We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from 0.02 to 20, we find significantly different magnetic field geometries, amplification rates, and saturation levels, decreasing strongly at the transition from subsonic to supersonic flows, due to the development of shocks. Both extreme types of turbulent forcing drive the dynamo, but solenoidal forcing is more efficient, because it produces more vorticity.
{Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows} / Federrath, C.; Chabrier, G.; Schober, J.; Banerjee, R.; Klessen, R. ~s.; Schleicher, Dominik Reinhold Georg. - In: PHYSICAL REVIEW LETTERS. - ISSN 1079-7114. - 107:11(2011). [10.1103/PhysRevLett.107.114504]
{Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows}
Schleicher, Dominik Reinhold Georg
2011
Abstract
We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from 0.02 to 20, we find significantly different magnetic field geometries, amplification rates, and saturation levels, decreasing strongly at the transition from subsonic to supersonic flows, due to the development of shocks. Both extreme types of turbulent forcing drive the dynamo, but solenoidal forcing is more efficient, because it produces more vorticity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


