Viscosity Estimation of a Suspension with Rigid Spheres in Circular Microchannels Using Particle Tracking Velocimetry

Kawaguchi, Misa; Fukui, Tsuguya; Funamoto, Kenichi; Tanaka, Miho; Tanaka, Mitsuru; Murata, Shigeru; Miyauchi, Satoshi; Hayase, Toshiyuki

doi:10.3390/mi10100675

Cited by 10 publications

(8 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was found that the PDF values were around 0.05 with some variations except for the peripheral layers (y/l = 1.0), indicating the particles flowed homogeneously and were dispersed uniformly in the y-axis direction. This is because inertial effects of the particles were negligible for low Reynolds number condition as we discussed in previous studies [8], [15], [21]. It is worth mentioning that the values of PDF were almost zero, i.e., no particles were observed, in the peripheral layers for the case  = 1.02 and 2.04% due to strong repulsive forces from the channel wall.…”

Section: Governing Equations For Suspended Particlessupporting

confidence: 49%

Consideration of the Microstructure of Particle Suspension to Estimate Its Intrinsic Viscosity

Fukui

Kawaguchi

Morinishi

2021

WIT Transactions on Engineering Sciences

View full text Add to dashboard Cite

It is important to comprehend rheology of particle suspension to facilitate useful and effective applications in many fields. It is well known that relative viscosity for higher concentration becomes higher than that form Einstein's viscosity equation. One of the reasons is interaction between suspended particles and suspending fluids. We previously considered the influence of interactions on increase in relative viscosity by focusing on the suspended particles' rotational motions. For higher concentrated suspensions, the rotational motions were disturbed because particles were too jammed to move freely, especially in rotational direction. Since these rotational motions were strongly related to the total macroscopic fluid resistance, the relative viscosity depended on the microscopic gaps between the particles. In the meantime, relationships between microstructure, i.e., spatial arrangement of the particles, and rheology are still unclear. In this study, therefore, numerical simulations were conducted to consider relative and intrinsic viscosities in terms of microstructure of suspensions. The results showed that the concentration profile of the particle suspension was almost flat except for near the channel wall. Few particles flowed near the wall because repulsive force from the wall increased exponentially with approaching the wall. They flowed away from the channel wall. For the higher concentrated suspension, on the other hand, particles were too jammed to flow smoothly near the channel center. Then some particles were pushed out toward the channel wall against the repulsive force. In this case, they flowed near the channel wall as well. Owing to these effects, the concentration profile for the concentrated suspension depicted almost flat including near the wall. The microstructure for higher concentrated suspension also changed with changes in concentration profile. Then the relative and intrinsic viscosities were consequently increased with concentration. The intrinsic viscosity was significantly related to the microstructure of the suspension.

show abstract

Section: Governing Equations For Suspended Particlessupporting

confidence: 49%

Consideration of the Microstructure of Particle Suspension to Estimate Its Intrinsic Viscosity

Fukui

Kawaguchi

Morinishi

2021

WIT Transactions on Engineering Sciences

View full text Add to dashboard Cite

show abstract

“…For the case Reynolds number Re = 4, particles flowed with spreading uniformly in the width direction. In our previous experimental study [16], [17], we have shown these uniform concentration profiles under lower Reynolds number conditions, in which lift force of the particles is negligible. For the case Re = 16, on the other hand, particles flowed with migrating widthwise toward specific regions around y = ±0.5l.…”

Section: Governing Equations For Suspended Particlesmentioning

confidence: 53%

Numerical Study of the Microstructure of a Dilute Suspension to Assess Its Thixotropic Behavior by a Two-Way Coupling Scheme

