Lack of universality in decaying magnetohydrodynamic turbulence

• Autores: Lee, E.; Brachet, M. E.; Pouquet, A.; Mininni, Pablo Daniel; Rosenberg, Duane
• Año de publicación: 2010
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Turbulent Flows; Magnetohydrodynamics And Electrohydrodynamics
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Using computations of three-dimensional magnetohydrodynamic (MHD) turbulence with a Taylor-Green flow, whose inherent time-independent symmetries are implemented numerically, and in the absence of either a forcing function or an imposed uniform magnetic field, we show that three different inertial ranges for the energy spectrum may emerge for three different initial magnetic fields, the selecting parameter being the ratio of nonlinear eddy to Alfvén time. Equivalent computational grids range from 1283 to 20483 points with a unit magnetic Prandtl number and a Taylor Reynolds number of up to 1500 at the peak of dissipation. We also show a convergence of our results with Reynolds number. Our study is consistent with previous findings of a variety of energy spectra in MHD turbulence by studies performed in the presence of both a forcing term with a given correlation time and a strong, uniform magnetic field. However, in contrast to the previous studies, here the ratio of characteristic time scales can only be ascribed to the intrinsic nonlinear dynamics of the paradigmatic flows under study. © 2010 The American Physical Society.
Fil: Lee, E.. Katholikie Universiteit Leuven; Bélgica. National Center for Atmospheric Research; Estados Unidos
Fil: Brachet, M. E.. National Center for Atmospheric Research; Estados Unidos. Ecole Normale Supérieure; Francia
Fil: Pouquet, A.. National Center for Atmospheric Research; Estados Unidos
Fil: Mininni, Pablo Daniel. National Center for Atmospheric Research; Estados Unidos. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina
Fil: Rosenberg, Duane. National Center for Atmospheric Research; Estados Unidos