Chandrasekhar number
The Chandrasekhar number is a
astrophysicist Subrahmanyan Chandrasekhar
.
The number's main function is as a measure of the magnetic field, being proportional to the square of a characteristic magnetic field in a system.
Definition
The Chandrasekhar number is usually denoted by the letter , and is motivated by a dimensionless form of the
Navier-Stokes equation in the presence of a magnetic force in the equations of magnetohydrodynamics
:
where is the Prandtl number, and is the magnetic Prandtl number.
The Chandrasekhar number is thus defined as:[1]
where is the
magnetic permeability
, is the density of the fluid, is the kinematic viscosity
, and is the magnetic diffusivity. and are a characteristic magnetic field and a length scale of the system respectively.
It is related to the Hartmann number, , by the relation:
See also
References
- ^ N.E. Hurlburt, P.C. Matthews and A.M. Rucklidge, "Solar Magnetoconvection," Solar Physics, 192, p109-118 (2000)