Animated illustration of shell decomposition
The video illustrates the shell decomposition we used to study energy transfer between different scales (eddies of different sizes) in compressible MHD turbulence.
Eddies are shown based on the Q-criterion and filtered to indicate regions where the flow is dominated by rotational motion. The left panel includes information of all spatial scales. The other panels include information of only one individual “shell” with decreasing spatial size from left to right.
The time evolution covers three large scale eddy turnover times in the stationary regime of a subsonic, super-Alfvenic simulation. More information can be found in our corresponding paper.
Illustration of subgrid-scale modeling
The image displays the magnetic energy in a turbulence simulation. The top left panel shows all relevant scales. Typically only a coarser level of detail can be resolved in a simulation (top right). Effects from the unresolved scales (bottom left) are missing in those simulations. The subgrid-scale model we proposed and verified (see research) is capable to account for those effects and allows to reintroduce them to the simulation.