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.

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.

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.

scholarly journals Effect of Valve Opening Manner and Sealing Method on the Steady Injection Characteristic of Gas Fuel Injector

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1479
Author(s):  
Tianbo Wang ◽  
Lanchun Zhang ◽  
Qian Chen
Keyword(s):  
Steady State ◽  
Three Dimensional ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Injection Efficiency ◽  
Mixing Performance ◽  
Cfd Models ◽  
Valve Opening ◽  
Gas Fuel

The steady-state injection characteristic of gas fuel injector is one of the key factors that affects the performance of gas fuel engine. The influences of different injection strategies, such as different injection angles and different injection positions, on the mixing performance in gas-fueled engine have been emphasized in previous literatures. However, the research on the injection characteristics of the gas fuel injector itself are insufficient. The three-dimensional steady-state computational fluid dynamics (CFD) models of two kinds of injectors, in different opening manners, and the other two kinds of injectors, in different sealing methods, were established in this paper. The core region speed, stagnation pressure loss and mass flow rate were compared. Additionally, the effective injection pressure (EIP) concept was also used to evaluate the injection efficiency of gas fuel injector. The simulation results show that the jet speed of the pull-open injector is higher than the push-open injector under the same operating conditions. The injection efficiency of the pull-open valve is about 56.0%, while the push-open valve is 50.3%. In general, the steady-flow characteristic of the pull-open injector is better than that of the push-open one. The injection efficiency of the flat sealing injector is 55.2%, slightly lower than the conical sealing method.

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.

scholarly journals Simulation Investigation on the Flow and Mixing in Ducts of the Rotary Energy Recovery Device

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Kai Liu ◽  
Lixing Zheng
Keyword(s):  
Fluid Dynamics ◽  
Energy Recovery ◽  
Swirling Flow ◽  
Three Dimensional ◽  
Working Process ◽  
Mixing Rate ◽  
Typical Structure ◽  
Mixing Performance ◽  
Swirl Intensity ◽  
High Turbulence

The rotary energy recovery device (RERD) is widely equipped in desalination to reduce the system energy consumption. In this study, the fluid dynamics and mixing performance of a typical structure RERD and a visualization apparatus of a RERD (V-RERD) had been compared by simulation. The effects of rotating components on fluid dynamics and mixing had been researched. Simulation results indicated that a swirling flow can be observed from flow fields in the device duct. In the RERD case, the swirling flow changed its rotating direction in the center of the duct, while in the V-RERD case, its rotating direction was unchanged. Then, a swirling number Sn was applied to characterize the degree of swirl intensity, and its formation mechanism in RERD had been discussed. In addition, the Q criterion was adopted to visualize the three-dimensional flow structures and identify vortex structures in the duct. The evolution of vortices in the working process had been investigated. It was found that vortices significantly affected the mixing performance, and the detached vortex could lead to high turbulence and mixing in the duct. Suppressing the vortex shedding may reduce the flow turbulence and gain a lower volumetric mixing rate.

scholarly journals Confocal Microscopic Evaluation of Mixing Performance for Three-Dimensional Microfluidic Mixer

2012 ◽  
Vol 28 (1) ◽  
pp. 57 ◽  
Author(s):  
Takao YASUI ◽  
Yusuke OMOTO ◽  
Keiko OSATO ◽  
Noritada KAJI ◽  
Norikazu SUZUKI ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Microfluidic Mixer ◽  
Mixing Performance ◽  
Microscopic Evaluation

Passive Vortex Micromixers Utilizing Hybrid Laminations

2008 ◽  
Author(s):  
Jyh-Jian Chen ◽  
Yu-Cheng Luo ◽  
Shin-Hau Su ◽  
Nai-Yu Jheng
Keyword(s):  
Mass Transfer ◽  
Theoretical Investigation ◽  
Vortex Flow ◽  
Three Dimensional ◽  
Taylor Number ◽  
Concentration Profiles ◽  
Mixing Index ◽  
Mixing Performance ◽  
Damping Effect ◽  
Square Prism

This theoretical investigation analyzed the three-dimensional momentum and mass transfer characteristics arising from the multiple inlets and single outlet in micro chamber which consists of a right square prism, an octagonal prism or a cylinder. The effects of various geometric parameters, inlet velocities, and the types of lamination on the mixing characteristics were investigated, and the results were presented in terms of flow fields, concentration profiles, and mixing index. Numerical results indicated that vortex flow and numbers of inlets dominate the mixing index. At larger Taylor number, more inertia caused the powerful vortex flow in the chamber, and the damping effect on diffusion was diminished, which then increased the mixing performance. Furthermore, passive micromixers utilizing hybrid laminations showed better mixing results than those with parallel laminations.

Distributive Mixing Performance and Mixing Efficiency of Discs in a Series Disc-Screw Extruder

2011 ◽  
Vol 221 ◽  
pp. 411-417
Author(s):  
Jing Yang ◽  
Bo Jiang
Keyword(s):  
Three Dimensional ◽  
Isothermal Flow ◽  
Mixing Efficiency ◽  
Screw Extruder ◽  
Mixing Performance ◽  
Mixing Parameters ◽  
In Series ◽  
Time Average ◽  
Overall Efficiency ◽  
Disc Configuration

This work aims at the simulation of three-dimensional isothermal flow between a pair of discs in series disc-screw (SDS) extruder by computational fluid dynamics. To analyze the distributive mixing performance and overall efficiency of discs, mixing parameters such as segregation scale and time-average efficiency were calculated. The effects of the disc configuration and the distance between a pair of discs on the distributive mixing were discussed. The more grooves on the disc, the better distributive performance. Good distributive mixing performance can be obtained by big gaps.

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