Turbulent magnetic Prandtl number and magnetic diffusivity quenching from simulations
نویسندگان
چکیده
منابع مشابه
Turbulent magnetic Prandtl number and magnetic diffusivity quenching from simulations
Forced turbulence simulations are used to determine the turbulent kinematic viscosity, νt, from the decay rate of a large scale velocity field. Likewise, the turbulent magnetic diffusivity, ηt, is determined from the decay of a large scale magnetic field. In the kinematic regime, when the field is weak, the turbulent magnetic Prandtl number, νt/ηt, is about unity. When the field is nonhelical, ...
متن کاملThe Turbulent Magnetic Prandtl Number of MHD Turbulence in Disks
The magnetic Prandtl number PrM is the ratio of viscosity to resistivity. In astrophysical disks the diffusion of angular momentum (viscosity) and magnetic fields (resistivity) are controlled by turbulence. Phenomenological models of the evolution of large scale poloidal magnetic fields in disks suggest that the turbulent magnetic Prandtl number PrM,T controls the rate of escape of vertical fie...
متن کاملNonlinear dynamos at infinite magnetic Prandtl number.
The dynamo instability is investigated in the limit of infinite magnetic Prandtl number. In this limit the fluid is assumed to be very viscous so that the inertial terms can be neglected and the flow is enslaved to the forcing. The forcing consist of an external forcing function that drives the dynamo flow and the resulting Lorentz force caused by the back reaction of the magnetic field. The fl...
متن کاملTurbulent magnetic field amplification from the smallest to the largest magnetic Prandtl numbers
The small-scale dynamo provides a highly efficient mechanism for the conversion of turbulent into magnetic energy. In astrophysical environments, such turbulence often occurs at high Mach numbers, implying steep slopes in the turbulent spectra. It is thus a central question whether the small-scale dynamo can amplify magnetic fields in the interstellar or intergalactic media, where suchMach numb...
متن کاملMagnetic Quenching of Alpha and Diffusivity Tensors in Helical Turbulence
The effect of a dynamo-generated mean magnetic field of Beltrami type on the mean electromotive force is studied. In the absence of the mean magnetic field the turbulence is assumed to be homogeneous and isotropic, but it becomes inhomogeneous and anisotropic with this field. Using the testfield method the dependence of the alpha and turbulent diffusivity tensors on the magnetic Reynolds number...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2003
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20031371