In axial compressors, shrouded stator cavity flows are responsible for performance degradation due to their interaction with the main channel flow. One way to further improve compressor performance is to understand cavity flows and associated effects to reach optimal cavity geometries and blade designs.

The present paper investigates the effect of different hub cavities layouts with different level of realism on both the overall performance and the cavity flow structures. At its final extent, the present work aims at providing numerical and experimental guidelines to assess cavity flows effects in industrial and academic contexts.

A high pressure compressor stage (LEMCOTEC H25) was experimentally characterized in the von Karman Institute R4 high-speed closed loop compressor rig. This configuration features a closed shrouded stator cavity where, contrary to real compressors, no downstream-to-upstream recirculation occurs. In a first step, the adopted RANS approach is validated against experimental results, both in terms of overall performance and of detailed flow field features. The closed cavity flow field is then thoroughly analyzed for two operating conditions at design speed, pointing out: *i)* its interactions with the power stream and, *ii)* the impact on the stator performance as well as on the one of the entire stage. In that regard, the sensitivity of the H25 cavity flow structures and stage to injection parameters is also addressed.

The present configuration serves as a baseline for forthcoming investigations on the effect of realistic cavity flows on the overall performance and stability of the aforementioned stage.


Numerical Characterization of a HP Compressor Stage Equipped With a Closed Shrouded Stator Cavity

Division / Sponsor:
International Gas Turbine Institute (IGTI)

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2020/volume/84058

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