performance evaluation of a ranque-hilsch vortex tube with optimum geometrical dimensions

a brass vortex tube (vt) with interchangeable parts is used to determine the optimum cold end orifice diameter, main tube length and diameter. experiments were carried out to study the effects of operating pressure as well. it is shown that there is an optimum value for cold end orifice diameter, which is equal to 4mm and there is an optimum value for cold and hot exit temperature difference at cf=0.4.a 2-d computational fluid dynamics (cfd) model is validated against the present experimental data. cfd code is applied to investigate the role of vortex tube diameter and length on the temperature separation. the code is also used to investigate and analyze the highly rotating flow field structure and its characteristic with respect to various cold fractions. finally the results are extrapolated for investigating the effect of inlet pressures up to 1053kpa, vt on separation performances.