MEchanics GAthering -MEGA- Seminar: Flapping flags in grid-induced turbulent flow
Event details
| Date | 16.12.2021 |
| Hour | 16:15 › 17:30 |
| Speaker | Stefano Olivieri (OIST, Japan) |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract Fluid-structure interaction is involved in a variety of intriguing problems and related applications, e.g., energy harvesting, bio-inspired locomotion and flow control. Although in many situations the incoming fluid flow manifests a turbulent behavior, the fundamental investigation on this kind of problems very often relies on assuming the flow to be laminar and unperturbed. As a result, we still lack a deep comprehension regarding the influence of incoming turbulence on altering the main features of aeroelastic instabilities and consequent self-sustained oscillations. We present a fully-resolved, direct numerical simulation (DNS) approach that we employ to investigate, as a representative example, the flapping motion of a flexible plate/flag interacting with a turbulent incoming flow at moderate Reynolds number. Turbulence is generated using a passive grid at the inlet of the numerical domain and the turbulence level impacting the flag can be controlled by varying the distance of the latter from the grid. First, we characterize the turbulent flow generated numerically by comparing with well-known results for decaying turbulence and experimental measurements. Then, we revisit the flag-in-the-wind problem by exploring the effect of turbulence on the main features of self-sustained flapping. We show that, whilst the latter mechanism is still manifesting, the amplitude and frequency of the oscillation are remarkably altered. Moreover, we show that the fingerprint of turbulent fluctuations can be qualitatively detected and effectively modelled by means of spectral analysis. Besides their relevance for fundamental understanding, our findings have potential impact for applications such as aeroelastic energy harvesting with passively flapping plates.
Bio Dr. Stefano Olivieri is currently a Postdoctoral Scholar in the Complex Fluids and Flows Unit at the Okinawa Institute of Science and Technology (OIST), Japan. He received his B.Sc./M.Sc. in Mechanical/Aeronautical Engineering and his Ph.D. in Fluid Dynamics and Environmental Engineering from the University of Genoa, Italy. His research interests concern fluid-structure interaction, bio-inspired aerodynamics as well as particle-laden flows, investigating such problems primarily by means of high-fidelity numerical simulations. Specifically, recent topics include the dynamics of filament-like objects in fully-developed turbulence, the development of passive aeroelastic energy harvesters, and the impact of turbulence on the self-sustained flapping motion of flexible plates.
Bio Dr. Stefano Olivieri is currently a Postdoctoral Scholar in the Complex Fluids and Flows Unit at the Okinawa Institute of Science and Technology (OIST), Japan. He received his B.Sc./M.Sc. in Mechanical/Aeronautical Engineering and his Ph.D. in Fluid Dynamics and Environmental Engineering from the University of Genoa, Italy. His research interests concern fluid-structure interaction, bio-inspired aerodynamics as well as particle-laden flows, investigating such problems primarily by means of high-fidelity numerical simulations. Specifically, recent topics include the dynamics of filament-like objects in fully-developed turbulence, the development of passive aeroelastic energy harvesters, and the impact of turbulence on the self-sustained flapping motion of flexible plates.
Practical information
- General public
- Free
Organizer
- MEGA.Seminar Organizing Committee