An experimental study of nozzle number on Ranque Hilsch counter-flow vortex tube

The present study investigates the effects of the orifice nozzle number and the inlet pressure experimentally on the cooling performance of the counter flow type vortex tube. The energy generation has been conducted using a generator of type stream-tek generator model GNMD-KIT with the number of nozzles (2, 3, and 6), and aspect ratio 1.6 and, an inner diameter of 7.5 mm. In the experiments, for each of the orifices, inlet pressures have been adjusted from 200 kPa to 600 kPa. The energy separation to be investigated here focuses on the cold temperature difference and coefficient of performance for cooling. The experimental results concluded in this paper proved that the higher effect of nozzle number is for nozzle number three and hence that nozzle number could affect the energy separation efficiently. A comparison of the present experiments with other published works has been conducted. An analytical study of the characteristics equation has been carried out to evaluate the best correlation of the ratio of cold temperature difference to the inlet temperature as a function of pressure, cold mass fraction and nozzle numbers. The goodness of fit of the regression model is inspected using the analysis of variance and t-test. The values of R-2 are adjusted close to 97% which show a very good agreement between the experimental and predicted values. (C) 2016 Elsevier Inc. All rights reserved.