https://za.rs-online.com/web/c/pneumatics-hydraulics/automated-air-blowers/vortex-tubes/
Vortex Tubes | Pneumatic Vortex Tubes | RS
vortex tubespneumaticrs
https://meetings.aps.org/Meeting/DFD17/Session/A9.1
APS -70th Annual Meeting of the APS Division of Fluid Dynamics - Event - From vortex tubes to...
https://farside.ph.utexas.edu/teaching/336L/Fluidhtml/node61.html
Vortex Lines, Vortex Tubes, and Vortex Filaments
Vortex Lines, Vortex Tubes, and Vortex Filaments
vortexlinestubesfilaments