Integratable Capacitive Sensor for Identification of Microfluidic Two-Phase Flow Patterns in Lab-on-Chip Devices

2016 ◽  
Vol 25 (1) ◽  
pp. 197-206 ◽  
Author(s):  
Zhaochu Yang ◽  
Tao Dong ◽  
Atle Jensen ◽  
Einar Halvorsen
Keyword(s):  
Two Phase Flow ◽  
Capacitive Sensor ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Lab On Chip ◽  
On Chip

Identification of microfluidic two-phase flow patterns in lab-on-chip devices

2014 ◽  
Vol 24 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Zhaochu Yang ◽  
Tao Dong ◽  
Einar Halvorsen
Keyword(s):  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Lab On Chip ◽  
On Chip

On Two Phase Flow Regimes in a Microscale Direct Methanol Fuel Cell

2008 ◽  
Author(s):  
Christian Weinmu¨ller ◽  
Nicole R. Bieri ◽  
Dimos Poulikakos
Keyword(s):  
Fuel Cell ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Research Attention ◽  
Lab On Chip ◽  
Research Activities ◽  
Wide Range ◽  
Direct Methanol ◽  
On Chip

The area of microfluidics has experienced a tremendous increase in research activities in recent years with a wide range of applications, such as micro heat exchangers and energy conversion devices, microreactors, lab-on-chip devices, micro total chemical analysis systems (μTAS) etc. The occurrence of two phase flow can lead to several mechanisms enhancing or extending the performance of single phase microfluidic devices [1]. On the other hand, in a micro fuel cell the second, non-immiscible phase is considered to hamper the performance of the fuel cell [2]. Regardless of its effect, two phase flows in microfluidics deserve special research attention.

Micro-PIV Measurements of Flowfields Within Plugs in Two Phase Flows for µ-TAS Applications

2006 ◽  
Author(s):  
Colin King ◽  
Edmond Walsh ◽  
Ronan Grimes
Keyword(s):  
Two Phase Flow ◽  
Fluid Velocity ◽  
Internal Diameter ◽  
Immiscible Fluid ◽  
Phase Flow ◽  
Internal Circulation ◽  
Two Phase ◽  
Lab On Chip ◽  
Micro Piv ◽  
On Chip

The use of two phase flow in lab-on-chip devices, where chemical and biological reagents are enclosed within plugs separated from each other by an immiscible fluid, offers significant advantages for the development of devices with high throughput of individual heterogeneous samples. Lab-on-chip devices designed to perform the polymerase chain reaction (PCR) are a prime example of such developments. The internal circulation within the plugs used to transport the reagents affects the efficiency of the chemical reaction within the plug, due to the degree of mixing induced on the reagents by the flow regime. It has been hypothesised in the literature that all plug flows produce internal circulation. This work demonstrates experimentally that this is false, and seeks to elucidate the parameters influencing the internal circulation of plugs. The particle image velocimetry (PIV) technique offers a powerful non-intrusive tool to study such flow fields. This paper presents micro-PIV experiments carried out to study the internal circulation of aqueous plugs in two phase flow within 762μm internal diameter FEP Teflon tubing with FC-40 as the segmenting fluid. Experiments have been performed and the results are presented for plugs ranging in length from 1mm to 13mm with an average fluid velocity ranging from 0.3mm/s to 50mm/s. The results demonstrate that circulation within the plugs is not always present and requires design considerations to benefit from this phenomenon.

scholarly journals Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou
Keyword(s):  
Mass Transfer ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Two Phase Flow ◽  
Oxygen Transfer Rate ◽  
Flow Patterns ◽  
Oxygen Mass Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

Liquid–Liquid Two-Phase Flow Patterns in a Serpentine Microchannel

2012 ◽  
Vol 51 (13) ◽  
pp. 5056-5066 ◽  
Author(s):  
P. S. Sarkar ◽  
K. K. Singh ◽  
K. T. Shenoy ◽  
A. Sinha ◽  
H. Rao ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase
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