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 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 stator vane that may be used in engine assemblies. The stator vane includes an airfoil having a first sidewall and a second sidewall that is coupled to the first sidewall at a leading edge and at a trailing edge. The airfoil extends radially from a root portion to a tip portion. Each of the leading and trailing edges includes at least one lean directional change and a plurality of sweep directional changes that are defined between the root portion and the tip portion.

Abstract: A stator vane that may be used in an engine assembly is provided. The stator vane includes an airfoil that has a first sidewall and a second sidewall, which connects to the first sidewall at a leading edge and at a trailing edge. The airfoil also includes a root portion and a tip portion. The first and second sidewalls both extend from the root portion to the tip portion. The airfoil root portion is formed with a negative lean, and the airfoil tip portion is formed with a positive lean.

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 turbine assembly for a gas turbine engine. The turbine assembly includes at least one stator assembly including a radially inner band and at least one stator vane that extends radially outward from the inner band. The stator vane includes an airfoil having a root portion adjacent to the inner band and a tip portion. The airfoil also includes at least one lean directional change that is defined between the root portion and the tip portion. The turbine assembly also includes at least one turbine blade assembly that includes at least one rotor blade. The blade assembly is coupled in flow communication with the stator assembly such that an axial spacing is defined therebetween. The axial spacing defined adjacent to the at least one lean directional change is wider than the axial spacing defined adjacent to the root portion.

Abstract: A trailing edge vortex reducing system includes a gas turbine engine airfoil extending in a spanwise direction, one or more spanwise extending plasma generators in a trailing edge region around a trailing edge of the airfoil. The plasma generators may be mounted on an outer wall of the airfoil with first and second pluralities of the plasma generators on pressure and suction sides of the airfoil respectively. The plasma generators may include inner and outer electrodes separated by a dielectric material disposed within a grooves in an outer hot surface of the outer wall of the airfoil. The plasma generators may be located at an aft end of the airfoil and the inner electrodes flush with the trailing edge base. A method for operating the system includes energizing one or more of plasma generators in steady state or unsteady modes.

Abstract: An downstream plasma boundary layer shielding system includes film cooling apertures disposed through a wall having cold and hot surfaces and angled in a downstream direction from a cold surface of the wall to an outer hot surface of the wall. A plasma generator located downstream of the film cooling apertures is used for producing a plasma extending downstream over the film cooling apertures. Each plasma generator includes inner and outer electrodes separated by a dielectric material disposed within a groove in the outer hot surface. The wall may be part of a hollow airfoil or an annular combustor or exhaust liner. A method for operating the downstream plasma boundary layer shielding system includes forming a plasma extending in the downstream direction over the film cooling apertures along the outer hot surface of the wall. The method may further include operating the plasma generator in steady state or unsteady modes.

Abstract: A leading edge vortex reducing system includes a gas turbine engine airfoil extending in a spanwise direction away from an end wall, one or more plasma generators extending in the spanwise direction through a fillet between the airfoil and the end wall in a leading edge region near and around a leading edge of the airfoil and near the fillet. The plasma generators being operable for producing a plasma extending over a portion of the fillet in the leading edge region. The plasma generators may be mounted on an outer wall of the airfoil with a first portion of the plasma generators on a pressure side of the airfoil and a second portion of the plasma generators on a suction side of the airfoil. A method for operating the system includes energizing one or more plasma generators to form the plasma in steady state or unsteady modes.

Abstract: A turbofan engine includes a fan, compressor, combustor, high pressure turbine, and low pressure turbine joined in serial flow communication. The high pressure turbine includes two stages of rotor blades to effect corresponding exit swirl in the combustion gases discharged therefrom. A transition duct includes fairings extending between platforms for channeling the combustion gases to the low pressure turbine with corresponding swirl. First stage rotor blades in the low pressure turbine are oriented oppositely to the rotor blades in the high pressure turbine for counterrotation.

Abstract: An upstream plasma boundary layer shielding system includes film cooling apertures disposed through a wall having cold and hot surfaces and angled in a downstream direction from a cold surface of the wall to an outer hot surface of the wall. A plasma generator located upstream of the film cooling apertures is used for producing a plasma extending downstream over the film cooling apertures. Each plasma generator includes inner and outer electrodes separated by a dielectric material disposed within a groove in the outer hot surface. The wall may be part of a hollow airfoil or an annular combustor or exhaust liner. A method for operating the upstream plasma boundary layer shielding system includes forming a plasma extending in the downstream direction over the film cooling apertures along the outer hot surface of the wall. The method may further include operating the plasma generator in steady state or unsteady modes.