Fukui

Kawaguchi

Morinishi

2020

WIT Transactions on Engineering Sciences

View full text Add to dashboard Cite

It is important to comprehend the microstructure of a suspension in a pressure-driven flow to control its rheological properties. The microstructure is usually assessed based on spatial arrangement of the particles, i.e., how suspended particles flow in a channel. The spatial patterns in the width direction rather than those in the axial one are more important because near-wall particles may increase the equivalent intrinsic viscosity significantly. The viscous dissipation near the channel wall, which is directly related to the pressure drop, depends on how and where suspended particles flow in a channel. A thixotropic behavior of a suspension is partly due to these microstructure changes; however, it has not been completely clarified yet. Therefore, the aim of this study is to consider microstructure changes of a dilute suspension attributed to the inertial effects of the suspended particles, and its accompanying macroscopic rheology changes by a two-way coupling scheme. Pressure-driven suspension flow simulations were conducted by regularized lattice Boltzmann method. A periodic boundary condition was applied in the axial direction of the channel to reduce computational costs. The suspended particles were assumed to be rigid, neutrally buoyant, and chemically stable. The flow simulations were then performed by up to 100 nondimensional time to consider temporal changes in the microstructure. As a result, the microstructure of a suspension was observed to change in time mainly due to inertial effects of the suspended particles. The thixotropic behavior of a dilute suspension due to inertial effects was successfully reproduced by considering changes in its microstructure.

show abstract

“…Current methods for particle tracking in holography and microscopy are limited in their ability to simultaneously provide a wide field of view (laterally and in depth) and real-time imaging while maintaining microscopic resolution. 3 – 5 Optical coherence tomography (OCT) is emerging as a modality that is particularly amenable to characterizing fluid flow and rheological properties because it offers high-speed, depth-resolved imaging with microscopic resolution. 6 , 7 Here we propose a new platform for visualizing biofluid motion under physiologic shear with OCT, which is capable of tracking microscale fluid motions over millimeter fields of view, in combination with a microparallel plate strain induction chamber (MPPSIC) amenable to real-time OCT imaging.…”

Section: Introductionmentioning

confidence: 99%

OCT particle tracking velocimetry of biofluids in a microparallel plate strain induction chamber

2021

View full text Add to dashboard Cite

. Significance: Imaging biofluid flow under physiologic conditions aids in understanding disease processes and health complications. We present a method employing a microparallel plate strain induction chamber (MPPSIC) amenable to optical coherence tomography to track depth-resolved lateral displacement in fluids in real time while under constant and sinusoidal shear. Aim: Our objective is to track biofluid motion under shearing conditions found in the respiratory epithelium, first validating methods in Newtonian fluids and subsequently assessing the capability of motion-tracking in bronchial mucus. Approach: The motion of polystyrene microspheres in aqueous glycerol is tracked under constant and sinusoidal applied shear rates in the MPPSIC and is compared with theory. Then 1.5 wt. % bronchial mucus samples considered to be in a normal hydrated state are studied under sinusoidal shear rates of amplitudes 0.7 to . Results: Newtonian fluids under low Reynolds conditions ( ) exhibit velocity decreases directly proportional to the distance from the plate driven at both constant and oscillating velocities, consistent with Navier–Stokes’s first and second problems at finite depths. A 1.5 wt. % mucus sample also exhibits a uniform shear strain profile. Conclusions: The MPPSIC provides a new capability for studying biofluids, such as mucus, to assess potentially non-linear or strain-rate-dependent properties in a regime that is relevant to the mucus layer in the lung epithelium.

show abstract

Viscosity Estimation of a Suspension with Rigid Spheres in Circular Microchannels Using Particle Tracking Velocimetry

Cited by 10 publications

References 52 publications

Consideration of the Microstructure of Particle Suspension to Estimate Its Intrinsic Viscosity

Consideration of the Microstructure of Particle Suspension to Estimate Its Intrinsic Viscosity

Numerical Study of the Microstructure of a Dilute Suspension to Assess Its Thixotropic Behavior by a Two-Way Coupling Scheme

OCT particle tracking velocimetry of biofluids in a microparallel plate strain induction chamber

Contact Info

Product

Resources

About