Numerical analysis of phase separation in curved Ranque–Hilsch vortex

P. H. Niknam*, University of Firenze - UNIFI, Italy; S. Farhangdoust, Florida International University, USA

The phase separation characteristic in a novel vortex tube using a turbulence model is discussed in the present research. The hydrodynamic behavior of the vortex tube performance revealed the presence of primary and secondary flows, which is investigated in different inlet boundary conditions by a 3D CFD model of the vortex tube which utilizes the SA turbulence model. The effect of the operating parameters on the turbulent viscosity ratio and the Mach number is also discussed. Strong swirling flows with a high order of tangential velocity in the counter current flows contribute to conduct a source-to-sink energy transport which in which the primary peripheral flow is the sink and the secondary (inner) flow is the source. The viscous heating is found to be rolling parameter of this cooling effect. Moreover, the feed includes heavy fraction with the dewpoint within the range of the minimum acquired temperature and the feed temperature. The condensation happens in secondary flow which is flowing toward the cold outlet of the tube. Meanwhile, the liquid phase is moved by the axial velocity and swirling effect to the wall side. The curvature design helps the liquid layer to be removed physically by a ring and a specific drainage considered at the half of the length of the tube. It was found that energy separation and cold side temperature depend mainly on the ratio of cold and hot gas mass flow rates and the inlet conditions. The feed of humid air with 0.05% mass fraction of vapor is considered in the simulation for determining the flow, pressure, temperature and liquid phase fields inside the computational domain. The results show that...

Session: G11 - Short Oral + Poster Presentations II
Day: 14 March 2018
Time: 14:45 - 16:45 h

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