NUMERICAL INVESTIGATION ON COOLING PERFORMANCE OF RANQUE-HILSCH VORTEX TUBE

A Ranque-Hilsch vortex tube is a mechanical device that separates a high pressure gas stream into low pressure hot and cold streams. In this study, four different two equation turbulence models namely the standard k-epsilon, RNG k-epsilon, Realizable k-epsilon, and Standard k-omega models were compared to identify the appropriate turbulence model for studying the energy separation effect in a Ranque-Hilsch vortex tube. Comparison between the numerical and experimental results indicates that the Standard k-epsilon model is better than other models in predicting the energy separation phenomenon. The distributions of temperature, pressure, and components of velocity have been obtained in order to understand the flow behavior inside the tube. The effect of cold outlet diameter on temperature drop and refrigeration capacity was studied. The effect of cold mass fraction on the movement of stagnation point and refrigeration capacity has been investigated. Moreover, the feasibility of improving the cooling performance of vortex tube using the cooling system was investigated. The present numerical results revealed that using the cooling system, the net energy transfer rate from cold inner region to the hot peripheral region increases, thereby improving the cooling performance of the device.