Comparative Study of Vorticity and Material Lines Evolution in Numerical Turbulence

A comparative study of the differences in the evolution processes of vorticity and material lines based on DNS of NSE is performed at low Reynolds number for time periods up to 15 Kolmogorov microscales. In order to observe such differences we looked for regions in which the forcing and the viscous terms are approximately balancing each other (in the sense as defined in the main text) and used the Lagrangian tracking of fluid particles originating from these regions for time periods during which the above balance between the forcing and the viscous terms remain valid.