The alpha dynamo parameter and measurability of helicities in magnetohydrodynamic turbulence

Journal Article · Thu May 01 04:00:00 EDT 1986 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.865668· OSTI ID:5959762

Matthaeus, W H; Goldstein, M L; Lantz, S R

Alpha, an important parameter in dynamo theory, is shown to be proportional to either the kinetic, current, magnetic, or velocity helicities of the fluctuating magnetic field and fluctuating velocity field. The particular helicity to which alpha is proportional depends on the assumptions used in deriving the first-order smoothed equations that describe the alpha effect. In two cases, viz., when alpha is proportional to either the magnetic helicity or velocity helicity, alpha can be determined experimentally from two-point measurements of the fluctuating fields in incompressible, homogeneous turbulence with arbitrary rotational symmetry. For the other two possibilities, alpha can be determined if the turbulence is isotropic.

• Research Organization: Bartol Research Foundation, Newark, Delaware 19716
• OSTI ID: 5959762
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 29:5; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

640430* -- Fluid Physics-- Magnetohydrodynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUATIONS
FLUCTUATIONS
FLUID FLOW
FLUID MECHANICS
HELICITY
HYDRODYNAMICS
INCOMPRESSIBLE FLOW
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICS
MECHANICS
NUMERICAL ANALYSIS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
TURBULENCE
VARIATIONS
VELOCITY