Numerical simulation for three-dimensional flow in a vortex tube with different turbulence models

Abstract

Three-dimensional flow in a vortex tube with straight nozzle was investigated numerically. Four different turbulence models, Spalart-Allmaras, standard $k-\epsilon ,$ SST $k-\omega$ and realizable $k-\epsilon$ were proposed to replicate the flow in the vortex tube. The simulation results of pressure, temperature and velocity field were compared with the experimental data based on dimensionless analysis. It was found that the sudden gas expansion in the vortex chamber causes a pressure drop. The secondary circulations phenomena were observed and identified. Furthermore, the friction between the gas and wall surface and the energy transfer between different laminar flows are the main factors of energy separation in the vortex tube. The realizable $k-\epsilon$ model predicts energy separation better than other models studied in this research.