A nonlinear wave coupling algorithm and its programing and application in plasma turbulences

Abstract

Abstract The fully developed turbulence can be regarded as a nonlinear system, with wave coupling inside, which causes the nonlinear energy transfer, and drives the turbulence to develop further or be suppressed. Spectral analysis is one of the most effective methods to study turbulence system. In order to apply it in the study of the nonlinear wave coupling process of edge plasma turbulence, an efficient algorithm based on spectral analysis technology was proposed to solve the nonlinear wave coupling equation. The algorithm is based on a mandatory temporal static condition after separating the nonideal spectra from the ideal spectra. The realization idea and programing flow were given. According to the characteristics of plasma turbulence, the simulation data were constructed and used to verify the algorithm and its implementation program. The simulation results and examples showed the accuracy of the algorithm and the corresponding program, which could play a great role in the study of the energy transfer in edge plasma turbulences. As an application, the energy cascade analysis of typical edge plasma turbulence was carried out using the results of a case calculation. Consequently, a physical image of the energy transfer in a kind of fully developed turbulence was constructed, which confirmed that the energy transfer in this turbulent system was from lower- to higher-frequency regions and from linear growing to damping waves.