Research on Flow Loss Decomposition and Loss Characteristics of Supercritical Carbon Dioxide Centripetal Turbine

To address the unclear coupling mechanism of flow losses and the lack of optimization direction in supercritical carbon dioxide （SCO₂）centripetal turbines, a 150 kW SCO₂ centripetal turbine is concentrated in this paper. Based on entropy generation theory, different boundary condition settings, multiple numerical simulations, and vorticity analysis methods are employed to decompose flow losses, identify loss sources, and analyze loss characteristics. The simulation results indicate that under design conditions, the flow losses in the centripetal turbine occur in the following order,from largest to smallest：leakage losses,stator losses, mixing losses, and rotor losses, accounting for 44.43%,31.82%,11.98%, and 11.77% of the total losses, respectively. When deviating from the design conditions, the proportions of leakage losses and stator losses decrease, while the proportion of mixing losses increases, with little change in rotor losses. The primary cause of leakage losses is the relatively high clearance at the inlet tip of the rotor, which leads to significant leakage through the turbine； reducing the blade tip clearance can notably decrease the turbine's entropy generation and leakage losses. Stator losses predominantly occur in the mid-to-late regions of the passage, while rotor losses increase sharply at the mid-section of the rotor. The findings provide data support for the aerodynamic design and profile optimization of 100 kW-class SCO₂ power cycle centripetal turbines.