MechE Colloquium: The role of added mass and circulatory forces in unsteady incompressible flows
Event details
| Date | 29.10.2019 |
| Hour | 12:15 › 13:15 |
| Speaker | Prof. Holger Babinsky, Engineering Department, University of Cambridge |
| Location | |
| Category | Conferences - Seminars |
Abstract:
Unsteady effects occur in many natural and technical flows, for example flapping wings or air vehicle gust encounters. If the accelerations are large the resulting unsteady forces can be quite considerable, a fact that is exploited by insects and small birds to generate additional lift at low Reynolds numbers. However, the exact physical mechanisms underlying the generation of unsteady force continue to challenge our understanding of such flows. One approach to improve our insight is to identify the dominant effects and describe these with low-order force models. An often-made classification is to group forces into circulatory (e.g. vortex lift or bound circulation) and non-circulatory (added-mass).
Although the concept of added mass has been around for more than a century and is superficially simple, its details continue to confound and confuse. In this talk I will re-visit the definition of added mass and propose a different interpretation. Using a series of simple, canonical, experiments and PIV I will show how the contributions made by different physical force mechanisms can be identified experimentally and thus clarify some open questions about this concept.
Bio:
Holger Babinsky originates from Bavaria and studied Aerospace Engineering at Stuttgart University in Germany. He obtained a PhD in hypersonic aerodynamics from Cranfield University (UK) in 1994. After 18 months as Research Associate at the Shock Wave Research Centre of Tohoku University in Sendai, Japan he returned to the UK to take up a position at the University of Cambridge. He is now Professor of Aerodynamics in the Engineering Department and Head of Energy, Fluid Mechanics and Turbomachinery as well as a Fellow of Magdalene College.
His main areas of research are in the field of experimental aerodynamics and associated measurement techniques. Apart from shock-wave/boundary-layer interactions, which he has studied for almost 30 years, his current research includes the aerodynamics of micro-air vehicles, road vehicles and flow control for transonic aircraft wings and supersonic engine inlets. He is the Editor-in-Chief of the Royal Aeronautical Society’s Aeronautical Journal (the worlds oldest aeronautical journal in production) and a Fellow of the Royal Aeronautical Society, an Associate Fellow of the American Institute of Aeronautics and Astronautics, and an Associate Editor of Experiments in Fluids.
Unsteady effects occur in many natural and technical flows, for example flapping wings or air vehicle gust encounters. If the accelerations are large the resulting unsteady forces can be quite considerable, a fact that is exploited by insects and small birds to generate additional lift at low Reynolds numbers. However, the exact physical mechanisms underlying the generation of unsteady force continue to challenge our understanding of such flows. One approach to improve our insight is to identify the dominant effects and describe these with low-order force models. An often-made classification is to group forces into circulatory (e.g. vortex lift or bound circulation) and non-circulatory (added-mass).
Although the concept of added mass has been around for more than a century and is superficially simple, its details continue to confound and confuse. In this talk I will re-visit the definition of added mass and propose a different interpretation. Using a series of simple, canonical, experiments and PIV I will show how the contributions made by different physical force mechanisms can be identified experimentally and thus clarify some open questions about this concept.
Bio:
Holger Babinsky originates from Bavaria and studied Aerospace Engineering at Stuttgart University in Germany. He obtained a PhD in hypersonic aerodynamics from Cranfield University (UK) in 1994. After 18 months as Research Associate at the Shock Wave Research Centre of Tohoku University in Sendai, Japan he returned to the UK to take up a position at the University of Cambridge. He is now Professor of Aerodynamics in the Engineering Department and Head of Energy, Fluid Mechanics and Turbomachinery as well as a Fellow of Magdalene College.
His main areas of research are in the field of experimental aerodynamics and associated measurement techniques. Apart from shock-wave/boundary-layer interactions, which he has studied for almost 30 years, his current research includes the aerodynamics of micro-air vehicles, road vehicles and flow control for transonic aircraft wings and supersonic engine inlets. He is the Editor-in-Chief of the Royal Aeronautical Society’s Aeronautical Journal (the worlds oldest aeronautical journal in production) and a Fellow of the Royal Aeronautical Society, an Associate Fellow of the American Institute of Aeronautics and Astronautics, and an Associate Editor of Experiments in Fluids.
Practical information
- General public
- Free