A NEW MEAN VELOCITY SCALING FOR TURBULENT BOUNDARY LAYERS
A NEW MEAN VELOCITY SCALING FOR TURBULENT BOUNDARY LAYERS
复制标题
湍流边界层的新平均速度标度
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
A. Smits
中科院分区：
文献类型：
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作者：
M. Zagarola;Creare Incorporated;A. Smits
本文将一种新的标度法推广到零压力梯度湍流边界层的情况。在低雷诺数，新的缩放导致的平均速度剖面的重叠区域的幂律。在高雷诺数下，还得到了由对数律给出的常规重叠区域。幂律和17个速度分布覆盖了大范围的雷诺数之间进行了比较。这种比较表明，从管流数据确定的经验常数的幂律与边界层数据吻合得很好。提出了一种新的外速度标度。新的外部速度尺度被用来规范化的17个速度配置文件，这些配置文件的崩溃是显着优于由摩擦速度或自由落体速度规范化的配置文件。
A new scaling, originally developed for the mean velocity profile of turbulent pipe flow, was extended to the case of zero pressure gradient turbulent boundary layers. At low Reynolds numbers, the new scaling leads to a power law for the overlap region of the mean velocity profile. At high Reynolds numbers, the conventional overlap region given by a log law is also obtained. Comparisons were made between the power law and 17 velocity profiles covering a large range of Reynolds numbers. This comparison showed that a power law with empirical constants determined from pipe flow data was in good agreement with boundary layer data. A new outer velocity scale was also proposed. The new outer velocity scale was used to normalize the 17 velocity profiles and the collapse of these profiles was significantly better than for profiles normalized by the friction velocity or the freestream velocity.