Navier Stokes equations Reynolds number Alpha models Energy spectrum Intermittency LES MHD Subgrid-scale processes Alpha model Approximation theory Current sheets Direct numerical simulation Energy spectra Filters (for fluids) Flow of fluids High Reynolds number Lagrange multipliers Local area networks Lorentz force Magnetohydrodynamics Mathematical models Navier Stokes Nonlocal Regularization models Rigid body Rigid structures Small scale Spectroscopy Subfilter scale Subfilter-scale physics