Abstract: A compressor has: a rotor and a stator having vanes, a vane of the vanes having an airfoil extending from a root proximate an inner hub to a radially outer tip, the airfoil having a leading edge, a trailing edge, and a chord extending between the leading edge and the trailing edge to define a chord length, the airfoil having a pressure side surface and a suction side surface, and a fillet disposed at the leading edge of the root of the airfoil and extending between the pressure side surface and the inner hub, the fillet having a radial height being maximum at the leading edge, the radial height decreasing from the leading edge to blend smoothly into a remainder of the airfoil, the fillet extending downstream from the leading edge a chord-wise distance of less than 50% of a chord length of the airfoil on the pressure side surface.

Abstract: A gas turbine engine for an aircraft having a centrifugal compressor including an impeller with impeller blades extending from a hub, the impeller mounted for rotation about a central longitudinal axis within an outer shroud. A main flow passage wall is located on a shroud side near the impeller exit, the main flow passage wall separating a cavity disposed on the shroud side from the main flow passage. One or more apertures are defined through the main flow passage wall and extending along a respective aperture axis between the cavity and the main flow passage. The apertures have a main flow passage side opening located radially outward from the impeller exit. The aperture axis is disposed at a radial angle relative to the central longitudinal axis.

Abstract: A compressor diffuser for a gas turbine engine is described which includes diffuser pipes having a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. A first curved side wall of the tubular body along the second portion is shorter than a second curved side wall of the tubular body along the second portion. The second portion of the tubular body has a cross-sectional profile defined in a plane normal to the pipe center axis. The first curved side wall of the cross-sectional profile has a smaller radius than a radius of the second curved side wall of the cross-sectional profile.

Abstract: A compressor of a gas turbine engine includes a rotor and a stator located downstream of the rotor. The stator has a plurality of vanes each with an airfoil extending span-wise between a root proximate an inner hub of the stator and a tip. A fillet is disposed at the leading edge of the root of the airfoil, and extends between a pressure side surface of the airfoil and the inner hub.

Abstract: A diffuser pipe has a tubular body with a first portion extending from an inlet of the diffuser pipe, a second portion extending along a generally axial direction relative to a center axis, and a bend portion fluidly connecting the first and second portions. An exit segment of the second portion defines a pipe outlet. The exit segment is curved radially outwardly relative to the center axis. A compressor diffuser, a gas turbine engine, and a method of supplying air from a compressor section to a combustor of the gas turbine engine are also disclosed.

Abstract: An impeller having a hub, blades extending from the hub along respective spans from roots to tips, the blades extending along respective chords from leading edges to trailing edges, the leading edge of at least one of the blades having a cutback section defining a sweep at the root, the cutback section extending in a spanwise direction from the hub to a location at least about 5% of the span from the hub of the at least one of the blades, and the cutback section extending in a chordwise direction along at least about 5% of the chord of the at least one of the blades

Abstract: A compressor diffuser for a gas turbine engine includes one or more diffuser pipes having a tubular body defining an internal flow passage extending therethrough. The tubular body includes a first portion extending in a first direction, a second portion extending in a second direction different from the first direction, and a curved portion fluidly linking the first portion and the second portion. A splitter vane is disposed within the internal flow passage of the curved portion of the tubular body, the splitter vane defining a convergent flow passage between itself and a radially inner wall of the curved portion, and a divergent flow passage between itself and a radially outer wall of the curved portion.

Abstract: A stator that has vanes extending between a first end and a second end along a span and from a leading edge to a trailing edge along a chord length, the vanes having a first end portion extending from the first end to about 30% of the span to a first location, a chord ratio of the chord length at the first end to the chord length at the first location greater than or equal to 1.1, a throat ratio of a width of a throat between two adjacent vanes at the first location to a width of the throat at the first end is greater than or equal to 1.3, a sweep angle difference between a maximum sweep angle of the leading edge along the first end portion and a minimum sweep angle of the leading edge along the first end portion is at least 15 degrees.

