Impact of viscosity ratio on falling two-layer viscous film flow inside a tube

2021 ◽  
Vol 6 (10) ◽  
Author(s):  
H. Reed Ogrosky
Keyword(s):  
Film Flow ◽  
Viscosity Ratio ◽  
Viscous Film ◽  
Viscous Film Flow

scholarly journals HESS Opinions: Unsaturated infiltration – the need for a reconsideration of historical misconceptions

2021 ◽  
Vol 25 (2) ◽  
pp. 1097-1101
Author(s):  
Peter F. Germann
Keyword(s):  
Preferential Flow ◽  
Film Flow ◽  
Capillary Flow ◽  
Equilibrium Flow ◽  
Macropore Flow ◽  
Viscous Film ◽  
Viscous Film Flow ◽  
Alternative Approach ◽  
Non Equilibrium

Abstract. Briggs (1897) deduced capillary flow from deviation of the equilibrium between capillarity and gravity. Richards (1931) raised capillary flow to an unproven soil hydrological dogma. Attempts to correct the dogma led to concepts of non-equilibrium flow, macropore flow, and preferential flow during infiltration. Viscous film flow is proposed as an alternative approach to capillarity-driven flow during unsaturated infiltration.

Non-linear waves in electrified viscous film flow down a vertical cylinder

2012 ◽  
Vol 77 (3) ◽  
pp. 430-440 ◽  
Author(s):  
A. W. Wray ◽  
O. Matar ◽  
D. T. Papageorgiou
Keyword(s):  
Film Flow ◽  
Vertical Cylinder ◽  
Viscous Film ◽  
Viscous Film Flow ◽  
Linear Waves ◽  
Non Linear

scholarly journals Resonance in viscous film flow over topography

PAMM ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 3020001-3020002
Author(s):  
Christian Heining ◽  
Andreas Wierschem ◽  
Vasilis Bontozoglou ◽  
Nuri Aksel ◽  
Hannes Uecker
Keyword(s):  
Film Flow ◽  
Viscous Film ◽  
Viscous Film Flow ◽  
Flow Over Topography

Viscous film flow in the stagnation region of the jet impinging on planar surface

AIChE Journal ◽  
1994 ◽  
Vol 40 (10) ◽  
pp. 1611-1617 ◽  
Author(s):  
Andrew Yeckel ◽  
Lisa Strong ◽  
Stanley Middleman
Keyword(s):  
Film Flow ◽  
Planar Surface ◽  
Stagnation Region ◽  
Viscous Film ◽  
Viscous Film Flow

scholarly journals Resonance in viscous film flow over topography

PAMM ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 4100025-4100026
Author(s):  
Christian Heining ◽  
Andreas Wierschem ◽  
Vasilis Bontozoglou ◽  
Nuri Aksel ◽  
Hannes Uecker
Keyword(s):  
Film Flow ◽  
Viscous Film ◽  
Viscous Film Flow ◽  
Flow Over Topography

Effect of surfactants on the long-wave stability of two-layer oscillatory film flow

2021 ◽  
Vol 928 ◽  
Author(s):  
Cheng-Cheng Wang ◽  
Haibo Huang ◽  
Peng Gao ◽  
Xi-Yun Lu
Keyword(s):  
Film Flow ◽  
Viscosity Ratio ◽  
Density Ratio ◽  
Thickness Ratio ◽  
High Frequency Oscillation ◽  
Key Factors ◽  
Layer Film ◽  
Wave Disturbances ◽  
Long Wave ◽  
The Stability

The stability of the two-layer film flow driven by an oscillatory plate under long-wave disturbances is studied. The influence of key factors, such as thickness ratio ( $n$ ), viscosity ratio ( $m$ ), density ratio ( $r$ ), oscillatory frequency ( $\beta$ ) and insoluble surfactants on the stability behaviours is studied systematically. Four special Floquet patterns are identified, and the corresponding growth rates are obtained by solving the eigenvalue problem of the fourth-order matrix. A small viscosity ratio ( $m\le 1$ ) may stabilize the flow but it depends on the thickness ratio. If the viscosity ratio is not very small ( $m>0.1$ ), in the $(\beta ,n)$ -plane, stable and unstable curved stripes appear alternately. In other words, under the circumstances, if the two-layer film flow is unstable, slightly adjusting the thickness of the upper film may make it stable. In particular, if the upper film is thin enough, even under high-frequency oscillation, the flow is always stable. The influence of density ratio is similar, i.e. there are curved stable and unstable stripes in the $(\beta ,r)$ -planes. Surface surfactants generally stabilize the flow of the two-layer oscillatory membrane, while interfacial surfactants may stabilize or destabilize the flow but the effect is mild. It is also found that gravity can generally stabilize the flow because it narrows the bandwidth of unstable frequencies.

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