Mayonnaise, a common kitchen condiment, is being used by researchers at Lehigh University to uncover insights into nuclear fusion, a potential source of limitless and clean energy.
When exposed to a pressure gradient, mayonnaise behaves like a plasma despite its usual solid behavior. Because of this fascinating property, scientists at Lehigh University are studying nuclear fusion using mayonnaise as a model.
“We use mayonnaise because it behaves like a solid, but when subjected to a pressure gradient, it starts to flow,” says Arindam Banerjee, the Paul B. Reinhold Professor of Mechanical Engineering and Mechanics at Lehigh University. This characteristic of mayonnaise is similar to how plasma behaves in similar situations.
The process that powers the sun, nuclear fusion, offers limitless clean energy. It is a difficult task to imitate the sun’s harsh conditions on Earth, though. Inertial confinement fusion (ICF) is a technique that requires compressing and heating tiny capsules containing hydrogen isotopes to achieve fusion. The fuel turns into plasma at high temperatures and pressures, generating energy.
“At those extremes, you’re talking about millions of degrees Kelvin and gigapascals of pressure as you’re trying to simulate conditions in the sun,” Banerjee elaborates.
The development of hydrodynamic instabilities, which can reduce energy production, is a major obstacle in ICF. “This process’s primary issue is that the plasma state forms these hydrodynamic instabilities, which can lower the energy yield,” Banerjee adds.
One such instability is the Rayleigh-Taylor instability (RTI), which is the result of opposing pressure and density gradients acting on materials with varying densities.
“Rayleigh-Taylor instability (RTI) is observed in soft materials that have significant resistance to yield,” notes the study.
The research team used mayonnaise to test RTI in a controlled setting. They replicated the plasma flow conditions at Banerjee’s Turbulent Mixing Laboratory using a specially constructed rotating wheel facility. Without using harsh lab settings, researchers may investigate the instability by looking at mayonnaise. The team examined the effects of acceleration rate, perturbation geometry, and material parameters on the change in RTI phases. They identified the circumstances in which elastic recovery—the process by which a material, under stress, returns to its original shape—is possible.
“As with a traditional molten metal, if you put a stress on mayonnaise, it will start to deform, but if you remove the stress, it goes back to its original shape. So there’s an elastic phase followed by a stable plastic phase. The next phase is when it starts flowing, and that’s where the instability kicks in,” Banerjee states.
These results may play a key role in inhibiting or postponing instabilities and improving the fusion process’s efficiency. By identifying the ideal circumstances for elastic recovery, the researchers may be able to create stable fusion capsule designs.
Although mayonnaise’s characteristics are different from those of plasma used in fusion tests, the researchers think their findings may apply to a variety of materials.
“In this paper, we have non-dimensionalized our data with the hope that the behavior we are predicting transcends these few orders of magnitude,” Banerjee concludes.
