Introduction of Annular Vortex Tube and experimental comparison with Ranque–Hilsch Vortex Tube

• Annular Vortex Tube has higher thermal separation performance comparing to RHVT.
• Annular Vortex Tube improves cooling efficiency about 24% comparing to RHVT.
• Vortex generator with higher nozzle area ratio represents better cooling efficiency.
• Conical valve angle has no effect on thermal performance of AVT.

In order to enhance the Ranque–Hilsch Vortex Tube (RHVT) performance, an improved design of a Vortex Tube (VT) is introduced here. The new design of the VT which called Annular Vortex Tube (AVT) is experimentally tested and compared with a similar design RHVT. The hot stream, after passing the hot conical valve, redirected along the outer wall of hot tube in the AVT. This increases heat lost from outer wall of the hot tube. Results show that AVT has higher thermal separation performance comparing to RHVT. For optimum cold mass fraction, AVT improves cooling efficiency about 24% comparing to RHVT. The conical valve angle has also no effect on thermal performance of AVT. For AVT, three vortex generators are tested with different nozzle areas. All vortex generators have the same coefficient of performance in heating while vortex generator with higher nozzle area ratio represents better cooling efficiency among the others.