A review on design criteria for vortex tubes

In this study, the past investigations of the design criteria of vortex tubes were overviewed and the detailed information was presented on the design of them. Vortex tubes were classified and the type of them was described. All criteria on the design of vortex tubes were given in detail using experimental and theoretical results from the past until now. Finally, the criteria on the design of them are summarized. List of symbols A cross section (m) CFD computational fluid dynamics COP coefficient of performance cp specific heat at constant pressure (kJ kg -1 K) cv specific heat at constant volume (kJ kg -1 K) d diameter (m) D diameter (m) h enthalpy (kJ kg) k specific heat ratio k Boltzmann constant (J K) L length (m) _ m mass flow rate (kg s) N number p pressure (Pa) _ Q heat transfer rate (W) R specific gas constant (kJ kg K) RHVT Ranque–Hilsch vortex tube S entropy (W K) T temperature (K) T sm temperature assumed to be T 1 e h T e c _ W power (W) X normalised pressure drop X 1⁄4 pin pc ð Þ=pin ð Þ Greek symbols a angle of cone-shaped control valve a ratio of hot end area to tube area b cold orifice diameter ratio b 1⁄4 dc=D ð Þ e cold fraction eo Lennard–Jones potential g efficiency DT temperature difference DT=Tin normalised temperature drop/rise C k 1 ð Þ=k H irreversibility parameter sp pressure ratio 1⁄4 pin=pc ð Þ Subscripts atm atmosphere c cold cr cooler cr critical h hot hp heat pump in inlet i irreversible M. Yilmaz (&) S. Karagoz Department of Mechanical Engineering, Engineering Faculty, Atatürk University, Erzurum, Turkey e-mail: [email protected] S. Karagoz e-mail: [email protected] M. Kaya Türk Hava Yolları Teknik A. Ş. Havaalanı, Erzurum, Turkey e-mail: [email protected] S. Erdogan Erzurum Vocational School of Higher Education, Atatürk University, Erzurum, Turkey e-mail: [email protected] 123 Heat Mass Transfer (2009) 45:613–632 DOI 10.1007/s00231-008-0447-8