Axisymmetric Wall Jet Development in Confined Jet Impingement
Axisymmetric Wall Jet Development in Confined Jet Impingement
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DOI：
10.1063/1.4975394
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发表时间：
2017-02
影响因子：
4.6
通讯作者：
Tianqi Guo;M. Rau;P. Vlachos;S. Garimella
中科院分区：
文献类型：
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作者：
Tianqi Guo;M. Rau;P. Vlachos;S. Garimella
对轴对称受限冲击射流周围的流场进行了研究，重点关注三层壁面射流结构的早期发展。在雷诺数从1000到9000的范围内，使用立体粒子图像测速技术在三种不同的受限间隙高度（2、4和8倍射流直径）下进行了实验。受限区域内的旋转流结构及其与周围流场的相互作用取决于受限间隙高度和雷诺数。随着雷诺数的增加，回流核心向下游移动。对于所研究的最小受限间隙高度，强烈的回流导致壁面射流发展受阻。在这个小间隙高度下观察到的回流核心的径向位置被发现与壁面射流最大速度衰减到冲击射流出口速度的15%的位置重合。在此之后，自相似性假设无法预测其演变……
The flow field surrounding an axisymmetric, confined, impinging jet was investigated with a focus on the early development of the triple-layered wall jet structure. Experiments were conducted using stereo particle image velocimetry at three different confinement gap heights (2, 4, and 8 jet diameters) across Reynolds numbers ranging from 1000 to 9000. The rotating flow structures within the confinement region and their interaction with the surrounding flow were dependent on the confinement gap height and Reynolds number. The recirculation core shifted downstream as the Reynolds number increased. For the smallest confinement gap height investigated, the strong recirculation caused a disruption of the wall jet development. The radial position of the recirculation core observed at this small gap height was found to coincide with the location where the maximum wall jet velocity had decayed to 15% of the impinging jet exit velocity. After this point, the self-similarity hypothesis failed to predict the evoluti...