Levich Institute Seminar Announcement, 12/08/2015
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor V. Kumaran
Indian Institute of Science
Department of Chemical Engineering
"Transition and Turbulence in the Flow Past Soft Surfaces"
The nature of the flow in a channel or a tube (laminar or turbulent flow) is of importance in chemical engineering applications, because the drag force and transport coefficients in turbulent flows are orders of magnitude higher than those in laminar flows. It is well known that the transition from a laminar to a turbulent flow in a rigid tube takes place at a Reynolds number of about 2100, and in a rigid channel at about 1200. Our experiments show that the transition Reynolds number in channels and tubes with soft walls could be significantly lower, and the flow after transition exhibits a high level of turbulence fluctuations and has transport coefficients up to five orders of magnitude higher than that in laminar flows. The difference in the nature of the transition and turbulence between rigid and flexible conduits can be traced to the difference in the nature of the hydrodynamic instability leading to transition. Our theoretical work on the hydrodynamic stability of flow past flexible surfaces, which accurately predicts the transition observed in experiments, will be discussed. This transition could have important implications for biological flows microfluidic systems.
BRIEF ACADEMIC/EMPLOYMENT HISTORY
B. Tech, IIT Madras, 1987; PhD Cornell University 1991; Postdoctoral Research Engineer, University of California, 1991-93; Assistant Professor (1993-99), Associate Professor (1999-2004), Professor (2004-Present), Department of Chemical Engineering, Indian Institute of Science, Bangalore.
RECENT RESEARCH INTERESTS
Transition to turbulence; Granular flows and suspensions; Rheology of complex fluids.