Nitrogen swirl: Creating rotating polygons in a boiling liquid

Nonlinear Schrodinger Equation Solitons on Quantum Droplets

“…At lab scale, the formation of periodic nonlinear waves, or cnoidal waves for Korteweg-de Vries models (KdV), on closed and bounded systems was detected and the results were matched with theoretical calculations in low temperature interfacial systems [35,40], in confined rotating flows [28], and along circular chains of magnetic pendulums [29]. Experiments demonstrate the formation of rotating hollow polygons in 2D fluids, within good match with theoretical models of cnoidal waves [39][40][41][42][43][44][45][46][47].…”

Shape dynamics of rotating polygons on the surface of liquid nitrogen in a Leidenfrost state

“…We were thus very happy that we were able to find similar instabilities in systems that are not rotating at all [16], relying on the Leidenfrost effect, where boiling creates a thin vapor layer that separates the liquid from the pot making the friction very small. If we pour liquid nitrogen into a heated cylindrical pot and set the nitrogen into rotation, either by stirring, or, as shown in Figure 6, by accelerating it down a ramp, it can rotate sufficiently long for spontaneous symmetry breaking to occur as seen in Figure 7 (from Gallery of Fluid Motion, 2018 [26]). Surprisingly, one can find very well-defined polygonal shapes (ranging from ellipses to hexagons) despite the transient and strongly turbulent nature of the flow.…”

“…Polygons formed by liquid nitrogen in the experiment shown inFigure 6, without the inclined pipe, simply stirring the fluid from rest and using a high-speed camera. The pictures are from[26] and the corresponding video, winner of the Gallery of Fluid Motion in 2018, can be found at https://gfm.aps.org/meetings/dfd-2018/ 5b992d40b8ac31610362f452. (m = 3), squares (m = 4) etc., and using this decomposition we can quantitatively follow the shape dynamics.…”