Experimental investigation of the performance of a Ranque–Hilsch vortex tube with regard to a plug located at the hot outlet

In this study, effects of position, diameter (5, 6, 7, 8 mm) and angle (30°–180°) of a mobile plug, located at the hot outlet side in a Ranque–Hilsch Vortex Tube (RHVT), were determined experimentally for best performance. In addition to plug parameters, effects of supply pressure (200–420 kPa) and number of nozzles (2, 4, 6) were also studied. The internal diameter (D) of the vortex tube used in the experiments was 9 mm; the ratio of the length of the vortex tube to its diameter (L/D) was 15. Four different plug locations were studied. The maximum difference in the temperatures of hot and cold streams was obtained for the plug diameter of 5 mm, tip angles of 30° and 60°, 4 nozzles and by keeping the plug location at the far extreme end.