Experimental and Numerical Investigation of Rectifier Designs for Enhancing Energy Separation Efficiency in Vortex Tubes

In this article, a comprehensive experimental investigation was conducted on several rectifier-incorporated vortex tube to quantify key thermal performance metrics, including cold-end temperature difference, hot-end temperature difference, and coefficients of performance (COP), under the same operational conditions. Among the tested configurations, the vortex tube with a double-ring rectifier exhibited the highest energy separation efficiency, achieving a cold-end temperature difference up to 8.6 K higher than that of the prototype. Furthermore, this configuration attained the highest COP value of 0.104, representing a 43.2% improvement over the prototype. A temperature-entropy analysis revealed that the rectifier effectively reduced irreversible losses during the energy separation process, thereby mitigating thermodynamic irreversibility associated with turbulent dissipation. Additionally, numerical simulations were performed on both the vortex tube prototype and the vortex tube with a double-ring rectifier. The numerical results demonstrated that the double-ring rectifier enhanced fluid rotational intensity and established distinct stratified flow regimes between the core and peripheral regions. Moreover, contour analysis identified a larger velocity gradient in the flow field near the rectifier, which disrupted the thermal boundary layer between the inner and peripheral fluid. This disruption facilitated greater heat transfer to both the peripheral fluid and the tube wall, thereby enhancing the vortex tube’s energy separation performance. Overall, the combined experimental and numerical findings confirm that rectifier-induced flow field optimization significantly enhances vortex tube energy separation efficiency.