Nonlinear structures in interchange mode turbulence

Nonlinear structures in interchange mode turbulence.

Generation of linearly unstable streamers and nonlinearly saturated zonal flows have been investigated using two-dimensional simulations of interchange mode turbulence. It has been shown that nonlinear diamagnetic interactions tend to inhibit spectral cascades towards larger length scales and consequently suppress the nonlinear excitation of zonal flows. The latter has also been found to be in ...

Coherent structures in electrostatic interchange mode turbulence

Drift Wave versus Interchange Turbulence in Tokamak Geometry: Linear versus Nonlinear Mode Structure

The competition between drift wave and interchange physics in general E-cross-B drift turbulence is studied with computations in three dimensional tokamak flux tube geometry. For a given set of background scales, the parameter space can be covered by the plasma beta and drift wave collisionality. At large enough plasma beta the turbulence breaks out into ideal ballooning modes and saturates onl...

Nonlinear dynamics of magnetic islands in presence of interchange turbulence

In this work, we study the interaction between a tearing mode and a pressure gradient instability (resistive interchange) by solving reduced MHD equations numerically. The numerical study shows existence of regimes where thetearing instability is driven by the pressure gradient. An interplay between the pressure and the magnetic flux controls the dynamics of the saturated state. A secondary ins...

Sliding Mode Control for Single-degree-of-freedom Nonlinear Structures

The occurrence of catastrophic earthquakes necessitates further researches in the structure engineering for retrofitting construction structures. In this paper, the application of the active control in the structures’ seismic response has been addressed. A single degree of freedom nonlinear structure has been studied. The nonlinear dynamic of the structure is considered in which, the nonlinear ...