The Mechanical Engineering seminar series provides an unparalleled opportunity to an individual to increase the depth of his scientific knowledge. The seminars are held every Friday 5 PM, and also offer an ideal platform to initiate inter-disciplinary work cutting across boundaries.
The department maintains a very vibrant academic atmosphere through various academic initiatives. There is a regular stream of visitors to the department, both for long term and short term, resulting in collaborative research, interactions and seminars. In addition, a number of conferences, workshops and schools have also been organized by the faculty of the department over the years, both at IIT Kanpur, and elsewhere.
18th March, 2026 (Wednesday) at 5:15 PM (IST), Venue: FB 370
Dr. V. Shankar (Indian Institute of Technology Kanpur)
"Pipe Dreams and Pipe Flows: Elastic Routes to Turbulence in Polymer Solutions"
Read Abstract & About the Speaker
Abstract:
Despite its hoary origins in the Reynolds experiments (1883), and routine mention of the threshold Reynolds number (of around 2000) in fluid mechanics texts, transition from the laminar state in Newtonian pipe flow (and other canonical rectilinear shearing flows such as plane Couette and Poiseuille flows) is a subtle and complex process. This is largely due to the absence (plane Couette and pipe-Poiseuille flows) or irrelevance (plane Poiseuille flow) of an underlying linear instability. Thus, it is only a hundred years after the Reynolds experiments, and with the relatively recent advent of a dynamical systems perspective, that the Newtonian transition has come to be understood as fundamentally nonlinear. In this view, transition is associated with the appearance of three-dimensional invariant solutions of the governing equations—so-called exact coherent states—that coexist with, but remain disconnected from, the laminar solution. The proliferation of such states and their interactions are believed to underlie the complex dynamics leading to turbulence.
Over the past decade, it has been established that flows of dilute polymer solutions can undergo transition at Reynolds numbers far below the Newtonian threshold, giving rise to a distinct flow state known as elasto-inertial turbulence (EIT). This state may be closely related to the maximum drag reduction (MDR) regime known from the drag-reduction literature. For sufficiently elastic polymer solutions, the transition to EIT occurs at an amplitude-independent threshold, and the coherent structures observed in this regime differ markedly from those characteristic of Newtonian turbulence. In contrast to the long-standing disconnect between linear stability theory and experimental observations in Newtonian pipe flow, we have shown that the onset of EIT can in fact be driven by an underlying linear instability. Linear stability analysis, based on viscoelastic models such as Oldroyd-B and FENEP, reveals the presence of an unstable center-mode whose phase speed is close to the maximum of the base flow. The predicted instability thresholds are in good agreement with experimental observations for moderately elastic polymer solutions. For channel flows, the same instability persists down to zero Reynolds number, indicating that the elasto-inertial center-mode instability continuously connects to a purely elastic one. This finding challenges the conventional view that purely elastic instabilities—leading to elastic turbulence—require streamline curvature and the associated hoop stresses. In this talk, we summarize recent advances in this area, drawing both from our work and from that of other groups. We also discuss the broader implications of the center-mode instability for viscoelastic flows in curvilinear configurations such as Taylor–Dean and Dean flows.
Bio-sketch:
V. Shankar has been a faculty member in the Department of Chemical Engineering, IIT Kanpur since July 2002. He obtained his PhD from IISc Bangalore, and did a post-doc stint at the University of Minnesota before joining IIT Kanpur. His group works in the broad area of hydrodynamic instabilities in rheologically complex fluids, and on the role of wall elasticity on laminar-turbulent transition in flow through deformable tubes. Their work employs a balanced combination of theory, numerics, and experimental observations to uncover novel physical phenomena in these areas.
11th March, 2026 (Wednesday) at 5:15 PM (IST), Venue: FB 370
Dr. P.K. Panigrahi (Indian Institute of Technology Kanpur)
"Application of Electrohydrodynamics for Flow Control in Energy Systems"
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Abstract:
Electrohydrodynamics, which explores the interaction between electric forces and fluid flow offers several applications in flow control of energy systems. This seminar will present some of the developmental activities carried out at IIT Kanpur on DBD plasma actuator, ionic wind generator and electrospray. The application of these systems for wind turbine, fuel-air mixing, micro-capsule fabrication for targeted drug delivery, electronics & battery thermal management and implementation of machine learning based control will be demonstrated. The advantages of these systems are simple design, light weight, no-moving part, cheap, fast response and low power consumption etc. The seminar will be informative in nature using flow visualizations, without going into detailed presentation of results, for discussion on future collaboration.
