Visualization of the trapping of finite Stokes number particles in a laminar flow. Three particles encounter a flow instability in a chaotic flow region and eventually settle into a Kolmogorov-Arnold-Moser (KAM) tube where they move in helical orbits. Particles used in this case are few LED capsules.
Particle flow instability —

Visualization of the trapping of finite Stokes number particles in a laminar flow. Three particles encounter a flow instability in a chaotic flow region and eventually settle into a Kolmogorov-Arnold-Moser (KAM) tube where they move in helical orbits. Particles used in this case are few LED capsules.

https://fluids.ac.uk/files/04_Steven_Wang_Ben_Xu_particle_flow_instability.1543871120.jpg