Gas–liquid flow stability and bubble formation in non-Newtonian fluids in microfluidic flow-focusing devices

2010 ◽  
Vol 10 (5) ◽  
pp. 1135-1140 ◽  
Author(s):  
Taotao Fu ◽  
Youguang Ma ◽  
Denis Funfschilling ◽  
Huai Z. Li
Keyword(s):  
Liquid Flow ◽  
Bubble Formation ◽  
Flow Stability ◽  
Newtonian Fluids ◽  
Flow Focusing ◽  
Microfluidic Flow ◽  
Gas Liquid Flow

scholarly journals Breakup Dynamics of Semi-dilute Polymer Solutions in a Microfluidic Flow-focusing Device

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 406
Author(s):  
Chun-Dong Xue ◽  
Xiao-Dong Chen ◽  
Yong-Jiang Li ◽  
Guo-Qing Hu ◽  
Tun Cao ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Polymer Solutions ◽  
Newtonian Fluids ◽  
Droplet Microfluidics ◽  
Droplet Generation ◽  
Flow Focusing ◽  
Polymeric Fluids ◽  
Practical Applications ◽  
Dilute Polymer Solutions ◽  
Microfluidic Flow

Droplet microfluidics involving non-Newtonian fluids is of great importance in both fundamental mechanisms and practical applications. In the present study, breakup dynamics in droplet generation of semi-dilute polymer solutions in a microfluidic flow-focusing device were experimentally investigated. We found that the filament thinning experiences a transition from a flow-driven to a capillary-driven regime, analogous to that of purely elastic fluids, while the highly elevated viscosity and complex network structures in the semi-dilute polymer solutions induce the breakup stages with a smaller power-law exponent and extensional relaxation time. It is elucidated that the elevated viscosity of the semi-dilute solution decelerates filament thinning in the flow-driven regime and the incomplete stretch of polymer molecules results in the smaller extensional relaxation time in the capillary-driven regime. These results extend the understanding of breakup dynamics in droplet generation of non-Newtonian fluids and provide guidance for microfluidic synthesis applications involving dense polymeric fluids.

Pinch-off mechanism for Taylor bubble formation in a microfluidic flow-focusing device

2013 ◽  
Vol 16 (6) ◽  
pp. 1047-1055 ◽  
Author(s):  
Yutao Lu ◽  
Taotao Fu ◽  
Chunying Zhu ◽  
Youguang Ma ◽  
Huai Z. Li
Keyword(s):  
Bubble Formation ◽  
Flow Focusing ◽  
Taylor Bubble ◽  
Microfluidic Flow

Bubble formation and breakup mechanism in a microfluidic flow-focusing device

2009 ◽  
Vol 64 (10) ◽  
pp. 2392-2400 ◽  
Author(s):  
Taotao Fu ◽  
Youguang Ma ◽  
Denis Funfschilling ◽  
Huai Z. Li
Keyword(s):  
Bubble Formation ◽  
Flow Focusing ◽  
Breakup Mechanism ◽  
Microfluidic Flow

Breakup dynamics of slender bubbles in non-newtonian fluids in microfluidic flow-focusing devices

AIChE Journal ◽  
2012 ◽  
Vol 58 (11) ◽  
pp. 3560-3567 ◽  
Author(s):  
Taotao Fu ◽  
Youguang Ma ◽  
Denis Funfschilling ◽  
Chunying Zhu ◽  
Huai Z. Li
Keyword(s):  
Newtonian Fluids ◽  
Flow Focusing ◽  
Microfluidic Flow

A microfluidic flow-focusing device for low sample consumption serial synchrotron crystallography experiments in liquid flow

2019 ◽  
Vol 26 (2) ◽  
pp. 406-412 ◽  
Author(s):  
Diana C. F. Monteiro ◽  
Mohammad Vakili ◽  
Jessica Harich ◽  
Michael Sztucki ◽  
Susanne M. Meier ◽  
...  
Keyword(s):  
Liquid Flow ◽  
High Repetition Rate ◽  
Microfluidic Chips ◽  
Flow Focusing ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Microfluidic Flow ◽  
Rate Experiment ◽  
Low X

Serial synchrotron crystallography allows low X-ray dose, room-temperature crystal structures of proteins to be determined from a population of microcrystals. Protein production and crystallization is a non-trivial procedure and it is essential to have X-ray-compatible sample environments that keep sample consumption low and the crystals in their native environment. This article presents a fast and optimized manufacturing route to metal–polyimide microfluidic flow-focusing devices which allow for the collection of X-ray diffraction data in flow. The flow-focusing conditions allow for sample consumption to be significantly decreased, while also opening up the possibility of more complex experiments such as rapid mixing for time-resolved serial crystallography. This high-repetition-rate experiment allows for full datasets to be obtained quickly (∼1 h) from crystal slurries in liquid flow. The X-ray compatible microfluidic chips are easily manufacturable, reliable and durable and require sample-flow rates on the order of only 30 µl h−1.

scholarly journals Study on Two-Phase Mixing inside Flow Focusing/Blurring Nozzle by Gray Distribution Analysis Method

2021 ◽  
Vol 11 (14) ◽  
pp. 6260
Author(s):  
Jin Zhao ◽  
Zhi Ning ◽  
Ming Lü ◽  
Chunhua Sun
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Water Flow Rate ◽  
Orifice Diameter ◽  
Inertia Force ◽  
Distribution Analysis ◽  
Flow Focusing ◽  
Two Phase ◽  
Phase Mixing ◽  
Gas Liquid Flow

The application prospect of a flow focusing/blurring nozzle is broad but research on gas-liquid flow inside the nozzle is not comprehensive. The gas-liquid mixing inside the nozzle is difficult to study by visualization experiment, so this paper proposes to study the gas-liquid flow or mixing inside the nozzle by the gray scale level distribution of the experimental images. The results show that the increase of air flow rate is beneficial to two-phase mixing inside the nozzle, while the influence of water flow rate, tube hole distance (the distance between inner tube and nozzle outlet) and orifice diameter increase is opposite. The influence of air inertia force on two-phase mixing is weaker than the water inertia force under different parameters, the effect of the air inertia force on two-phase mixing is similar to tube hole distance under a small flow rate, the effect of the orifice diameter on two-phase mixing is relatively weak. In addition, the analysis of the gas-liquid flow field in the mixing zone shows that the gas-liquid flow in the nozzle is stable in the flow focusing mode. In the flow blurring mode, the gas-liquid flow inside the nozzle has radial stability but axial pulsation. In the transition mode, the gas-liquid flow inside the nozzle is unstable, but the gas-liquid flow is close to the flow blurring mode.

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