Static and dynamic seal performances of axial force self-balancing devices

:Excessive axial force poses a critical challenge to the operational stability and reliability of turbomachinery, necessitating effective axial force balancing strategies. This study proposes a comprehensive methodology for the performance-oriented design and optimization of axial-force self-balancing devices operating with compressible fluids. The numerical model is experimentally validated using compressed air and is subsequently extended numerically to supercritical carbon dioxide (S-CO2) conditions by incorporating the corresponding thermophysical properties. The results show that, at inlet pressures of 0.2, 0.3, and 0.4 MPa, the predicted variation trends of load-carrying capacity with respect to gas-film clearance in the radial flow channel agree well with experimental measurements, with deviations maintained within 2%∼5%. The proposed approach provides a reliable tool for the design and optimization of axial-force self-balancing structures and offers new insights for turbomachinery operating in S-CO2 environments.