 Magnetic Prandtl number

The Magnetic Prandtl number is a dimensionless quantity occurring in magnetohydrodynamics which approximates the ratio of momentum diffusivity (viscosity) and magnetic diffusivity. It is defined as:
where:
 Re_{m} is the magnetic Reynolds number
 Re is the Reynolds number
 ν is the momentum diffusivity (kinematic viscosity)
 η is the magnetic diffusivity
At the base of the Sun's convection zone the Magnetic Prandtl number is approximately 10 ^{− 2}, and in the interiors of planets and in liquidmetal laboratory dynamos is approximately 10 ^{− 5}.
See also
Dimensionless numbers in fluid dynamics Archimedes · Atwood · Bagnold · Bejan · Biot · Bond · Brinkman · Capillary · Cauchy · Damköhler · Dean · Deborah · Eckert · Ekman · Eötvös · Euler · Froude · Galilei · Graetz · Grashof · Görtler · Hagen · Keulegan–Carpenter · Knudsen · Laplace · Lewis · Mach · Marangoni · Morton · Nusselt · Ohnesorge · Péclet · Prandtl (magnetic · turbulent) · Rayleigh · Reynolds (magnetic) · Richardson · Roshko · Rossby · Rouse · Ruark · Schmidt · Sherwood · Shields · Stanton · Stokes · Strouhal · Suratman · Taylor · Ursell · Weber · Weissenberg · Womersley
References
 Critical Magnetic Prandtl Number for Small Scale Dynamo, Schekochihin, A.A., et al. 2004, Physical Review Letters, 92, 5
Categories: Dimensionless numbers
 Fluid mechanics
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