Based on Menter's SST (shear stress transport) turbulence model coupled with Langtry-Menter transition model

the effects of fully contoured casing and partial contoured casing on the tip-leakage loss was numerically investigated in the highly-loaded low-pressure turbine cascade T106 with tip clearance. The results show that: the contoured casing design changes the vortex structures and loss components in tip region

and such effect is obviously impacted by the height of contoured casing arc. The increase of the spanwise size of the pressure side/tip junction separation bubble leads to stronger blocking effect

thus reducing the kinetic energy of the tip-leakage flow. Partial contoured casing could reduce the additional cross flow near the endwall caused by the local divergence of blade passage

and lead to larger spanwise loss reduction area at outlet. Therefore the cascade outlet loss is reduced essentially

and the maximum is up to 6.1% compared with original casing. The tip-gap size sensitivity analysis shows that both kinds of contoured casings can effectively reduce the tip-leakage loss in a certain. Moreover

the partial contoured casing achieves broader effective tip-gap size and lower loss.