Experimental study on the flow instability of a binary mixture driven by rotation and surface-tension gradient in a shallow Czochralski configuration

A three-dimensional numerical simulation of flow in patterned microchannel with alternate layers of hydrophilic and hydrophobic surfaces at the bottom wall is studied here. Surface characteristics of the microchannel are accounted by specifying the contact angle and the surface tension of the fluid. Meniscus profiles with varying amplitude and shapes are obtained under the different specified surface conditions. Flow instability increases as the fluid at the bottom wall traverses alternately from hydrophilic region to hydrophobic region. To understand the surface tension effect of the side walls, a two-dimensional numerical study has also been carried out for the microchannel and the results are compared with three-dimensional simulation. The surface tension effect of the side walls enhances the capillary effect for three-dimensional case.

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Fluxing of protective oxide scales on superalloys via a thermal surface tension gradient

Journal of Materials Science ◽

10.1007/bf00540748 ◽

1983 ◽

Vol 18 (12) ◽

pp. 3743-3748 ◽

Cited By ~ 2

Author(s):

S. K. Lau ◽

S. C. Singhal

Keyword(s):

Surface Tension ◽

Surface Tension Gradient ◽

Oxide Scales ◽

Protective Oxide

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Influence of viscosity, surface tension, and inclination angle on motion of long bubbles in closed tubes

Journal of Fluid Mechanics ◽

10.1017/s0022112066000442 ◽

1966 ◽

Vol 25 (4) ◽

pp. 821-837 ◽

Cited By ~ 234

Author(s):

E. E. Zukoski

Keyword(s):

Experimental Study ◽

Surface Tension ◽

Inclination Angle ◽

Bubble Velocity ◽

Vertical Tubes

An experimental study has been made of the motion of long bubbles in closed tubes. The influence of viscosity and surface tension on the bubble velocity is clarified. A correlation of bubble velocities in vertical tubes is suggested and is shown to be useful for the whole range of parameters investigated. In addition, the effect of tube inclination angle on bubble velocity is presented, and certain features of the flow are described qualitatively.

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Numerical Simulation of Oil-Droplet Cleavage by Surfactant

Journal of Biomechanical Engineering ◽

10.1115/1.2795960 ◽

1996 ◽

Vol 118 (2) ◽

pp. 201-209 ◽

Cited By ~ 6

Author(s):

Xiaoyi He ◽

Micah Dembo

Keyword(s):

Experimental Data ◽

Numerical Simulation ◽

Surface Tension ◽

Large Deformation ◽

Concentration Gradient ◽

Surface Tension Gradient ◽

Oil Droplets ◽

Numerical Computations ◽

Oil Droplet ◽

Pure Surface

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan’s experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.

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