Abstract
The instability properties of isolated monopolar vortices have been investigated experimentally and the corresponding multipolar quasisteady states have been compared with semianalytical vorticity-distributed solutions to the Euler equations in two dimensions. A novel experimental technique was introduced to generate unstable monopolar vortices whose nonlinear evolution resulted in the formation of multipolar vortices. Dye-visualization and particle imaging techniques revealed the existence of tripolar, quadrupolar, and pentapolar vortices. Also evidence was found of the onset of hexapolar and heptapolar vortices. The observed multipolar vortices were found to be unstable and generally broke up into multipolar vortices of lesser complexity. The characteristic flow properties of the quadrupolar vortex were in close agreement with the semianalytical model solutions. Higher-order multipolar vortices were observed to be susceptible to strong inertial oscillations.
| Original language | English |
|---|---|
| Article number | 094104 |
| Journal | Physics of Fluids |
| Volume | 22 |
| Issue number | 9 |
| DOIs | |
| State | Published - 30 Sep 2010 |
Bibliographical note
Funding Information:We are grateful to Bert Lodewijks, Stefan Nieuwenhuijsen, and Dimitry Foures for their contributions to the laboratory experiments. We are also indebted to Dr. Leon Kamp for the help with computations and to Professor M. Ungarish for helpful discussions. The Trondheim Marine Systems Research Infrastructure and, in particular, Professor T. A. McClimans are thanked for the opportunity provided to Z.K. in September 2004 to test some methodological ideas of laboratory production of shielded monopoles. Z.K. also acknowledges the support from the Israel Science Foundation Grant No. 628/06 and the financial support from the Netherlands Organization for Scientific Research (NWO) for his working visit at TUE.
Funding
We are grateful to Bert Lodewijks, Stefan Nieuwenhuijsen, and Dimitry Foures for their contributions to the laboratory experiments. We are also indebted to Dr. Leon Kamp for the help with computations and to Professor M. Ungarish for helpful discussions. The Trondheim Marine Systems Research Infrastructure and, in particular, Professor T. A. McClimans are thanked for the opportunity provided to Z.K. in September 2004 to test some methodological ideas of laboratory production of shielded monopoles. Z.K. also acknowledges the support from the Israel Science Foundation Grant No. 628/06 and the financial support from the Netherlands Organization for Scientific Research (NWO) for his working visit at TUE.
| Funders | Funder number |
|---|---|
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
| Israel Science Foundation | 628/06 |