Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




TIME AND SPACE
Physics of fluids explained 100 years after original discovery
by Staff Writers
Blacksburg VA (SPX) Mar 29, 2013


This figure shows two fluid jets merging into one on the right when just a 20 percent speed increase is applied. Credit: Virginia Tech.

Sunghwan Jung is a fan of the 19th Century born John William Strutt, 3rd, also known as Lord Baron Rayleigh. An English physicist, Rayleigh, along with William Ramsay, discovered the gas argon, an achievement for which he earned the Nobel Prize for Physics in 1904.

But it was Rayleigh's lesser-known discovery of a physical phenomenon in 1878 that was more intriguing to Jung. Some 135 years ago, Rayleigh wrote that two fluid jets or drops do not always merge into one body of liquid, a counter-intuitive topic or phenomena in physics that has since been studied in much detail, cited Jung, Virginia Tech assistant professor of engineering science and mechanics.

The significance today of this fact is that when noncoalescence takes place between two fluids, it might impact a variety of industrial and everyday processes such as fuel efficiency, ink jet printing, and the development of spray coatings.

New information on Rayleigh's verbal description of the collision of fluids now appears in a contemporary paper authored by Jung and Pavlos Vlachos, professor of mechanical engineering at Virginia Tech, and Navish Wadhwa, of Blacksburg, Va., a doctoral candidate in engineering science and mechanics. The paper, accepted in Physical Review Letters, a peer-reviewed journal of the American Physical Society, is called "Noncoalescence in the oblique collision of fluid jets."

"In Rayleigh's original paper, he mentioned two things: drop bouncing on a liquid bath and jets bouncing. No pictures were given. Much work has been done in drop-bath bouncing, but no work has been done in bouncing jets except for a couple of demonstrations in textbooks. We are the first ones to rationalize the physical mechanism of bouncing jets," Jung explained.

In their experiments, the researchers studied two silicone oil jets bouncing off each other upon collision. Silicone oil is used in most experiments in order to avoid any surface contamination, Jung said, and it is often the base for hydraulic fluids or lubricants.

"Intuition tells us that two or more jets of the same fluid impinging into each other will readily coalesce to form a single mass of fluid, and are well-studied phenomena," Jung explained.

Velocity is key to bringing the two silicone oil jets into a single flow of liquid. Since these jets of fluid drag along air, considered to act as a cushion, the two jets will bounce off of each other. But when the speed of the flow is increased beyond a certain threshold, the air is no longer stable due to the high inertia of jets, and the liquid jets will coalescence, Jung added.

To attain fuel efficiency in space rockets, two different fuel fluids need to mix well to maximize the combustion.

"In our experiments, we showed they are able to bounce off each other and inhibit the mixing. However, in rocket fuel tanks, the fluids come out of the nozzles are a very high speed, so no bouncing happens in their cases," Jung said.

Jung's earlier work on fluid flow won him the 2010 international Milton Van Dyke award at the 63rd annual meeting of the American Physical Society.

.


Related Links
Virginia Tech
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TIME AND SPACE
Analysis brings Higgs confirmation closer
Upton, N.Y. (UPI) Mar 14, 2013
The new particle detected by the Large Hadron Collider in Switzerland last summer is looking more and more like the long-sought Higgs boson, scientists report. Results of analysis of the LHC data released Thursday bolster confidence the particle discovered is the Standard Model Higgs, U.S. researchers said. Confirmation of the Higgs, a particle thought to give mass to other eleme ... read more


TIME AND SPACE
Lunar cycle determines hunting behaviour of nocturnal gulls

Ultraviolet spectrograph observes mercury and hydrogen in GRAIL impact plumes

NASA's LRO Sees GRAIL's Explosive Farewell

Amazon's Bezos recovers Apollo 11 engines

TIME AND SPACE
SwRI study finds liquid water flowing above and below frozen Alaskan sand dunes, hints of a wetter Mars

Opportunity Moves Into Place for Quiet Period of Operations

Measuring Mars: The MAVEN Magnetometer

Opportunity Heads to Matijevic Hill

TIME AND SPACE
Miners shoot for the stars in tech race

Space Innovation Center Will Help Govt Agencies Launch Future Space Missions

The Future of Exploration Starts With 3-D Printing

Lockheed Martin to Continue Providing Life Sciences Support To NASA

TIME AND SPACE
Shenzhou 10 sent to launch site

China's Next Women Astronauts

Shenzhou 10 - Next Stop: Jiuquan

China's fourth space launch center to be in use in two years

TIME AND SPACE
New crew takes express ride to space station

Soyuz Docks At Space Station Four Orbits After Launch

Three astronauts blast off on express ride to ISS

Russia may recycle space station modules

TIME AND SPACE
Future Looks Bright for Private US Space Ventures

Europe's next ATV resupply spacecraft enters final preparatio?ns for its Ariane 5 launch

ILS Proton Launches Satmex 8 Satellite for Satmex

When quality counts: Arianespace reaffirms its North American market presence

TIME AND SPACE
The Great Exoplanet Debate

Astronomers Detect Water in Atmosphere of Distant Planet

Distant planetary system is a super-sized solar system

Water signature in distant planet shows clues to its formation

TIME AND SPACE
CO2 could produce valuable chemical cheaply

Catalyst in a teacup: New approach to chemical reduction

Lasers could yield particle research tool

Paint-on plastic electronics: Aligning polymers for high performance




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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. Privacy Statement