The study of key design parameters effects on the vortex tube performance

In this paper, energy separation effect in a vortex tube has been investigated using a CFD model. The numerical simulation has been done due to the complex structure of flow. The governing equations have been solved by FLUENT code in 2D and 3D compressible and turbulent model. The effects of geometrical and thermo-physical parameters have been investigated. The results have shown that the optimum length to diameter ratio is from 25 to 35. Increasing the number of nozzles from 2 to 4 with convergent shape is found to be an efficient configuration for the swirl generator. The optimum value of orifice diameter to tube diameter ratio, for the maximum cold air temperature difference and efficiency, has been determined to be around 0.58. The results show that if the inlet pressure increases up to a critical value, the efficiency will increase. Nevertheless, if it increases to higher values, the efficiency will decrease. Moreover, it is found out that increasing the cold fraction decreases the cold temperature difference and efficiency.