Using dynamical mode decomposition to extract the limit cycle dynamics of modulated turbulence in a plasma simulatiom

Using dynamical mode decomposition to extract the limit cycle dynamics of modulated turbulence in a plasma simulatiom

Using dynamical mode decomposition to extract the limit cycle dynamics of modulated turbulence in a plasma simulatiom 150 150 UKAEA Opendata
UKAEA-CCFE-PR(19)32

Using dynamical mode decomposition to extract the limit cycle dynamics of modulated turbulence in a plasma simulatiom

The novel technique of dynamical mode decomposition (DMD) is applied to the outputs of a numerical simulation of Kelvin-Helmholtz turbulence in a cylindical plasma, so as to capture and quantify the time evolution of the dominant nonlinear structures. These structures comprise rotationally symmetric deformations together with spiral patterns, which are shown to be identifiable as DMD modes. A new method to calculate the time evolution of DMD mode amplitudes is proposed, based on convolution-type correlation integrals, and then applied to the simulation outputs in a limit cycle regime. The resulting time traces capture the essential physics far better than Fourier techniques applied to the same data.

Collection:
Journals
Journal:
Plasma Physics and Controlled Fusion
Publisher:
IOP (Institute of Physics)
Published date:
10/11/2019