The role of helicity in turbulent fluid dynamics
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| Title: | The role of helicity in turbulent fluid dynamics |
|---|---|
| Authors: | Lipscombe, Trevor |
| Committee Members: | Haar, D. ter |
| Summary: | In this thesis we consider turbulent fluid systems. We develop a closure scheme in which the mean velocity field of an incompressible fluid is driven by a turbulent velocity field possessing a non-zero mean helicity. We use this to investigate the formation of large scale vortices and the behaviour of the mean kinetic energy, enstrophy and helicity. The same technique is then applied to the equations of magneto-hydrodynamics, in order to explain the self-generation of mean magnetic fields, and the joint formation of current and vortex structures. We then discuss the convection of a passive scalar by the fluid and determine an equation for the mean temperature. Finally we present a theory to account for the behaviour of a two-dimensional electrically conducting fluid subject to a constant external magnetic field driven by external forces. We explain the peaks in the power spectrum, the saturation of the magnetic and kinetic energies, and the insensitiveness of their equilibrium value on the external field. All of these are observed in numerical experiments. |
| URL: | https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375269 |
| Database: | OpenDissertations |
| FullText | Text: Availability: 0 |
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| Header | DbId: ddu DbLabel: OpenDissertations An: ddu.oai.ethos.bl.uk.375269 AccessLevel: 6 PubType: Dissertation/ Thesis PubTypeId: dissertation PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: The role of helicity in turbulent fluid dynamics – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Lipscombe%2C+Trevor%22">Lipscombe, Trevor</searchLink> – Name: Author Label: Committee Members Group: Au Data: <searchLink fieldCode="CO" term="%22Haar%2C+D%2E+ter%22">Haar, D. ter</searchLink> – Name: Abstract Label: Summary Group: Ab Data: In this thesis we consider turbulent fluid systems. We develop a closure scheme in which the mean velocity field of an incompressible fluid is driven by a turbulent velocity field possessing a non-zero mean helicity. We use this to investigate the formation of large scale vortices and the behaviour of the mean kinetic energy, enstrophy and helicity. The same technique is then applied to the equations of magneto-hydrodynamics, in order to explain the self-generation of mean magnetic fields, and the joint formation of current and vortex structures. We then discuss the convection of a passive scalar by the fluid and determine an equation for the mean temperature. Finally we present a theory to account for the behaviour of a two-dimensional electrically conducting fluid subject to a constant external magnetic field driven by external forces. We explain the peaks in the power spectrum, the saturation of the magnetic and kinetic energies, and the insensitiveness of their equilibrium value on the external field. All of these are observed in numerical experiments. – Name: URL Label: URL Group: URL Data: <link linkTarget="URL" linkTerm="https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375269" linkWindow="_blank">https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375269</link> |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=ddu&AN=ddu.oai.ethos.bl.uk.375269 |
| RecordInfo | BibRecord: BibEntity: Languages: – Code: eng Text: English Subjects: – SubjectFull: 532 Type: general – SubjectFull: Fluid dynamics ; Particles (Nuclear physics) ; Helicity ; Turbulence Type: general Titles: – TitleFull: The role of helicity in turbulent fluid dynamics Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Lipscombe, Trevor IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 01 Type: published Y: 1986 |
| ResultId | 1 |
