MECHANISM OF ENERGY TRANSFORMATIONS IN SHEAR MAGNETOHYDRODYNAMIC FLOWS

Evolution of slow magnetoacoustic perturbations is used to demonstrate a new mechanism of plane Couette flow shear energy transformation. Th e initial uniform magnetic field is considered to be directed along th e unperturbed flow velocity. We find that the amplification of waves i s nonordinary-it occurs in a limited time interval and is anomalously strong. The unusual behavior is manifested also by the fact that the c haracteristic length scale of perturbation diminishes down to the diss ipative scales not only due to nonlinear cascade processes, but due to a linear drift in the k space as well.