ABSTRACT: We begin with a simple model of a bluff body with a single dof motion in a uniform flow. Lock-in in vortex-induced vibration (VIV) of a rigid body mounted on an elastic support is described. The response of the body and its effect on the modes of vortex shedding in the flow are discussed for low vs high Reynolds number flows. Hysteresis and intermittency, with respect to increasing- and decreasing-flow speed, in the response of the body is investigated. FIV of a flexible filament/plate attached behind a bluff body placed in a uniform flow is studied. A plate has infinite natural frequencies; multiple lock-ins are observed. The effect of ratio of the density of structure to the fluid is profound. Galloping response is observed in certain parameter range. The response of the system from the point of view of effective placement of sensors for energy harvesting is discussed. A strategy is proposed to choose appropriate flexibility of the splitter plate to minimize FIV of a body on elastic supports. The fluid-structure response of multiple bodies in a flow are considered next. The inflation and deflation of a balloon is modeled via a membrane. Ovalling oscillations are observed during inflation. A simple model for failure of balloon is proposed. Fluid-structure interaction of a badminton shuttlecock is presented to bring out the major differences between the aerodynamics of a duck-feather and nylon shuttlecock.

BIOSKETCH: Sanjay Mittal received his undergraduate education in Aeronautical Engineering at the Indian Institute of Technology Kanpur, India. He went to the University of Minnesota, Minneapolis, USA for his graduate education.  Presently, he is a Professor in the Department of Aerospace Engineering at Indian Institute of Technology Kanpur, India. His research interests include fluid-structure interactions, flow-induced vibration, bluff body flows, aerodynamic shape optimization, shock-boundary layer interactions, high performance computing, modeling of traffic flow, sports aerodynamics and low speed wind-tunnel testing. He is an active badminton player and his love for sports has found its way in his research. He is passionate about teaching, and  recently received the Excellence-in-Teaching Award and the Gopal Das Bhandari Distinguished Teacher Award from his Institute. He is a Fellow of the Indian National Academy of Engineering, Indian National Science Academy, Indian Academy of Sciences and National Academy of Sciences. He received the prestigious Shanti Swarup Bhatnagar Prize in Engineering Sciences in 2006 and the G. D. Birla Award for Scientific Research in 2015.