Ingredients involved in splashing revealed

Nov 21, 2011

"Splashing" plays a central role in the transport of pollutants and the spread of diseases, but while the sight of a droplet striking and splashing off of a solid surface is a common experience, the actual physical ingredients and mechanisms involved in splashing aren't all that well understood.

A team of Brown University and Harvard University researchers has discovered that there is indeed more involved in splashing than previously believed. They will discuss their findings at the upcoming American Physical Society's 64th Annual Division of Meeting, which will be held Nov. 20-22, 2011, in Baltimore, Maryland.

"In recent studies, it was highlighted that the surrounding air plays an important role in the splashing process. Decreasing the inhibits splashing," explains Julie Albagnac, a postdoctoral research associate in engineering at Brown. "The observations led to a hypothesis of the existence of a of air trapped between the drop and the surface."

To better understand droplet splashing, the researchers initially wanted to observe and measure this layer of trapped air. They hypothesized that splashing may occur even before actual contact of the drop on the surface, while the drop is still spreading on an air film.

Unfortunately, they found that experimental equipment available today isn't sophisticated enough to catch a length as small as the air layer thickness (hundreds of ) during the short time of existence of this air layer (hundreds of nanoseconds). So they instead studied the time evolution and behavior of droplets splashing with various impact velocities under a variety of ambient pressures to examine different scenarios involving splashing.

For this purpose, experiments performed at Harvard provide side and bottom views of the . "This study shows a new signature of a precursor to the splashing through the wriggling of the contact line at the interface between the droplet and the surface," says Albagnac.

The splashing/spreading of a droplet doesn't seem to be an on/off situation, according to the team. A transition regime exists between the spreading and splashing, which they observed by changing either the impact velocity or the ambient pressure while the other is fixed.

Explore further: New pathway to valleytronics

Provided by American Institute of Physics

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Image: Orion drop test at Langley

Nov 10, 2011

Engineers at NASA Langley conducted the third drop test of the Orion test article as part of Phase 1 water impact testing on Nov. 8.

How are droplets displaced by ultrasounds?

Mar 31, 2010

Understanding the physical mechanisms that enable a droplet to be displaced by propagating an acoustic wave along the substrate on which it lies is the hurdle that has been overcome by researchers from the Institut d'Electronique ...

Know the Facts About Drowning for Adequate Prevention

Jul 22, 2010

(PhysOrg.com) -- Most of us have seen depictions of drowning on TV -- there's splashing, yelling and a lifeguard running to the rescue. But emergency medicine professionals caution that's not how it happens ...

Brazil launches rocket into orbit

Dec 13, 2010

Brazil on Sunday successfully launched a midsized unmanned rocket into space, with hundreds of kilograms (pounds) in cargo and experiments in tow, space officials here said.

Droplets that Roll Uphill

Sep 24, 2007

A recent experiment conducted by physicists at University of Bristol in the United Kingdom has shown that liquid drops can defy gravity. Droplets of liquid on an inclined plate that is shaken up and down can ...

Recommended for you

New pathway to valleytronics

23 hours ago

A potential avenue to quantum computing currently generating quite the buzz in the high-tech industry is "valleytronics," in which information is coded based on the wavelike motion of electrons moving through ...

New portable vacuum standard

Jan 26, 2015

A novel Portable Vacuum Standard (PVS) has been added to the roster of NIST's Standard Reference Instruments (SRI). It is now available for purchase as part of NIST's ongoing commitment to disseminate measurement ...

Prototype for first traceable PET-MR phantom

Jan 26, 2015

As cancer diagnostic tools, a new class of imagers – which combines positron-emission tomography (PET) with magnetic resonance imaging (MR or MRI) – has shown promise in the few years since these hybrid ...

User comments : 0

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.