PEOPLE Postdoctoral Fellow
International Centre for Theoretical Sciences, Bengaluru
Area of Research:  Fluid Mechanics
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  sangeethkrishnan  ictsresin

My expertise and research interest lie in the field of fluid mechanics. The common theme of my research is the dynamics of liquid-gas interface or free surface ranging from micrometer to planetary length scale. The dynamics of free surfaces is particularly interesting to me as it is crucial in the transportation of various physical quantities. 

In smaller length scales, where surface tension is dominant, interfaces generate shapes countering gravitational pull in static equilibrium. When this balance is disturbed, they undergo complex yet fascinating shape transitions that involve surface tension, inertia, viscosity and sometimes even gravity until another equilibrium state is reached. These shape changes are strongly unsteady motions, extremely fast in some problems and often encounter singularities in their physical model.

Bursting of bubbles at liquid surfaces is such a scenario that lead to a variety of complex fluid motions resulting in the formation of tiny jets that fragment to generate droplets. One crucial application is the dispersal of disease-causing microbes due to the bursting of bubbles at contaminated liquid surfaces. I explored the dynamics of singular jets further in a different context where the sudden acceleration of curved interfaces forms the jets. This mechanism also yields finer droplets when the jet fragments, which is crucial in determining various transport quantities in fuel tanks in space application. 

Larger scale interface motions are dominated by gravity. They are encountered commonly in geophysical applications like surface gravity waves.  My present study focuses on the weakly nonlinear interaction of gravity waves that lead to (coherent) vortical structures characterised by a fine balance of two or more physical effects. An example is the vortical structures visible in ocean basins, such as in the Bay of Bengal.