A vortex tube produces cold and hot streams simultaneously from a source of compressed gas. We are using vortex tube device for cooling and heating. A 3D model vortex tube model that exploit standard k-Ɛ model used to simulate the physical behavior of the flow such as temperature inside the Ranque-Hilisch vortex tube. In this study, we addressed performance analysis of RHVT three-dimensional fluid flows; the domain using computational fluid dynamics CFD methods. Through the CFD analysis carried out varying the number of nozzle and the L/D ratio. The best performance parameters obtained the highest hot end temperature and lowest cold and temperature and it also increases the coefficient of performance (COP) and cold mass fraction of the RHVT taking air as refrigerant. From this investigation, we found that, the total temperature difference between hot and cold exit COP predicted by the CFD model of 4 numbers of nozzles were found to be better comparing with different nos of nozzle and maximum temperature difference obtained at L/D ratio 8.