An experimental contribution to near-wall measurements by means of a special laser Doppler anemometry technique
An experimental contribution to near-wall measurements by means of a special laser Doppler anemometry technique
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DOI：
10.1007/s003480100365
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发表时间：
2002-03
影响因子：
2.4
通讯作者：
D. Poggi;A. Porporato;L. Ridolfi
中科院分区：
文献类型：
--
作者：
D. Poggi;A. Porporato;L. Ridolfi
本文介绍了一种用激光多普勒测速仪研究近壁湍流的新实验技术，它可以精确测量非常靠近壁面的流场，具有良好的分辨率和高的数据率。在充分发展的湍流（雷诺数在4，300和67，000之间）中，通过对近壁区域内的流向和壁面法向速度分量进行仔细的统计分析，对这种技术进行了测试，距离壁面的距离约为y += 1 toy+= 100。给出了二维边界层的速度分布、雷诺应力和高阶矩。计算结果与文献中的最新数据一致，证明了所提出的实验解的有效性。此外，结果的准确性允许摩擦速度被计算为总应力曲线的最佳线性拟合的壁处的截距;以这种方式，可以明确地检查归一化统计。
A new experimental technique for the investigation of near-wall turbulence using laser Doppler anemometry is presented, which allows an accurate measurement of the flow field very close to the wall, with good resolution and a high data rate. Such a technique is tested in a fully developed turbulent flow (with Reynolds numbers between 4,300 and 67,000) by carrying out a careful statistical analysis of the streamwise and wall-normal velocity components within the near-wall region, at distances from the wall ranging from approximatelyy+= 1 toy+= 100. The velocity profiles, Reynolds stresses and higher-order moments of the two-dimensional boundary layer are presented. The results, which are in agreement with the most recent data in the literature, testify the validity of the proposed experimental solution. Moreover, the accuracy of the results allows the friction velocity to be calculated as the intercept at the wall of the best linear fit of the total stress profile; in this way, an unambiguous examination of the normalized statistics is possible.