MechE Colloquium: Unsteady deformations of elastic structures driven by vortex shedding
Event details
| Date | 24.05.2022 |
| Hour | 12:00 › 13:00 |
| Speaker | Prof. Kenny Breuer, Breuer Lab, School of Engineering, Brown University |
| Location | Online |
| Category | Conferences - Seminars |
Face masks are recommended for in-person attendance in MED 0 1418.
Abstract: Elastic bodies, when immersed in a flow, can experience violent flow-induced-oscillations due to unsteady forces generated by vortex shedding. These tightly-coupled fluid-structure interactions (FSI) lead to large-scale elastic deformation of the structure, which, in turn, changes the nature of the vortex shedding, as well as the lift and drag forces experienced by the body. In this talk I will present two tales of FSI. The first describes the deformation of a soft membrane disk in a flow. The membrane deforms, much like a soap bubble and vibrates due to the unsteady vortex shedding. Using a combination of experiments and theory we describe the membrane deformation and the changes in the steady and unsteady drag forces experienced by the disk. The second tale addresses the use of a soft membrane airfoil heaving and pitching in a freestream in order to harvest the flow energy. The elastic deformation of the membrane wing generates an adaptive camber which enhances the lift generation and leads to a greatly enhanced power coefficient. Again, we will use a mixture of experiments with some theoretical modeling to understand the behavior of this FSI system.
Biography: Kenny Breuer received his Sc.B. from Brown University in Mechanical Engineering (1982) and his Ph.D. from MIT in Aeronautics and Astronautics (1988). He spent two years back at Brown as a Post Doctoral Fellow in Applied Mathematics and nine years on the faculty at MIT, before finally returning to Brown in 1999, where he is currently Professor of Engineering. In 2010 he received a courtesy appointment as Professor of Ecology and Evolutionary Biology. From 2011 to 2014 he served as Senior Associate Dean of Engineering for Academic Programs. Professor Breuer’s research interests are in the broad field of Fluid Dynamics and cover a wide range of diverse topics. At the micron-scale, he has been active in the development of diagnostic techniques for micron-scale and near-surface velocimetry, in the characterization of slip flows, the mechanics of bacterial motility and flagellar and cilliar mechanics and the nanoscale flow near a moving contact line. At the macro-scale, he has worked on the mechanics of animal flight (particularly bat flight), vortex interactions with compliant structures and, most recently, energy harvesting from fluid flows. With his students and collaborators, he has co-authored over one hundred peer-reviewed articles in scientific journals, numerous book chapters, and has edited several books, including Microscale Diagnostic Techniques (Springer, 2004). Professor Breuer has also been active in fluid dynamics education and outreach, He is a co-author on the best-selling DVD: Multimedia Fluid Mechanics (Camb. Univ. Press), and co-editor of the compilation: A Gallery of Fluid Motion (Camb. Univ. Press). He has also appeared on programs such as PBS’s NOVA, NPR’s Science Friday, the Discovery Channel’s series Weird Connections, and the BBC’s series Invisible Worlds. His research has been features in popular press such as the New York Times, Discover magazine and has been highlighted on the website of the National Science Foundation. Professor Breuer has received a number of honors and awards including Fellow of the American Society of Mechanical Engineers (2013), Fellow of the American Physical Society (2010), Associate Fellow if the American Insitute of Aeronautics and Astronautics (2013), Chair of the APS-Division of Fluid Dynamics (2012), National Merit Scholar (1978), ONR Graduate Fellowship (1982-7). He was selected as the Midwest Mechanics lecturer in 200&. And was the Paris Sciences Professor at ESPCI in 2015.
Abstract: Elastic bodies, when immersed in a flow, can experience violent flow-induced-oscillations due to unsteady forces generated by vortex shedding. These tightly-coupled fluid-structure interactions (FSI) lead to large-scale elastic deformation of the structure, which, in turn, changes the nature of the vortex shedding, as well as the lift and drag forces experienced by the body. In this talk I will present two tales of FSI. The first describes the deformation of a soft membrane disk in a flow. The membrane deforms, much like a soap bubble and vibrates due to the unsteady vortex shedding. Using a combination of experiments and theory we describe the membrane deformation and the changes in the steady and unsteady drag forces experienced by the disk. The second tale addresses the use of a soft membrane airfoil heaving and pitching in a freestream in order to harvest the flow energy. The elastic deformation of the membrane wing generates an adaptive camber which enhances the lift generation and leads to a greatly enhanced power coefficient. Again, we will use a mixture of experiments with some theoretical modeling to understand the behavior of this FSI system.
Biography: Kenny Breuer received his Sc.B. from Brown University in Mechanical Engineering (1982) and his Ph.D. from MIT in Aeronautics and Astronautics (1988). He spent two years back at Brown as a Post Doctoral Fellow in Applied Mathematics and nine years on the faculty at MIT, before finally returning to Brown in 1999, where he is currently Professor of Engineering. In 2010 he received a courtesy appointment as Professor of Ecology and Evolutionary Biology. From 2011 to 2014 he served as Senior Associate Dean of Engineering for Academic Programs. Professor Breuer’s research interests are in the broad field of Fluid Dynamics and cover a wide range of diverse topics. At the micron-scale, he has been active in the development of diagnostic techniques for micron-scale and near-surface velocimetry, in the characterization of slip flows, the mechanics of bacterial motility and flagellar and cilliar mechanics and the nanoscale flow near a moving contact line. At the macro-scale, he has worked on the mechanics of animal flight (particularly bat flight), vortex interactions with compliant structures and, most recently, energy harvesting from fluid flows. With his students and collaborators, he has co-authored over one hundred peer-reviewed articles in scientific journals, numerous book chapters, and has edited several books, including Microscale Diagnostic Techniques (Springer, 2004). Professor Breuer has also been active in fluid dynamics education and outreach, He is a co-author on the best-selling DVD: Multimedia Fluid Mechanics (Camb. Univ. Press), and co-editor of the compilation: A Gallery of Fluid Motion (Camb. Univ. Press). He has also appeared on programs such as PBS’s NOVA, NPR’s Science Friday, the Discovery Channel’s series Weird Connections, and the BBC’s series Invisible Worlds. His research has been features in popular press such as the New York Times, Discover magazine and has been highlighted on the website of the National Science Foundation. Professor Breuer has received a number of honors and awards including Fellow of the American Society of Mechanical Engineers (2013), Fellow of the American Physical Society (2010), Associate Fellow if the American Insitute of Aeronautics and Astronautics (2013), Chair of the APS-Division of Fluid Dynamics (2012), National Merit Scholar (1978), ONR Graduate Fellowship (1982-7). He was selected as the Midwest Mechanics lecturer in 200&. And was the Paris Sciences Professor at ESPCI in 2015.
Practical information
- General public
- Free