Syneresis in Silica Gel

MRS Proceedings ◽

10.1557/proc-121-179 ◽

1988 ◽

Vol 121 ◽

Cited By ~ 1

Author(s):

George W. Scherer

Keyword(s):

Fluid Flow ◽

Sample Size ◽

Silica Gel ◽

Chemical Reactions ◽

Driving Force ◽

Viscoelastic Behavior ◽

Accurate Representation ◽

Flow Through ◽

Kinetics Of ◽

Gel Network

ABSTRACTThe driving force for syneresis is generally attributed to the same chemical reactions that produce gelation, but it has also been proposed that shrinkage could be driven by interracial energy. The latter possibility is explored and discounted. The kinetics of syneresis depend on the driving force, the mobility of the gel network, and the rate of fluid flow through the contracting gel. A model that allows for viscoelastic behavior of the gel and fluid flow according to Darcy's law is shown to provide a quantitatively accurate representation of the shape of the shrinkage curves and the dependence of the shrinkage rate on sample size.

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A DOS-Enhanced Numerical Simulation of Heat Transfer and Fluid Flow Through an Array of Offset Fins With Conjugate Heating in the Bounding Solid

Electronic and Photonic Packaging, Electrical Systems and Photonic Design, and Nanotechnology ◽

10.1115/imece2003-42380 ◽

2003 ◽

Author(s):

Ephraim M. Sparrow ◽

John P. Abraham ◽

Paul W. Chevalier

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Fluid Flow ◽

Basic Problem ◽

Accurate Representation ◽

Flow And Heat Transfer ◽

Flow Through ◽

Heat And Momentum Transfer ◽

Independent Parameters ◽

Dimensionless Heat

The method of Design of Simulation (DOS) was used to guide and enhance a numerical simulation of fluid flow and heat transfer through offset-fin arrays which from the interior geometry of a cold plate. The basic problem involved 12 independent parameters. This prohibitive parametric burden was lessened by the creative use of nondimensionalization that was brought to fruition by a special transformation of the boundary conditions. Subsequent to the reduction of the number of parameters, the DOS method was employed to limit the number of simulation runs while maintaining an accurate representation of the parameter space. The DOS method also provided excellent correlations of both the dimensionless heat transfer and pressure drop results. The results were evaluated with respect to the Colburn Analogy for heat and momentum transfer. It was found that the offseting of the fins created a larger increase in the friction factor than that which was realized for the dimensionless heat transfer coefficient.

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A DOS-Enhanced Numerical Simulation of Heat Transfer and Fluid Flow Through an Array of Offset Fins With Conjugate Heating in the Bounding Solid

Journal of Heat Transfer ◽

10.1115/1.1800531 ◽

2005 ◽

Vol 127 (1) ◽

pp. 27-33 ◽

Cited By ~ 14

Author(s):

Ephraim M. Sparrow ◽

John P. Abraham ◽

Paul W. Chevalier

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Fluid Flow ◽

Basic Problem ◽

Accurate Representation ◽

Flow And Heat Transfer ◽

Flow Through ◽

Heat And Momentum Transfer ◽

Independent Parameters ◽

Dimensionless Heat

The method of Design of Simulation (DOS) was used to guide and enhance a numerical simulation of fluid flow and heat transfer through offset-fin arrays which form the interior geometry of a cold plate. The basic problem involved 11 independent parameters. This prohibitive parametric burden was lessened by the creative use of nondimensionalization that was brought to fruition by a special transformation of the boundary conditions. Subsequent to the reduction of the number of parameters, the DOS method was employed to limit the number of simulation runs while maintaining an accurate representation of the parameter space. The DOS method also provided excellent correlations of both the dimensionless heat transfer and pressure drop results. The results were evaluated with respect to the Colburn Analogy for heat and momentum transfer. It was found that the offseting of the fins created a larger increase in the friction factor than that which was realized for the dimensionless heat transfer coefficient.

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