We developed a new mean-field theory of turbulent convection by considering only the small-scale part of
spectra as ‘‘turbulence’’ and the large-scale part, as a ‘‘mean flow,’’ which includes both regular and semiorganized
motions. The developed theory predicts the convective wind instability in a shear-free turbulent
convection. This instability causes formation of large-scale semiorganized fluid motions in the form of cells.
The developed theory allows to determine spatial characteristics of these motions, e.g., the minimum size of the
growing perturbations and the size of perturbations with the maximum growth rate, and predicts also the existence of the
convective shear instability in a sheared turbulent convection. This instability causes formation of large-scale
rolls and generation of convective shear waves which have a nonzero hydrodynamic helicity. Increase of shear
promotes excitation of the convective shear instability. The obtained results have important implications for
to the atmospheric turbulent convection and the laboratory experiments on turbulent convection.
- T. Elperin, N. Kleeorin, I. Rogachevskii, and S. Zilitinkevich,
Formation of Large-Scale Semiorganized Structures in Turbulent Convection.
Physical Review E, 66, 066305(1-15), 2002.
PDF: 350 KB
- T. Elperin, N. Kleeorin, I. Rogachevskii, and S. Zilitinkevich, Tangling turbulence and semi-organized structures in convective boundary layers,
Boundary-Layers Meteorology, 119, 449-472, 2006.
PDF: 276 KB
- T. Elperin, I. Golubev, N. Kleeorin, I. Rogachevskii, Large-scale instabilities in a nonrotating turbulent convection,
Physics of Fluids, 18, 126601, 2006.
PDF: 223 KB