A New Form of Velocity Distribution in Rectangular Microchannels with Finite Aspect Ratios

Kashaninejad, Navid

doi:10.20944/preprints201905.0316.v1

Cited by 3 publications

(3 citation statements)

References 34 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 2-dimensional velocity distribution was obtained on the plane where y = 0 in the z-axis direction as Equation (1) [28,29]. The inlet flow rate, Q in , was calculated by integrating the velocity distribution over the width as Equation (2).…”

Section: 𝑢 (𝑥 𝑦mentioning

confidence: 99%

Prevention of Microsphere Blockage in Catheter Tubes Using Convex Air Bubbles

et al. 2020

View full text Add to dashboard Cite

This paper presents a novel method to prevent blockages by embolic microspheres in catheter channels by using convex air bubbles attached to the channels’ inner wall surface. The clogging by microspheres can occur by the arching of the microspheres in the catheter. A few studies have been done on reducing the blockage, but their methods are not suitable for use with embolic catheters. In this study, straight catheter channels were fabricated. They had cavities to form convex air bubbles; additionally, a straight channel without the cavities was designed for comparison. Blockage was observed in the straight channel without the cavities, and the blockage arching angle was measured to be 70°, while no blockage occurred in the cavity channel with air bubbles, even at a geometrical arching angle of 85°. The convex air bubbles have an important role in preventing blockages by microspheres. The slip effect on the air bubble surface and the centrifugal effect make the microspheres drift away from the channel wall. It was observed that as the size of the cavity was increased, the drift distance became larger. Additionally, as more convex air bubbles were formed, the amount of early drift to the center increased. It will be advantageous to design a catheter with large cavities that have a small interval between them.

show abstract

Section: 𝑢 (𝑥 𝑦mentioning

confidence: 99%

Prevention of Microsphere Blockage in Catheter Tubes Using Convex Air Bubbles

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The physics of the problem and governing equations have been thoroughly explained in our previous manuscript [34]. In that work, we limited our approach to no-slip BCs and solve the equations based on that assumption.…”

Section: Formulations and Governing Equationsmentioning

confidence: 99%

“…Previously, we obtained the momentum equation as follows [34]: where and ⁄ is the velocity and pressure gradient in the streamwise direction (i.e., z)…”

Section: =0mentioning

confidence: 99%

Analytical Modeling of Fluid Flow in Hydrophobic, Rectangular Microchannels with General Navier-Slip Boundary Conditions

Kashaninejad¹

2019

Preprint

Self Cite

View full text Add to dashboard Cite

Fluid mechanics of flow in hydrophobic, rectangular microchannels with finite aspect ratios is of paramount importance. In such microchannels, not only the effect of the side walls should be taken into account, but also the classical assumption of no-slip boundary condition (BC) is no longer valid at the solid-liquid interface. Accordingly, slip flow can occur in microchannels fabricated from surfaces with low wetting conditions, hydrophobic surfaces. Determining the interactions of liquid molecules adjacent to solid surface is still a challenging issue, and it is especially important in small scale domains. Herein, the fluid mechanics of flow through rectangular hydrophobic microchannels has been reconsidered by taking into account the general Navier-slip BCs at the solid-liquid interface. For fully developed incompressible flow in microchannels at low Reynolds number, partial differential equation (PDE) of the momentum equation simplifies to the classical Poisson equation. Accordingly, by analytically solving the Poisson equations with general Navier-slip BCs, the most general forms of velocity distributions, flow rate, friction factor and Poiseuille number have been obtained.

show abstract

Acoustophoretic trapping of particles by bubbles in microfluidics

González

Candil²,

Luzuriaga³

2023

Front. Phys.

View full text Add to dashboard Cite

We present in this paper a simple method to produce strategic acoustic particle capture sites in microfluidic channels in a controlled way. Air bubbles are intermittently injected into a micro-capillary with rectangular cross section during a flow motion of liquid suspensions containing micron-sized particles or particles to create bubble-defined “micro-gaps” with size close to 200 µm and spheroidal geometry. The establishment of a 3D standing acoustic wave inside the capillary at a frequency close to 1 MHz produces different radiation forces on solid particles and bubbles, and acoustic streaming around the bubble. While the sample flows, part of the particles collect along the acoustic pressure node established near the central axis and continue circulating aligned through the capillary until reaching the end, where are released enriched. Meanwhile, the bubble travels very fast toward positions of maximum pressure amplitude beside the channel wall, driven by Bjerkness forces, and attach to it, remaining immovable during the acoustic actuation. Some particles adhere to its membrane trapped by the acoustic streaming generated around the oscillating bubble. Changes of frequency were applied to analyze the influence of this parameter on the bubble dynamics, which shows a complete stability once attached to the channel wall. Only increasing the flow motion induces the bubble displacements. Once reached the open air at the end of the capillary, the bubble disappears releasing the trapped particles separated from their initial host suspension with a purity degree. The device presents a very simple geometry and a low-cost fabrication.

show abstract

A New Form of Velocity Distribution in Rectangular Microchannels with Finite Aspect Ratios

Cited by 3 publications

References 34 publications

Prevention of Microsphere Blockage in Catheter Tubes Using Convex Air Bubbles

Prevention of Microsphere Blockage in Catheter Tubes Using Convex Air Bubbles

Analytical Modeling of Fluid Flow in Hydrophobic, Rectangular Microchannels with General Navier-Slip Boundary Conditions

Acoustophoretic trapping of particles by bubbles in microfluidics

Contact Info

Product

Resources

About