Study on swirls to optimize contacts between fluids

March 21, 2012

Physicists who have studied the mixing between two incompatible fluids have found that it is possible to control the undercurrents of one circulating fluid to optimise its exposure to the other. This work, which is about to be published in EPJ E¹, was performed by Jorge Peixinho from CNRS at Le Havre University, France, and his colleagues from the Benjamin Levich Institute, City University of New York, USA.

The authors compared quantitative experimental observations of a viscous fluid, similar to honey, with numerical simulations. They focused on a fluid, which partially filled the space between two concentric cylinders with the inner one rotating. This system was previously used to study roll coating and papermaking processes. To interpret this seemingly simple system, they factored in interface flows, film spreading, and the formation of free surface cusps - a phenomenon relevant to fluid mixing, but which is not quantitatively captured by conventional numerical calculation.

The authors observed the presence of several flow eddies, stemming from fluid flowing past the inner cylinder, causing it to swirl, and the appearance of reverse currents including one orbiting around the rotating cylinder and a second underneath. They made the second eddy disappear by increasing the fluid filling or its velocity. This is akin to turning a spoon full of honey fast enough to prevent it from draining.

This model is based on a highly viscous oil combined with air as a top fluid. When combined with a light oil containing nutriments as a top fluid, it could also apply to a suspension of bioreactor cells typically used to produce biotech medicines. Ultimately, it could help identify the right parameters and adequate mixing time scales to ensure that nutriments feed all the cells homogeneously without segregation.
-end-
References:
1. Peixinho J., Mirbod M. and Morris J.F. (2012), Free surface flow between two horizontal concentric cylinders, European Physical Journal E (EPJ E) 35: 19, DOI 10.1140/epje/i2012-12019-8

2. For more information, please visit www.epj.org.

The full-text article is available to journalists on request.

Springer

Related Circulating Fluid Articles from Brightsurf:

Study reveals higher COVID-19 mortality in men could be explained by differences in circulating proteins and immune system cells
New research presented at the ESCMID Conference on Coronavirus Diseases (ECCVID, online 23-25 September) suggests that the higher risk of poor COVID-19 outcomes in men could be explained by differences in circulating proteins and immune system cells compared with women.

A simpler, high-accuracy method to detect rare circulating tumor cells in blood samples
Results from a recent study -- a collaboration between Lehigh University, Lehigh Valley Cancer Institute, and Pennsylvania State University -- demonstrates the potential for a new method of detecting circulating tumor cells.

Fluid mechanics mystery solved
An environmental engineering professor has solved a decades-old mystery regarding the behavior of fluids, a field of study with widespread medical, industrial and environmental applications.

Brain drowns in its own fluid after a stroke
Cerebral edema, swelling that occurs in the brain, is a severe and potentially fatal complication of stroke.

Fluid dynamics taught through dance
A collaboration at University of Michigan is taking a unique approach to fluid mechanics by teaching it through dance.

Study shows how circulating tumor cells target distant organs
Most cancers kill because tumor cells spread beyond the primary site to invade other organs.

Circulating molecules in blood may be stepping stone for type 1 diabetes early prediction
Researchers from the Turku Bioscience Centre in Finland have found changes in molecules in the blood that might be new markers of type 1 diabetes.

Marathoners, take your marks...and fluid and salt!
Legend states that after the Greek army defeated the invading Persian forces near the city of Marathon in 490 B.C.E., the courier Pheidippides ran to Athens to report the victory and then immediately dropped dead.

WPI liquid biopsy chip snares circulating tumor cells in blood drops from cancer patients
Researchers at Worcester Polytechnic Institute have developed a chip made of carbon nanotubes that can capture circulating tumor cells (CTCs) of all sizes and types, and can do so with far greater sensitivity than existing technologies.

Microfluidics device captures circulating cancer cell clusters
About 90% of cancer deaths are due to metastases, when tumors spread to other vital organs, and a research group recently realized that it's not individual cells but rather distinct clusters of cancer cells that circulate and metastasize to other organs.

Read More: Circulating Fluid News and Circulating Fluid Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.