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Physical Review E - Statistical, Nonlinear, and Soft Matter Physics


Department of Physics and Astronomy


We present direct numerical simulations and α-model simulations of four familiar three-dimensional magnetohydrodynamic (MHD) turbulence effects: selective decay, dynamic alignment, inverse cascade of magnetic helicity, and the helical dynamo effect. The MHD α model is shown to capture the long-wavelength spectra in all these problems, allowing for a significant reduction of computer time and memory at the same kinetic and magnetic Reynolds numbers. In the helical dynamo, not only does the α model correctly reproduce the growth rate of magnetic energy during the kinematic regime, it also captures the nonlinear saturation level and the late generation of a large scale magnetic field by the helical turbulence.



Original Citation

Mininni PD, Montgomery DC, Pouquet A. Numerical solutions of the three-dimensional magnetohydrodynamic alpha model. Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Apr;71(4 Pt 2):046304. doi: 10.1103/PhysRevE.71.046304. Epub 2005 Apr 20. PMID: 15903783.