title: Role of cross-helicity in magnetohydrodynamic turbulence.
abstract: Strong incompressible three-dimensional magnetohydrodynamic turbulence is investigated by means of high-resolution direct numerical simulations. The simulations show that the configuration space is characterized by regions of positive and negative cross-helicity, corresponding to highly aligned or antialigned velocity and magnetic field fluctuations, even when the average cross-helicity is zero. To elucidate the role of cross-helicity, the spectra and structure of turbulence are obtained in "imbalanced" regions where cross-helicity is nonzero. When averaged over regions of positive and negative cross-helicity, the result is consistent with the simulations of balanced turbulence. An analytical explanation for the obtained results is proposed.
authors.affiliation: Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Jean Carlos
authors.initials: JC
authors.lastname: Perez
authors.forename: Stanislav
authors.initials: S
authors.lastname: Boldyrev