Investigation of Spiral-Groove Dry Gas Seal Performance Using an Experimental Data-Driven Kriging Surrogate Model

Spiral-groove dry gas seals are widely used in turbomachinery. However, high-fidelity numerical simulations remain challenging because the gas film is micron-scale and features high shear and pronounced boundary-layer effects, while experimental studies are often expensive due to the large design space and tight machining tolerances. To address these issues, this study integrates a Kriging surrogate model with surrogate-based optimization (SBO) to systematically identify the key structural and operating parameters governing seal performance. The results quantify the individual effects of key geometric parameters, providing practical guidance for spiral-groove seal design and optimization. The Kriging model captures the nonlinear relationships between performance and design variables and shows good generalization, with a maximum residual standard deviation of 2.78 and all others below 1.0. Sobol analysis reveals that structural parameters dominate performance: groove depth and width exhibit total-effect indices of approximately 0.74 and 0.56, respectively, while rotational speed is the most influential operating parameter (≈0.75). Among eight structural variables, groove depth is the most critical, increasing leakage by more than 200% as it rises from 5 to 8 μm, followed by spiral angle and groove number; all remaining parameters each contribute less than 10%.