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 European Physical Journal E, 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 of a viscous fluid, similar to honey, with . 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 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 .

Explore further: Exploring the characteristics of viscoelastic fluids

More information: 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

Related Stories

Exploring the characteristics of viscoelastic fluids

February 4, 2010

(PhysOrg.com) -- There are many microorganisms out there, navigating through complex biological fluids. “One of the most common migrations takes place with spermatozoa as it navigates the female reproductive tract,” Joseph ...

Photos show how a specific fluid defies normal activity

November 30, 2010

An illustration showing a scientific phenomenon that defies common intuition has garnered Sunghwan (Sunny) Jung, assistant professor of engineering science and mechanics at Virginia Tech, and his doctoral student, Navish ...

Recommended for you

New blow for 'supersymmetry' physics theory

July 27, 2015

In a new blow for the futuristic "supersymmetry" theory of the universe's basic anatomy, experts reported fresh evidence Monday of subatomic activity consistent with the mainstream Standard Model of particle physics.

Rogue wave theory to save ships

July 29, 2015

Physicists have found an explanation for rogue waves in the ocean and hope their theory will lead to devices to warn ships and save lives.

Researchers build bacteria's photosynthetic engine

July 29, 2015

Nearly all life on Earth depends on photosynthesis, the conversion of light energy into chemical energy. Oxygen-producing plants and cyanobacteria perfected this process 2.7 billion years ago. But the first photosynthetic ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.