scholarly journals Comparison of mixing performances of T, Y and arrow-shaped micromixers using Villermaux-Dushman protocol at low Reynolds number

2020 ◽  
Vol 85 (3) ◽  
pp. 381-394
Author(s):  
Onyeka Okwundu ◽  
Mohammed Fuseini ◽  
Ahmed El-Shazly ◽  
Marwa Elkady
Keyword(s):  
Reynolds Number ◽  
Performance Test ◽  
Mixing Time ◽  
Low Reynolds Number ◽  
Mixing Times ◽  
Uv Absorbance ◽  
Reliable Technique ◽  
Mixing Performance ◽  
Extraction Test ◽  
Low Reynolds

Mixing performance is commonly assessed using the Villermaux? ?Dushman protocol. Mixing in passive mixers may need to be at very low Reynolds number (Re). This study is aimed at comparing the mixing performances of T, Y and arrow-shaped micromixers using the Villermaux?Dushman protocol at Re < 100. The mixing performance test was run at flow rates of 500 to 1 mL h-1 with the pressure drop measurement. Based on UV absorbance values and experimental mixing times of mixed fluids from the three micromixers, the order of mixing performance at Re > 26.5 was Y < T < arrow-shaped micromixers. At lower Re values, the order of performance based on the absorbance and the experimental mixing times, became inconsistent. However, the comparison of mixing performance based on predicted mixing time gave consistent order of performance at all Re values. The instability in UV absorbance of mixed reagents in Villermaux?Dushman protocol was noted as the major cause of the reported inconsistency at very low Re. The inadequacy of Villermaux? ?Dushman protocol at low Re was verified via facile solvent extraction test. A more reliable technique should be used to assess the mixing performance of micromixers at very low Re and on-line UV measurement should be adopted for the Villermaux?Dushman experiment.

scholarly journals A suitable k-epsilon model for CFD simulation of pump-around jet mixing tank with moderate jet reynolds number

2018 ◽  
Vol 192 ◽  
pp. 03010 ◽  
Author(s):  
Satapan Phapatarinan ◽  
Eakarach Bumrungthaichaichan ◽  
Santi Wattananusorn
Keyword(s):  
Reynolds Number ◽  
Numerical Methods ◽  
Cfd Simulation ◽  
Mixing Time ◽  
Low Reynolds Number ◽  
Turbulence Models ◽  
Suitable Model ◽  
Mixing Times ◽  
Jet Mixing ◽  
Low Reynolds

This paper presents the appropriate turbulence model for predicting the overall mixing time inside an open 45° inclined side entry pump-around jet mixing tank with moderate jet Reynolds number of about 17,515. The model was carefully developed by using appropriate hexahedral grid arrangement and proper numerical methods. The two different k-epsilon turbulence models, including realizable k-epsilon model and low Reynolds number k-epsilon model, were simulated. The overall mixing times predicted by these turbulence models were compared with the previous data reported by Patwardhan (Chem. Eng. Sci. 57 (2002) 1307-1318). The results revealed that the low Reynolds number k-epsilon model was a suitable model for predicting the overall mixing time of jet mixing tank with moderate jet Reynolds number.

Use of Bacterial Carpets to Enhance Mixing in Microfluidic Systems

2006 ◽  
Vol 129 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Min Jun Kim ◽  
Kenneth S. Breuer
Keyword(s):  
Reynolds Number ◽  
Metabolic Activity ◽  
Thermal Environment ◽  
Low Reynolds Number ◽  
Microfluidic Systems ◽  
Mixing Performance ◽  
Bacterial System ◽  
Tracer Particles ◽  
Oxygen Starvation ◽  
Low Reynolds

We demonstrate that flagellated bacteria can be utilized in surface arrays (carpets) to achieve mixing in a low-Reynolds number fluidic environment. The mixing performance of the system is quantified by measuring the diffusion of small tracer particles. We show that the mixing performance responds to modifications to the chemical and thermal environment of the system, which affects the metabolic activity of the bacteria. Although the mixing performance can be increased by the addition of glucose (food) to the surrounding buffer or by raising the buffer temperature, the initial augmentation is also accompanied by a faster decay in mixing performance, due to falling pH and oxygen starvation, both induced by the higher metabolic activity of the bacterial system.

Experimental Investigation on Blunt-Edged UTM Delta Wing VFE-2 Configurations at Low Reynolds Number

2018 ◽  
Vol 12 (3) ◽  
pp. 255
Author(s):  
Muhammad Zal Aminullah Daman Huri ◽  
Shabudin Bin Mat ◽  
Mazuriah Said ◽  
Shuhaimi Mansor ◽  
Md. Nizam Dahalan ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Delta Wing ◽  
Low Reynolds Number ◽  
Low Reynolds

HEAT TRANSFER OF IMPINGING JET AT LOW REYNOLDS NUMBER

2018 ◽  
Author(s):  
Vadim V. Lemanov ◽  
Viktor I. Terekhov ◽  
Vladimir V. Terekhov
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Low Reynolds Number ◽  
Impinging Jet ◽  
Low Reynolds
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