α effect in three-dimensional vortex of conducting rotating liquid.

Abstract

We study one-point statistics of helical turbulent pulsations in the background of a three-dimensional large-scale vortex in a rotating fluid. Assuming that the helical flow is created by a statistically axially symmetric random force with broken mirror symmetry, we analytically calculate the velocity-vorticity mean including its magnitude and the anisotropy. For electrically conducting liquid, we examine the α-effect in the system. The found elements of the α-matrix strongly depend on the relation between Rossby Ro and magnetic Prandtl Pr_{m} numbers in the considered region Ro≪1, Pr_{m}≪1. We establish a criterion for the numbers when the α-effect leads to instability of large-scale magnetic field.