Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691, USA.
Phys Rev Lett. 2010 May 28;104(21):218301. doi: 10.1103/PhysRevLett.104.218301. Epub 2010 May 24.
Turbulent channel flow of drag-reducing polymer solutions is simulated in minimal flow geometries. Even in the Newtonian limit, we find intervals of "hibernating" turbulence that display many features of the universal maximum drag reduction asymptote observed in polymer solutions: weak streamwise vortices, nearly nonexistent streamwise variations, and a mean velocity gradient that quantitatively matches experiments. As viscoelasticity increases, the frequency of these intervals also increases, while the intervals themselves are unchanged, leading to flows that increasingly resemble maximum drag reduction.
减阻聚合物溶液的紊流通道流动在最小流型中进行了模拟。即使在牛顿极限下，我们也发现了“休眠”湍流的区间，这些区间显示了聚合物溶液中观察到的普遍最大减阻渐近线的许多特征：弱流向涡，几乎不存在流向变化，以及定量匹配实验的平均速度梯度。随着粘弹性的增加，这些区间的频率也增加，而区间本身保持不变，导致流动越来越类似于最大减阻。
