Numerical investigations of a tandem stator stage for a small turbo-shaft engine

The highly loaded small compressor is typically characterized by the large adverse pressure gradient, the complex endwall flow and the thick boundary layer, and the layout of the tandem blade is a good way to deal with high loading case according to large amounts of cascade experiments. However, dated design methods can't meet the needs for the advanced tandem stator and the flow mechanism should to be understood profoundly in small engines. As a result, a redesigned tandem stator is simulated in a highly loaded transonic small compressor with the commercial solver EURANUS. Incidences, deviations and loading splits of tandem blades are inspected to find the three dimensional characteristics. Contrasts are made to capture the flow field benefits between the tandem stator and the original stator. It is found that both the front blade's deviations and the rear blade's incidences are not sensitive to the incidence variations, and the front blade undertakes the whole incidence variations nearly. It's beneficial to distribute the loading uniformly for highly loading stators at the design point in the manner of tandem layout.