S. S. Moiseev

The role of helicity in turbulent MHD flows

We have studied the behavior of a helical homogeneous small-scale MHD turbulent flow under the influence of a weak inhomogeneous large-scale disturbance. We have shown that turbulent energy redistribution in the presence of nonzero helicity occurs mainly over large scales. Helicity increases correlation time, leading to the weakening of a direct cascade and to the formation of steep spectra over small scales, with simultaneous turbulent energy growth over large scales. Furthermore, an expression for the effective viscosity of the mean flow is derived. It is shown that the magnetic field, in addition to the helicity, reduces the effective viscosity of the medium. This may be important in the study of MHD flow around obstacles in the presence of an external magnetic field.

Helicity generation in turbulent MHD flows

We study turbulent flow of a conducting liquid in a uniform external magnetic field. It is shown that intense helicity generation is possible in the presence of a mean shear flow. It is noted that even though the mean helicity of the initial flow can be zero, the presence of internal topological structure of the flow, for example the presence of helicity of different signs at different scales, is nevertheless necessary for helicity generation.

Parametrization and universal properties of turbulence of an incompressible fluid

AbstractA relation is established between the properties of turbulent flow, the force f0 setting the fluid in motion, and the spatial r0 and temporal τ0 turbulence scales. It is established that the Lo

On the crack pattern formation in a freely drying protein film

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Structure of turbulent flows of incompressible fluids and the parametrization of turbulence

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Peculiarities of charged particle dynamics under cyclotron resonance conditions

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Transport Damping by Fluctuations and Cluster-Type Expansions in Kinetics

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