Abstract: A turbofan engine includes a fan, compressor, combustor, single-stage high pressure turbine, and low pressure turbine joined in serial flow communication. First stage rotor blades in the low pressure turbine are oriented oppositely to the rotor blades in the high pressure turbine for counterrotation. First stage stator vanes in the low pressure turbine have camber and twist for carrying swirl directly between the rotor blades of the high and low pressure turbines.

Abstract: A turbine nozzle includes a row of vanes joined to radially outwardly inclined outer and inner bands. Each vane has camber and an acute twist angle for importing swirl in combustion gases discharged at trailing edges thereof. The trailing edges are tilted forwardly from the inner band to the outer band for increasing aerodynamic efficiency.

Abstract: A stator vane that may be used in engine assemblies. The stator vane includes an airfoil having a first sidewall and a second sidewall that is coupled to the first sidewall at a leading edge and at a trailing edge. The airfoil extends radially from a root portion to a tip portion. Each of the leading and trailing edges includes at least one lean directional change and a plurality of sweep directional changes that are defined between the root portion and the tip portion.

Abstract: A stator vane that may be used in an engine assembly is provided. The stator vane includes an airfoil that has a first sidewall and a second sidewall, which connects to the first sidewall at a leading edge and at a trailing edge. The airfoil also includes a root portion and a tip portion. The first and second sidewalls both extend from the root portion to the tip portion. The airfoil root portion is formed with a negative lean, and the airfoil tip portion is formed with a positive lean.

Abstract: A turbine assembly for a gas turbine engine. The turbine assembly includes at least one stator assembly including a radially inner band and at least one stator vane that extends radially outward from the inner band. The stator vane includes an airfoil having a root portion adjacent to the inner band and a tip portion. The airfoil also includes at least one lean directional change that is defined between the root portion and the tip portion. The turbine assembly also includes at least one turbine blade assembly that includes at least one rotor blade. The blade assembly is coupled in flow communication with the stator assembly such that an axial spacing is defined therebetween. The axial spacing defined adjacent to the at least one lean directional change is wider than the axial spacing defined adjacent to the root portion.

Abstract: A leading edge vortex reducing system includes a gas turbine engine airfoil extending in a spanwise direction away from an end wall, one or more plasma generators extending in the spanwise direction through a fillet between the airfoil and the end wall in a leading edge region near and around a leading edge of the airfoil and near the fillet. The plasma generators being operable for producing a plasma extending over a portion of the fillet in the leading edge region. The plasma generators may be mounted on an outer wall of the airfoil with a first portion of the plasma generators on a pressure side of the airfoil and a second portion of the plasma generators on a suction side of the airfoil. A method for operating the system includes energizing one or more plasma generators to form the plasma in steady state or unsteady modes.

Abstract: A trailing edge vortex reducing system includes a gas turbine engine airfoil extending in a spanwise direction, one or more spanwise extending plasma generators in a trailing edge region around a trailing edge of the airfoil. The plasma generators may be mounted on an outer wall of the airfoil with first and second pluralities of the plasma generators on pressure and suction sides of the airfoil respectively. The plasma generators may include inner and outer electrodes separated by a dielectric material disposed within a grooves in an outer hot surface of the outer wall of the airfoil. The plasma generators may be located at an aft end of the airfoil and the inner electrodes flush with the trailing edge base. A method for operating the system includes energizing one or more of plasma generators in steady state or unsteady modes.

Abstract: An upstream plasma boundary layer shielding system includes film cooling apertures disposed through a wall having cold and hot surfaces and angled in a downstream direction from a cold surface of the wall to an outer hot surface of the wall. A plasma generator located upstream of the film cooling apertures is used for producing a plasma extending downstream over the film cooling apertures. Each plasma generator includes inner and outer electrodes separated by a dielectric material disposed within a groove in the outer hot surface. The wall may be part of a hollow airfoil or an annular combustor or exhaust liner. A method for operating the upstream plasma boundary layer shielding system includes forming a plasma extending in the downstream direction over the film cooling apertures along the outer hot surface of the wall. The method may further include operating the plasma generator in steady state or unsteady modes.