Vortex breakdown and wake states in swirling flows
Event details
| Date | 09.04.2013 |
| Hour | 13:15 › 14:15 |
| Speaker |
Prof. Jens Nørkær Sørensen Bio : Jens Nørkær Sørensen is professor of fluid mechanics and the head of fluid mechanics section of the newly established DTU Wind Energy department. His research interests cover basic as well as applied topics in fluid mechanics, such as aerodynamics, rotating flows, vortex breakdown, wind energy and bio fluid mechanics. He received his PhD degree in 1986, and after a post-doc at ONERA in France he became faculty member at the mechanical engineering department at DTU in 1989. He has been full professor since 2001 and in 2012 he moved to the new wind energy department. His latest research effort deals with rotating flows associated with wakes and vortex breakdown. |
| Location | |
| Category | Conferences - Seminars |
Abstract : Vortex breakdown is a phenomenon inherent to many practical problems in aerodynamics, geophysics, and engineering, such as tip vortices over wings and behind propellers, atmospheric tornadoes and cyclones, flame-holder vortices in combustion devices etc. The breakdown of these vortices is associated with an abrupt deceleration of the axial velocity on the vortex axis which sometimes develops to a recirculation zone. Although now about ten forms of vortex breakdown have been identified, the gist of the phenomenon is not yet fully explained.
In this presentation I will give some examples of vortex breakdown, introduce some of theories explaining the phenomenon, and discuss results from both numerical simulations and experiments. In particular, I will show some recent results from stability analysis of helical vortices that may explain the appearance of vortex breakdown with multiple vortices and explain how the phenomenon of vortex breakdown may shed some light on the so-called vortex ring state seen in wakes behind propellers.
In this presentation I will give some examples of vortex breakdown, introduce some of theories explaining the phenomenon, and discuss results from both numerical simulations and experiments. In particular, I will show some recent results from stability analysis of helical vortices that may explain the appearance of vortex breakdown with multiple vortices and explain how the phenomenon of vortex breakdown may shed some light on the so-called vortex ring state seen in wakes behind propellers.
Practical information
- General public
- Free
Organizer
- IGM
Contact
- Géraldine Palaj