Meandering rivulets

With Stéphanie Couvreur, Jens Eggers, Nolwenn Le Grand, Laurent Limat, Nadine Valade

Images of a rivulet of water running down a polyethylene substrate, for various flow-rates. The black spots on the ruler at the right hand side are 10cm apart. The rivulet meanders sway at amplitudes which are much larger that the rivulet width. By comparison, the lateral excursions of an isolated drop sliding down the plane would only be of the order of the drop size. The bending radius of the stationary meanders dépends on the wetting properties of the incline (Le Grand et al 2006).

This video shows the real-time dynamics of the rivulet, which can take more than half an hour to settle to a stationary shape.

This submission to the Gallery of Fluid Motion explains the basic mechanism for the meandering instability, and the influence of the contact line roughness on the critical flow rate (Couvreur & Daerr 2012). This video is also available at a higher resolution: 1280x720, format mp4.

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Last modified: 31 Jan 2016