Numerical study of temperature separation characteristics of vortex tubes: Effects of structural parameters and modeling of cooling performance correlations. (1st March 2023)

• Record Type: Journal Article
• Authors: Chen, Weiwei; Luo, Zibing; Li, Xinjun; Lu, Shihua; Guo, Feihong
• Is Part Of: Thermal science and engineering progress. Volume 39(2023)
• Publication Date: 2023-03-01
• Subjects: Vortex tube -- Temperature separation -- Cooling performance -- Structural parameters -- Correlation; Heat engineering -- Periodicals; Heat engineering; Thermodynamics; Periodicals; 621.402
• DOI: 10.1016/j.tsep.2023.101715
• Languages: English
• ISSNs: 2451-9049

Abstract

Highlights: The energy separation effect is explained based on detailed flow structure. The optimal structural parameters of vortex tube are obtained numerically. Dimensionless parameters affecting the energy separation are introduced. Correlations modeling the cooling performance of vortex tubes are proposed. Abstract: Vortex tube is widely used as a cooling system in manufacturing, gas separation devices and biological device, etc., for it has the advantages of simple structure, low-cost, lightweight, and no moveable parts. This paper is aimed to study the influence of the parameters related to the temperature separation characteristics of several types of vortex tubes through the flow field structure obtained by an experimentally proven numerical method. The results show that the compressed air passes through the vortex chamber tangentially to generate a high-speed swirl flow, which creates a large temperature gradient in both axial and radial directions of the vortex tubes, especially near the vortex chamber. Five dimensionless parameters concerning the structure and operating conditions are characterized as the prime influential factors in the cooling performance of the vortex tubes, and a promising dimensionless number combination is obtained as μ = 0.3, λ = 3, SD = 0.038, Pe = 7.91, and LD = 12.7. Further sensitivity analysis of the five dimensionless numbers indicates that the cooling performance of the vortex tubes is mainly affected by the values of μ, λ and SD . Consequently, the dimensionless number combination of μ, λ and SD is adopted to develop correlations of the cold end exit temperature and isentropic temperature efficiency of the vortex tubes to balance the simplicity and predictive power of the formula. The evaluation of the prediction performance shows that the two correlations have a high precision for the cooling performance prediction with 77.8 % and 76.0 % of all the data predicted within ±10 % error band, respectively.