Lemoult Grégoire, Aider Jean-Luc, Wesfreid José Eduardo
Laboratoire de Physique et Mécanique des Milieux Hétérogènes, UMR 7636 Centre National de la Recherche Scientifique-École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Université Pierre et Marie Curie, Université Paris Diderot, 10 rue Vauquelin, F-75005 Paris, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Feb;85(2 Pt 2):025303. doi: 10.1103/PhysRevE.85.025303. Epub 2012 Feb 21.
We present an experimental study of the transition to turbulence in a plane Poiseuille flow. Using a well-controlled perturbation, we analyze the flow by using extensive particle image velocimetry and flow visualization (using laser-induced fluorescence) measurements, and use the deformation of the mean velocity profile as a criterion to characterize the state of the flow. From a large parametric study, four different states are defined, depending on the values of the Reynolds number and the amplitude of the perturbation. We discuss the role of coherent structures, such as hairpin vortices, in the transition. We find that the minimal amplitude of the perturbation triggering transition scales asymptotically as Re(-1).
我们展示了一项关于平面泊肃叶流中向湍流转变的实验研究。通过使用精心控制的扰动，我们利用广泛的粒子图像测速技术和流动可视化（使用激光诱导荧光）测量来分析流动，并使用平均速度剖面的变形作为表征流动状态的标准。通过大量的参数研究，根据雷诺数和扰动幅度的值定义了四种不同的状态。我们讨论了诸如发卡涡等相干结构在转变过程中的作用。我们发现触发转变的扰动的最小幅度渐近地按Re(-1)缩放。
