These videos depict solitary waves or solitons at the interface of a buoyant viscous fluid conduit created by a "pulse" of additional fluid. 聽The geometry of soliton interaction depends on the sizes of the two solitons. 聽Video (except the colored ones) has been rotated 90 degrees, sped up, and aspect ratios have been changed. 聽The videos titled "Single soliton closed streamlines" and "Solitons transfer fluid" are rotated 90 degrees and are in real time with a 1:1 aspect ratio. 聽Associated paper.
Dispersive shock waves in a viscous fluid conduit are created by ramping up the injection rate to a sustained, larger value. 聽Wavebreaking (gradient catastrophe) eventually occurs, leading to the spontaneous emergence of coherent, rank-ordered, expanding, nonlinear oscillations. 聽For large jumps in the injection rate, the trailing edge envelope can propagate聽opposite聽to the direction of fluid flow upward. 聽Video has been rotated 90 degrees, sped up, and aspect ratios have been changed. 聽Associated聽theory听补苍诲听experiment.听
Dispersive Hydrodynamics of Viscous Fluid Conduits
Dispersive hydrodynamics encompasses the large scale dynamics of dissipationless, dispersive fluids. 聽The video depicts the overtaking interaction of a soliton and a dispersive shock wave. 聽The image above is a space-time snapshot of the entire video (a contour plot of the experimental conduit amplitude in space-time), showing that the soliton is actually decelerated or聽refracted聽by the dispersive shock wave. 聽Associated聽experiment.
Here, the soliton is launched first followed by a dispersive shock wave. 聽The soliton is eventually absorbed into the interior of the expanding dispersive shock wave. 聽Associated聽experiment.
Interaction of two dispersive shock waves resulting in a merged dispersive shock wave that is decelerated (accelerated) relative to the trailing (leading) shock. 聽Associated聽experiment.
Dispersive hydrodynamics in thin film ferromagnets