March 06, 2019
The hydraulic jump, seen easily in a kitchen sink, with the water level rising on its own, is an intriguing phenomenon in fluid dynamics. The flow in a kitchen sink provides an example of a circular hydraulic jump. We look at this physical problem from the perspective of gravitational analogues. Considering dynamics, we extract relevant time scales of the system, with which we provide both a simple analyticalm method of scaling the jump position and a physical explanation of this phenomenon. We extend the argument by showing a formal closeness between an Eulerian perturbation on the steady base flow and the metric structure of an acoustic white hole (the opposite of a black hole). The horizon of the white hole behaves like an impenetrable barrier to a wave that travels against the flow, carrying information. The horizon is so unyielding, in fact, that a wall of water is forced to stand by itself between two colliding hydraulic jumps. We provide photographic evidence in favour of this particular claim.
About the Speaker: Dr. Arnab Kumar Ray is an associate professor at Dhirubhai Ambani Institute of Information and Communication Technology (DAIICT), Gandhinagar. He received his Master's degree from Calcutta University, Kolkata, his PhD from Indian Association of Cultivation of Sciences, Kolkata and he has spent time at various reputed institutes such as Harish Chandra Research Institute, Prayagraj (Allahabad), Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, Homi Bhabha Centre for Science Education (HBCSE), TIFR, Mumbai etc. His research interests are in the field of astrophysical fluid dynamics.
Keywords: AU research seminar series