Skin-friction behavior in the transitionally-rough regime
Skin-friction behavior in the transitionally-rough regime
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DOI：
10.1016/j.ijheatfluidflow.2016.05.008
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发表时间：
2016-10-01
影响因子：
2.6
通讯作者：
Kim, Y. C.
中科院分区：
文献类型：
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作者：
Flack, K. A.;Schultz, M. P.;Kim, Y. C.
在充分发展，湍流槽道流的粗糙表面的范围内的表面摩擦的实验研究结果。这15个表面是用各种类型和尺寸的介质通过喷砂处理产生的。基于整体平均速度和通道高度的实验雷诺数（R-em）范围为10，000 - 300，000。所有这些表面的粗糙度函数（Delta U+）的形状显示出具有有效粗糙度高度（k（eff）（+））的自相似性，这表明在整个粗糙度函数中确实存在使结果崩溃的尺度。粗糙度函数在过渡粗糙状态下以与Nikuradse对均匀沙的结果相似的方式显示弯曲行为。等效砂粒粗糙度高度可以通过粗糙度幅值概率密度函数的k（rms）和偏度（Sk）来预测。基于泰勒微尺度（λ）的粗糙度的长波长过滤程序，并建议在类似于100 λ的尺度下过滤粗糙度轮廓。爱思唯尔公司出版
Results of an experimental investigation of the skin friction for a range of rough surfaces in fully-developed, turbulent channel flow are presented. The fifteen surfaces were generated by grit blasting with various types and sizes of media. The Reynolds number (R-em) for the experiments based on the bulk mean velocity and the channel height spanned from 10,000-300,000. The shape of the roughness function (Delta U+) for all of these surfaces shows self-similarity with an effective roughness height (k(eff)(+)) indicating that a scale does exist to collapse results throughout the entire roughness function. The roughness function displays inflectional behavior in the transitionally-rough regime in a similar manner to the results of Nikuradse for uniform sand. The equivalent sand grain roughness height can be predicted using k(rms) and the skewness (Sk) of the probability density function of the roughness amplitude. A long-wavelength filtering procedure based on the Taylor microscale (lambda) of the roughness is presented, and it is recommended that roughness profiles be filtered at a scale of similar to 100 lambda. Published by Elsevier Inc.