# Dimensionless Measures of Turbulent Magnetohydrodynamic Dissipation Rates - Astrophysics

Dimensionless Measures of Turbulent Magnetohydrodynamic Dissipation Rates - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The magnetic Reynolds number R M, is defined as the product of acharacteristic scale and associated flow speed divided by the microphysicalmagnetic diffusivity. For laminar flows, R M also approximates the ratio ofadvective to dissipative terms in the total magnetic energy equation, but forturbulent flows this latter ratio depends on the energy spectra and approachesunity in a steady state. To generalize for flows of arbitrary spectra we definean effective magnetic dissipation number, R {M,e}, as the ratio of theadvection to microphysical dissipation terms in the total magnetic energyequation, incorporating the full spectrum of scales, arbitrary magnetic Prandtlnumbers, and distinct pairs of inner and outer scales for magnetic and kineticspectra. As expected, for a substantial parameter range R {M,e}\sim {O}1 <

Author: ** Eric G. Blackman, George B. Field**

Source: https://arxiv.org/