ICTS

Education

• BTech (1984) Chemical Engineering, IIT (Indian Institute of Technology) Delhi (in 2022 won the Distinguished Alum Award of IIT Delhi)
• PhD (1994) Aerospace Engineering, IISc (Indian Institute of Science) Bengaluru (in 2017 won the Platinum Jubilee Prize of this Department)
• Postdoctoral Fellow (1994) Caltech (California Institute of Technology).

Employment 

• 1998-1998: Scientist, National Aerospace Laboratories, Bengaluru.
• 1998-2012: Faculty member, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru.
• July 2012-Present: Professor in the Tata Institute of Fundamental Research, (at TIFR Hyderabad till July 2016). Currently Senior Professor and Dean Academic, International Centre for Theoretical Sciences, TIFR Bengaluru.

Research interests

Our present group is very interested in particulate (and droplet) flows. Some examples: (i) We ask how rain formation depends on the turbulence level in a cloud. Vortices are a building block of turbulent flows, and small heavy inertial particles or droplets are centrifuged out of them. This gives particles a bigger opportunity to collide, and maybe get attached / coalesce and thus grow bigger. We show how caustics formation, a process which leads to singularities in particle number density, is an important ingredient in this process. (ii) The Basset-Boussinesq history force is among the forces that act on small inertial particles in flow. This force appears in the form of a fractional derivative, which is notoriously difficult to compute and prima-facie requires ever-increasing computer memory. So it is usually neglected whether or not such neglect is justified. With our collaborator, Vishal Vasan, we work out how this force may be reinterpreted, rewritten and computed to high orders of accuracy with constant memory requirements. (iii) When particles are not in very dilute suspension, they interact with each other and their dynamics changes. We show how sedimenting ellipsoids can interact to stabilize themselves, whereas sedimenting spheres cannot.

Our group has always been interested in flow stability. We ask how gradients of density and viscosity, and thermodynamic effects brought about by phase change affect in a deep way the tendency of a laminar flow to go unstable. 


Selected Publications

• Flows with varying viscosity. Ritabrata Thakur, Arjun Sharma, Sharath Jose & Rama Govindarajan. Invited paper in preparation for Reviews of Modern Physics, 2024
• The waltz of tiny droplets and the flow they live in. S Ravichandran & Rama Govindarajan. Physical Review Fluids, 7, 110512, 2022
• Early evolution of optimal perturbations in a viscosity-stratified channel. Ritabrata Thakur, Arjun Sharma & Rama Govindarajan, Journal of Fluid Mechanics, Special Volume in Celebration of the GK Batchelor Centenary, 2021, 914, A10
• Waves, Algebraic Growth and Clumping in Sedimenting Disk Arrays. Rahul Chajwa, Narayanan Menon, Sriram Ramaswamy & Rama Govindarajan. Physical Review X, 10, 041016 2020
• Accurate solution of the Maxey-Riley equation, and effects of Basset history, S Ganga Prasath, Vishal Vasan and Rama Govindarajan, Journal of Fluid Mechanics, 2019. https://doi.org/10.1017/jfm.2019.194