Energy Transfer Mechanisms In The Ranque-Hilsch Vortex Tube

The Ranque-Hilsch Vortex Tube (RHVT) is a small tube without any moving parts receiving compressed air from a tangential inlet and exhausting cold air from a small hole at one end of the tube while exhausting hot air from an annular exit at the opposite end. Nearly a century has passed since the RHVT was first patented, and the mechanism responsible for this socalled "temperature separation" remains unclear. The present work tests the hypothesis that kinetic energy is transferred from the stream of air leaving the cold exit to the air stream leaving the hot exit. To test the hypothesis, a parametric study using an axisymmetric model of the RHVT has been carried out using CFD software, wherein the pressure at the hot exit was varied. The study has been validated against previous experimental and computational models. The results show that the dominant mode of energy transfer between the two streams is work transfer, which supports the hypothesis.