Microfluidics using the surface tension force in microscale

2000 ◽  
Author(s):  
Chang-Jin Kim
Keyword(s):  
Surface Tension ◽  
Surface Tension Force ◽  
Tension Force

Prediction of the Condensation Coefficient on Horizontal Integral-Fin Tubes

1985 ◽  
Vol 107 (2) ◽  
pp. 369-376 ◽  
Author(s):  
R. L. Webb ◽  
T. M. Rudy ◽  
M. A. Kedzierski
Keyword(s):  
Surface Tension ◽  
Theoretical Model ◽  
Surface Tension Force ◽  
Tension Force ◽  
Condensation Coefficient ◽  
Film Drainage ◽  
Predicted Values ◽  
Experimental Values ◽  
Fin Tubes

A theoretical model is developed for prediction of the condensation coefficient on horizontal integral-fin tubes for both high and low surface tension fluids. The model includes the effects of surface tension on film drainage and on condensate retention between the fins. First, the fraction of the tube circumference that is flooded with condensate is calculated. Typically, the condensation coefficient in the flooded region is negligible compared to that of the unflooded region. Then the condensation coefficient on the unflooded portion is calculated, assuming that surface tension force drains the condensate from the fins. The model is used to predict the R-11 condensation coefficient on horizontal, integral-fin tubes having 748, 1024, and 1378 fpm. The predicted values are within ±20 percent of the experimental values.

Inward Flow of Micro-Particles in an Evaporating Di-Dispersed Colloid Droplet on Hydrophilic Surface

2009 ◽  
Author(s):  
Jung-Yeul Jung ◽  
Young Won Kim ◽  
Jung Yul Yoo
Keyword(s):  
Surface Tension ◽  
Contact Line ◽  
Surface Tension Force ◽  
Nano Particles ◽  
Tension Force ◽  
Hydrophilic Surface ◽  
Micro Particles

It is well known that the liquid and the nanoparticles in an evaporating colloid droplet on the hydrophilic surface move radially outward for the contact line to maintain its position. However, the motion of micro-/nano-particles in an evaporating di-dispersed colloid droplet has not been reported to date. In this study, an experiment on an evaporating di-dispersed colloid droplet on the hydrophilic surface is carried out. It is found that nano-particles move radially outward and remain at the contact line while micro-particles move inward toward the center of the droplet. Further the mechanism of the micro-particles moving toward the center of the droplet is found to be due to the surface tension force of the liquid.

A Viscoelastic VOF-PROST Code for the Study of Drop Deformation

Volume 3 ◽  
2004 ◽  
Author(s):  
Y. Renardy ◽  
M. Renardy ◽  
T. Chinyoka ◽  
D. B. Khismatullin ◽  
J. Li
Keyword(s):  
Surface Tension ◽  
Constitutive Equation ◽  
Viscoelastic Medium ◽  
Three Dimensional ◽  
Surface Tension Force ◽  
Volume Of Fluid ◽  
Tension Force ◽  
Drop Deformation ◽  
Volume Of Fluid Method ◽  
Viscoelastic Liquids

A volume of fluid method is developed with a parabolic representation of the interface for the surface tension force (VOF-PROST). This three-dimensional transient code is extended to treat viscoelastic liquids with the Oldroyd-B constitutive equation. Simulations of deformation for a Newtonian drop in a viscoelastic medium under shear are reported.

Nonlinear deformation and breakup of stretching liquid bridges

1996 ◽  
Vol 329 ◽  
pp. 207-245 ◽  
Author(s):  
X. Zhang ◽  
R. S. Padgett ◽  
O. A. Basaran
Keyword(s):  
Surface Tension ◽  
Liquid Bridge ◽  
Method Of Lines ◽  
Inertial Force ◽  
Surface Tension Force ◽  
Tension Force ◽  
Geometrical Parameters ◽  
Liquid Density ◽  
Liquid Bridges ◽  
Disk Radius

