Physicists Trash Turbulence Lab

April 13, 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 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.

Source: University of Warwick

Explore further: Venus

Related Stories

Venus

July 27, 2015

As the morning star, the evening star, and the brightest natural object in the sky (after the Moon), human beings have been aware of Venus since time immemorial. Even though it would be many thousands of years before it was ...

Could 'windbots' someday explore the skies of Jupiter?

July 23, 2015

Among designers of robotic probes to explore the planets, there is certainly no shortage of clever ideas. There are concepts for robots that are propelled by waves in the sea. There are ideas for tumbleweed bots driven by ...

Sunny, with a chance of nuclear bullets

July 23, 2015

In space, far above Earth's turbulent atmosphere, you might think the one thing you don't have to worry about is weather. But you would be wrong. Just ask the people charged with the safety of the Cloud-Aerosol Lidar and ...

Recommended for you

For 2-D boron, it's all about that base

September 2, 2015

Rice University scientists have theoretically determined that the properties of atom-thick sheets of boron depend on where those atoms land.

0 comments

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.