Reynolds stress scaling in pipe flow turbulence—first results from CICLoPE
Reynolds stress scaling in pipe flow turbulence—first results from CICLoPE
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DOI：
10.1098/rsta.2016.0187
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发表时间：
2017-03
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通讯作者：
R. Örlü;T. Fiorini;Antonio Segalini;G. Bellani;A. Talamelli;P. Alfredsson
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作者：
R. Örlü;T. Fiorini;Antonio Segalini;G. Bellani;A. Talamelli;P. Alfredsson
本文报道了在长管实验国际合作中心（CICLoPE）长管设备上进行的首次湍流测量。特别地，报告了从许多直线和边界层型单线和x线探针获得的摩擦雷诺数为3.8×104的雷诺兹应力分量。与湍流边界层实验以及Superpipe的结果一致，目前的测量结果显示，在流向变化剖面中有一个明显的对数区域，Townsend-Perry常数为A2≈1.26。墙-正态方差曲线表现为雷诺兹数无关的平台，而展向分量在比其他两个分量更宽的墙-正态距离上服从对数标度，其斜率几乎是Townsend-Perry常数（即A2，w≈A2/2）的一半。因此，本研究结果为基于附加涡假设的雷诺应力张量标度提供了强有力的支持。有趣的是，与之前的研究相比，墙向和展向分量表现出更高的振幅，因此需要在CICLoPE以及其他大型设施中进行后续研究。本文是“大雷诺数下壁湍流高保真模型的发展”专题的一部分。
This paper reports the first turbulence measurements performed in the Long Pipe Facility at the Center for International Cooperation in Long Pipe Experiments (CICLoPE). In particular, the Reynolds stress components obtained from a number of straight and boundary-layer-type single-wire and X-wire probes up to a friction Reynolds number of 3.8×104 are reported. In agreement with turbulent boundary-layer experiments as well as with results from the Superpipe, the present measurements show a clear logarithmic region in the streamwise variance profile, with a Townsend–Perry constant of A2≈1.26. The wall-normal variance profile exhibits a Reynolds-number-independent plateau, while the spanwise component was found to obey a logarithmic scaling over a much wider wall-normal distance than the other two components, with a slope that is nearly half of that of the Townsend–Perry constant, i.e. A2,w≈A2/2. The present results therefore provide strong support for the scaling of the Reynolds stress tensor based on the attached-eddy hypothesis. Intriguingly, the wall-normal and spanwise components exhibit higher amplitudes than in previous studies, and therefore call for follow-up studies in CICLoPE, as well as other large-scale facilities. This article is part of the themed issue ‘Toward the development of high-fidelity models of wall turbulence at large Reynolds number’.