Experimental investigation on the flow regime and impingement heat transfer of dual synthetic jet
Experimental investigation on the flow regime and impingement heat transfer of dual synthetic jet
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双合成射流流态及冲击传热实验研究
DOI：
10.1016/j.ijthermalsci.2019.02.039
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发表时间：
2019-11-01
影响因子：
4.5
通讯作者：
Gong, Wei-jie
中科院分区：
文献类型：
--
作者：
Deng, Xiong;Luo, Zhen-bing;Gong, Wei-jie
对用于紧凑型热管理的双合成射流激励器的流态和冲击换热进行了实验研究。除无合流区的三个区域外，双流喷口的时均流场由四个区域组成，即形成区、汇合区、发展区和衰减区。SJ和DSJ的下游涡度集中分区分别向外扩展约22.5度和26.6度。通过与合成射流(SJ)的比较，分析了冲击射流的换热特性。结果表明，在相同的无量纲撞击间距H/d(H)=5.5时，SJ和DSJ的局部Nusselt数都达到最大值，且SJ的最大局部Nusselt数比DSJ高11.4%。在仅为H/d(H)一半的情况下，对撞面平均Nu数的最大值比对撞面SJ高8.6%，这对于空间受限的电子冷却是更好的选择。此外，还研究了缝隙尺寸对冲击流道内换热的影响。在相同的H/d(H)下，峰值努塞尔数与槽颈长度成正比，与槽径比成反比。在较小的H/d(H)处，面均Nusselt数随槽颈长度的增加而减小，而在较大的H/d(H)处则相反。撞击流道的换热性能在中等展宽比时达到最佳。研究结果为空间受限电子设备的散热封装设计提供了依据。
An experimental investigation is carried out to analyze the flow regime and impingement heat transfer of a dual synthetic jet (DSJ) actuator for the compact thermal management. The time-averaged flow field of DSJ is observed to consist of four regions, namely, the formation region, merging region, development region and decay region other than three regions of SJ without the merging region. The downstream vorticity-concentrated partitions of the SJ and the DSJ spread outwards at about 22.5 degrees and 26.6 degrees, respectively. The heat transfer characteristic of an impinging DSJ is analyzed by comparing with a synthetic jet (SJ). It is found that the local Nusselt number reaches a maximum at a same dimensionless impingement spacing of H/d(h) = 5.5 both for the SJ and the DSJ, and the maximum local Nusselt number of the impinging DSJ is 11.4% higher. The maximum area-averaged Nusselt number of the impinging DSJ is 8.6% higher at only half of H/d(h) than the impinging SJ, which is more preferable for the space-restricted electronic cooling. In addition, the effects of slot dimensions on the heat transfer of the impinging DSJ are studied. The peak Nusselt number is directly proportional to the slot neck length and inversely proportional to the slot aspect ratio at a same H/d(h). The area-averaged Nusselt number reduces with the increase of the slot neck length at a smaller H/d(h), and varies contrarily at a larger H/d(h). The best heat transfer performance of the impinging DSJ is achieved at a midlevel aspect ratio. The results provide a design guideline for the cooling packages of space-restricted electronics.