منابع مشابه
Dimensionless Measures of Turbulent Magnetohydrodynamic Dissipation Rates
The magnetic Reynolds number RM , is defined as the product of a characteristic scale and associated flow speed divided by the microphysical magnetic diffusivity. For laminar flows, RM also approximates the ratio of advective to dissipative terms in the total magnetic energy equation, but for turbulent flows this latter ratio depends on the energy spectra and approaches unity in a steady state....
متن کاملBounds on dissipation in magnetohydrodynamic problems in plane shear geometry
The total dissipation rate for magnetohydrodynamic ~MHD! flows in plane geometry with both velocity and magnetic shear is studied. For some boundary conditions it is shown that the lower bound on the dissipation rate is achieved by the equivalent of Stokes flow for MHD. Using the background method @Doering and Constantin, Phys. Rev. Lett. 69, 1648 ~1992!# upper bounds for the dissipation rate a...
متن کاملMagnetohydrodynamic dissipation range spectra for isotropic viscosity and resistivity
Dissipation range spectra for incompressible magnetohydrodynamic turbulence are derived for isotropic viscosity and resistivity . The spectra are obtained from heuristic closures of spectral transfer correlations for cases with Pm= / 1, where Pm is the magnetic Prandtl number. Familiar inertial range power laws are modified by exponential factors that dominate spectral falloff in the dissipatio...
متن کاملNonuniversality and Finite Dissipation in Decaying Magnetohydrodynamic Turbulence.
A model equation for the Reynolds number dependence of the dimensionless dissipation rate in freely decaying homogeneous magnetohydrodynamic turbulence in the absence of a mean magnetic field is derived from the real-space energy balance equation, leading to Cϵ=Cϵ,∞+C/R-+O(1/R-(2)), where R- is a generalized Reynolds number. The constant Cϵ,∞ describes the total energy transfer flux. This flux ...
متن کاملBounds on dissipation in Magnetohydrodynamic Couette and Hartmann shear
Shear ow with an applied cross-stream magnetic eld is studied using dissipative incompressible magnetohydrodynamics. The study incorporates exact solutions, the energy stability method, and exact bounds on the total energy dissipation rate. Two physical con gurations are examined: magnetic Couette ow and Hartmann ow, the latter being Poiseuille ow with the existence of a perpendicular magnetic ...
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: Symposium - International Astronomical Union
سال: 1958
ISSN: 0074-1809
DOI: 10.1017/s0074180900226739