**ABSTRACT**

The work presented in this paper is dealing with numerical simulation of energy separation mechanism and flow phenomena within a Ranque-Hilsch vortex tube. Simulation of turbulent, compressible, highly swirling flow inside vortex tube is performed using RANS approach, with Favre averaged conservation equations. For turbulence closure, k-ε and k-ω shear-stress transport models are used. It is assumed that the mean flow is axisymmetric, so the 2-D computational domain is used. Computations were performed using open-source CFD software Open- FOAM. All compressible solvers available within OpenFOAM were tested, and it was found that most of the solvers cannot predict energy separation. Code of two chosen solvers, which proved as the most robust, is modified in terms of mean energy equation implementation. Newly created solvers predict physically accepted behavior in vortex tube, with good agreement with experimental results. Comparison between performances of solvers is also presented. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 35046]

**KEYWORDS**

PAPER SUBMITTED: 2016-02-23

PAPER REVISED: 2016-05-17

PAPER ACCEPTED: 2016-06-19

PUBLISHED ONLINE: 2016-08-07

**THERMAL SCIENCE** YEAR

**2017**, VOLUME

**21**, ISSUE

**Supplement 3**, PAGES [S745 - S758]

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