Flow structure and mechanism of heat transfer in a Ranque–Hilsch vortex tube

Flow structure of incompressible fluid in a Ranque–Hilsch vortex tube was studied experimentally. A pattern of streamlines in the whole volume of the vortex tube was constructed from the velocity distributions measured using laser Doppler anemometry. The radial distributions of the azimuthal velocity in the Ranque–Hilsch vortex tube are shown to be different from those in a vortex tube with a tangential inlet and a single central exit orifice. Based on the obtained structure of the flow, a simple qualitative model is proposed to explain the physical mechanism of the temperature separation effect.