Efficient microfluidic rectifiers for viscoelastic fluid flow

Sousa, P.C.; Pinho, F.T.; Oliveira, Mónica; Alves, M.A.

doi:10.1016/j.jnnfm.2010.03.005

Cited by 69 publications

(64 citation statements)

References 56 publications

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“…Moreover, it is also worth noting that the curve obtained for the real porous medium lies between those obtained for the microchannels. In real porous media, there indeed exists a critical value for the Deborah number (De cr ) above which the pressure gradient rises significantly due to elastic effects that also grow with the flow rate (Sousa et al 2010;Rodd et al 2005;Groisman et al 2003). For the PAA solutions here considered this critical value is De % 1:6; as it is clear from Fig.…”

Section: Pressure Lossesmentioning

confidence: 75%

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Microfluidic systems for the analysis of viscoelastic fluid flow phenomena in porous media

Galindo-Rosales

Campo-Deaño

Pinho

et al. 2011

Microfluid Nanofluid

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The Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. RESEARCH PAPERMicrofluidic systems for the analysis of viscoelastic fluid flow phenomena in porous media Abstract In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application.

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Section: Pressure Lossesmentioning

confidence: 75%

“…These concentrations are well below the overlap concentration (c Ã ¼ 512 ppm) (Sousa et al 2010). Solutions were prepared by mixing the polymer into the solvent (de-ionized water) at different concentrations, utilizing magnetic stirrers at low angular speed to avoid mechanical degradation of the polymer molecules.…”

Section: Methodsmentioning

confidence: 99%

Microfluidic systems for the analysis of viscoelastic fluid flow phenomena in porous media

Galindo-Rosales

Campo-Deaño

Pinho

et al. 2011

Microfluid Nanofluid

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“…In this microchannel, the higher value of the εH or total deformation experienced by the cells, indicates that the extensional flow is enhanced. On the other hand, it is important to note that the shear effects in the narrow part of the microchannel with εH = 3 can be more significant than in the microchannel with εH = 2 16 . Moreover, it is also clear that the enhancement is more pronounced by increasing the number of the series of contractions.…”

Section: Resultsmentioning

confidence: 99%

“…Hence, the current work has performed, for the first time, in vitro blood experiments in hyperbolic-shaped microchannels with different Hencky strains, in order to assess the effect of the extensional flow on the CFL thickness. In addition, knowing that viscoelastic fluids subjected to extensional effects are enhanced when a sequence of hyperbolic-type contractions are used 16 , the current study have tested series of elements containing hyperbolic contractions followed by an abrupt expansion in order to evaluate the separation of RBCs from blood plasma.…”

Section: Introductionmentioning

confidence: 99%

In vitro blood flow and cell-free layer in hyperbolic microchannels: Visualizations and measurements

et al. 2015

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Red blood cells (RBCs) in microchannels has tendency to undergo axial migration due to the parabolic velocity profile, which results in a high shear stress around wall that forces the RBC to move towards the centre induced by the tank treading motion of the RBC membrane. As a result there is a formation of a cell free layer (CFL) with extremely low concentration of cells. Based on this phenomenon, several works have proposed microfluidic designs to separate the suspending physiological fluid from whole in vitro blood. This study aims to characterize the CFL in hyperbolic-shaped microchannels to separate RBCs from plasma. For this purpose, we have investigated the effect of hyperbolic contractions on the CFL by using not only different Hencky strains but also varying the series of contractions. The results show that the hyperbolic contractions with a Hencky strain of 3 and higher, substantially increase the CFL downstream of the contraction region in contrast with the microchannels with a Hencky strain of 2, where the effect is insignificant. Although, the highest CFL thickness occur at microchannels with a Hencky strain of 3.6 and 4.2 the experiments have also shown that cells blockage are more likely to occur at this kind of microchannels. Hence, the most appropriate hyperbolic-shaped microchannels to separate RBCs from plasma is the one with a Hencky strain of 3.

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“…27 Moreover, the flow of a Newtonian fluid (de-ionized water) is also investigated in order to validate the experimental techniques and to be used as reference.…”

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confidence: 99%

High performance microfluidic rectifiers for viscoelastic fluid flow

et al. 2012

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This version is available at https://strathprints.strath.ac.uk/41334/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the The flow of Newtonian and non-Newtonian fluids within microfluidic rectifiers with a hyperbolic shape was investigated to assess the effect of the bounding walls on the diodicity of the microfluidic device and achieve high flow anisotropy. Three microchannels were used, with different depths and the same geometrical configuration, which creates a strong extensional flow and generates high anisotropic flow resistance between the two flow directions. The Newtonian fluid, de-ionized water, was used as a reference fluid. The viscoelastic fluid used was an aqueous solution of polyethylene oxide (0.1% w/w) with high molecular weight. The flow patterns were visualized using streak photography and the velocity field was investigated using micro-particle image velocimetry. Moreover, pressure drop measurements were performed in order to compare the diodicity achieved in the microfluidic rectifiers. For the Newtonian fluid flow, the experimental results are compared with numerical predictions obtained using a finite-volume method and good agreement was found between both. For the viscoelastic fluid, significant anisotropic flow resistance can be achieved. The effect of the bounding walls is analysed and found to be qualitatively similar for all microchannels. Nevertheless, in quantitative terms, the diodicity is enhanced when the wall effect is reduced, i.e. when the channels are deeper. A maximum diodicity above six was found for the deeper channel, a value well beyond those previously reported.

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Efficient microfluidic rectifiers for viscoelastic fluid flow

Cited by 69 publications

References 56 publications

Microfluidic systems for the analysis of viscoelastic fluid flow phenomena in porous media

Microfluidic systems for the analysis of viscoelastic fluid flow phenomena in porous media

In vitro blood flow and cell-free layer in hyperbolic microchannels: Visualizations and measurements

High performance microfluidic rectifiers for viscoelastic fluid flow

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