An experimental investigation of the optimum geometry of two nozzle counter flow vortex tube.

An experimental study of two nozzle Ranque-Hilsch vortex tube are carried out with air as the working medium. Performance of the vortex tube is measured by varying the operating and geometric parameters such as L/D ratio, cold mass fraction, operating pressure and cold end orifice diameter and number of nozzles. Three Cold end orifices diameters 3 mm, 4 mm and 5 mm are tested with three L/D ratios vortex tubes 12.5, 13.5 and 17.5. Inlet pressure is varied from 2 bar to 8 bar with the increment of 1 bar. It was found that for 4 mm cold end orifices diameter brings maximum cold end temperature drop of 25°C. It is observed that cold end temperature drop in case of double nozzle is better than that of with single nozzle. Maximum temperature drop is obtained with cold mass fraction in the range of 0.45 to 0.55 for the cases, single nozzle and double nozzles. Vortex tube with L/D ratio 17.5 performs better than other two chosen L/D ratios.