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In order to collect data from our experiment, we tracked using video processing software buoyant particles at the surface of the fluid, as well as particles with density in between that of the two fluids which sat just above the frontal boundary. The shape of the front, although relatively stable, did vary slightly throughout the course of the experiment, as can be seen from the following images.
Figure 1: The progression of the front. The time stamp shown is relative to the time at which the can was removed, first allowing the two fluids to meet.
Initially, the shape of the front resembles a Gaussian, with a wide sloping surface and flat top. As the experiment progresses, the front boundary gradually sinks relative to the free surface and its sides flatten, leaving a sharp peak in while its peak at the center sharpens.
Using equation x, we calculate the radius of deformation to be around 20 centimeters, or half of the width of the tank. Given that the boundary of the front extends all the way to the outside of the tank, close to, but not at, the bottom of the tank, the actual radius of deformation for this front is slightly larger than this prediction. Because of this, we see the slope of the front decrease towards the edge of the tank, as the front has no more room to spread outwards.
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From the two above plots, one can see that the fluid does behave cyclonically at the surface, as we expected. At large radii, where the frontal boundary has a very small slope, the azimuthal velocity is small, as would be expected from the Margules relation. As the radius decreases, the slope increases, and so does the azimuthal velocity of the fluid, reaching its peak at around 5 centimeters. At very small radii, the azimuthal velocity decreases again as the frontal boundary flattens.
We also tracked the particles which sat just above the frontal surface. In the
5 Challenge: Inverting the Dome!
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