Abstract: A drum is provided having a peripheral surface with texture features thereon. The texture features may be a plurality of grooves for applying riblets to an airfoil surface. Methods of using the drum are also provided.

Abstract: An airfoil having active actuators and at least one morphing area allowing shape change of the airfoil and further allowing for optimization of the airfoil shape at more than one operating condition.

Abstract: An airfoil section of a propeller for a propulsion device includes a pressure surface and a suction surface, the pressure surface and suction surface intersecting at a leading edge and a trailing edge. The airfoil section has a meanline defined midway between the pressure surface and the suction surface and a meanline angle is defined as an angle between a tangent to the meanline and a centerline of the propeller. The blade has a meanline curvature defined as the slope of a meanline angle with respect to chord fraction along the meanline, and at least a portion of the meanline has a meanline curvature that increases from between approximately 0.1 chord fraction progressing toward the leading edge and at least a portion of the meanline has a meanline curvature that decreases from between approximately 0.1 chord fraction progressing toward the leading edge.

Abstract: A drum is provided having a peripheral surface with texture features thereon. The texture features may be a plurality of grooves for applying riblets to an airfoil surface. Methods of using the drum are also provided.

Abstract: A method of operating a compressor having a row of blades for preventing a compressor stall is disclosed, the method comprising the steps of mounting a plasma generator in a casing or a shroud radially outwardly and apart from the blade tips wherein the plasma generator comprises a radially inner electrode and a radially outer electrode separated by a dielectric material; and supplying an AC potential to the radially inner electrode and the radially outer electrode.

Abstract: A rotor blade having an airfoil for a compressor is described. The airfoil has an airfoil root, an airfoil tip located at a spanwise distance from the airfoil root, a leading edge extending from the airfoil root to the airfoil tip, an inner span region (“S1”) between the airfoil root and a first height location on the airfoil leading edge, a midspan region (“S2”) between the first height location and a second height location on the airfoil leading edge located radially outward from the first height location; an outer span region (“S3”) between the second height location and the airfoil tip, wherein the airfoil has a normalized camber profile such that the normalized camber increases in the outer span region in a spanwise direction towards the tip and is more than 2.2 in the outer span region.

Abstract: A stator vane for a compressor is described. The stator vane has an airfoil root, an airfoil tip, a leading edge, a trailing edge, an inner span region, a midspan region and an outer span region, wherein the stator vane has a normalized camber profile that increases in the outer span region in a spanwise direction towards the tip and is more than 1.4 in the outer span region.

Abstract: An airfoil for a compressor is described. The airfoil has a root, an airfoil tip, a leading edge, a trailing edge, airfoil pressure and suction sides extending between the leading edge and the trailing edge. The airfoil has an inner span region and an outer span region and the trailing edge has a dihedral profile such that the trailing edge dihedral angle decreases in at least a portion of the inner span region and the outer span region.

Abstract: A variable stator vane airfoil is mounted on a button centered about a rotational axis and includes circular leading and trailing edges circumscribed about the rotational axis at a button radius. Contoured pressure and suction sides extend from the circular leading edge to the circular trailing edge and are recessed inwardly from a perimeter circumscribed about the rotational axis at the button radius. One of upstream and downstream pressure side portions of the contoured pressure side is straight and another of the upstream and downstream pressure side portions is convexly curved. One of the upstream and downstream suction side portions is straight and another of the upstream and downstream suction side portions is convexly curved. One of the upstream pressure side portion and upstream suction side portion is straight and another of the upstream pressure side portion and upstream suction side portion is convexly curved.

Abstract: A blade row for a rotary machine includes a radially inner endwall, a radially outer endwall having a radially inner surface, and an airfoil including a root section coupled to the inner endwall and a tip section coupled to the outer endwall such that the airfoil extends radially between the inner and outer endwalls. The radially outer endwall includes a projection extending radially inward from the outer endwall inner surface such that the outer endwall inner surface includes a non-axisymmetric shape.

Abstract: A system for detecting onset of a stall in a rotor is disclosed, the system comprising a plasma sensor spaced radially outwardly and apart from tips of a circumferential row of blades at a location on a static component that is between a first location and a second location wherein the first location is at a first distance of about 25% blade tip-chord length axially forward from the leading edge of a blade and the second location is at a second distance of about 25% blade tip-chord length axially aft from the trailing edge of a blade and wherein the plasma sensor is capable of generating an input signal corresponding to a flow parameter at a location near the tip of a blade and indicative of the onset of a stall and a correlation processor that generates a stability correlation signal.

