Mean-field dynamos in random Arnold-Beltrami-Childress and Roberts flows
  We study magnetic field evolution in flows with fluctuating in time governing parameters in electrically conducting fluid. We use a standard mean-field approach to derive equations for large-scale magnetic field for the fluctuating ABC-flow as well as for the fluctuating Roberts flow. The derived mean-field dynamo equations have growing solutions with growth rate of the large-scale magnetic field which is not controlled by molecular magnetic diffusivity. Our study confirms the Zeldovich idea that the nonstationarity of the fluid flow may remove the obstacle in large-scale dynamo action of classic stationary flows. 
N. Kleeorin, I. Rogachevskii, D. Sokoloff, D. Tomin