Numerical Study of Inlet Pressure Effects on the Performance of Vortex Tube Machine

Vortex tube or Ranque–Hilsch vortex tube is a mechanical device with a simple geometry and without any intricacy in its components, which can produce two colder and hotter streams from compressible inlet air. In this investigation, computational fluid dynamics (CFD) technique is used to study of key design parameter influence, i.e. inlet pressure on the performance of vortex tubes and energy separation phenomenon. The novelty of the present paper is the special focus on the Mach number inside vortex chamber and its changes due to the inlet pressure effect which has not been investigated in other papers yet. The governing equations have been solved by FLUENT code in 3D compressible and turbulent model using standard k-ε turbulence model. In this study on the basis of obtained results by the CFD study, different inlet pressures of vortex tube are studied. Finally in order to attain the more temperature separation in the vortex tube system, some suggestions and results is presented. This article believes that every vortex tube has an optimum pressure which is commercially optimized in heating and cooling processes. This optimum pressure was found to be 4.8 bar in the present research. The present obtained software results indicate that for cooling purpose, the cold mass fraction of about 0.3 will be recommended for higher cold temperature difference and for heating purposes in throughput of the cold mass ratio of about 0.8 is used. The obtained CFD results are validated by available experimental results. Also the inlet pressure increment reveals the increase of entropy generation and irregularity in the system.