Performance of the High-Speed Conventional Loading Cascade Influenced by the Blade End Slots

The helicity based Spalart-Allmaras turbulence model (SA-Helicity model) is used to numerically investigate the end slotted effect in controlling the three-dimensional corner separation flow for the high-speed conventional loading NACA65-K48 cascade. Performances are compared between the datum blade and the end slotted blade with single slot or double slots respectively. Conclusions are drawn that the blade end slots can effectively reduce the total pressure loss under a large range of incidence angles, thus improving the cascade performance. The jet flow from the slot outlet is adaptive with its velocity a bit larger than the local main flow velocity. Showing a perfect potential in bringing the local accumulated low momentum fluid downstream. The adaptive outflow from the blade end slots can effectively push the corner separation downstream, reduce the spanwise proportion of the separation zones, enlarge the two-dimensionality and eliminate the blockage in the blade middle zones, when the slot outlet is placed ahead of the separation zones on the blade suction surface. The jet flow effect of the single blade end slot is limited, while it can be enhanced through the implement of the second slot downstream.