Scientists expanding knowledge of nuclear physics…using Hellmann’s Real Mayonnaise

Scientists are expanding their knowledge of nuclear physics by conducting a series of experiments – using Hellmann’s Real Mayonnaise.

Professor Arindam Banerjee and his team are making great leaps studying how certain materials react in extreme environments – which may one day be used to help pioneer space travel.

They are conducting experiments using the condiment in a series to see how materials of different densities could interact under certain stresses, like in space or inside nuclear reactors.

Hellmann’s Real Mayonnaise was chosen because it is a non-Newtonian fluid and has similar properties to molten metals.

Crucially, it is significantly easier and cheaper to handle and conduct experiments with sandwich spread than molten metal.

Prof Banerjee is an associate professor of mechanical engineering and mechanics at Lehigh University in Pennsylvania, America.

He said: “In the presence of gravity―or any accelerating field―the two materials penetrate one another like ‘fingers’.”

They picked Hellmann’s because it is an elastic-plastic material, and conducted a series of experiments to see how its surface changes when it is put under certain stresses.

He said: “There has been an ongoing debate in the scientific community about whether instability growth is a function of the initial conditions or a more local catastrophic process.

“Our experiments confirm the former conclusion: that interface growth is strongly dependent on the choice of initial conditions, such as amplitude and wavelength.”

The results of Banerjee’s experiments using mayonnaise could apply to high-energy density physics problems, including fusion.

In the experiments, Hellmann’s Real Mayonnaise was poured into a plexiglass container and rotated at high speed and photographed.

By analysing how the mayo changed shape, they could work out how a molten metal, or other similar substances, would change in similar conditions.

Different wave-like shapes were formed on the mayonnaise and the sample was then accelerated on a rotating wheel experiment.

The growth of the shapes in the mayo was tracked using a high-speed camera and an image-processing algorithm was applied to work out the parameters of the instability.

In scientific terms, plasticity refers to non-reversible changes to a material while elasticity refers to reversible changes.

The results of Banerjee’s experiments using mayonnaise could apply to high-energy density physics problems relevant to inertial confinement fusion – because the physical properties of the beloved condiment act similarly to molten metal, but is far easier and safer to work with.

He says that the properties and dynamics of metal at a high temperature are much like those of mayonnaise at low temperature.

By working out how the Hellmann’s changed shapes, under different circumstances, they were able to visualise elastic-plasticity and instability evolution which would also occur in non-ersatz materials, like molten metal.

Prof Banerjee added that the new understanding of the “instability threshold” of elastic-plastic material under acceleration could help solve a variety of scientific and engineering challenges.

These include challenges in geophysics, astrophysics, industrial processes such as explosive welding, and high-energy density physics problems.

Prof Banerjee and his team have spent more than four years building a device specifically for these experiments.

These results were published in Physical Review E called “Rayleigh-Taylor-instability experiments with elastic-plastic materials.”

 

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