Research on compressor slotted stator based on multi-objective optimization and shapley additive exPlanation (SHAP) method

Slotted blade is an effective flow control strategy for suppressing boundary layer separation (BLS). However, the flow control mechanism of slotted blade remains to be further explored in stage environment, and its design has long been lacking a reference principle. Therefore, this study proposes for the first time a three-dimensional (3D) modeling method for slotted blade, and applies multi-objective optimization and the Shapley Additive exPlanation (SHAP) method to slotted blade. This paper investigates the mechanism underlying the influence of slotted blade on total performance of a single-stage compressor. Validated numerical methods were employed to perform numerical simulations at the design point (with a mass flow rate outlet boundary condition) and the near stall (NS) point (with an average static pressure outlet boundary condition). By taking the design point efficiency and the total pressure recovery coefficient at the NS point as the objectives for multi-objective optimization, optimal schemes were obtained. The optimal schemes achieve a 1.07 % improvement in efficiency at the NS point, with only a slight loss in design point efficiency. Flow field analysis revealed a novel flow control mechanism in stage environment: the slot-jet, with relatively low energy, promotes the radial flow of low-speed fluids and reduces flow losses near the casing. SHAP analysis indicates that inlet width, outlet axial position, radial position of the upper wall at slot inlet, and radial position of the upper wall at slot outlet exert the most significant influence on compressor performance. Finally, the paper proposes a design principle for slotted blade. This research provides a sufficient theoretical basis and valuable design guidance for the engineering application of slotted blade in stage environment.