Bio-sketch:
P. K. Panigrahi is a faculty in ME, IIT Kanpur since January 1998 after receiving his Ph.D. (Mechanical Engineering) and M.S. (Mechanical Engineering and Computer Science) from LSU, USA. He has implemented several experimental techniques (primarily optical) in both large- and small-scale systems like Interferometry, LDV, Schlieren, Holography, LCT, PIV, LIF, IRT, Thermophoretic Sampling, Scattering etc. These techniques have been used for investigation and design of several energy systems like gas turbine blade cooling, fluid structure interaction, combustion, battery cooling, crystal growth, gas hydrate, electro-atomization, jet mixing, synthetic jets, DBD plasma actuators, thermal hydraulics of nuclear power plants, drug delivery systems, underwater vehicles etc.
24th February, 2026 (Tuesday) at 5:15 PM (IST), Venue: FB 370
Dr. Arun Shukla (University of Rhode Island)
"Structural Response Under Extreme Underwater Loadings"
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Abstract:
This seminar presents recent advances in understanding the mechanics of underwater implosion and strategies for mitigating the resulting pressure pulses. Experimental investigations of sympathetic implosions and the interaction between an imploding cylinder and nearby structures are discussed. State-of-the-art pressure vessel facilities are employed to study the implosion process. These vessels are equipped with multiple optical windows to enable three-dimensional Digital Image Correlation (3D-DIC). Pressure histories generated during implosion events are recorded using dynamic pressure transducers positioned near the test specimens and are correlated with real-time deformation and velocity measurements of the shells. High-speed imaging combined with 3D-DIC provides detailed insight into deformation mechanisms and collapse modes.
The second part of the talk focuses on experimental studies of fluid–structure interaction between the gas bubble produced by an underwater explosion (UNDEX) and nearby rigid or flexible plates. Plates are clamped to support structures that are either air-backed or water-backed. While the initial shockwave from detonation can cause significant damage, the subsequent collapse of the gas bubble can be even more destructive. Results demonstrate that explosive standoff distance, plate rigidity, and hydrostatic pressure strongly influence bubble shape, size, migration velocity and direction, jetting behavior, and the resulting structural damage. For the dimensionless standoff parameters investigated, bubble collapse and associated jetting are identified as the primary mechanisms responsible for plate rupture and failure.
Bio-sketch:
Dr. Shukla is the Simon Ostrach Professor of Mechanical Engineering at the University of Rhode Island (URI). He is also the co-founder and inaugural co-director of the National Institute for Undersea Vehicle Technology at URI. Dr. Shukla was elected to the European Academy of Sciences and Arts in 2011 and the Russian Academy of Engineering in 2015. He is a Fellow of the American Society of Mechanical Engineers (ASME), American Academy of Mechanics, Shock Wave Society (India) and the Society for Experimental Mechanics (SEM). He received the M.M. Frocht and the B.J. Lazan Award from the SEM for “outstanding technical contributions.” In 2003 he served as the President of SEM and in 2011 delivered the prestigious Murray Lecture at SEM. He has served as the Technical Editor of Experimental Mechanics and currently serves on the Editorial Boards of key engineering journals. Dr. Shukla has received the Distinguished Alumnus Award from his alma mater, IIT Kanpur. In 2023, he received the prestigious Drucker Medal from the ASME, and the Theocaris Award from the SEM. He is the recipient of the URI Scholarly Excellence Award and the URI Graduate School Outstanding Mentoring Award. He has served as the Clark B. Millkan Visiting Professor of Aerospace at the California Institute of Technology, USA and as the Satish Dhawan Visiting Chair at the Indian Institute of Sciences, Bangalore India. He has also served as the chair of ASME’s Applied Mechanics Division, Executive Committee. Along with his many Ph.D. and M.S. students, he has published more than 450 papers in journals and proceedings. Dr. Shukla has also authored and edited 10 books. Dr. Shukla is currently visiting IIT Kanpur as the Distinguished Visiting Professor.