Homogenization of Equations for Miscible Fluids

Author(s):  
Y. Amirat ◽  
V. V. Shelukhin
Keyword(s):  
2008 ◽  
Vol 44 (2) ◽  
pp. 135-142 ◽  
Author(s):  
C. Derec ◽  
P. Boltenhagen ◽  
S. Neveu ◽  
J.-C. Bacri

2021 ◽  
Author(s):  
Swagatika Acharya ◽  
Vijay Kumar Mishra ◽  
Jitendra Kumar Patel

Wave Motion ◽  
2021 ◽  
Vol 102 ◽  
pp. 102712
Author(s):  
Jan Erik H. Weber ◽  
Kai H. Christensen

2002 ◽  
Vol 451 ◽  
pp. 239-260 ◽  
Author(s):  
J. FERNANDEZ ◽  
P. KUROWSKI ◽  
P. PETITJEANS ◽  
E. MEIBURG

Density-driven instabilities between miscible fluids in a vertical Hele-Shaw cell are investigated by means of experimental measurements, as well as two- and three-dimensional numerical simulations. The experiments focus on the early stages of the instability growth, and they provide detailed information regarding the growth rates and most amplified wavenumbers as a function of the governing Rayleigh number Ra. They identify two clearly distinct parameter regimes: a low-Ra, ‘Hele-Shaw’ regime in which the dominant wavelength scales as Ra−1, and a high-Ra ‘gap’ regime in which the length scale of the instability is 5±1 times the gap width. The experiments are compared to a recent linear stability analysis based on the Brinkman equation. The analytical dispersion relationship for a step-like density profile reproduces the experimentally observed trend across the entire Ra range. Nonlinear simulations based on the two- and three-dimensional Stokes equations indicate that the high-Ra regime is characterized by an instability across the gap, wheras in the low-Ra regime a spanwise Hele-Shaw mode dominates.


2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000096-000102
Author(s):  
Houari Cobas Gomez ◽  
Bianca Oliveira Agio ◽  
Jéssica Gonçalves da Silva ◽  
Natalia Neto Pereira Cerize ◽  
Adriano Marim de Oliveira ◽  
...  

Abstract The present work shows a ceramics microfluidic device for non-miscible fluids microemulsion generation using 3D serpentine micromixers. The technology used for device fabrication was Low Temperature Cofired Ceramics (LTCC) which allows us for complex, high temperature and pressure resistant 3D microfluidic devices. The proposed device aims to obtain microemulsion with controlled drop size, low dispersion index and high production volumes using Top-Down approach. Previous simulation work had showed 3D serpentine as one of the best structures for rapid mixing due the chaotic advection generated on every 90 deg direction change. This effect, when mixing two fluids as oil and water leads to streamlines pinching-off making possible drop generation. We have used this effect on our device. For the experimental section, it was fabricated a 3D serpentine mixer microfluidic device with working region suitable for variable total flow rate. For certain value of total flow rate, the microemulsion showed higher drop diameter and polydispersity values. In this region, no control could be done in order to obtain the same drop value with the same process parameters. Inside the working region drop diameter values repeatability was obtained. In this region our experimental results had showed a relation between drop diameter and total flow rate. As a total flow rate increase the drop diameter decrease due to a stronger chaotic advection effect. In the other hand, the polydispersity index also decreases. Microemulsions with average size lower than few micrometer or submicron were obtained. When compared with other reported devices, our device presented a production volume in the range of tens of ml/s for the same output microemulsion size.


Author(s):  
Wen Song ◽  
Natarajan N. Ramesh ◽  
Anthony R. Kovscek
Keyword(s):  

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