Numerical investigation of the vortex tube performance in novel precooling methods in the hydrogen fueling station

Experimental analysis on impact of navigator’s angle on velocimetry and thermal capability of RH-vortex tube

Exergy analysis of the flow process and exergetic optimization of counterflow vortex tubes working with air

Flow and heat transfer in swirl tubes — A review

The paper considers the process of energy separation in a vortex tube with an original screw-type vortex generator, which was not previously used for this purpose. The effects of inlet pressure, pressure at hot and cold outlets of the tube, and mass fraction of the cold stream in the total flow on the temperature separation and process efficiency have been investigated. It is shown that increasing inlet pressure, the effect of the flow temperature separation increases, and an increase in the outlet pressure leads to a decrease in the effect. To determine the region of energy separation, the vortex gas flow in a screw swirl placed in a round tube and designed to swirl the flow in a Ranque-Hilsch vortex tube was experimentally studied. It has been experimentally shown that the temperature of the swirling gas flow leaving the screw swirl at the periphery increases with respect to the inlet gas temperature, and the temperature of the swirling gas flow in the axial region decreases. This indicates that energy separation occurs in the screw vortex generator.

Experimental study of energy separation in a Ranque-Hilsch tube with a screw vortex generator.

Various methods had been taken for the flow field studies, among them, qualitative visualizations and probe intrusive measurements have a long history and had been adopted since last 50s, while laser non-intrusive measurements and numerical simulations are the emerging methods, especially the former. Nowadays, more and more researchers have realized there are specific and regular flow structures in the strong turbulence of vortex tube, and the flow structures have great significance on understanding the energy separation process and performance. However, there still did not exist a review on the flow structure studies. The aim of this paper is to offer a critical review and discussion on the current studying methods, findings and differences on the flow structures in vortex tube. In addition, future scopes were proposed on the experimentally and theoretically verification of these flow structures and their effects on the energy separation process and performance.

Xiang Xu

Papers

A critical review on the flow structure studies of Ranque–Hilsch vortex tubes