The Flow Crisis and an Inner Source of Heating in the Vortex Tube

Abstract

The analysis of current complex experimental investigation of the vortex tube with square cross section is made focusing on the criticality of the inner flow in the framework of the flow crisis concept. The criticality condition is proved to take place in the vortex tube by operating with LDA obtained velocity experimental data. As the measured axial velocity exceeds the calculated velocity of centrifugal elastic waves on the boundary between the longitudinal circulation zone and the near wall swirling jet, two scenarios are supposed possible for the transition of the supercritical state to a subcritical one, similar to the vortex breakdown in a swirling jet at its discharge into the quiet liquid volume: the mild oscillations or a series of hydraulic jumps become possible, leading to a flow pattern choke change with the transformation to heat of excess kinetic energy.