Steady-state stress analysis in a supercritical CO₂ radial-inflow impeller using fluid solid interaction

According to the geometry and the state parameters, a single channel model of a supercritical CO₂ radial-inflow turbine is established. The finite volume method, the finite element method, and the shear stress transport turbulence model are used for solid-fluid interaction. In 3-D finite element analysis, the results of flow analysis and thermal analysis are adopted to obtain the stress distribution of the impeller in working condition. The results show that the maximum equivalent stress of the impeller is 550 MPa, which is located at the blade root of trailing edge and lower than the yield limit. Meanwhile, the centrifugal load increases the stress level on the inside back end surface and the surface of the blade root. The aerodynamic load causes obvious stress concentration at the blade root of the trailing edge and increases the stress level in the downstream position of the impeller. The thermal load increases the stress level on the outside edge of the back-end surface and the surface near the blade root of the leading edge.