Capillary wave dynamics of thin liquid polymer films

2014 ◽  
Vol 141 (10) ◽  
pp. 104903 ◽  
Author(s):  
Fan-Yen Lin ◽  
Werner Steffen
Keyword(s):  
Polymer Films ◽  
Capillary Wave ◽  
Wave Dynamics ◽  
Liquid Polymer

scholarly journals Capillary Wave Dynamics of Thin Polymer Films over Submerged Nanostructures

2012 ◽  
Vol 109 (20) ◽  
Author(s):  
K. J. Alvine ◽  
Y. Dai ◽  
H. W. Ro ◽  
S. Narayanan ◽  
A. R. Sandy ◽  
...  
Keyword(s):  
Polymer Films ◽  
Capillary Wave ◽  
Thin Polymer Films ◽  
Wave Dynamics ◽  
Thin Polymer

Thin Liquid Polymer Films Rupture via Defects

Langmuir ◽  
1998 ◽  
Vol 14 (4) ◽  
pp. 965-969 ◽  
Author(s):  
Karin Jacobs ◽  
Stephan Herminghaus ◽  
Klaus R. Mecke
Keyword(s):  
Polymer Films ◽  
Liquid Polymer

Self-organized patterning of molecularly thin liquid polymer films utilizing molecular flow induced by ultraviolet irradiation

2007 ◽  
Vol 90 (12) ◽  
pp. 123119 ◽  
Author(s):  
Hedong Zhang ◽  
Yasunaga Mitsuya ◽  
Natsuko Fukuoka ◽  
Masashi Imamura ◽  
Kenji Fukuzawa
Keyword(s):  
Polymer Films ◽  
Ultraviolet Irradiation ◽  
Molecular Flow ◽  
Liquid Polymer ◽  
Self Organized

Entanglement Effects in Capillary Waves on Liquid Polymer Films

2008 ◽  
Vol 101 (24) ◽  
Author(s):  
Zhang Jiang ◽  
Mrinmay K. Mukhopadhyay ◽  
Sanghoon Song ◽  
Suresh Narayanan ◽  
L. B. Lurio ◽  
...  
Keyword(s):  
Polymer Films ◽  
Capillary Waves ◽  
Liquid Polymer

Experimental study of flow separation in laminar falling liquid films

2009 ◽  
Vol 637 ◽  
pp. 73-104 ◽  
Author(s):  
GEORG F. DIETZE ◽  
F. AL-SIBAI ◽  
R. KNEER
Keyword(s):  
Reynolds Number ◽  
Velocity Field ◽  
Film Thickness ◽  
Cross Section ◽  
Capillary Wave ◽  
Excitation Frequency ◽  
Liquid Films ◽  
Wave Dynamics ◽  
Wave Region ◽  
Falling Liquid Films

In a previous publication, Dietze, Leefken & Kneer (J. Fluid Mech., vol. 595, 2008, p. 435) showed that flow separation takes place in the capillary wave region of falling liquid films. That investigation focused on the mechanistic explanation of the phenomenon mainly on the basis of numerical data. The present publication for the first time provides clear experimental evidence of the phenomenon obtained by way of highly resolving velocity measurements in a specifically designed optical test set-up. Characteristically, the refractive index of the working fluid was matched to that of the glass test section to provide optimal access to the cross-section of the film for the employed optical velocimetry techniques, namely, laser doppler velocimetry (LDV) and particle image velocimetry (PIV). Using LDV, time traces of the streamwise velocity component were recorded in high spatial (0.025 mm) and temporal resolutions (0.4 ms) showing negative velocity values in the capillary wave region. In addition, simultaneous film thickness measurements were performed using a Confocal Chromatic Imaging (CCI) technique enabling the correlation of velocity data and wave dynamics. Further, using PIV the spatio-temporal evolution of the velocity field in the cross-section of the film was measured with high spatial (0.02 mm) and temporal (0.5 ms) resolutions yielding insight into the topology of the flow. Most importantly these results clearly show the existence of a separation eddy in the capillary wave region. Due to the high temporal resolution of the PIV measurements, enabled by the use of a high-speed camera with a repetition rate of up to 4500 Hz, the effect of wave dynamics on the velocity field in all regions of the wavy film was elucidated. All experiments were performed using a dimethylsulfoxide (DMSO)–water solution and focused on laminar vertically falling liquid films with externally excited monochromatic surface waves. Systematic variations of both the Reynolds number (Re = 8.6–15.0) and the excitation frequency (f = 16–24 Hz) were performed. Results show that an increase in the wavelength of large wave humps, produced either by an increase in the Reynolds number or a decrease in the excitation frequency, leads to an increase in the size of the capillary separation eddy (CSE). Thereby, the CSE is shown to grow larger than the local film thickness, assuming an open shape with streamlines ending at the free surface.

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