Visualization of an initially circular material loop advected by a turbulent flow

The twisting and folding action of the turbulent flow creates a complex loop geometry while the length of the loop increases exponentially on average. The visualization is obtained from a direct numerical simulation of fully developed turbulence. The material loop is composed of Lagrangian tracer particles which follow the flow. The exponential expansion of the line necessitates an adaptive refinement which we realize using B-spline interpolation.
For more details, see arxiv.org/abs/2106.11622
The visualization has been created with Blender.