Secondary flow in a vortex tube

Abstract

A novel Pitot probe was used to measure the axial and azimuthal velocities in a vortex tube. The probe has only a single measuring port and is hence smaller than standard devices. It monitors stagnation and reference pressure sequentially as the probe is rotated around its axis. From the measured velocity field in the 25 mm diameter vortex tube the local mass flux was determined and it was observed that the return flow at the center of the tube is much larger than the cold mass flow emerging out of the cold end. Therefore, the vortex tube must have a secondary circulation imbedded into the primary vortex, which moves fluid from the back flow core to the outer regions.

Maxwell’s Demon in the Ranque-Hilsch Vortex Tube

“…[2,[6][7][8][9][10][11][12][13][14][15][16][17]) what causes the energy separation process in the RHVT? Although all existing theories give ideas of possible process(es) inside the RHVT, it appears that quantitative comparison of the existing theories with experiments is very difficult.…”

“…Experimental results of the swirl Mach number inside the vortex chamber that we have measured with a cylindrical type pitot tube, or CPT (more about this method is found in Refs. [12,21]) are shown with symbols in Fig. 3.…”

An Investigation of a Micro-Scale Ranque-Hilsch Vortex Tube

“…Schematic of the experiment setup 28 The temperatures o f the inlet, cold and hot air are measured using type T thermocouple probes located at (5), (8) and (11) respectively. The compressed air is injected into the vortex tube through the manifold (6) and then the inlet slot (7).…”

Study of a Vortex Tube by Analogy with a Heat Exchanger

“…1 Many different qualitative explanations have been presented: internal friction theory 2 ; turbulent heat transfer of thermal energy in an incompressible flow; 3 Goertler vortices theory; 4 acoustic streaming processes leading to increased flow velocities which therefore enhance the kinetic energy available for conversion into heat; 5 and the secondary flow theory, 6,7 which shows that the thermal and fluid dynamics of the vortex tube are like the heat-pump cycle. However, none of these explanations so far has led to a quantitative model for the Ranque-Hilsch effect.…”