Numerical investigation of high-peclet-number mixing in periodically curved microchannel with strong curvature

Kuo, Ming Ying; Wu, Chih Yang; Hsu, Kai-Lan; Chang, Chia Yuan; Jiang, Wei

doi:10.1080/01457632.2018.1497120

Cited by 11 publications

(10 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The grid-based solutions of the convective–diffusive equation suffer from the false numerical diffusion at a high Peclet number [ 42 ]. Therefore, to simulate fluid mixing in the proposed micromixers under various conditions, we adopt the particle tracking method with an approximation diffusion model (ADM), which is virtually free of numerical diffusion in high-Peclet-number flows and takes less computation time than the random-walk particle-tracking method [ 43 , 44 ]. To determine the non-diffused concentration field, we undertake the particle-tracking simulation, which is illustrated by an example shown in Figure 2 .…”

Section: Mixer Geometry Governing Equations and Computational Promentioning

confidence: 99%

“…The displacements are repeated until the particle crosses either of the two inlets. The details of the backward particle-tracking simulation were reported by Kuo et al [ 44 ]. Next, the diffused concentration field is obtained by solving the approximation diffusion equation with the non-diffused concentration field as the initial condition.…”

Section: Mixer Geometry Governing Equations and Computational Promentioning

confidence: 99%

See 1 more Smart Citation

Numerical Study of T-Shaped Micromixers with Vortex-Inducing Obstacles in the Inlet Channels

Lai

2020

Micromachines

Self Cite

View full text Add to dashboard Cite

To enhance fluid mixing, a new approach for inlet flow modification by adding vortex-inducing obstacles (VIOs) in the inlet channels of a T-shaped micromixer is proposed and investigated in this work. We use a commercial computational fluid dynamics code to calculate the pressure and the velocity vectors and, to reduce the numerical diffusion in high-Peclet-number flows, we employ the particle-tracking simulation with an approximation diffusion model to calculate the concentration distribution in the micromixers. The effects of geometric parameters, including the distance between the obstacles and the angle of attack of the obstacles, on the mixing performance of micromixers are studied. From the results, we can observe the following trends: (i) the stretched contact surface between different fluids caused by antisymmetric VIOs happens for the cases with the Reynolds number (Re) greater than or equal to 27 and the enhancement of mixing increases with the increase of Reynolds number gradually, and (ii) the onset of the engulfment flow happens at Re≈125 in the T-shaped mixer with symmetric VIOs or at Re≈140 in the standard planar T-shaped mixer and results in a sudden increase of the degree of mixing. The results indicate that the early initiation of transversal convection by either symmetric or antisymmetric VIOs can enhance fluid mixing at a relatively lower Re.

show abstract

Section: Mixer Geometry Governing Equations and Computational Promentioning

confidence: 99%

Section: Mixer Geometry Governing Equations and Computational Promentioning

confidence: 99%

Numerical Study of T-Shaped Micromixers with Vortex-Inducing Obstacles in the Inlet Channels

Lai

2020

Micromachines

Self Cite

View full text Add to dashboard Cite

show abstract

“…The method used for mixing index is by using the particle tracking procedure as explained in the recent research paper. 36 The mixing index formula (37) used is given by the formula…”

Section: Numerical Equations and Boundary Conditionsmentioning

confidence: 99%

“…The method used for mixing index is by using the particle tracking procedure as explained in the recent research paper. 36 The mixing index formula ( 37 ) used is given by the formula Standard variance in the form of the mass fraction on a cross-sectional plane is where n is the number of sample points, C i is the mass fraction sampling point value at a different position on the cross-sectional cut plane. C opt equals 0.5 represents the optimal mixing value.…”

Section: Modeling and Simulationmentioning

confidence: 99%

Numerical analysis of non-aligned inputs M-type micromixers with different shaped obstacles for biomedical applications

Irfan

Shah

Niazi³

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part E:

View full text Add to dashboard Cite

Fluid mixing in lab-on-a-chip devices at laminar flow conditions result in a low mixing index. The reason is dominant diffusion over the convection process. The mixing index can be improved by certain changes in the micromixer structural design like introducing obstacles in the path of fluid flow. These obstacles will make dominant the advection process over the diffusion process. The main contribution of this work is based on proposing the novel hybrid type micromixer design for enhancing the mixing quality. Three non-aligned M-type and non-aligned M-type with obstacles passive type micromixers are analyzed by COMSOL5.5. These designs are hybrid types because different structural changes are combined in a single design for mixing improvement. First of all the straight non-aligned inlets, M-type passive micromixer (SMTM) is analyzed. It is observed that mixing performance is improved because of M-shaped mixing units and non-aligned inlets. This improvement is deemed to be not enough so different shaped obstacles are introduced in the micromixer design. These designs based on obstacles are named horizontal rectangular M-type micromixer, square M-type micromixer, and vertical rectangular M-type micromixer. The mixing index for SMTM, square M-type micromixer, horizontal rectangular M-type micromixer, and vertical rectangular M-type micromixer at Reynolds number Re = 60 is respectively given by 71.1%, 83.21%, 84.45%, and 89.99%. The mixing index of vertical rectangular M-type micromixer was 59.34% − 87.65% for Re = 0.5–100. Vertical rectangular M-type micromixer is concluded with the better-mixing capability design among the proposed ones. Based on these simulation results, the vertical rectangular M-type micromixer design can be utilized for mixing purposes in biomedical applications like nanoparticle synthesis and biomedical sample preparation for drug delivery.

show abstract

“…Thus, during the tracing procedure, the refractive-index value and gradient of each Runge-Kutta point have to be retreived from the refractive indices at grid points obtained by the CFD software and Equation (7). Here, we use Moving Least Squares (MLS) method [ 32 , 33 ] to reconstruct the refractive index at the Runge-Kutta points.…”

Section: Numerical Simulations and Geometrical Parameter Analysismentioning

confidence: 99%

Numerical Investigation of a Designed-Inlet Optofluidic Beam Splitter for Split-Angle and Transmission Improvement

Lin

2021

Micromachines

Self Cite

View full text Add to dashboard Cite

The beam splitter is one of the important elements in optical waveguide circuits. To improve the performance of an optofluidic beam splitter, a microchannel including a two-stage main channel with divergent side walls and two pairs of inlet channels is proposed. Besides, the height of the inlets injected with cladding fluid is set to be less than the height of other parts of the microchannel. When we inject calcium chloride solution (cladding fluid) and deionized water (core fluid) into the inlet channels, the gradient refractive index (GRIN) developed in fluids flowing through the microchannel split the incident light beam into two beams with a larger split angle. Moreover, the designed inlets yield a GRIN distribution which increases the light collected around the middle horizontal line on the objective plane, and so enhances the transmission efficiency of the device. To demonstrate the performance of the proposed beam splitter, we use polydimethylsiloxane to fabricate the microchannel. The results obtained by simulation and experiment are compared to show the effectiveness of the device and the validity of numerical simulation. The influence of the microchannel geometry and the flow rate ratio on the performance of the proposed beam splitter is investigated.

show abstract

Numerical investigation of high-peclet-number mixing in periodically curved microchannel with strong curvature

Cited by 11 publications

References 27 publications

Numerical Study of T-Shaped Micromixers with Vortex-Inducing Obstacles in the Inlet Channels

Numerical Study of T-Shaped Micromixers with Vortex-Inducing Obstacles in the Inlet Channels

Numerical analysis of non-aligned inputs M-type micromixers with different shaped obstacles for biomedical applications

Numerical Investigation of a Designed-Inlet Optofluidic Beam Splitter for Split-Angle and Transmission Improvement

Contact Info

Product

Resources

About