Abstract: A plasma leakage flow control system for a compressor is disclosed, comprising a circumferential row of compressor blades, an annular casing surrounding the tips of the blades, located radially apart from the tips of the blades and at least one annular plasma generator located on the annular casing. The annular plasma generator comprises an inner electrode and an outer electrode separated by a dielectric material. A gas turbine engine having a plasma leakage flow control system further comprises an engine control system which controls the operation of the annular plasma generator such that the blade tip leakage flow can be changed.

Abstract: A method of operating a compressor having a row of blades for preventing a compressor stall is disclosed, the method comprising the steps of mounting a plasma generator in a casing or a shroud radially outwardly and apart from the blade tips wherein the plasma generator comprises a radially inner electrode and a radially outer electrode separated by a dielectric material; and supplying an AC potential to the radially inner electrode and the radially outer electrode.

Abstract: A method for using an aerodynamic stability management system is disclosed. The method includes placing at least one pressure sensor in a compressor, the at least one pressure sensor communicating with an aerodynamic stability management system controller and monitoring gas turbine engine performance using the aerodynamic stability management system controller. The controller includes a memory, an input/output interface and a processor. The method also includes defining a correlation threshold value and calculating a correlation measure using a plurality of pressure signals generated by the at least one pressure sensor and comparing the correlation measure with the correlation threshold value. When the correlation measure is less than the correlation threshold value a corrective action is implemented.

Abstract: A variable stator vane airfoil is mounted on a button centered about a rotational axis and includes circular leading and trailing edges circumscribed about the rotational axis at a button radius. Contoured pressure and suction sides extend from the circular leading edge to the circular trailing edge and are recessed inwardly from a perimeter circumscribed about the rotational axis at the button radius. One of upstream and downstream pressure side portions of the contoured pressure side is straight and another of the upstream and downstream pressure side portions is curved. One of the upstream and downstream suction side portions is straight and another of the upstream and downstream suction side portions is curved. One of the upstream pressure side portion and upstream suction side portion is straight and another of the upstream pressure side portion and upstream suction side portion is curved.

Abstract: A system for detecting onset of a stall in a rotor is disclosed, the system comprising a sensor spaced radially outwardly and apart from tips of a circumferential row of blades at a location on a static component that is between a first location and a second location wherein the first location is at a first distance of about 25% blade tip-chord length axially forward from the leading edge of a blade and the second location is at a second distance of about 25% blade tip-chord length axially aft from the trailing edge of a blade and wherein the sensor is capable of generating an input signal corresponding to a flow parameter at a location near the tip of a blade and indicative of the onset of a stall and a correlation processor that generates a stability correlation signal.

Abstract: A gas turbine engine is disclosed, comprising a compressor having a circumferential row of blades, a casing surrounding the tips of the blades, located radially apart from the tips of the blades and at least one plasma generator located on the casing. The plasma generator comprises a first electrode and a second electrode separated by a dielectric material. The gas turbine engine further comprises an engine control system which controls the operation of the plasma generator such that the stable operating range of the compressor is increased.

Abstract: An actuation system for a plurality of variable stator vanes pivotally mounted in a casing of a compressor. The system includes a plurality of levers each having a proximal end and an opposite distal end. Each of the proximal ends are fixedly coupled to a corresponding stator vane of the plurality of variable stator vanes for pivoting the corresponding stator vane about a stator vane axis. The system also includes an actuation ring coaxially surrounding the casing adjacent the plurality of levers. The actuation ring is coupled to the distal ends of each of the plurality of levers for pivoting the levers as the actuation ring is rotated about a compressor rotation axis. The actuation ring includes a pin extending outward from a radially outward surface of the actuation ring. The system also includes a template comprising a slot for receiving at least a portion of the actuation ring pin.

Abstract: A method, rotor assembly, and apparatus for ordering blades in a rotatable machine is provided. The rotor assembly includes a disk including a plurality of circumferentially-spaced blade root slots defined therein, and a plurality of blades, each blade including a root, a tip, and an airfoil therebetween, each blade positioned within a pre-determined slot based on a blade map, the blade map generated by a computer system configured to receive a geometric parameter measurement of each blade in a row of blades, determine a shape factor for the row of blades using the geometric parameter measurement of each blade, and determine a sequence map of each blade using the shape factor for the row of blades.

Abstract: A blade row for a rotary machine includes a radially inner endwall, a radially outer endwall having a radially inner surface, and an airfoil including a root section coupled to the inner endwall and a tip section coupled to the outer endwall such that the airfoil extends radially between the inner and outer endwalls. The radially outer endwall includes a projection extending radially inward from the outer endwall inner surface such that the outer endwall inner surface includes a non-axisymmetric shape.