论从DNS确定卡门“常数”的困难性
On the difficulty of determining Karman 'constants' from DNS
AI总结：
本文分析槽道流DNS确定卡门常数κ的困难，指出需将平均流向动量方程残差降低至少一个数量级才能实现2-3%的不确定度。
摘要：
本文针对槽道流，讨论了从直接数值模拟（DNS）确定壁面湍流平均速度剖面中著名对数律斜率——即卡门“常数”κ的倒数——的困难性。文中考虑并分析了一些非常规方法以及标准对数指示函数，得出结论：若要从DNS中以例如2-3%的不确定度确定槽道流的κ，就需要将模拟中平均流向动量方程的残差至少降低一个数量级。
英文摘要：
The difficulty of determining the slope of the famed logarithmic law in the mean velocity profile in wall-bounded turbulent flows, the inverse of the Karman 'constant' $κ$, from direct numerical simulations (DNS) is discussed for channel flow. Unusual approaches, as well as the analysis of the standard log-indicator function are considered and analyzed, leading to the conclusion that a definitive determination of the channel flow $κ$ from DNS with an uncertainty of, say, 2-3% will require the residue of the mean stream-wise momentum equation in the simulations to be reduced by at least an order of magnitude.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
