Professor Ganesh Subramanian

Associate Professor, Jawaharlal Nehru centre for advanced scientific research


Areas of Interest:

Fluid mechanics and transport phenomena.

Specialization:

Dynamics and rheology of complex fluids such as suspensions, emulsions, polymer solutions etc, Hydrodynamic stability of Newtonian and non-Newtonian flows.

Consultancy Areas:

None

Sector Associated With:

Academia

Sectors Interested to Offer Service:

Educational / Academic institutions, R&D Organizations

Major Professional Contributions:

Dynamics and rheology of complex Fluids:
Our interests span a wide range of complex fluids that include suspensions, emulsions and polymer solutions, and more recently, suspensions of swimming microorganisms. We have established the crucial role of micro-scale inertia, and the breakage of Stokesian reversibility, in transport processes in suspensions of particles and drops. Recently, we have identified the `tumbling-spinning transition' in suspensions of anisotropic
particles induced by micro-scale inertial forces, with consequences similar to the classical coilstretch
transition in polymer physics. We have also demonstrated, both
theoretically and by means of numerical simulations, the existence of a threshold for the transition of a bacterial suspension from a quiescent `rest' state to a state of collective motion characterized by the spontaneous growth of long wavelength velocity fluctuations.

2. Hydrodynamic stability:
The equations governing the stability of high-Reynolds-number shearing flows, the Rayleigh and Orr-Sommerfeld equations, support both discrete and continuous spectra. Over the last few years, we have highlighted the role of the continuous spectrum in inviscid hydrodynamic instability, and its role in the transient algebraic growth of small-amplitude perturbations. This is relevant to the bypass scenario in the laminar-turbulent transition of many shearing flows. Our current interests extend to the stability of viscoelastic shearing flows at large
Reynolds and Deborah numbers, with a particular emphasis on a deeper understanding of the well-known phenomenon of turbulent drag reduction. Our work in this regard should, on one hand, overthrow prevailing wisdom with regard to the origin of drag reduction (that is rooted in so-called coherent structures or non-linear exact solutions of the Navier-Stokes equations);
and, on the other hand, help highlight connections between equations of polymer dynamics and magnetohydrodynamics in the relaxation-less limit.

3. Thermal structure of the nocturnal boundary layer:
Our research in this area has contributed fundamentally to an understanding of radiative processes in the lowest meters of the nocturnal boundary layer. We have derived a correct consistent emissivity scheme that governs the longwave radiative exchanges in the nocturnal boundary layer, rectifying errors in a host of earlier calculations based on erroneous radiative schemes, and thereby, conclusively established the origin of an eighty-four-year-old micrometeorological phenomenon called the Ramdas layer which entails the formation of a lifted temperature minimum in the vertical temperature profile. Our research shows the crucial importance of aerosols in the formation of the elevated cold layer of air..

Professional Experience:

  • Post-doctoral fellow
  • Department of chemical and bio-molecular engineering, Cornell University, 2002-2005
  • Visiting associate professor and Fulbright-Nehru scholar, Cornell University, August-December 2012.

Keywords:

Complex fluids, soft condensed matter, non-Newtonian rheology, microhydrodynamics, suspensions, hydrodynamic stability.

 

Contact Information

Office

Ganesh Subramanian, Engineering Mechanics Unit, JNCASR, Bengaluru, 560064.
Phone: 080-22082296
Fax: 080-22082766

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Education

  • B.Tech (chemical engineering), UDCT, 1996.
  • PhD (chemical engineering), California Institute of Technology, USA, 2002.

 

Awards and Major Professional Recognitions

  • C.V. Seshadri distinguished lecturer for the year 2015 in the Department of Chemical Engineering, IIT Kanpur (November 2nd, 2015).
  • Invited speaker in 'Dynamics of suspensions, gels, cells and tissues' at the Isaac Newton Institute for Mathematical Sciences, Cambridge (June 2013).
  • Visiting associate professor at the school of chemical and bio-molecular engineering, Cornell University (August-December 2012).
  • Fulbright-Nehru fellowship for senior researchers (2012-2013).
  • INAE Young Engineer Award (2010).
  • Young Associate of the Indian Academy of Sciences (2007-2010)

Link to Website


INAE Section Affiliated IV: Chemical Engineering


Year of Election to Fellowship: INAE Young Engineer Award in 2010


Year of Birth: 1975