Abstract: A guide vane wheel of a turbomachine, has a plurality of guide vanes, forming a blade row extending radially inward in a flow path of the turbomachine, and two borescope accesses. The guide vanes form two segments each with a plurality of guide vanes circumferentially spaced apart, with the two segments having the same, constant cascade pitch and the two segments spaced such that the respective outermost guide vane adjacent to the respective other segment has an enlarged spacing in the circumferential direction from the adjacent guide vane of the other segment equal to 1.3 to 1.7 times the cascade pitch, the sum of the increased spacings being equal to 3 times the cascade pitch. The increased distance between the respective two adjacent outermost guide vanes of the two segments creates an enlarged vane passage between these guide vanes where the borescope accesses are formed.

Abstract: A guide vane wheel of a turbomachine, has a plurality of guide vanes, forming a blade row extending radially inward in a flow path of the turbomachine, and two borescope accesses. The guide vanes form two segments each with a plurality of guide vanes circumferentially spaced apart, with the two segments having the same, constant cascade pitch and the two segments spaced such that the respective outermost guide vane adjacent to the respective other segment has an enlarged spacing in the circumferential direction from the adjacent guide vane of the other segment equal to 1.3 to 1.7 times the cascade pitch, the sum of the increased spacings being equal to 3 times the cascade pitch. The increased distance between the respective two adjacent outermost guide vanes of the two segments creates an enlarged vane passage between these guide vanes where the borescope accesses are formed.

Abstract: A casing (2) includes at least one casing structure (casing treatment) for stabilizing a flow in an area of blade tips of rotor blades (4) in a fluid-flow machine, with the casing structure (casing treatment) being provided in at least one stage on an inner circumference of the casing (2). To provide a casing which improves compressor stability, is simply designed, features low weight and operates reliably without heating-up fluid in the fluid-flow machine, the casing structure is designed as a duct (20) which includes a first end (21) and a second end (22), with the first end (21) issuing into the interior of the casing (2) in the area of the blade tips of a rotor blade row and with the second end (22) being closed.

Abstract: A gas-turbine compressor has a casing (1) in which a rotor hub (2) is rotatably borne, and a compressor duct (9) being disposed between the casing (1) and the rotor hub (2), in which at least one rotor (4), which is rotatable about a machine axis (5), and one stator (5) are arranged. Recesses (12) of a bleed-air tapping device (6) are provided in the casing (1), which—in at least one circumferential area (11)—are arranged circumferentially to each other recess (12) and include a circumferential leading edge (16) in the circumferential direction and a circumferential trailing edge (17), each of which includes an identical angle ?E with the surface (18) of the casing (1).

Abstract: A gas-turbine compressor has a casing 1 in which a rotor hub 2 is rotatably borne, and a compressor duct 9 being disposed between the casing 1 and the rotor hub 2, in which at least one rotor 4, which is rotatable about a machine axis 5, and one stator 5 are arranged Recesses 12 of a bleed-air tapping device 6 are provided in the casing 1, which—in at least one circumferential area 11—are arranged circumferentially to each other. Recess 12 includes a circumferential leading edge 16 in the circumferential direction and a circumferential trailing edge 17, each of which includes an identical angle ?E with the surface 18 of the casing 1.

Abstract: A casing (2) includes at least one casing structure (casing treatment) for stabilizing a flow in an area of blade tips of rotor blades (4) in a fluid-flow machine, with the casing structure (casing treatment) being provided in at least one stage on an inner circumference of the casing (2). To provide a casing which improves compressor stability, is simply designed, features low weight and operates reliably without heating-up fluid in the fluid-flow machine, the casing structure is designed as a duct (20) which includes a first end (21) and a second end (22), with the first end (21) issuing into the interior of the casing (2) in the area of the blade tips of a rotor blade row and with the second end (22) being closed.