Kelvin-Helmholtz unstable, sheared flows are common in astrophysics.  Hydrodynamically, this instability is well studied, and in 3-D it should lead to turbulence.  However, the general presence of a magnetic field and  finite electrical conductivity  in most astrophysical media mean that we must understand the role of magnetohydrodynamical processes. We have carried out 3-D MHD simulations of periodic flow sections that are K-H unstable. Our objective is to understand the role of magnetic fields that are too weak to add linear stability, but that may still modify the nonlinear evolution of the instability. We find that, through dynamical alignment, remarkably weak fields can produce flow self-organization that is relatively  smooth, with its shear preserved.  Previous, 2-D simulations are published in the Astrophysical Journal (Frank etal 1996, ApJ, 460, 777; Jones etal 1997, ApJ, 482, 230).

This presentation outlines the 3-D results, including representative still images and two sets of  full MPEG animations. It is now published on a CD ROM accompanying the paper: Jones etal 1999, "Numerical Astrophysics" S. Miyama etal (eds.) (Kluwer), p 95.