Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bubble study could improve industrial splash control

14.12.2012
For the first time, scientists witnessed the details of the full, ultrafast process of liquid droplets evolving into a bubble when they strike a surface. Their research determined that surface wetness affects the bubble's fate.
This research could one day help eliminate bubbles formed during spray coating, metal casting and ink-jet printing. It also could impact studies on fuel efficiency and engine life by understanding the splashing caused by fuel hitting engine walls.

"How liquid coalesces into a drop or breaks up into a splash when hitting something solid is a fundamental problem in the study of fluid dynamics," said Jung Ho Je, one of the lead authors on the result “How Does an Air Film Evolve into a Bubble During Drop Impact?”, published in the journal Physical Review Letters, and a physicist at Pohang University of Science and Technology in Korea.

A team of Korean and U.S. scientists used the Advanced Photon Source at the Department of Energy’s Argonne National Laboratory to profile the film of air that gets trapped between a droplet and a surface and to study how it evolves into a bubble. Visualizing this process required the use of ultrafast X-ray phase-contrast imaging done at the APS’s 32-ID beamline. The APS is the only synchrotron light source currently providing this technique, which is key for bubble research.

The bubble formation was captured at a speed of 271,000 frames per second. For comparison, a camera needs to shoot at 600 frames per second to capture a bullet fired from a .38 Smith & Wesson Special handgun.

“This is the first time we can clearly visualize the detailed profile of air dynamics inside of a droplet, which made understanding what forces are at play much easier,” said Kamel Fezzaa, a physicist working at the APS.

It is known that the surrounding air pressure influences splashing, but it also leaves an air layer under the drop that evolves into a bubble. The researchers found that a sweet spot exists for controlling whether the emerging bubbles stay attached to the substrate or detach and float away. This sweet spot is a combination of the wetness of the surface material and the fluid properties of the droplet.

X-rays are an ideal tool for studying bubble formation. Visual-light imaging techniques have proved challenging because of reflection and refraction problems, and interferometry and total internal-reflection microscopy techniques can’t track changes in the air thickness. Scientists used the APS’s unique combination of phase-contrast imaging and ability to take 0.5 microsecond snapshots at intervals of 3.68 microseconds, or 3.68 millionths of a second, to create a new technique for tracking changes at the interface of air and liquid in real time.

Numerous studies during the last few years have revealed the trapped air under the droplet, but this is the first time the bubble profile and cause of collapse has been visualized and explained. The planned APS upgrade will enable viewing of even faster occurrences and a wider field of view to capture the droplet and smaller bubble formation in the same video.

In future experiments, scientists plan to test whether other conditions such as the temperature of the impact surface or the pressure and nature of surrounding gases affect the bubble formation.

The research was supported by the National Research Foundation of Korea. The APS is supported by DOE’s Office of Science.

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security. To learn more about the Office of Science X-ray user facilities, visit the user facilities directory.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Tona Kunz | EurekAlert!
Further information:
http://www.anl.gov

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>