Abstract: A gas turbine engine shroud for surrounding one of a rotor and a stator having a plurality of radially extending airfoils is provided. The shroud includes an annular body defining an axial and a radial direction. The body has a radially inner surface and a plurality of indentations is annularly defined therein. Each of the plurality of indentations has a depth of an order of magnitude of a clearance between the one of the rotor and the stator and the inner surface. The plurality of indentations is defined in a region of the inner face defined axially between projections of leading and trailing edges of the airfoils onto the inner surface of the annular body.

Abstract: A compressor is described which includes a non-axial first rotor, and a second rotor disposed immediately downstream from the first rotor and being co-axial therewith about a longitudinal axis of rotation. The second rotor rotates in a direction opposite the non-axial first rotor to discharge fluid flow into an uninterrupted passage between an outlet of the second rotor and one of a downstream combustor or a further compression stage. The uninterrupted passage is free of a diffusing passage. A gas turbine engine including such a compressor and a method of compressing fluid flow is also described.

Abstract: A gas turbine engine shroud for surrounding one of a rotor and a stator having a plurality of radially extending airfoils is provided. The shroud includes an annular body defining an axial and a radial direction. The body has a radially inner surface and a plurality of indentations is annularly defined therein. Each of the plurality of indentations has a depth of an order of magnitude of a clearance between the one of the rotor and the stator and the inner surface. The plurality of indentations is defined in a region of the inner face defined axially between projections of leading and trailing edges of the airfoils onto the inner surface of the annular body.

Abstract: A compressor comprises a casing having an inner surface surrounding a rotor assembly, the rotor assembly having a plurality of circumferentially spaced radially outwardly extending rotor blades, each blade having leading and trailing edges and a tip, the compressor further comprising at least one plasma actuator for suppressing rotating stall inception of the compressor, the at least one plasma actuator being mounted adjacent to the blade tips.

Abstract: A compressor comprises a casing having an inner surface surrounding a rotor assembly, the rotor assembly having a plurality of circumferentially spaced radially outwardly extending rotor blades, each blade having leading and trailing edges and a tip, the compressor further comprising at least one plasma actuator for suppressing rotating stall inception of the compressor, the at least one plasma actuator being mounted adjacent to the blade tips.