Analysis of the influence of pipe materials on the energy separation effect in vortex tubes

In this study, we aim to enhance the efficiency and performance of vortex tubes by identifying the optimal material for their manufacture under specific conditions using computational fluid dynamics (CFD) simulations. We first establish a theoretical model of vortex tubes and propose a dynamic partition modeling method. Through theoretical analysis, we demonstrate the superiority of metallic materials in vortex tube applications, particularly regarding their energy distribution efficiency. We then conduct CFD simulations and experimental validations to systematically analyze the performance of vortex tubes made from different materials. The simulations utilize compressed air as the working fluid, with inlet pressures ranging from 0.1 MPa to 0.5 MPa. The materials considered include Copper, Aluminum, Steel, PVC, and Wood. Throughout the simulations, the cold mass fraction is maintained at 0.1, and the length-to-diameter ratio (L/D) of the vortex tube is set at 16. Using the standard k-ε model, steady-state numerical simulations of the gas flow inside the vortex tube are performed to analyze the variations in velocity, pressure, and temperature for different materials, pressures, and roughness conditions. Based on the physical properties of the materials, we find that metallic materials, particularly Copper, exhibit higher temperature gradients compared to non-metallic materials, with the order being Copper > Aluminum > Steel > PVC > Wood.