The present work investigates the flow physics inside an elliptical vortex tube. Two different 3D (three-dimensional) domains of circular and elliptical vortex tubes with four nozzles are studied. The cross-sectional area and length of the vortex tube are constant for both of its shape. The pressure at the inlet is 320 kPa for both the shapes and air as a working fluid. Standard k- ε turbulence model is used to predict the flow physics and temperature separation effect inside the tubes. The experimental and numerical findings of earlier researchers provide as validation for the present results. The deviation of the results is found within the permissible limit. The temperature separation phenomenon in an elliptical tube at various cold mass fractions is discussed. The range of cold mass fraction is 0.1 to 0.9. This work also examines the fluid characteristics and flow parameters by tracing the fluid particles within the tube. Fluid characteristics such as static pressure, density, total temperature, static temperature are evaluated. Also, the flow parameters like velocity magnitude, turbulent kinetic energy, axial velocity, and swirl velocity are discussed at the various radial locations inside the tube to get the flow pattern information. It’s an attempt to determine the feasible flow mechanism inside an elliptical vortex tube. The comparison between the circular vortex tube and the elliptical vortex tube has been done based on various fluid characteristics and temperature separation. It is found that energy separation is elevated in an elliptical tube by 49.89% at the hot end tube at 0.2 cold mass fraction whereas it is low for cold temperature separation as compared to the circular vortex.

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An experimental investigation was conducted to investigate the effects of different cold orifice diameters and operating pressures of the vortex tube. A vortex tube test rig was employed to conduct the experiments for various cold orifice diameters and operating pressures. Cold orifice diameters range from 1 mm to 6 mm, whereas the pressure condition ranges from 2 to 5 bar. The vortex generators were made up of brass material having six inlet nozzles. It was found that the temperature separation of the vortex tube significantly depends on the cold orifice diameter of the vortex tube and operating pressure. The study demonstrates the deviation of cold temperature separation with respect to the cold orifice diameters and inlet pressure for different cold mass fractions. In addition, present experimental results are used to determine the optimum cold orifice diameter, which is 5 mm at 5 bar inlet pressure. The percentage improvement in average cold temperature separation for 5 mm cold orifice diameter is 66.18% compared to rest of the cold orifice diameters at an inlet pressure of 5 bar. The maximum cooling power separation is 0.08 kW at 0.3 cold mass fraction and inlet pressure of 5 bar. The CFD technique was approached to discuss the complex fluid flow inside the tube at various radial distances. A three-dimensional numerical study was done and validated with the present experimental work. It was found that the numerical results are in good agreement with the present experimental data.