There was once a saying from the renowned American physicist Richard Feynman about turbulence. He said that it remains to be the most important "unsolved" problem in classical physics.
The challenge for the experts is recognizing the behavior of vortices paired with the tough understanding of how turbulence could be determined through tracking the motion of vortex tubes through a simple model.
To arrive at this study, researchers from Florida State University (FSU) have seen the vortex tubes located in a quantum fluid. The finds will later help them to have a grasp of what is going on with turbulence inside the liquid.
Vortex Tubes Emerge in the Quantum Fluid
Researchers from FSU devised an experiment to better understand turbulence which involves the vortex tubes as published in a study entitled "Superdiffusion of quantized vortices uncovering scaling laws in quantum turbulence" in PNAS.org.
According to a mechanical engineering associate professor, Wei Guo, their study will help them to know the concept of turbulence. Besides, it could also serve other areas of study including vortex tubes, neutron stars, and superconductors.
The quantum liquid called helium-4 has been studied. It is known to thrive in extremely low temperatures which have the characteristic to endlessly flow with the absence of friction in a narrow space.
This is the first time that Guo's group has seen that when vortex tubes emerged, the tracer particles inside the vortices seemed to exhibit a random, rapid pattern from the get-go.
There is also a so-called superdiffusion, a process when an increasing displacement happens among the trapped tracers.
Over time, the velocities of the vortex will be studied to dive deeper for the necessary modeling of the quantum-fluid turbulence. The Levy flights, the unusual, long displacements are also integrated into superdiffusion.
However, the researchers found out that the Levy flights were not responsible for the superdiffusion in the experiment.
"We finally figured out that the superdiffusion we observed was caused by the relationship between the vortex velocities at different times," Yuan Tang, one of the authors said.
Tang continued that there is a positive correlation between the segment's velocity and its next instant velocity even though the pattern is random.
How the Researchers Conduct the Vortex Tubes Experiment
Moreover, Tan described the vortex tubes in superfluid helium-4 as "tiny tornadoes" with hollow cores, but that does not mean that they can be viewed easily with the naked eye and even with a powerful microscope.
For the experiment, the FSU researchers made use of a helium-deuterium gas mixture which was injected into the helium. When the injection has finished, the gas produced small ice particles which are used as fluid tracers, Scitech Daily reported.
Globally, scientists have been using this visualization technique, but the most impressive discovery here is the algorithm used to recognize the trapped tracers in a whirling fluid from those untrapped ones.
Related Article: NASA Scientists Report Strange 'Dark Vortex' In Neptune's Atmosphere
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Written by Joen Coronel
