Numerical study of the characteristics of a double-circuit vortex tube in a stationary and a nonstationary settings

The results of numerical modeling of thermodynamics of a swirled flow in an energy separation chamber of vortex devices in stationary and non-stationary settings are presented in the paper. The results of investigation confirmed the presence of precession motion of the paraxial vortex core, velocity, pressure and temperature pulsations in the energy separation chamber. The processing of these made it possible to design a reverse cycle produced by large-scale vortex structures in a p, v-diagram. The cycle is responsible for the major portion of energy transfer from the periphery to the near-axial layers. It was found that the heated masses of gas are added to the cooled flow near the end surface of the diaphragm due to the angle vortex produced. We propose making the nozzle inlet inclined in the form of a slope using the Bernoulli lemniscate, which results in the improvement of energy separation characteristics by 1.5-2.0 per cent. Different areas of the flow such as the recirculation zone, the vortex core, the open jet at the outlet of the slot diffuser are the components of a single vibration system. Numerical simulation of flow in a vortex energy separator and analysis of non-stationary phenomena taking place in a DCVT show that vortex core precession is the source of large-scale periodic vibrations in a vortex tube.