Streams with moving contact lines: Complex dynamics due to contact-angle hysteresis

We have investigated experimentally the spatiotemporal behavior of a narrow water stream flowing between two parallel inclined Plexiglass plates bounded laterally by air. Complex broadband dynamics occurs as a result of the velocity dependence of the contact angle at the water-air-Plexiglass contact line, which introduces critical values into the pressure required for contact line motion over the Plexiglass plates. This mechanism causes a stick-slip type of motion similar to that appearing in other systems such as flows in granular materials, models of earthquake dynamics, and charge-density-wave motion in solids. We find that above a certain flow rate Q(s), a stationary spatial modulation of the width of the stream appears. At higher flow rates, a hysteretic transition occurs in which the contact line begins to move, and the pattern slips down the plates with broadband dynamics. The statistical properties of the motion are presented.

Title	Streams with moving contact lines: Complex dynamics due to contact-angle hysteresis
Creator	Rubio, M. A.
	Gollub, J. P.
	Gluckman, B. J.
	Dougherty, Andrew
Publisher	Physical Review A
Academic Department	Physics
Division	Natural Sciences
Organization	Lafayette College
Date Issued	January 15, 1991
Date Available	2013-02-25T18:22:22Z
Type	Article
Language	English
Bibliographic Citation	Rubio, M. A., et al. (1991 Jan. 15) "Streams with moving contact lines: Complex dynamics due to contact-angle hysteresis." Physical Review A 43 (2): 811-818.
Standard Identifier	Handle 10385/1114
Standard Identifier	DOI 10.1103/PhysRevA.43.811
Permalink	http://hdl.handle.net/10385/1114
Rights Statement	In Copyright
Rights Holders	The American Physical Society