B-free

Shown is the splash in the Bore Soliton Splash experiment. In a long water-filled channel, two solitons are generated by sudden opening of a sluice gate, which holds back a finite amount of water at a higher
level. As we can see the channel linearly converges from both sides at the far end, forming a narrowing V-shape, when viewed from above. The first soliton quickly develops a jump/bore, and crashes in this
contracting part of the channel. This first wave reflects from the convergence with a limited increase in the water level at the
convergence, and then draws a trough in which the unbroken second soliton crashes. That results into the 3-4m high vertical jet displayed, but only when initial water levels in the canal and sluice gate are
finely tuned: 0.41m versus 0.9m.

More info: http://www.woutzweers.nl/text%202010/2010%20soliton%20splash.html