Abstract: Turbine assemblies for gas turbine engines are provided. In one embodiment, a turbine assembly includes a row of circumferentially adjacent turbine rotor blades, each blade in the row of blades including an airfoil defining a chord extending axially between opposite leading and trailing edges of the airfoil. The chords in a mid-span region of each blade are shorter than the chords in span regions adjacent to the blade root and the blade tip. In another exemplary embodiment, a turbine assembly includes a row of circumferentially adjacent turbine stator vanes, each vane in the row of vanes including an airfoil defining a chord extending axially between opposite leading and trailing edges of the airfoil. The chords in a mid-span region of each vane are shorter than the chords in span regions adjacent to the vane root and the vane tip. A turbine rotor blade for a gas turbine engine also is provided.

Abstract: A turbine blade includes an airfoil and integral platform at the root thereof. The platform is contoured in elevation from a ridge to a trough, and is curved axially to complement the next adjacent curved platform.

Abstract: An instability mitigation system is disclosed, comprising a rotor having a row of blades arranged around a centerline axis, and a mitigation system comprising at least one plasma actuator mounted on a blade that facilitates the improvement of the stability of the rotor, and a control system for controlling the operation of the mitigation system. An instability mitigation system further comprising a detection system for detecting an onset of an instability in a rotor and a control system for controlling the detection system and the mitigation system are disclosed.

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: An instability mitigation system is disclosed, comprising a detection system for detecting an onset of an instability in a rotor during the operation of the rotor, a mitigation system that facilitates the improvement of the stability of the rotor when the onset of instability is detected by the detection system, a control system for controlling the detection system and the mitigation system.

Abstract: An instability mitigation system is disclosed, comprising a stator stage located axially proximate to a rotor, the stator stage having a row of a plurality of stator vanes arranged around a centerline axis, and a mitigation system comprising at least one plasma actuator mounted on the stator vane that facilitates the improvement of the stability of the rotor, and a control system for controlling the operation of the mitigation system. An instability mitigation system further comprising a detection system for detecting an onset of an instability in a rotor and a control system for controlling the detection system and the mitigation system are disclosed.

Abstract: A micro-electromechanical system (MEMS) dielectric barrier discharge (DBD) based aerodynamic actuator is configured to modify a shockwave boundary layer interaction and limit incident boundary layer growth caused by a reflected shockwave.

Abstract: A turbine blade includes an airfoil having a root, a tip, a concave pressure side, and a laterally opposite convex suction side, the pressure and suction sides extending in chord between opposite leading and trailing edges; an outer platform disposed at the tip of the airfoil, the outer platform having spaced-apart lateral edges which each define an interlocking element; an inner platform with two spaced-apart curved lateral edges disposed at the root of the airfoil, the inner platform having a hot side facing the airfoil which is contoured in a non-axisymmetric shape; and a dovetail extending radially inward from the opposite side of the inner platform, wherein the dovetail is axially straight.

Abstract: A plasma enhanced rapidly expanded duct system includes a gas turbine engine inter-turbine transition duct having radially spaced apart conical inner and outer duct walls extending axially between a duct inlet and a duct outlet. A conical plasma generator produces a conical plasma along the outer duct wall. An exemplary embodiment of the conical plasma generator is mounted to the outer duct wall and including radially inner and outer electrodes separated by a dielectric material. The dielectric material is disposed within a conical groove in a radially inwardly facing surface of the outer duct wall. An AC power supply is connected to the electrodes to supply a high voltage AC potential to the electrodes.

Abstract: An instability mitigation system is disclosed, comprising a rotor having a row of blades arranged around a centerline axis, and a mitigation system comprising at least one plasma actuator mounted on a blade that facilitates the improvement of the stability of the rotor, and a control system for controlling the operation of the mitigation system. An instability mitigation system further comprising a detection system for detecting an onset of an instability in a rotor and a control system for controlling the detection system and the mitigation system are disclosed.

