A novel prediction model for leakage flow of scallop bionic damper seals operating in the supercritical CO₂ compressor

The scallop bionic damper seal (SDS) is a novel sealing technology for supercritical CO₂ (S-CO₂) centrifugal compressors with superior sealing performance compared to labyrinth seals. However, the complicated turbulence dissipation of the leakage flow inside the seal is unclear yet, which poses a challenge for the application of this sealing solution. In this study, the high-order real gas flow solver is presented, and the accuracy of the solver is evaluated by conducting leakage experiments of SDS and visualization experiments for S-CO₂. Additionally, the turbulence dissipation and friction dissipation of leakage flow are investigated to uncover the leakage reduction mechanism of SDS, and the prediction model for leakage flow of SDS is proposed for the first time, and the advantages of this novel model are evaluated. The results indicate that the vortices in the seal cavities significantly enhance the turbulence dissipation of leakage flow, changing the cavity structure can synergize the effects of turbulence and friction dissipation to reduce the leakage flow rate. The prediction model contains ten variables, considering the thermodynamic state, expansion effect, and dissipation effect, and the prediction deviation is less than ±20 %. This work provides technical support for the application design of scallop bionic damper seals.