Effects of gas properties and geometrical parameters on performance of a vortex tube

In this paper, energy separation effects in a vortex tube have been investigated using a CFD model. A numerical simulation has been undertaken, due to the complex structure of flow. The governing equations have been solved by the FLUENT™ code in a 2D compressible and turbulent model. Three turbulent models, namely, RSM, Standard kk-epsilon and Spalart–Allmaras, have been used. The Spalart–Allmaras turbulent model, which is the first equation, was not so bad in predicting temperature results, although the Standard kk-epsilon model better predicts the results in most regions. The effects of geometrical parameters have been investigated. The results have shown that the hot outlet size and its shape do not affect the energy distribution in the vortex tube, and a very small diameter will decrease the temperature separation. Different kinds of gas have been examined for the vortex tube, and it was concluded that using helium as a refrigerant produces the largest energy separation.