Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists Trash Turbulence Lab & Turn Pleasant Stream Into Raging Torrent

14.04.2005


Researchers at the University of Warwick have trashed the world’s biggest turbulence lab by turning a pleasant stream into a raging torrent - but they say their actions will lead to new understandings in one of the main unsolved problems in physics- turbulence.



Turbulence is one of the main unsolved problems in physics. Turbulent systems fluctuate wildly and understanding this will also help us understand (and put a number on the likelihood of) extreme events in other systems that look the same in terms of the mathematics, such as the weather, and stock market prices.

It is technically very challenging to study turbulence on earth, either in the laboratory or on even the largest computers that are available. A very large experiment is needed, and so researchers have turned to space to use the whole solar system as a turbulence laboratory. The solar system is filled by the sun’s expanding atmosphere - the solar wind, we see its effects directly here on earth as "space weather" (the northern lights). The solar wind also effects how cosmic rays reach the earth, which may have important consequences for earth weather and climate change.


A familiar example of turbulence is a stream flowing over a weir. A trick often used to study this is to follow a "passive scalar" - an element of the flow that follows the flow but does not cause or suffer significant change. In the case of a stream a passive scalar might be a leaf floating downstream. In the case of the solar wind it was hoped that the density of the wind is passive, allowing researchers to use a relatively simple set of mathematical tools to model the turbulence.

However new results about to appear in Physics Review Letters by researchers at the University of Warwick has shown that the density in the solar wind behaves less like a leaf in a stream and more like a pile of enormous boulders and tree trunks being smashed along a raging torrent of water.

The research by Dr Bogdan Hnat, Professor Sandra Chapman, and Professor George Rowlands at The University of Warwick’s Department of Physics, and which drew on data from the NASA ACE satellite indicates that turbulence scientists will have to abandon using the density of the solar wind as their "passive scalar" leaf and seek more complex solutions to their problems.

Prof. Sandra Chapman | EurekAlert!
Further information:
http://www.warwick.ac.uk

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: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>