. 24/7 Space News .
Wobbling droplets in space confirm late professor's theory
by Staff Writers
Ithaca NY (SPX) Aug 19, 2022

Experimentally-observed modes overlaid throughout an oscillation cycle.

At a time when astronomers around the world are reveling in new views of the distant cosmos, an experiment on the International Space Station has given Cornell researchers fresh insight into something a little closer to home: water.

Specifically, the space station's microgravity environment illuminated the ways that water droplets oscillate and spread across solid surfaces - knowledge that could have very earthbound applications in 3D-printing, spray cooling, and manufacturing and coating operations.

The team's paper, "Oscillations of Drops with Mobile Contact Lines on the International Space Station: Elucidation of Terrestrial Inertial Droplet Spreading," published Aug. 16 in Physical Review Letters. The lead author is Joshua McCraney, M.S. '19, Ph.D. '21.

The experiment and its findings, while successful, are also bittersweet. The paper's co-senior author Paul Steen, the Maxwell M. Upson Professor in the Smith School of Chemical and Biomolecular Engineering in the College of Engineering, died in September 2020, just before the experiment was conducted.

"It's sad that Paul didn't get to see the experiments launch into space," said co-senior author Susan Daniel, the Fred H. Rhodes Professor in the Smith School of Chemical and Biomolecular Engineering, and Steen's longtime collaborator. "We hope that we did right by him in the end, and that the paper that we produced from the work would make him proud."

Daniel began collaborating with Steen shortly after she first came to Cornell as an assistant professor in 2007. While her current research is focused on the biological interface of the coronavirus, her graduate work was in chemical interfaces and fluid mechanics - a field in which Steen was advancing a number of theoretical predictions based upon how droplets resonate when subjected to vibrations. The two researchers instantly connected.

"He knew the theory and made predictions, and I knew how to execute the experiments to test them," Daniel said. "Basically, from the moment I got here in 2007 until he passed away, we worked on trying to understand how liquids and surfaces interact with each other, and how the contact line at the interface between them behaves under different conditions."

Their collaboration resulted in a "photo album" of the dozens of possible shapes that an oscillated drop of water can take. Steen later expanded on that project by cataloging the droplets' energy states as evidenced by those resonant shapes, organizing them into a "periodic table" classification.

In 2016, Steen and Daniel received a four-year grant from the National Science Foundation (NSF) and NASA's Center for the Advancement of Science in Space to conduct fluid dynamics research aboard the International Space Station U.S. National Laboratory.

Space is an ideal place to study the behavior of fluids because of the radical reduction of gravity, which on the ISS is about one-millionth of its terrestrial level. This means that fluid-surface interactions which are so small-scale and speedy on Earth that they are practically invisible can be, in space, nearly 10 times larger - from microns to centimeters - and their duration slows nearly 30-fold.

"It's harder to study these drop motions, experimentally and fundamentally, when you have gravity in your way," Daniel said.

Steen and Daniel selected a few resonance shapes from their photo album that they wanted to explore in detail, with a focus on how a water droplet's contact line - or outer edge - slides back and forth across a surface, driving the way the liquid will spread, a phenomenon that can be controlled by varying vibration frequencies.

The team prepared meticulous instructions for the astronauts to follow, compressing four years of planning into a several-minute experiment in which every second was tightly choreographed.

With the researchers monitoring and providing feedback in real time on the ground, the astronauts deposited 10 mL water droplets via a syringe onto nine different hydrophobic surfaces with varying degrees of roughness. They also forced pairs of droplets to coalesce together, and placed droplets onto an oscillator and tuned its vibrations to achieve the targeted resonance shapes. The water droplets' wobbling and jiggling movements were filmed, and the researchers spent the next year analyzing the data.

That analysis ultimately confirmed Steen's theories about the way a liquid's density and surface tension control the contact line's mobility, overcoming a surface's roughness.

Daniel credits co-author Joshua Bostwick, Ph.D. '11, a former student of Steen's and now the Stanzione Collaboration associate professor at Clemson University, with ensuring that the experiment results squared with Steen's theoretical predictions.

"Josh was able to carry on with the theoretical side of this work in Paul's absence, which was not something I was ready to step into and do. It was nice to have him rejoin the team and help us make sure that we were able to extract everything we could from the data we collected," Daniel said. "Now we can essentially use the theory that Paul created to make predictions, for example, in processes where you're spraying droplets on surfaces, or in 3D-printing, or where liquids spread across a surface really quickly."

Vanessa Kern, Ph.D. '20, was also a co-author of the paper.

Research Report:"Oscillations of Drops with Mobile Contact Lines on the International Space Station: Elucidation of Terrestrial Inertial Droplet Spreading,"

Related Links
Cornell University
Space Technology News - Applications and Research

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only
SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Matter at extreme temperature and pressure turns out to be remarkably simple and universal
London, UK (SPX) Aug 15, 2022
Scientists at Queen Mary University of London have made two discoveries about the behaviour of 'supercritical matter' - matter at the critical point where the differences between liquids and gases seemingly disappear. Previously, while the behaviour of matter at reasonably low temperature and pressure was well understood, the picture of matter at high temperature and pressure was blurred. Above the critical point, differences between liquids and gases seemingly disappear, and the supercritical mat ... read more

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Yale project brings creative expression to space flight

Exposed! International Space Station tests organisms, materials in space

Russia launches Iranian satellite amid Ukraine war concerns

NASA Goddard's 'Web Around Asteroid Bennu' Shows in SIGGRAPH Film Fest

Northrop Grumman invests in new solid rocket motor manufacturing facilities in Magna, Utah

J-Space partners with Virgin Orbit to bring sovereign air-launch capability to South Korea

Private rocket company completes third orbital mission

The space economy gets major tech advancement with hybrid mobility packages

Sols 3562-3563: Adventures Over Sand

Building on Mars or the Luna: You'll need extraterrestrial cement for that

New Year, New Challenges: Sols 3558-3559

Progressing through the pass: Sols 3560-3561

Wentian's small mechanical arm completes in-orbit tests

Reusable experimental spacecraft put into orbit

China launches six new satellites

China's Tianzhou-3 cargo craft re-enters atmosphere under control

HKATG tooling up for satellite mass production

AST SpaceMobile's BlueWalker 3 test satellite arrives at Cape Canaveral

Space Accelerator catalyses multi-million pound investment

Spire Global to scale up constellation for HANCOM inSPACE with second satellite

Matter at extreme temperature and pressure turns out to be remarkably simple and universal

Wobbling droplets in space confirm late professor's theory

Pitt is the only university in the U.S. with this giant 3D printer for metal

Building the best zeolite

Scientists detect newborn planet that could be forming moons

A cosmic tango points to a violent and chaotic past for distant exoplanet

New research on the emergence of the first complex cells challenges orthodoxy

Super-earth skimming habitable zone of red dwarf

Why Jupiter doesn't have rings like Saturn

You can help scientists study the atmosphere on Jupiter

SwRI scientists identify a possible source for Charon's red cap

NASA's Europa Clipper Mission Completes Main Body of the Spacecraft

The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.