Computer game graphics reveal vortex physics

London, Oct 26 : State-of-the-art computer graphic systems developed for movies and games have made it possible to model in unprecedented detail the swirling rings and tubes that are a characteristic of turbulent vortices.

According to a report in New Scientist, the models will help explain the forces that govern vortex decay.

This could lead to ways to control them in places where they cause problems, such as over aircraft wings or in blood vessels.

Computer graphics technology for games and movies has progressed to the point that it can render photoreal simulations of flowing liquids.

Two researchers at the Federal Institute of Technology Lausanne are now harnessing this new-found modelling power to explore the physics of turbulent vortices.

The physical laws of momentum, energy and mass conservation that govern vortex behaviour are already well known, according to Diego Rossinelli, who is working with Petros Koumoutsakos on the project.

"But knowing the equations is not enough. Solving them is the real challenge," he said.

Creating virtual vortices is simple enough when they are newly formed and regular in shape, but those simple forms evolve more complexity over time.

"The only hope to understand the underlying physics is to simulate the phenomena using computers," said Rossinelli.

Rossinelli and Koumoutsakos used a supercomputer with 16,000 processors to produce numerical simulations of both a vortex ring, similar to those blown by smokers, and in a vortex tube, such as are produced over the wings of aeroplanes during take-off.

Their simulations move around 10 billion independent virtual particles.

According to Koumoutsakos, "That's an unprecedented level of detail. No one has ever modelled more than a couple of million particles before."

The researchers then fed the solutions through 16 dedicated graphical processors to visualise the data.

The combination of such detailed mathematical modelling with state-of-the-art graphics visualisations allows us to look at physics with a new level of detail, according to Koumoutsakos.

"It's a very powerful new way of looking at vortex structures," he said.

Rossinelli and Koumoutsakos said that studying how vortices evolve with time can help identify the factors that lead to their eventual decay and disappearance.

That should help design structures that can speed up that decay process, which could have a number of applications.

ANI