Energy spectra stemming from interactions of Alfvén waves and turbulent eddies
We present a numerical analysis of an incompressible decaying magnetohydrodynamic turbulence run on a grid of 15363 points. The Taylor Reynolds number at the maximum of dissipation is 1100, and the initial condition is a superposition of large-scale Arn'old-Beltrami-Childress flows and random n...
| Authors: | , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2007 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/67757 |
| Online Access: | http://hdl.handle.net/11336/67757 |
| Access Level: | Open access |
| Keyword: | https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Summary: | We present a numerical analysis of an incompressible decaying magnetohydrodynamic turbulence run on a grid of 15363 points. The Taylor Reynolds number at the maximum of dissipation is 1100, and the initial condition is a superposition of large-scale Arn'old-Beltrami-Childress flows and random noise at small scales, with no uniform magnetic field. The initial kinetic and magnetic energies are equal, with negligible correlation. The resulting energy spectrum is a combination of two components, each moderately resolved. Isotropy obtains in the large scales, with a spectral law compatible with the Iroshnikov-Kraichnan theory stemming from the weakening of nonlinear interactions due to Alfvén waves; scaling of structure functions confirms the non-Kolmogorovian nature of the flow in this range. At small scales, weak turbulence emerges with a k-2 spectrum, the perpendicular direction referring to the local quasiuniform magnetic field. © 2007 The American Physical Society. |
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