Numerical benchmark for air vortex tube flows using a 2^(5-1) resolution V fractional factorial design.

Computational fluid dynamics models are commonly used to investigate the local fluid flow and heat transfer features inside vortex tubes. For design purpose, extensive calculations are required to optimize the vortex tube and a trade-off must be found between accuracy and computational efforts. A 25-1 resolution IV design is used here with a 2D axisymmetric model of the experiments of Camire (1995) to evaluate the influence of different modelling parameters on the prediction of the cold mass fraction, the cold outlet temperature and the localization of the stagnation point. This study demonstrates that the k-w SST turbulence model predicts the cold mass fraction with great accuracy while the standard k-e model is associated with a significant error. The k-w SST is used to determine the localization of the stagnation point. This point moves downstream as the cold mass fraction and inlet pressure increase and is affected by the mesh refinement.