Computational fluid dynamics comparison of separation performance analysis of uniform and non-uniform counter-flow Ranque-Hilsch Vortex Tubes (RHVTs)
International Journal of Heat and Technology
In the present work, uniform and non-uniform cross section vortex tubes have been optimized utilizing straight, convergent (φ) and divergent (θ) hot-tube axial angles. A computational fluid dynamic (CFD) techniques with RNG k-ԑ turbulence model was employed to investigate the influence of divergent (θ) and convergent (φ) angles on the flow behavior within the vortex tube. The isentropic efficiency ( ) and coefficient of performance (COP) of machine was studied under five different divergent
... erent divergent angles (θ), namely 1, 2, 3, 4 and 6 degree, two different convergent angles (φ) named 1 and 2 degree adjusted to the hot-tube. In this study, some factors such as axial angle of inlet nozzles, inlet pressure, mass flow rates and number of inlet nozzles as well as the effect of different kinds of inlet gas have been analyzed in detailed in order to optimize the cooling efficiency of vortex tube (straight). The results show that utilizing the divergent hot-tubes increases the isentropic efficiency ( ) and coefficient of performance (COP) of device for most values of inlet pressures and helps to become more efficient than the other shape of vortex tubes (straight and convergent). Also, helium has shown produces the largest energy separation as a refrigerant.