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 system for detecting onset of a stall in a rotor is disclosed, the system comprising a sensor located on a static component spaced radially outwardly and apart from tips of a row of blades arranged circumferentially on the rotor wherein the sensor is capable of generating an input signal corresponding to a flow parameter at a location near the tip of a blade, a control system capable of generating a rotor speed signal, and a correlation processor capable of receiving the input signal and the rotor speed signal wherein the correlation processor 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 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 gas turbine engine plasma blade tip clearance control system includes an annular shroud surrounding rotatable blade tips and an annular plasma generator spaced radially outwardly and apart from the blade tips. An exemplary embodiment of the annular plasma generator is mounted to the annular shroud and includes radially inner and outer electrodes separated by a dielectric material disposed within an annular groove in a radially inwardly facing surface of the annular shroud. The plasma generator is operable for producing an annular plasma between the annular shroud and blade tips and an effective clearance produced by the annular plasma between the annular shroud and blade tips that is smaller than a clearance between the annular shroud and blade tips.

Abstract: A plasma enhanced rapidly expanded duct system includes a gas turbine engine inter-turbine transition duct having radially spaced apart conical inner and outer duct walls extending axially between a duct inlet and a duct outlet. A conical plasma generator produces a conical plasma along the outer duct wall. An exemplary embodiment of the conical plasma generator is mounted to the outer duct wall and including radially inner and outer electrodes separated by a dielectric material. The dielectric material is disposed within a conical groove in a radially inwardly facing surface of the outer duct wall. An AC power supply is connected to the electrodes to supply a high voltage AC potential to the electrodes.

Abstract: A plasma boundary layer lifting system includes at least one gas turbine engine vane having a spanwise extending airfoil with an outer surface extending in a chordwise direction between opposite leading and trailing edges and chordwise spaced apart plasma generators for producing a plasma extending in the chordwise direction along the outer surface. Each plasma generator may include inner and outer electrodes separated by a dielectric material disposed within a spanwise extending groove in the outer surface. The airfoil may be hollow having an outer wall and the plasma generators being mounted on the outer wall. A method for operating the system includes forming a plasma extending in the chordwise direction along the outer surface of the airfoil. The method may further include operating the plasma generators in steady state or unsteady modes.

Abstract: A FLADE fan assembly includes radially inner and outer airfoils extending radially inwardly and outwardly respectively from an annular shroud circumferentially disposed about a centerline. Inner and outer chords extend between inner and outer leading and trailing edges of inner and outer airfoil cross-sections of the radially inner and outer airfoils respectively. Inner and outer stagger angles between the inner and outer chords respectively at the shroud and the centerline are different. The radially outer airfoils may outnumber the radially inner airfoils and particularly by a ratio in a range of 1.5:1 to about 4:1. Load paths or radii may extend radially through the inner and outer airfoils and through the rotating shroud between the inner and outer airfoils and may pass near or through the inner and outer leading edges and through the inner and outer trailing edges.

Abstract: A FLADE fan assembly includes radially inner and outer airfoils extending radially inwardly and outwardly respectively from an annular shroud circumferentially disposed about a centerline. Inner and outer chords extend between inner and outer leading and trailing edges of inner and outer airfoil cross-sections of the radially inner and outer airfoils respectively. Inner and outer stagger angles between the inner and outer chords respectively at the shroud and the centerline are different. The radially outer airfoils may outnumber the radially inner airfoils and particularly by a ratio in a range of 1.5:1 to about 4:1. Load paths or radii may extend radially through the inner and outer airfoils and through the rotating shroud between the inner and outer airfoils and may pass near or through the inner and outer leading edges and through the inner and outer trailing edges.

Abstract: A compression system is disclosed, comprising a first compressor having a first flowpath, a second compressor having a second flowpath located axially aft from the first compressor, and a transition duct capable of flowing an airfow from the first compressor to the second compressor, the transition duct having at least one plasma actuator mounted in the transition duct.