Open-channel separating-flows
Event details
| Date | 17.12.2012 |
| Hour | 12:15 › 13:15 |
| Speaker | Prof. Emmanuel Mignot |
| Location |
GC D0 386
|
| Category | Conferences - Seminars |
In the field or in laboratory conditions, as a flow reaches a geometrical singularity, it usually detaches from the wall. A recirculation zone (also named “bubble”) takes place along this wall. The typical velocity magnitude in the recirculation zone is at least an order of magnitude lower than that of the main flow. Meanwhile, the main flow accelerates as the flow section is reduced. Consequently, a mixing layer takes place between the rapid main flow and the slow recirculating flow and this mixing layer strongly rotates from the detachment point towards downstream. Analysis of such separating mixing layer thus requires the use of a local frame-axis.
We investigate a separating flow on an experimental set-up of open-channel bifurcation with one incoming and two outing flows. Time-averaged PIV data permit to characterize this mixing-layer in terms of mean and turbulent flow characteristics. Moreover, a comparison between the analysis using Cartesian and local frame-axis confirms that the second methodology is much more convenient. We show for instance that the failure of eddy-viscosity concept in Cartesian frame-axis can be explained based on geometrical aspects and can be corrected using a local frame-axis.
Bio: Emmanuel Mignot is assistant professor at INSA (Lyon, France) for his academic work and LMFA (Laboratory for Fluid Mechanics and Acoustics, Lyon, France) for his research activities. His research is mainly based on an experimental approach and is dedicated to urban flooding and environmental fluid mechanics. Specific attention is paid towards complex mixing-layer configurations such as lateral cavities, junction and bifurcation flows, sudden flow enlargements, and flows around obstacles.
We investigate a separating flow on an experimental set-up of open-channel bifurcation with one incoming and two outing flows. Time-averaged PIV data permit to characterize this mixing-layer in terms of mean and turbulent flow characteristics. Moreover, a comparison between the analysis using Cartesian and local frame-axis confirms that the second methodology is much more convenient. We show for instance that the failure of eddy-viscosity concept in Cartesian frame-axis can be explained based on geometrical aspects and can be corrected using a local frame-axis.
Bio: Emmanuel Mignot is assistant professor at INSA (Lyon, France) for his academic work and LMFA (Laboratory for Fluid Mechanics and Acoustics, Lyon, France) for his research activities. His research is mainly based on an experimental approach and is dedicated to urban flooding and environmental fluid mechanics. Specific attention is paid towards complex mixing-layer configurations such as lateral cavities, junction and bifurcation flows, sudden flow enlargements, and flows around obstacles.
Practical information
- General public
- Free
Organizer
- Prof. Nikolas Geroliminis and Prof. Katrin Beyer
Contact
- Prof. Anton Schleiss