An investigation of energy separation in a vortex tube

The process of energy separation in a vortex tube with air as a working medium is studied in detail. Experimental data of the temperatures of the cold and hot air leaving the vortex tube are presented. The variation of the maximum wall temperature along the vortex tube surface provides useful information about the location of the stagnation point of the flow field at the axis of the vortex tube. Experimental results indicate that the Goertler vortex produced by the tangential velocity on the inside wall of the vortex tube is a major driving force for the energy separation. A similarity relation for the prediction of the temperature of the cold exit air, obtained from the dimensional analysis, is presented and confirmed by experimental data.