Oscillations and Cavity Modes in the Circular Hydraulic Jump

Now You See It, Now You Don’t

“…The bank, known as a circular hydraulic jump, is a boundary between two flow regimes and has been the subject of investigation for centuries-Leonardo da Vinci noted it in his journals. Now Aurélien Goerlinger of the Institute of Electronics, Microelectronics and Nanotechnology in France and his colleagues turn up a new feature in this familiar phenomenon [1]. They find that, under certain conditions, the pond can appear and disappear multiple times per second.…”

“…Comparing experimental data to a theoretical model of the system, the team determined that the effect stems from waves generated by the jump itself. These waves propagate Credit: A. Goerlinger et al [1] Video 1: Disappearance and reappearance of a circular hydraulic jump on a circular plate. The jet has a diameter of 0.9 mm, and the plate has a diameter of 9 cm.…”

“…The jet has a diameter of 0.9 mm, and the plate has a diameter of 9 cm. Credit: A. Goerlinger et al [1] outward from the jump, hit the edge of the surface, and then reflect inward. If the waves constructively interfere as they travel inward and outward, they repeatedly flood the pond and hide the hydraulic jump.…”