Multi-objective optimization of labyrinth seal for aero-engine based on Kriging model

The improvement of sealing performance in labyrinth seals is crucial for enhancing the operational efficiency of aero-engines. This study proposes a novel parametric modeling method that enables independent adjustment of geometric parameters for each fin in labyrinth seals. A multi-objective optimization platform based on Kriging surrogate modeling was established to conduct multi-objective optimization design targeting both leakage and windage heating characteristics. Comparative analysis was performed on the leakage and windage heating characteristics of the labyrinth seal structure before and after optimization under different pressure ratio conditions. Global sensitivity analysis was conducted on the design parameters, and the intrinsic flow mechanism of performance improvement was analyzed in combination with the highly sensitive parameters. The results demonstrate that for the selected solution, under the optimized pressure ratio of 1.2, a 12.38% reduction in leakage was achieved with only a 0.98 K increase in windage heating. As the pressure ratio increases, the leakage reduction rate improves from 11.91% to 14.57%, while the windage heating increase rate decreases from 3.08% to −0.2%. Global sensitivity analysis confirms that the tip clearance plays a dominant role in both leakage and windage heating characteristics. The optimized design induces significant changes in the vortex structure of the flow field and temperature distribution, effectively enhancing the overall performance of the labyrinth seal.