Quasi-Two-Dimensional MHD Turbulence in Three-Dimensional Flows

We simulate how nearly two-dimensional magnetohydrodynamic turbulence can be initiated and how it evolves with distance in the third dimension. Expanding flows lead to a suppression of the nonlinear cascades, mainly due to the changing transverse length scales. Velocity fluctuation levels are determined more from the 2D dynamics than from the expansion except when the velocity fluctuations are initially dominant. With expansion, magnetic fluctuations always dominate velocity fluctuations at late times.