Enhanced thermal performance with high-amplitude intermittent impingement cooling
Enhanced thermal performance with high-amplitude intermittent impingement cooling
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DOI：
10.1016/j.ijheatmasstransfer.2021.122359
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发表时间：
2022-04
影响因子：
5.2
通讯作者：
Zhihan Zhang;Qianhui Li;C. Bruecker;Qiang Zhang
中科院分区：
文献类型：
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作者：
Zhihan Zhang;Qianhui Li;C. Bruecker;Qiang Zhang
许多未来工程应用的进步依赖于有效的冷却技术。除了传统的热管理解决方案外，非稳态冲击冷却的设计潜力仍未得到充分开发。作为一个结合实验和数值研究，本文报道了高振幅间歇冲击冷却与控制非定常模式的新发现。特别注意间歇流关闭时间比。实验工作涉及非稳态冷却性能测量与小规模水洞系统。采用非定常雷诺平均Navier-Stokes模拟（URANS）来说明非定常流动物理，并在更宽的流动条件范围（平均雷诺数2800 < Rem<10，000，脉动频率0.1 Hz < f < 2 Hz，关闭时间比0.2 <γ< 0.8）下评估冷却性能。实验和数值模拟数据都证实了高振幅间歇冲击流对整体冷却效率的显著提高。特别是在壁面射流区附近，增强效果可达50%以上。涡环的产生和相互作用破坏了热边界层的发展，增强了近壁湍流的产生，特别是对壁面射流区。同时还论证了高幅值间歇冲击冷却技术在实际应用中的节能效果。本文提出的新概念可广泛应用于电子冷却、除冰、燃气涡轮机叶片冷却等领域。
The advances of many future engineering applications rely on effective cooling techniques. Beyond the traditional thermal management solutions, the design potential of unsteady impingement cooling is still under-explored. As a combined experimental and numerical study, this paper reports new findings on high-amplitude intermittent impingement cooling with controlled unsteady patterns. Specifical attention was paid on the intermittent flow close time ratio. The experimental work involved unsteady cooling performance measurement with a small-scale water tunnel system. Unsteady Reynolds Averaged Navier-Stokes Simulation (URANS) was conducted to illustrate the unsteady flow physics, and to evaluate the cooling performance at a wider range of flow conditions (average Reynolds number 2800 < Rem< 10,000, pulsating frequency 0.1 Hz < f < 2 Hz, close time ratio 0.2 <γ< 0.8). Both experimental and numerical data confirm a remarkable improvement of overall cooling efficiency by high-amplitude intermittent impingement flow. Especially around the wall jet region, the enhancement can reach as high as 50%. The generation and interaction of vortex rings break the development of thermal boundary layer, and enhance the generation of near wall turbulence, especially for the wall jet region. Saving in coolant consumption with high-amplitude intermittent impingement cooling technique in practice is also demonstrated. The novel concept presented in this paper can be applied to a wide range of applications including electronic cooling, deicing, gas turbine blade cooling, etc.