Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


What happens when a stone impacts on water

Researchers at the Foundation for Fundamental Research on Matter (FOM), the University of Twente in the Netherlands and the University of Seville in Spain have explained the formation and behaviour of the very fast water jet that is formed when an object impacts on a water surface.

They have observed precisely what happens using a super-fast camera and have made a computer simulation of the process. This shows how the jet is forced upwards, layer by layer, by the surrounding water pressure. The simulation corresponds very closely with observations.

They have also formulated a theoretical model based on this that explains the extremely high speed of the water jet. The researchers are publishing their findings in the renowned journal, Physical Review Letters. These results are not only of academic significance as jets on the impact of an object on a liquid are frequent occurrences in nature and industry.

If one drops a stone into a pond, a very rapid, thin jet of water spouts upwards. This is an everyday phenomenon that occurs frequently in nature and industry. However, the rich and complex dynamics underlying such a system are only revealed if viewed using a high-speed camera. The latter shows how the downward movement of the object is converted into the upward movement of the jet.

A cavity forms behind the object during impact on the water surface. This cavity is subsequently compressed by hydrostatic pressure, which leads to the formation of the jet. In their experiments, FOM PhD candidate Stephan Gekle, José Manuel Gordillo of the University of Seville and Devaraj van der Meer and Detlef Lohse of the University of Twente demonstrate how the wall of the cavity forces the jet upward as it implodes, just like toothpaste being squeezed out of a tube, but many times faster, of course. Incidentally, a jet which is forced downward, deeper into the liquid, is also created at the same time. This second jet is not visible on the surface.

In order to examine the dynamics of the impact in a highly controlled manner, the researchers draw a circular disc through the water surface using a linear motor with a constant speed. Subsequently a high-speed camera is used to take images with a speed of up to 30,000 frames per second.

The formation and constriction of the cavity and the formation of the jet can thus be followed in detail. A computer simulation of the process – which corresponds very closely to the experiment – enables the researchers to study the resulting flow profile. It appears that the jet is forced upward, layer by layer, by the imploding wall. The researchers have formulated a theoretical model to explain the enormous speed of the water jet on the basis of this observation.

Wiebe van der Veen | alfa
Further information:

More articles from Physics and Astronomy:

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

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: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>