Impact of the Stator-Side Swirler on Turbine Rim Sealing Effectiveness

Abstract Ingestion of hot mainstream flow into the wheel space between the turbine stator and rotor disks can cause thermal damage and reduce component lifespan. Recent studies suggest that reducing the swirl difference between the main and sealing flows can suppress ingestion. Previous research introduced a rotor-side swirler to enhance sealing effectiveness by increasing the swirl of the sealing flow, but it consumed some (albeit small) rotor power. Alternatively, this study presents the first experimental investigation of a stator-side swirler, which increases the swirl of the sealing flow without consuming rotor power. The stator-side swirler enhances sealing effectiveness by increasing the sealing flow swirl up to 18% at the wheel space outer radius, thereby reducing the swirl difference with the main flow. Additionally, it lowers the minimum sealing mass flow rate required for complete sealing by 10%, corresponding to a 0.25% increase in the overall engine power output. This gain in the net power is comparable to that of the rotor-side swirler.