Mixing performance of an electroosmotic micromixer with Koch fractal structure

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Siyue Xiong ◽  
Xueye Chen
Keyword(s):  
Fractal Structure ◽  
Low Voltage ◽  
Mixing Efficiency ◽  
Electrode Position ◽  
Fractal Structures ◽  
Mixing Performance ◽  
Electrode Voltage ◽  
Koch Fractal ◽  
Koch Fractal Principle ◽  
Short Time

Abstract In this paper, we have designed a Koch fractal electroosmotic micromixer (KFEM). A low-voltage electroosmotic micromixer. In order to optimize the electrode position, Koch microchannel is designed according to the Koch fractal principle and the electrode pairs based on the fractal are arranged. Then the effect of electrode voltage, electrode distribution positions, the number of electrode pairs, two kinds of Koch fractal structures, Reynolds (Re) number and the frequency of alternating current (AC) on the mixing performance are studied. The results show that the mixing efficiency can reach 99% in a short time when the AC voltage is 1 V, the AC frequency is 12 Hz and the electroosmotic micromixer has two sets of electrode pairs.

Numerical simulation of three-dimensional passive micromixer based on the principle of Koch fractal

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Siyue Xiong ◽  
Xueye Chen
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Cross Section ◽  
Three Dimensional ◽  
Mixing Efficiency ◽  
Mixing Performance ◽  
Chaotic Convection ◽  
Passive Micromixer ◽  
Koch Fractal ◽  
Koch Fractal Principle

Abstract In this paper, We arrange the obstacles based on the Koch fractal principle (OKF) in the micromixer. By changing the fluid flow and folding the fluid, a better mixing performance is achieved. We improve the mixing efficiency by placing OKF and changing the position of OKF, then we studied the influence of the number of OKF and the height of the micromixer on the mixing performance. The results show that when eight OKF are staggered in the microchannel and the height is 0.2 mm, the mixing efficiency of the OKF micromixer can reach 97.1%. Finally, we compared the velocity cross section and velocity streamline of the fluid, and analyzed the influence of OKF on the concentration trend. Through analysis, it is concluded that OKF can generate chaotic convection in the fluid, and enhance the mixing of fluids by generating vortices and folding the fluid. It can effectively improve the mixing efficiency of the micromixer.

CO2 LASER ABLATION MICROCHANNEL BASED ON KOCH FRACTAL PRINCIPLE

2019 ◽  
Vol 27 (05) ◽  
pp. 1950141
Author(s):  
XUEYE CHEN ◽  
YUE TIAN ◽  
SHUAI ZHANG
Keyword(s):  
Mixing Time ◽  
Laser System ◽  
Scanning Speed ◽  
Mixing Efficiency ◽  
Thermal Bonding ◽  
Manufacturing Method ◽  
Laser Systems ◽  
Koch Fractal ◽  
Koch Fractal Principle ◽  
The Impact

In this paper, we focussed on the processing power of CO2 laser systems and the impact of scanning speed, scanning power and number of scans on the quality of microchannels. We created microchannels which are based on the Koch fractal principle through a flexible and low-cost CO2 laser system. The processing and manufacturing method of Koch fractal micromixer on polymethyl methacrylate (PMMA) substrate was also studied. The microchannel structure based on the Koch fractal principle can increase the contact area and mixing time of the fluid and improve the mixing efficiency of the micromixer. In the experiment, our speed is 2, 4 and 6[Formula: see text]mm/s, the number of scans is 2/3/4 times and the power is 4, 8 and 12[Formula: see text]W. As the power and number of scans increase and the speed decreases, the width and depth of the microchannel are changed more clearly, which contributes to the successful thermal bonding of the Koch fractal micromixer and avoids thermal bonding due to overvoltage. By comparing the experimental data, we found that the width and depth of the channel are ideal when the speed is 2[Formula: see text]mm/s, the number of scans is 4 and the power is 12[Formula: see text]W. Because of the lower cost of PMMA, the use of CO2 laser systems to fabricate microchannels on PMMA substrates will have broad application value, reduce cost and be easier to manufacture.

scholarly journals A novel three-dimensional electroosmotic micromixer based on the Koch fractal principle

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12860-12865
Author(s):  
Siyue Xiong ◽  
Xueye Chen ◽  
Jinyuan Wang
Keyword(s):  
Three Dimensional ◽  
Mixing Performance ◽  
Koch Fractal ◽  
Koch Fractal Principle

Mixing performance of micromixers. (a) The voltage value is 0 V. (b) The voltage value is 3 V. (c) The voltage value is 10 V.

Comparison Study of Hilbert Sierpinski and Koch Fractal Structure on Coplanar Vivaldi Antenna for L/S band Application

2020 ◽  
Author(s):  
Nurhayati Nurhayati ◽  
Alexandre M. De Oliveira ◽  
Antonio. M. de Oliveira ◽  
Raimundo Eider Figueredo ◽  
Marco Antonio B. Pinto ◽  
...  
Keyword(s):  
Fractal Structure ◽  
Comparison Study ◽  
Vivaldi Antenna ◽  
Koch Fractal

MATHEMATICAL MODELS OF GEOFILTRRATION AND GEOMIGRATION IN POROUS MEDIA WITH FRACTAL STRUCTURE

2020 ◽  
Vol 6 (3) ◽  
pp. 21-27
Author(s):  
R.A. Yusupov ◽  
◽  
Sh.S. Axrolov ◽  
N.M. Mirzanova ◽  
A.N. Nasiriddinov ◽  
...  
Keyword(s):  
Porous Media ◽  
Mathematical Models ◽  
Linear Models ◽  
Fractal Structure ◽  
Fractal Structures

In this study 2-D linear models are coming from generalised, Boussinesq eqution describing geofiltration in soils with fractal structures are presented. In this study are presented too mathematical models geomigration of contaminations with groundwater in classical way and in soils with fractal structures.

