Numerical investigation on the effect of convergent-divergent tube on energy separation characteristic of vortex tube

• Published in: International communications in heat and mass transfer Vol. 133; p. 105927
• Main Authors: Liang, Fachun, Zeng, Qinggang, Tang, Guoxiang, Xin, Lingqi, Li, Qigui, Li, Naiming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022
• Subjects: CFD; Convergent-divergent angle; Energy separation; Vortex tube; CFD; Vortex tube; Convergent-divergent angle; Energy separation
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2022.105927

The geometric structure of the hot end tube affects the energy separation of the vortex tube greatly. The computational fluid dynamics (CFD) technique is used to study the difference of velocity and temperature distribution between the straight tube and the convergent-divergent tube. The convergent-divergent angle varies within 3°-5°, and the results show that the temperature separation capability of the convergent-divergent structure performs better than the traditional straight tube. As the convergent-divergent angle increase, the temperature at the throat of the vortex tube gradually decreases and the velocity increases under a given cold mass fraction. At a high cold mass fraction, the increase of the convergent-divergent angle will increase the cooling capacity and heating capacity. The work-heat exchange theory is firstly applied to the convergent-divergent vortex tube. It is found that the tangential work and heat transfer of the vortex tube reaches maximum in case of convergent-divergent angle equals to 4° under a given cold mass fraction. •Effect of convergent-divergent angle on vortex tube performance is investigated.•Influence of convergent-divergent angle on velocity and temperature distribution is simulated.•Heat and work transfer under different convergent-divergent angle is compared and discussed.