Experimental investigation of the flow characteristics within a vortex tube with different configurations

The energy separation in a vortex tube is a combined result of different factors and its explanation remains debatable. As a classical fluid mechanics phenomenon, understanding of the complex helical flow mechanism within a vortex tube is a necessary foundation. The small scale of an industrial vortex tube and the extremely complex flow conditions are the two main challenges in obtaining the internal flow properties. This paper reports the results of an experimental investigation on the flow behaviour within a confined cylindrical system having different configurations corresponding to the actual flow field in a vortex tube at different conditions. Transparent devices were used to enable flow visualisation and Particle Image Velocimetry (PIV) measurement. The results of the flow visualisation and PIV experiments show that a precessing vortex core is significant only in a specific range of swirling strength. A good agreement between the observed flow characteristics and previously published results was observed.