An Experimental Study of a Free-Surface Shear Layer With and Without the Presence of Surfactants

2002 ◽  
Author(s):  
Amy Wamcke Lang ◽  
Carlos E. Manglano
Keyword(s):  
Experimental Study ◽  
Surface Tension ◽  
Free Surface ◽  
Shear Layer ◽  
Turbulence Intensity ◽  
Shear Flows ◽  
Surface Shear ◽  
Surface Deformations

A free-surface shear layer was studied to ascertain the effects due to the presence of surface tension gradients on the directional shift of the shear layer and turbulence intensities in the vicinity of the water free-surface. It was found that the presence of surfactants altered the direction of the shear layer in the vicinity of the free surface, with the shear layer being pulled to the higher surface tension side. In addition, the turbulence intensity in the plane of the free surface was dramatically reduced, also leading to damped surface deformations. These results show conclusively that the role surfactants play in turbulent free-surface shear flows needs to be considered.

Experimental study of shear layer instability below a free surface

2015 ◽  
Vol 27 (11) ◽  
pp. 112103 ◽  
Author(s):  
Matthieu A. André ◽  
Philippe M. Bardet
Keyword(s):  
Experimental Study ◽  
Free Surface ◽  
Shear Layer ◽  
Shear Layer Instability

scholarly journals HYDRODYNAMIC FORCE EXERTING ON A SQURE PILLAR IN STEADY FREE SURFACE SHEAR FLOWS

2002 ◽  
Vol 46 ◽  
pp. 827-832
Author(s):  
Juichiro AKIYAMA ◽  
Mirei SHIGE-DA ◽  
Toshihiko KOBAYASHI ◽  
Kazumasa OOTA
Keyword(s):  
Free Surface ◽  
Shear Flows ◽  
Hydrodynamic Force ◽  
Surface Shear

Free-Surface Shear Layer Instabilities on a High-Speed Liquid Jet

2000 ◽  
Vol 37 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Kazuhiro Itoh ◽  
Yoshiyuki Tsuji ◽  
Hideo Nakamura ◽  
Yutaka Kukita
Keyword(s):  
Free Surface ◽  
Shear Layer ◽  
High Speed ◽  
Liquid Jet ◽  
Surface Shear

The effect of surfactant on bursting gas bubbles

1995 ◽  
Vol 302 ◽  
pp. 231-257 ◽  
Author(s):  
Jeremy M. Boulton-Stone
Keyword(s):  
Surface Tension ◽  
Free Surface ◽  
Stress Condition ◽  
Numerical Technique ◽  
Gas Bubbles ◽  
Free Surface Flows ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Surface Shear ◽  
Surface Compression

A numerical technique, based on the boundary integral method, is developed to allow the modelling of unsteady free-surface flows at large Reynolds numbers in cases where the surface is contaminated by some surface-active compound. This requires the method to take account of the tangential stress condition at the interface and is achieved through a boundary-layer analysis. The constitutive relation that forms the surface stress condition is assumed to be of the Boussinesq type and allows the incorporation of surface shear and dilatational viscous forces as well as Marangoni effects due to gradients in surface tension. Sorption kinetics can be included in the model, allowing calculations for both soluble and insolube surfactants. Application of the numerical model to the problem of bursting gas bubbles at a free surface shows the greatest effect to be due to surface dilatational viscosity which drastically reduces the amount of surface compression and can slow and even prevent the information of a liquid jet. Surface tension gradients give dilatational elasticity to the surface and thus also significantly prevent surface compression. Surface shear viscosity has a smaller effect on the interface motion but results in initially increased surface concentrations due to the sweeping up of surface particles ahead of the inward-moving surface wave.

Experimental study of shear-layer/acoustics coupling in Mach 5 cavity flow

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 242-252
Author(s):  
O. H. Unalmis ◽  
N. T. Clemens ◽  
D. S. Dolling
Keyword(s):  
Experimental Study ◽  
Shear Layer ◽  
Cavity Flow
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