Featured Research

from universities, journals, and other organizations

Fluid mechanics: Bubble impacts caught on film

Date:
February 27, 2013
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
When a bubble of air rising through water hits a sheet of glass, it doesn't simply stop -- it squishes, rebounds, and rises again, before slowly moving to the barrier. An international research team with high-speed cameras reveal the complex physics at work as air meets water and glass.

When a bubble of air rising through water hits a sheet of glass, it doesn't simply stop -- it squishes, rebounds, and rises again, before slowly moving to the barrier. This seemingly simple process actually involves some knotty fluid mechanics. An international research team, including researchers at the A*STAR Institute of High Performance Computing, and Nanyang Technological University, Singapore, has now unpicked this physical process.

The researchers used a fine capillary to blow air bubbles 0.5 to 1.5 millimeters wide into a glass of de-ionized water. The bubbles rose 5 millimeters before hitting a glass cover, all under the watchful eye of a high-speed camera. Meanwhile, a laser beam shining from above illuminated the contact points between glass, water and the bubble, created a changing interference pattern that was captured by a second camera running at up to 54,000 frames per second.

A bubble typically took about 17 milliseconds to impact, bounce and return to the glass slide. But a film of water remained between them; it took a further 250 milliseconds for that to drain away before the bubble's air came into direct contact with the glass. "The film drains slowly because the process is controlled by viscosity and surface tension," says team member Rogerio Manica. "Eventually, this layer breaks and a three-phase contact line -- water, glass and air -- forms, with a region on the glass surface that is not wet." This 'dewetting' stage is about 100 times faster than the film drainage process.

The researchers found that a simple mathematical model, called lubrication theory, could accurately describe the film drainage measured in the experiments. "We thus understand the fluid mechanics now in very great detail," says Manica. "Many industrially relevant processes use impacting bubbles, including wastewater cleaning and mineral extraction," he says, adding that simulations of these processes can now be improved by incorporating the team's bubble model.

Other researchers had studied the behavior of much smaller bubbles when rising at very slow speeds. They found that the bubbles settled on to the cover without bouncing, thus skipping the most complex parts of the process.

Manica notes that their experiments also demonstrated the utility of synchronizing cameras to study two very different length scales -- the side view is measured in millimeters, while the interferometry camera captures features thousands of times smaller. The researchers are now investigating how rising bubbles behave if the water contains small amounts of other materials, such as surfactants.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing.

A YouTube video illustrating the research can be found at: http://www.youtube.com/watch?v=X6r7Y9oP8qw


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Maurice H. W. Hendrix, Rogerio Manica, Evert Klaseboer, Derek Y. C. Chan, Claus-Dieter Ohl. Spatiotemporal Evolution of Thin Liquid Films during Impact of Water Bubbles on Glass on a Micrometer to Nanometer Scale. Physical Review Letters, 2012; 108 (24) DOI: 10.1103/PhysRevLett.108.247803

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Fluid mechanics: Bubble impacts caught on film." ScienceDaily. ScienceDaily, 27 February 2013. <www.sciencedaily.com/releases/2013/02/130227124653.htm>.
The Agency for Science, Technology and Research (A*STAR). (2013, February 27). Fluid mechanics: Bubble impacts caught on film. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2013/02/130227124653.htm
The Agency for Science, Technology and Research (A*STAR). "Fluid mechanics: Bubble impacts caught on film." ScienceDaily. www.sciencedaily.com/releases/2013/02/130227124653.htm (accessed September 30, 2014).

Share This



More Matter & Energy News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins