Thermal Separation in 2D Vortex Tube for a Different Tube Length and Cold Mass Flow Ratio

Abstract

Vortex tube (VT) is used to disperse the pressurized gas (air) into hot and cold streams. Further, the gas is inserted tangentially into the vortex tube with extreme pressure and with the high degree of the swirl. The outer most part of the fluid flow within the vortex tube is allowed to escape from the hot outlet, and the inner fluid part is to escape from the cold outlet. In this paper, the computational fluid dynamics (CFD) model is designed as a 2D axisymmetric model with an axial annular inlet and a radial annular outlet which provides required rotational fluid flow inside the vortex tube. Model was analysed for thermal separation for a counter-flow vortex tube in commercially available software ANSYS Fluent 19.0 by taking working fluid as air. The standard k-e model is used for turbulent flow within the vortex tube. The CFD model is used to check the VT boundary conditions on the thermal separation and to provide detailed information on the flow velocities, temperature and pressure distributions, as well as the cooling/heating effect. It is clearly observed that the obtained cooling effect is maximum for a vortex tube of length 100 mm. Also, cooling effect and heating effect with variation in cold mass flow ratio are validated with already reported research data (Guo and Zhang in Int J Refrig 85:42–57, 2018 (Aljuwayhel et al. in Int J Refrig 28:442–450, 2005)).