Small Grants for Exploratory Research: Skin-Friction Drag in the Turbulent Boundary Layer

在探索性研究小额赠款的支持下，将进行一项搜索，以寻找存在一个非常大的雷诺数区域的证据，在该区域内，湍流特征与该区域以下的区域不同。无论是现有的边界层湍流测量，还是即将建立的大雷诺数充分发展的管流实验的新数据，都将寻找这一证据。重点是在非常靠近壁面的波动和更远进入流动的波动的耦合中，两种猜测的区域之间的差异。在很高的雷诺数下发现湍流特性的变化，将与通常认为的湍流特性随着雷诺数的增加而变得更加普遍的观点相矛盾。这将影响湍流预测模型的构建，并提高其精度和对各种工程系统的实用性。

With support from a Small Grant for Exploratory Research, a search will be conducted for evidence that there exists a regime of very large Reynolds numbers in which turbulence characteristics differ from those below this regime. Both existing boundary layer turbulence measurements, and new data from a large Reynolds numbers fully developed pipe flow experiment to be built, will be searched for this evidence. Focus is on differences between the two conjectured regimes in the coupling of fluctuations very near the wall and those further out into the flow. Discovery of changes in turbulence characteristics at very high Reynolds numbers would contradict the commonly held view that turbulence characteristics become more universal as Reynolds number increases. This would impact the construction of predictive turbulence models and improve their accuracy and utility for various engineering systems.