2015/05/15 by E. Varga, C. F. Barenghi, Y. A. Sergeev +1
Engineering · Physics and Astronomy · #Drag #Flow visualization #Fluid dynamics and aerodynamics studies #Particle image velocimetry #Particle tracking velocimetry #Quantum fluid #Quantum, superfluid, helium dynamics #Superconducting Materials and Applications #Superfluid helium-4 #Superfluidity #Tangle #Vortex #Vorticity #cond-mat.other #cond-mat.stat-mech
paper · pdf · doi:10.1007/s10909-015-1430-7
arxiv created 2015/05/15 · openalex publication_date 2015/12/29 · arxiv updated 2016/01/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report computer simulations of the interaction of seeding particles with quantized vortices and with the normal fluid flow in thermal counterflow of superfluid 4He. We show that if the particle concentration is too large, the vortex tangle is significantly affected, posing problems in the interpretation of visualization experiments. The main effects are an increase in vortex line density and a change in polarization of the vortex tangle, caused by the action of the Stokes drag of the viscous normal fluid on the trapped particles. We argue that in the case of large particle concentration, typically used for the particle image velocimetry technique, the tangle properties might become significantly changed. On the contrary, the particle tracking velocimetry technique that uses smaller particle concentration should not be appreciably affected.