Three-dimensional observation of Brownian particles under steady shear flow by stereo microscopy

Takikawa, Yuichi; Nunokawa, Takahiro; Sasaki, Yuji; Iwata, Makoto; Orihara, Hiroshi

doi:10.1103/physreve.100.022102

Cited by 8 publications

(5 citation statements)

References 17 publications

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“…One possible explanation could be the Brownian motion of the nanoparticles. In shear flow, the Brownian motion exhibits anomalous (higher) di↵usion in the flow direction, modifying the mean square displacement from a proportionality with time t (as in the neutral direction) to t 3 [47,48].…”

Section: Splashing Transition Correlationmentioning

confidence: 99%

“…One possible explanation could be the Brownian motion of the nanoparticles. In shear flow, the Brownian motion exhibits anomalous (higher) diffusion in the flow direction, modifying the mean square displacement from a proportionality with time t (as in the neutral direction) to t 3 [47,48]. The feedback between the lower diffusivity of the nanoparticles compared to the fluid molecules, higher inertia of the particles and hydrodynamic interactions modifies the lamella velocity and hence the gas stress.…”

Section: Splashing Transition Correlationmentioning

confidence: 99%

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Spreading-splashing transition of nanofluid droplets on a smooth flat surface

Aksoy,

Eneren,

Koos

et al. 2021

Preprint

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Hypothesis: Even a small fraction of nanoparticles in fluids affects the splashing behavior of a droplet upon impact on a smooth surface.Experiments: Nanofluid drop impact onto a smooth sapphire substrate is experimentally investigated over wide ranges of Reynolds (10 2 < Re < 10 4 ) and Weber (50 < We < 500) numbers for several nanofluid concentrations (0.01% < φ < 1%) using high-speed photography. Nanofluid suspensions are prepared at different nanoparticle concentrations by diluting a commercial Al2O3-water nanofluid without dispersants in aqueous glycerol. Every sample is experimentally characterized in terms of density, viscosity, and surface tension to demonstrate the observed outcomes on the We-Re maps.Findings: The non-monotonous behavior of the spreading-to-splashing boundary remains the same for nanofluids. However, nanofluids influence this boundary either positively or negatively depending on the Reynolds number; the nanofluids suppress splashing at high Reynolds numbers whereas they promote splashing at low Reynolds numbers. We have explained this behavior caused by the addition of nanoparticles as resulting from an increase in the lamella expansion speed during the initial spreading stage. Finally, we developed an empirical relationship to describe the dependence of the splashing threshold to the nanoparticle concentration for the first time. Highlights• We-Re map is plotted for various nanofluid concentrations.

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Section: Splashing Transition Correlationmentioning

confidence: 99%

Section: Splashing Transition Correlationmentioning

confidence: 99%

Spreading-splashing transition of nanofluid droplets on a smooth flat surface

Aksoy,

Eneren,

Koos

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…With technology to visualize sub-micron scale particles, calculations of diffusion quantification under shear flow have also been experimentally verified (Derksen and van de Water 1990 ). Using 2D planar and 3D stereo imaging systems can visualize the exact trajectories of particles exhibiting Brownian motion, fully capable of characterizing the diffusion aspect of particles under various types of flow (Orihara and Takikawa 2011 ; Takikawa et al 2019 ).…”

Section: Introductionmentioning

confidence: 99%

Quantifying Brownian motion in the presence of simple shear flow with particle diffusometry

Lee

Clayton²,

Kinzer‐Ursem

et al. 2023

Exp Fluids

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Particle diffusometry, a technology derived from particle image velocimetry, quantifies the Brownian motion of particles suspended in a quiescent solution by computing the diffusion coefficient. Particle diffusometry has been used for pathogen detection by measuring the change in solution viscosity due to amplified DNA from a specific gene target. However, particle diffusometry fails to calculate accurate measurements at elevated temperatures and fluid flow. Therefore, these two current limitations hinder the potential application where particle diffusometry can further be used. In this work, we expanded the usability of particle diffusometry to be applied to fluid samples with simple shear flow and at various temperatures. A range of diffusion coefficient videos is created to simulate the Brownian motion of particles under flow and temperature conditions. Our updated particle diffusometry analysis forms a correction equation under three different polynomial degrees of shear flow with varying flow rates and temperatures between 25 and 65 °C. An experiment in a channel with a rectangular cross section using a syringe pump to generate a constant flow is done to analyze the modified algorithm. In simulation analysis, the modified algorithm successfully computes the diffusion coefficients with 10% error for an average flow rate of up to 8 on all three flow types. Complementary experiments confirm the simulation results. Graphical abstract

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“…With technology to visualize sub-micron scale particles, calculations of diffusion quanti cation under shear ow have also been experimentally veri ed (Derksen and van de Water 1990). The exact movements of Brownian particles can be visualized using 2D planar and 3D stereo imaging systems, which are fully capable of characterizing the diffusion aspect of particles under various types of ow (Orihara and Takikawa 2011;Takikawa et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Quantifying Brownian Motion in the Presence of Simple Shear Flow with Particle Diffusometry

Lee

Clayton²,

Kinzer‐Ursem

et al. 2022

Preprint

View full text Add to dashboard Cite

Particle Diffusometry, a technology derived from particle image velocimetry, quantifies the Brownian motion of particles suspended in a quiescent solution by computing the diffusion coefficient. Particle Diffusometry has been used for pathogen detection by measuring the change in solution viscosity due to the presence of amplified DNA from a specific gene target. However, Particle Diffusometry fails to calculate accurate measurements at elevated temperatures and in the presence of fluid flow. Therefore, these two current limitations hinder the potential application where Particle Diffusometry can further be used.In this work, we expanded the usability of Particle Diffusometry to be applied to fluid samples with the simple shear flow and at various temperatures. A range of diffusion coefficient videos is created to simulate the Brownian motion of particles under flow and temperature conditions. From our updated Particle Diffusometry analysis, a correction equation is formed under three different polynomial degrees of shear flow with varying flow rates and temperatures between 25 and 65 degrees. A model experiment involving the syringe pump and rectangular channel geometry provided a uniform flow for analyzing the modified algorithm. In simulation analysis, the modified algorithm successfully computes the diffusion coefficients with ± 10% error for shear rates as large as 8 pixel/Δt on all three flow types. Complementary experiments confirm the simulation results.

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Three-dimensional observation of Brownian particles under steady shear flow by stereo microscopy

Cited by 8 publications

References 17 publications

Spreading-splashing transition of nanofluid droplets on a smooth flat surface

Spreading-splashing transition of nanofluid droplets on a smooth flat surface

Quantifying Brownian motion in the presence of simple shear flow with particle diffusometry

Quantifying Brownian Motion in the Presence of Simple Shear Flow with Particle Diffusometry

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