Abstract:
Pressure-induced drag and lift are key to the
performance of wings, rotors and propellers; undulating fins and
flapping wings generate forces that are key to locomotion in fish, birds
and insects; time-varying fluid dynamic forces drive flutter
and flow-induced vibrations of flexible structures in engineering and
biology, and these same forces enable the extraction of energy from flow
via devices such as wind-turbines. Pressure on a body immersed in a
flow is however induced simultaneously by vortices,
acceleration reaction (a.k.a. added mass) effects associated with body
and/or flow acceleration, and viscous diffusion of momentum, and
determining the relative contribution of these different mechanisms on
surface pressure remains one of the most important
and fundamental issues in fluid dynamics. I will describe the force
partitioning method (FPM), a new data-enabled method that partitions
pressure forces into components due to vorticity, acceleration reaction
and viscous diffusion. FPM has been used to gain
new insights into a variety of vortex dominated flows including dynamic
stall in pitching foils, vortex-induced vibration of bluff-bodies,
hydrodynamics of schooling fish and rough-wall boundary layers, and
results from these analyses will be presented. Application
of FPM to data generated from experiments will also be described.
Finally, FPM has been extended to aeroacoustics, and applications of the
aeroacoustic partitioning method (APM) to aeroacoustic noise in
engineering and biological flows will be presented.
Bio:
Rajat Mittal is Professor of Mechanical Engineering at the Johns
Hopkins University with a secondary appointment in the School of
Medicine. He received the B. Tech. degree from the Indian Institute of
Technology at Kanpur in 1989, the M.S degree in Aerospace
Engineering from the University of Florida, and the Ph.D. degree in
Applied Mechanics from The University of Illinois at Urbana-Champaign,
in 1995. His research interests include computational fluid dynamics,
vortex dominated flows, biomedical engineering,
biological fluid dynamics, fluid-structure interaction, and flow
control. He has published over 200 technical articles and multiple
patents in these application areas. He is the recipient of the 1996
Francois Frenkiel and the 2022 Stanley Corrsin Awards from
the Division of Fluid Dynamics of the American Physical Society, and
the 2006 Lewis Moody as well as 2021 Freeman Scholar Awards from the
American Society of Mechanical Engineers (ASME). He is a Fellow of ASME
and the American Physical Society, and an Associate
Fellow of the American Institute of Aeronautics and Astronautics. He is
an associate editor of the Journal of Computational Physics, Frontiers
of Computational Physiology and Medicine, and serves on the editorial
boards of the International Journal for Numerical
Methods in Biomedical Engineering, and Physics of Fluids.
The AEM Post-Seminar Happy Hour will be in 227 Akerman Hall @ 3:30 pm right after the seminar.