A NOVEL 3D MICROMIXER WITH QUARTIC KOCH CURVE FRACTAL

2021 ◽  
pp. 2150049
Author(s):  
SIYUE XIONG ◽  
XUEYE CHEN
Keyword(s):  
Numerical Simulation ◽  
Deflection Angle ◽  
Reynolds Numbers ◽  
Mixing Efficiency ◽  
Flow State ◽  
Koch Curve ◽  
Mixing Performance ◽  
Chaotic Convection ◽  
The Deflection Angle ◽  
High Application

In this paper, we mainly study the mixing performance of the micromixer with quartic Koch curve fractal (MQKCF) by numerical simulation. Changing the structure of the microchannel based on the fractal principle can significantly improve the fluid flow state in the microchannel and improve the mixing efficiency of the micromixer. This paper discussed the effects of different fractal deflection angles, microchannel heights and different fractal times on the mixing efficiency under four different Reynolds numbers (Re). It is found that changing the deflection angle of the fractal can bring extremely high benefits, which makes the fluid deflect and fold in the microchannel, enhancing the chaotic convection in the microchannel, and improve the mixing efficiency of the fluid. Under the reasonable arrangement of the quartic Koch curve fractal principle, it can give the micro-mixture more than 99% mixing efficiency. Based on the excellent mixing performance of MQKCF, it also has extremely high application value in the biochemical neighborhood.

scholarly journals A 3D Printed Jet Mixer for Centrifugal Microfluidic Platforms

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 695 ◽  
Author(s):  
Yunxia Wang ◽  
Yong Zhang ◽  
Zheng Qiao ◽  
Wanjun Wang
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Mixing Efficiency ◽  
Medical Applications ◽  
Microfluidic Platforms ◽  
Mixing Performance ◽  
Wide Range ◽  
3D Printed ◽  
Miscible Liquids ◽  
Biological And Medical Applications

Homogeneous mixing of microscopic volume fluids at low Reynolds number is of great significance for a wide range of chemical, biological, and medical applications. An efficient jet mixer with arrays of micronozzles was designed and fabricated using additive manufacturing (three-dimensional (3D) printing) technology for applications in centrifugal microfluidic platforms. The contact surface of miscible liquids was enhanced significantly by impinging plumes from two opposite arrays of micronozzles to improve mixing performance. The mixing efficiency was evaluated and compared with the commonly used Y-shaped micromixer. Effective mixing in the jet mixer was achieved within a very short timescale (3s). This 3D printed jet mixer has great potential to be implemented in applications by being incorporated into multifarious 3D printing devices in microfluidic platforms.

Visualizing Coherent and Fractal Structures in Numerical Experiments on Chaotic Advection in Fluids

2005 ◽  
Author(s):  
M. V. Budyansky ◽  
S. V. Prants
Keyword(s):  
Numerical Experiments ◽  
Fractal Structure ◽  
Point Vortex ◽  
Chaotic Advection ◽  
Mixing Zone ◽  
Background Current ◽  
Fractal Structures ◽  
Chaotic Scattering ◽  
And Topology ◽  
Fractal Properties

We investigate typical mixing and fractal properties of chaotic scattering of passive particles in open hydrodynamic flows taking as an example a model two-dimensional incompressible flow composed of a fixed point vortex and a background current with a periodic component, the model inspired by the phenomenon of topographic eddies over mountains in the ocean and atmosphere. We have found, described and visualized a non-attracting invariant chaotic set defining chaotic scattering, fractality, and trapping of incoming particles. Geometry and topology of chaotic scattering have been studied and visualized. Scattering functions in the mixing zone have been found to have a fractal structure with a complicated hierarchy that has been described in terms of strophes and epistrophes. Mixing, trapping, and fractal properties of passive particles have been studied under the influence of a white noise with different amplitudes and frequency ranges. A new effect of clustering the particles in a noised flow has been demonstrated in numerical experiments.

scholarly journals Uncertainty Analysis of Mixing Efficiency Variation in Passive Micromixers due to Geometric Tolerances

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Irina Stanciu
Keyword(s):  
Simulation Model ◽  
Numerical Study ◽  
Geometric Parameters ◽  
Mixing Efficiency ◽  
Mixing Performance ◽  
Probabilistic Simulation ◽  
Geometric Tolerances ◽  
The Monte Carlo Method ◽  
Key Factor ◽  
Geometric Layout

The geometric layout is the key factor for enhancing the efficiency of the fluid mixing in passive micromixers. Therefore, by adjusting the geometric design and by controlling the geometric parameters, one can enhance the mixing process. However, through any fabrication process, the geometric parameters present slight, inherent variation from the designed values than might affect the performance of the micromixer. This paper proposes a numerical study on the influence of the unavoidable geometric tolerances on the mixing efficiency in passive micromixers. A probabilistic simulation model, based on the Monte Carlo method, is developed and implemented for this purpose. An uncertainty simulation model shows that significant deviations from the deterministic design can appear due to small variations in the geometric parameters values and demonstrates how a more realistic mixing performance can be estimated.

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