In this paper, the nonlinear dynamics of an axisymmetric liquid bridge held captive between two coaxial, circular, solid disks that are separated at a constant velocity are considered. As the disks are continuously pulled apart, the bridge deforms and ultimately breaks when its length attains a limiting value, producing two drops that are supported on the two disks. The evolution in time of the bridge shape and the rupture of the interface are investigated theoretically and experimentally to quantitatively probe the influence of physical and geometrical parameters on the dynamics. In the computations, a one-dimensional model that is based on the slender jet approximation is used to simulate the dynamic response of the bridge to the continuous uniaxial stretching. The governing system of nonlinear, time-dependent equations is solved numerically by a method of lines that uses the Galerkin/finite element method for discretization in space and an adaptive, implicit finite difference technique for discretization in time. In order to verify the model and computational results, extensive experiments are performed by using an ultra-high-speed video system to monitor the dynamics of liquid bridges with a time resolution of 1/12 th of a millisecond. The computational and experimental results show that as the importance of the inertial force – most easily changed in experiments by changing the stretching velocity – relative to the surface tension force increases but does not become too large and the importance of the viscous force – most easily changed by changing liquid viscosity – relative to the surface tension force increases, the limiting length that a liquid bridge is able to attain before breaking increases. By contrast, increasing the gravitational force – most readily controlled by varying disk radius or liquid density – relative to the surface tension force reduces the limiting bridge length at breakup. Moreover, the manner in which the bridge volume is partitioned between the pendant and sessile drops that result upon breakup is strongly influenced by the magnitudes of viscous, inertial, and gravitational forces relative to surface tension ones. Attention is also paid here to the dynamics of the liquid thread that connects the two portions of the bridge liquid that are pendant from the top moving rod and sessile on the lower stationary rod because the manner in which the thread evolves in time and breaks has important implications for the closely related problem of drop formation from a capillary. Reassuringly, the computations and the experimental measurements are shown to agree well with one another.

scholarly journals Implementation of surface tension force in fluid flow during reactive rotational molding

2015 ◽  
Vol 9 (2) ◽  
pp. 131-148 ◽  
Author(s):  
A. Hamidi ◽  
S. Khelladi ◽  
A. illoul ◽  
M. Shirinbayan ◽  
F. Bakir ◽  
...  
Keyword(s):  
Surface Tension ◽  
Fluid Flow ◽  
Surface Tension Force ◽  
Tension Force ◽  
Rotational Molding ◽  
Reactive Rotational Molding

scholarly journals Application of Chahn-Hilliard Equation to the Evaluation of Surface Tension Force

2006 ◽  
Vol 20 (3) ◽  
pp. 244-251 ◽  
Author(s):  
Kosuke HAYASHI ◽  
Naoki TAKADA ◽  
Akio TOMIYAMA
Keyword(s):  
Surface Tension ◽  
Surface Tension Force ◽  
Tension Force ◽  
Hilliard Equation

Multichip Module Planarity Requirements Derived From Solder Surface Tension Models

2018 ◽  
Vol 15 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Thomas F. Marinis ◽  
Joseph W. Soucy
Keyword(s):  
Surface Tension ◽  
Solder Ball ◽  
High Surface ◽  
Surface Tension Force ◽  
Design Tool ◽  
Tension Force ◽  
Multichip Module ◽  
Multichip Modules ◽  
Electrical Connections ◽  
Module Performance

The number of die and routing layers in multichip modules and fan-out packages has been steadily increasing, which has exasperated the problem of maintaining module planarity for interconnect to a system board. The usual remedies are to try to match coefficients of thermal expansion as closely as possible, balance composition of layers on either side of a module's neutral axis, and build on stiff, planar interposers. All of these strategies can affect module performance, size, and cost. We have examined an alternative approach to accommodating module bow, by allowing the solder ball interconnects to compress or elongate as necessary to maintain electrical connections. This approach is further enhanced by making the module very thin, which does not reduce its bow, but rather allows the high surface tension force exerted by molten solder to flatten the module. We have derived a model for the surface tension force exerted by a solder ball as a function of the degree to which it is compressed or elongated. This model also predicts the maximum elongation that the solder connection can sustain before it ruptures. We have applied this model in a design tool, which allows us to predict the maximum module bow that can be accommodated as a function of the number, size, and location of the solder connections and the physical composition of the multichip module.

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