Liquid ropes: a geometrical model for thin viscous jet instabilities.

Authors
Brun, P-T 
Audoly, Basile 
Ribe, Neil M 
Eaves, TS 
Lister, John R 

Change log
Abstract

Thin, viscous fluid threads falling onto a moving belt behave in a way reminiscent of a sewing machine, generating a rich variety of periodic stitchlike patterns including meanders, W patterns, alternating loops, and translated coiling. These patterns form to accommodate the difference between the belt speed and the terminal velocity at which the falling thread strikes the belt. Using direct numerical simulations, we show that inertia is not required to produce the aforementioned patterns. We introduce a quasistatic geometrical model which captures the patterns, consisting of three coupled ordinary differential equations for the radial deflection, the orientation, and the curvature of the path of the thread's contact point with the belt. The geometrical model reproduces well the observed patterns and the order in which they appear as a function of the belt speed.

Publication Date
2015-05-01
Online Publication Date
2015-04-30
Acceptance Date
Keywords
0915 Interdisciplinary Engineering
Journal Title
Phys Rev Lett
Journal ISSN
0031-9007
1079-7114
Volume Title
114
Publisher
American Physical Society (APS)
Sponsorship
P.-T. B. was partially funded by the ERC Grant No. SIMCOMICS 280117.