices, cooling of microelectronic components, etc. In the grooved channel formed in this way, two main flow regions can be recognized: (i) the bulk flow over the heated blocks in the main channel and (ii) the weak recirculating vortex flow in the groove between adjacent heated blocks. In laminar, steady-state conditions, warm fluid is trapped in the slow recirculating flow in the groove, heated by both upstream and downstream blocks, with diffusion being the dominant heat transfer mechanism through the shear layer between the groove region and main channel flow. This situation impedes the overall heat transport along one heated block and groove periodicity unit. Heat transfer in the reference geometry, the asymmetrically heated parallel plate channel, was compared with that for the basic grooved channel, and the same geometry enhanced by cylinders and vanes placed above the downstream edge of each heated block.; Oscillating temperature fields in the investigated channel geometries were visualized with holographic interferometry, an ideal tool for gaining quantitative insight into the fast changing temperature distributions. Reynolds numbers were varied in the range Re = 200 ÷ 6500, corresponding to flow velocities from 0.76 m/s ÷ 2.36 m/s. Heat transfer in the grooved channels with cylinders and with vanes showed an increase by a factor of 1.2 ÷ 1.8 and 1.5 ÷ 3.5, respectively, when compared to data obtained for the basic grooved channel; however, the accompanying pressure drop penalties also increased significantly. Measurements of the ratio of Nusselt number gain to friction factor gain indicated that the grooved channel with cylinders does not offer any reduction in pressure drop for the requisite heat removal to the basic grooved channel. Based on the same criterion, the performance of the grooved channel with vanes exceeded that of the basic grooved channel for Re ≤ 400.
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机译：在许多重要的工程应用中，例如工业热交换器，生物医学设备，微电子元件的冷却等，都遇到了由加热块构成的平行板通道的强制对流冷却。在以这种方式形成的带槽通道中，有两个主要方面可以识别出以下流动区域：（i）主通道中加热块上方的总体流动，以及（ii）相邻加热块之间的凹槽中的弱循环涡流。在层流，稳态条件下，温暖的流体被困在沟槽中的缓慢循环流中，并由上游和下游块加热，扩散是通过沟槽区域和主通道流之间的剪切层的主要传热机制。这种情况阻碍了沿着一个加热的块和槽周期性单元的总体热传递。将参考几何形状，非对称加热的平行板通道的传热与基本槽形通道的传热进行了比较，相同的几何形状通过放置在每个加热块下游边缘上方的圆柱和叶片而得到了增强。全息干涉法可以可视化研究通道几何形状中的振荡温度场，全息干涉法是获得定量了解快速变化的温度分布的理想工具。雷诺数在Re = 200÷6500的范围内变化，对应于0.76 m / s÷2.36 m / s的流速。与从基本带槽通道获得的数据相比，带圆柱和带叶片的带槽通道的传热分别增加了1.2÷1.8和1.5÷3.5。但是，随之而来的压降损失也明显增加。对努塞尔数增益与摩擦因数增益之比的测量结果表明，带圆柱的带槽沟槽不会为基本的带沟槽沟槽的必要散热提供任何压降降低。基于相同的标准，当Re≤400时，带叶片的沟槽式沟槽的性能超过了基本沟槽式沟槽的性能。
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