Effect of High-Frequency Vibration on Convection in Miscible Fluids

Gaponenko, Yuri; Volpert, Vladimir A.; Zen'kovskaya, S. M.; Pojman, D. A.

doi:10.1007/s10808-006-0042-z

Cited by 10 publications

(11 citation statements)

References 7 publications

(7 reference statements)

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“…We point out that g-jitter can affect fluid processes (Alexander 1994;Ishikawa et al 1994;Tang et al 1994Tang et al , 1995Tang et al , 1996Wheeler and Murray 1998). Gaponenko et al (2006) have considered the effect of vibration on this miscible polymer-monomer system. Their simulations show that for k ≥ 10 −10 N, g-jitter would not essentially perturb the flow.…”

Section: Effects Of Conversion and Thermal Expansionmentioning

confidence: 99%

Numerical Simulations of Convection Induced by Korteweg Stresses in a Miscible Polymer–Monomer System: Effects of Variable Transport Coefficients, Polymerization Rate and Volume Changes

Chekanov

Wyatt

Bessonov

et al. 2008

Microgravity Sci. Technol

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We modeled a miscible polymer-monomer system with a sharp transition zone separating the two fluids to determine if convection analogous to Marangoni convection in immiscible fluids could occur because of thermal and concentration gradients. We considered three cases: with a temperature gradient along the transition zone, with a variable transition zone width, and one with a gradient in the conversion of polymerization. Using the Navier-Stokes equations with an additional term, the Korteweg stress term arising from non-local interactions in the fluid, we demonstrated with realistic parameters that measurable fluid flow would result in the absence of buoyancy-driven convection for all three cases. We show that even if the Korteweg stress is not a function of temperature, the increase in the diffusion coefficient with temperature can result in convection because a gradient in the transition zone width develops. We also examine the effects of a polymer viscosity that is not only a function of concentration but also temperature. We demonstrate that a constant flux of heat, as would be realistic for a heating element in contact with the side of the reactor, would produce a greater flow than a linear thermal gradient parallel to the transition zone. We demonstrate that qualitatively different flow patterns can be realized by using unusual initial conditions that could be realized with different masks for the photopolymerization. We also demonstrate that the volume change during polymerization and caused by side heating could not cause significant fluid flow that would confound the observation of Korteweg-stress induced flows. To avoid buoyancy-driven convection, the experiment would have to be performed in microgravity.

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Section: Effects Of Conversion and Thermal Expansionmentioning

confidence: 99%

Numerical Simulations of Convection Induced by Korteweg Stresses in a Miscible Polymer–Monomer System: Effects of Variable Transport Coefficients, Polymerization Rate and Volume Changes

Chekanov

Wyatt

Bessonov

et al. 2008

Microgravity Sci. Technol

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“…The exciton binding energy Eex for the quantum dots with a size a little larger than the exciton Bohr radius is described by the equation [17]:…”

Section: Resultsmentioning

confidence: 99%

Thermal Conductivity of Zinc Oxide Micro- and Nanocomposites

Turko¹,

Kapustianyk²,

Rudyk³

et al. 2016

J. Nano- Electron. Phys.

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The thermal conductivity of the composite materials based on the zinc oxide powders with different average particle sizes (micrometer, submicrometer and nanometer) dispersed in the polymethylsiloxane (silicone oil) was measured using the radial heat flow method. The thermal conductivity of the composite material based on the commercial ZnO micropowder with an average particle size of 50 m was found to be 0.8 W/(m•K). The thermal conductivity of the composite material on the basis of ZnO nanopowder with an average particle size of approximately 3 nm synthesized using the wet chemistry methods was found to be 2.5 W/(m•K). The discovered enhancement of the above mentioned parameter is considered as manifestation of the quantum size effects in heat transfer.

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“…ADI method is used to solve the time-dependent problem for vorticity, the concentration, the pulsatory pressure amplitude and the stream function. More detail about numerical procedure one may find in (Gaponenko et al 2006).…”

Section: Formulation Of the Problemmentioning

confidence: 99%

Mixing Under Vibrations in Reduced Gravity

Gaponenko¹,

Shevtsova²

2008

Microgravity Sci. Technol

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The aim of this study is to analyze the physical mechanism by which vibrations affect the mixing characteristic of two initially stratified miscible fluids. The translational periodic vibrations of a rigid cell filled with different mixtures (Sc = 7125) are considered. The vibrations with a constant frequency are imposed parallel to the initially planar interface. The ability of the applied vibrations to enhance the flow is examined. At the early stage after imposing the vibrations the KelvinHelmholtz instability is observed in absence and at low level of gravity. Later in time the system undergoes a transition to Rayleigh-Taylor instability. With increasing of gravity level the life-time of Kelvin-Helmholtz instability is decreased. We found the critical value of Gr above which this instability do not developed.

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Effect of High-Frequency Vibration on Convection in Miscible Fluids

Cited by 10 publications

References 7 publications

Numerical Simulations of Convection Induced by Korteweg Stresses in a Miscible Polymer–Monomer System: Effects of Variable Transport Coefficients, Polymerization Rate and Volume Changes

Numerical Simulations of Convection Induced by Korteweg Stresses in a Miscible Polymer–Monomer System: Effects of Variable Transport Coefficients, Polymerization Rate and Volume Changes

Thermal Conductivity of Zinc Oxide Micro- and Nanocomposites

Mixing Under Vibrations in Reduced Gravity

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