Mysterious vortex rings could hold the key to helping make fusion energy viable, new research reveals – The Debrief

Scientists say a breakthrough that could help make nuclear fusion a viable energy source could be made with a mathematical model that improves our understanding of the swirling ring-shaped disturbances known as vortex rings, according to new research.

Moving vortex rings have long intrigued scientists as they carry rotating fluids or gases as they travel. Similar to how friction is reduced between the moving wheel of a car and the road below when the wheel begins to rotate, vortex rings reduce friction between the surrounding fluid or gaseous medium and the vortex core. This allows vortex rings to travel significant distances while maintaining their structure, without losing much mass or kinetic energy as they move.

Although they appear frequently in liquids and gases, vortex rings often go unnoticed unless they occur in a medium in which suspended particles reveal their presence. One of the more common varieties includes rings of smoke that cigarette smokers sometimes produce when they exhale, although other examples include rings of fire, microbursts, and mushroom clouds produced by massive explosions.

Now, new research funded by Lawrence Livermore National Laboratory and the Department of Energy demonstrates that vortex control for use in manufacturing energy systems could be enabled by leveraging links to more common types of vortex rings. In particular, the scientists believe that vortex rings could be useful in new applications for fuel compression that could greatly enhance efforts to make nuclear fusion energy more viable.

Nuclear fusion occurs naturally in our Sun and distant stars when hydrogen is converted to helium, whereby some of the mass is converted into the energy that heats them. Inside a nuclear reactor, energy is most easily lost during the ignition process of the reaction attempting to replicate this stellar process.

However, University of Michigan researchers report that a mathematical model they recently developed could help minimize this energy loss with the design of more efficient fuel pods used to power nuclear fusion, along with other potentially useful applications. .

Currently, the fuel capsules used in fusion research are nearly perfectly spherical granules composed of deuterium and tritium atoms that provide the energy for the ignition process. As the outer shell of the fuel capsule is vaporized under the bombardment with lasers, the carbon atoms are ejected outward, producing a shock wave which exerts enormous pressure on the fuel, fusing the hydrogen atoms together. ‘internal.

The fuel pellets are designed with a small filler tube where the fuel enters to a point where a vortex ring jet appears once compression occurs during fusion experiments. Michael Wadas, a mechanical engineering doctoral candidate at the University of Michigan and corresponding author of a study detailing the new research, says previous studies have noted the appearance of this jet, though it hasn’t always been recognized as a vortex ring; a crucial observation that allowed the team to correctly characterize the jet and its behaviour.

Eric Johnsen, an associate professor of mechanical engineering at the University of Michigan who oversaw the recent study, said in a statement that because of how fast fusion experiments occur, we really only need to delay the jet’s formation by a few nanoseconds. .

The team says applying their model to vortex rings could help researchers understand processes such as the mixing of elements of different heavier and lighter compositions, such as when stellar explosions occur. In a cosmological sense, understanding such processes could help planetary scientists understand what led to the formation of planets like Earth. In the laboratory, it could eventually help make energy from nuclear fusion viable in the near future.

The model developed by Wadas, Johnsen and team could ultimately help researchers understand the energy limits of vortex rings, as well as conditions that present modeling challenges, such as how much fluid or gas can be pushed ahead of other phenomena. as turbulence begin to occur.

The team’s paper, Saturation of Vortex Rings Ejected from Shock-Accelerated Interfaces, appeared earlier this year in Physical Review Letters.

Micah Hanks is managing editor and co-founder of The Debrief. He can be reached by email atmicah@thedebrief.org. Follow his work onwww.micahhanks.comand on Twitter:@MicahHanks.