Treatment of a non-axisymmetric casing comprising a plenum, with controlled opening
A casing of a turbine engine compressor including an inner annular wall and an outer annular wall delimiting therebetween an annular cavity. The inner annular wall includes a plurality of slots hollowed out in the thickness of the wall, the slots being arranged next to one another in a circumferential direction and each extending in an axial direction. The casing further includes a sliding ring present in the annular cavity of the casing. The sliding ring is movable in the axial direction between an open position in which the slots in the inner annular wall of the casing open into the annular cavity and a closed position in which the sliding ring covers at least some slots.
1 . A casing of a turbine engine compressor comprising an inner annular wall and an outer annular wall delimiting therebetween an annular cavity, the inner annular wall of the casing comprising a plurality of slots hollowed out in the thickness of the inner annular wall, the slots being arranged next to one another in a circumferential direction and each extending in an axial direction, the casing further comprising a sliding ring present in the annular cavity of said casing, the sliding ring being movable in the axial direction between an open position in which said slots in the inner annular wall of the casing open into the annular cavity and a closed position in which the sliding ring covers at least some slots, the casing additionally comprising an actuating device to move the sliding ring between the open and closed positions, wherein the sliding ring comprises cavities on the inner surface thereof opposite the outer surface of the inner annular wall, the cavities being positioned on the inner surface of the sliding ring at determined points such that the cavities coincide with the slots in the closed position.
2 . The casing according to claim 1 , wherein the sliding ring is formed of one piece.
3 . The casing according to claim 2 , wherein the actuating device comprises a pressurised air injection system communicating with one or more injection orifices in the downstream end part of the annular cavity, a plurality of springs being held under compression between an upstream end part of the annular cavity and the sliding ring.
4 . The casing according to claim 1 , wherein the sliding ring is divided into several annular segments able to slide individually within the annular cavity in the axial direction.
5 . The casing according to claim 4 , wherein the actuating device comprises a pressurised air injection system communicating with at least one injection orifice provided in the downstream end part of the annular cavity opposite each annular segment of the sliding ring, at least one spring being held under compression between an upstream end part of the annular cavity and each annular segment of the sliding ring.
6 . The casing according to claim 1 , wherein the cavities of the sliding ring have an aerodynamic shape.
7 . The casing according to claim 1 , wherein the cavities of the sliding ring and the slots of the casing have the same dimensions.
8 . A turbine engine compressor comprising the casing according to claim 1 .