Abstract:

The four kinds of compressor treated casings, i.e., grooved, slotted, sloped trench and recess vane casings, were designed and researched experimentally with the help of a subsonic isolated rotor. Aimed at the different geometric parameters of each treated casing, the influence on the stall margin and the efficiency at the stall boundary and the extreme value was investigated in detail. On the basis of analysing the experimental results, the mechanism that they affect the rotor performance was explained.

Key words: casing treatment, stallmargin, efficiency