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First, looking at v vs r, we find that the particle's velocity increases as it gets closer to the center of the tank, as we would expect from conservation of angular momentum.
This shows basically the same thing, though less directly. As time goes on and particles move closer to the center of the tank, their velocities increase, consistent with conservation of angular momentum.
This is an example of one of the particles we tracked and selected for analysis. Note that its radius steadily decreases as it spirals inward, as we would expect, but that its path appears to be slightly ellipsoidal and off center, which introduced error into our calculations.
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