IVIDIL: on-board g-jitters and diffusion controlled phenomena

Shevtsova, Valentina; Lyubimova, T. P.; Saghir, Ziad; Melnikov, Denis; Gaponenko, Yuri; Sechenyh, Vitaliy; Legros, Jean Claude; Mialdun, Aliaksndr

doi:10.1088/1742-6596/327/1/012031

Cited by 34 publications

(39 citation statements)

References 18 publications

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“…On one of the days the gravitational environment had stronger perturbations, measured by SAMS (Space Acceleration Measurement System). It resulted in a slightly larger scattering of the experimental points (Shevtsova et al 2011a), but the results coincided with those from the other days and with the numerical separation for the free-convection case.…”

Section: Impact Of the Microgravity Environment Onboard The Iss On DIsupporting

confidence: 81%

Dynamics of a binary mixture subjected to a temperature gradient and oscillatory forcing

et al. 2015

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We examine the dynamics of a binary mixture in a cubic cell subjected to a temperature differential and oscillatory forcing. The Soret effect, which is negative in the present study, provides a coupling mechanism by which a temperature gradient establishes a concentration gradient in a mixture. We present the results of experiments that were performed on the International Space Station (ISS) and compare the observations with the results of direct numerical simulations. The evolution of temperature and concentration fields is investigated by optical digital interferometry. One advantage of the experimental technique is the observation of the fields along two perpendicular directions of the cell, allowing us to restore the three-dimensional field. Experimental evidence disproves speculations that the ISS microgravity environment always affects diffusion-controlled processes. Furthermore, we demonstrate that imposed vibrations with constant frequency and amplitude create slow mean flows and that they do influence the diffusion kinetics. The perturbation of the diffusive fields scales as the square of the vibrational velocity. In addition to calculations of the full three-dimensional Navier-Stokes equations, a two-time-scale computational methodology is used for situations in which the forcing period is very small compared to the natural time scales of the problem. The simulations show excellent agreement with experimental observations.

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Section: Impact Of the Microgravity Environment Onboard The Iss On DIsupporting

confidence: 81%

Dynamics of a binary mixture subjected to a temperature gradient and oscillatory forcing

et al. 2015

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“…The fluids used were 90 % (mass) of water in isopropanol and 50 % (mass) of water in isopropanol. The concentrations of the liquids were chosen for their well-known properties due to the experience of handling them (Mazzoni et al 2010;Shevtsova et al 2011). The parameters of the mixtures are presented in table 1.…”

Section: The Experimentsmentioning

confidence: 99%

Dynamics of the interface between miscible liquids subjected to horizontal vibration

et al. 2015

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We present experimental evidence of the existence of an interfacial instability between two miscible liquids of similar (but non-identical) viscosities and densities under horizontal vibration. A stably stratified two-layer system is composed of the same binary mixture with different concentrations placed in a confined cell (with length twice as large as the height). Unlike the case of immiscible fluids, here, the interface is a transient layer of small but non-zero thickness. In the experiments, the frequency and amplitude were varied within the ranges 2-24 Hz and 1.5-16 mm, respectively. When the value of the oscillatory forcing increases, the amplitudes of the interface perturbations grow continuously, forming a saw-tooth frozen structure. This evolution is also examined numerically. In addition to the solutions of full 3-D Navier-Stokes equations, an averaging approach with separation of time scales is used for situations in which the forcing period is very small compared to the natural time scales of the problem. The simulation of averaged equations provides the explanation of the instability development, the calculations of the full nonlinear equations shed light on the decay of a wavy pattern. The results of numerical modelling perfectly support the experimental observations.

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“…19 The technique was subsequently used to measure thermodiffusion in water-isopropanol mixtures in the International Space Station, 25 and investigate the influence of vibrations on the diffusion in liquids. 37,38 In space, ODI from two perpendicular views was used to follow a component separation C of less than 1% of its initial mean value. In these experiments, however, the measurement time is rather long, e.g., about 18 h for the space experiments.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Soret and Fickian diffusion coefficients by orthogonal phase-shifting interferometry and its application to protein aqueous solutions

Torres

Komiya

Henry

et al. 2013

The Journal of Chemical Physics

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We have developed a method to measure thermodiffusion and Fickian diffusion in transparent binary solutions. The measuring instrument consists of two orthogonally aligned phase-shifting interferometers coupled with a single rotating polarizer. This high-resolution interferometer, initially developed to measure isothermal diffusion coefficients in liquid systems [J. F. Torres, A. Komiya, E. Shoji, J. Okajima, and S. Maruyama, Opt. Lasers Eng. 50, 1287 (2012)], was modified to measure transient concentration profiles in binary solutions subject to a linear temperature gradient. A convectionless thermodiffusion field was created in a binary solution sample that is placed inside a Soret cell. This cell consists of a parallelepiped cavity with a horizontal cross-section area of 10 × 20 mm(2), a variable height of 1-2 mm, and transparent lateral walls. The small height of the cell reduces the volume of the sample, shortens the measurement time, and increases the hydrodynamic stability of the system. An additional free diffusion experiment with the same optical apparatus provides the so-called contrast factors that relate the unwrapped phase and concentration gradients, i.e., the measurement technique is independent and robust. The Soret coefficient is determined from the concentration and temperature differences between the upper and lower boundaries measured by the interferometer and thermocouples, respectively. The Fickian diffusion coefficient is obtained by fitting a numerical solution to the experimental concentration profile. The method is validated through the measurement of thermodiffusion in the well-known liquid pairs of ethanol-water (ethanol 39.12 wt.%) and isobutylbenzene-dodecane (50.0 wt.%). The obtained coefficients agree with the literature values within 5.0%. Finally, the developed technique is applied to visualize biomolecular thermophoresis. Two protein aqueous solutions at 3 mg∕ml were used as samples: aprotinin (6.5 kDa)-water and lysozyme (14.3 kDa)-water. It was found that the former protein molecules are thermophilic and the latter thermophobic. In contrast to previously reported methods, this technique is suitable for both short time and negative Soret coefficient measurements.

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IVIDIL: on-board g-jitters and diffusion controlled phenomena

Cited by 34 publications

References 18 publications

Dynamics of a binary mixture subjected to a temperature gradient and oscillatory forcing

Dynamics of a binary mixture subjected to a temperature gradient and oscillatory forcing

Dynamics of the interface between miscible liquids subjected to horizontal vibration

Measurement of Soret and Fickian diffusion coefficients by orthogonal phase-shifting interferometry and its application to protein aqueous solutions

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