Jens Eggers The role of singularities in hydrodynamics
- Slides: 23
Jens Eggers The role of singularities in hydrodynamics
A shock wave a jump in density occurs at some finite time t 0 ! W. C. Griffith, W. Bleakney
Pinch-off singularity Burton et al, PRL `04 L Harold Edgerton neck radius shrinks to zero in finite time
Universality experiment by Shi et al.
Drops and bubbles water drop in air Shi et al. very different! air bubble in water Thoroddsen et al.
Corner singularity U Huh and Scriven’s paradox: Quéré, Fermigier, Clanet
Pouring a viscous liquid fluid jet Eggers, PRL `01 Lorenceau, Restagno, Quéré, PRL `03 Lorenceau, Quéré, Eggers, PRL `04 viscous fluid cusp forms
Charged drop experiment: Leisner et al. theory: Fontelos et al.
Making small things
Boundary layer separation Re=500 Ut/d=1 Ut/d=3 Coutanceau, Bouard finite time singularity of boundary layer equations!
Why singularities? • Crucial events in the evolution of the flow-describe changes in topology, seeds for new structures ØUniversality determines structure of flow, independent of boundary conditions ØBuilding blocks of a partial differential equation • Points where computers stop Main mathematical ingredient: self-similarity!
Scale invariance: Self-similarity glycerol drop center experiment by Tomasz Kowalewski 1 mm
Weak shock wave power laws, self-similarity, and all that. . .
Similarity solution regular at
Matching condition size of critical region:
Approach to the similarity solution is fixed point! stability?
Fixed point: stability eigenvalue problem eigenvalue: only stable solution!
Bubble breakup: beyond simple self-similarity
Bubble breakup 101 surface tension-inertia S. T. Thoroddsen bubble Longuet-Higgins et al. , JFM 1991 Oguz and Prosperetti, JFM 1993 Keim et al. PRL `06
Slender body joint with M. Fontelos, D. Leppinen, J. Snoeijer. fluid xxxxx air z : exp. by Burton + Taborek
Self-similarity
Approach to the fixed point define: linearize: cubic equation! very slow approach! Thoroddsen
Singularities: Outlook are the building blocks of PDEs Øform small things Øare seeds for new structures üare scale-invariant üuniversal ülink micro-and macroworld A catalogue of singularities: classify singularities …may possess complex according to dynamics close to fixed point inner structure
- Jens eggers
- Snom
- Thomas scaffidi
- Shark body shape
- Talia weiss
- Hydrodynamics
- Smoothed particle hydrodynamics
- Frother hydrodynamics
- Gem
- Web role in azure
- Rollendistanz krappmann beispiel
- Statuses and their related roles determine
- Jens peter bonde eu
- Jens lindström
- Jens de sme
- Jens peter friis
- Jens grell
- Jens.sis
- Jens lindström
- Jens horbach
- Jens havskov
- Jens reddersen
- Hvor du sætter din fod tekst
- Uvm landscape change