Abstract: There is disclosed a fan assembly including a fan rotor including a hub and fan blades. The fan blades have a leading edge and a trailing edge. A fan stator downstream of the fan rotor relative to a direction of an airflow through the fan assembly. The fan stator includes vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet downstream of radially inner ends of the vanes of the fan stator and an outlet upstream of radially inner ends of the vanes. A recirculation stator has a plurality of stationary guide vanes circumferentially distributed around the axis and located in the flow recirculation circuit between the inlet and the outlet A method of operating the fan assembly is also disclosed.

Abstract: A method of operating a compressor of a gas turbine engine is described which includes directing a main airflow through tandem stator rows in a gaspath of the compressor, extracting a first portion of the main airflow from a first location proximate radially inner roots of stators of the first or second stator rows, extracting a second portion of the main airflow from a second location proximate the radially inner roots of the stators of the first or second stator rows, the second location being downstream of the first location relative to the main airflow, and re-injecting the combined extracted flow back into the main airflow at a third location. The third location is located upstream of the first and second locations, and is upstream of a leading edge of stators of the first stator row.

Abstract: A compressor diffuser for a gas turbine engine includes diffuser pipes having a tubular body including a generally radial portion, a bend portion and a generally axial portion. The generally axial portion has an exit segment extending parallel to the center axis and terminating at a pipe outlet. The bend portion is disposed radially further from the center axis than the exit segment.

Abstract: A diffuser pipe is disclosed having a tubular body including a first portion extending in a generally radial direction, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The pipe outlet is scalloped.

Abstract: A compressor diffuser for a gas turbine engine comprises a plurality of diffuser pipes having a tubular body. The pipes have a first portion having a radial component and defining a throat at a location along the first portion, a second portion having an axial component, and a curved portion fluidly linking the first portion and the second portion. The first portion has an inner surface with a local surface contour located between the throat and the curved portion. The local surface contour extends along a portion of and around less than an entire perimeter of the first portion.

Abstract: A vane diffuser for diffusing gases is disclosed. The diffuser has an annular diffuser body including a plurality of diffuser vanes defining diffuser passages. The diffuser passages are circumferentially distributed. A direction of main gas flow through the diffuser passages is defined from a passage inlet in fluid communication with the outlet of the compressor to a passage outlet. A plurality of fluid injection conduits each extend between a conduit inlet and a conduit outlet for at least one of the diffuser vanes. The conduit outlet defines at least one opening in at least one of the pressure and suction side surfaces and is configured to inject fluid along one of the pressure and suction side surfaces in the direction of main gas flow through the corresponding diffuser passage.

Abstract: A method of operating a compressor of a gas turbine engine is described which includes directing a main airflow through tandem stator rows in a gaspath of the compressor, extracting a first portion of the main airflow from a first location proximate radially inner roots of stators of the first or second stator rows, extracting a second portion of the main airflow from a second location proximate the radially inner roots of the stators of the first or second stator rows, the second location being downstream of the first location relative to the main airflow, and re-injecting the combined extracted flow back into the main airflow at a third location. The third location is located upstream of the first and second locations, and is upstream of a leading edge of stators of the first stator row.

Abstract: A compressor diffuser for a gas turbine engine is described which includes diffuser pipes having a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. A first curved side wall of the tubular body along the second portion is shorter than a second curved side wall of the tubular body along the second portion. The second portion of the tubular body has a cross-sectional profile defined in a plane normal to the pipe center axis. The first curved side wall of the cross-sectional profile has a smaller radius than a radius of the second curved side wall of the cross-sectional profile.

Abstract: An inter-compressor case for a gas turbine engine is disclosed. The inter-compressor case comprises: an outer casing and an inner casing radially spaced apart relative to a longitudinal axis; a gas path extending from a plurality of radial inlets arranged in a circumferentially spaced apart array around the outer casing to an annular outlet defined by an axially extending downstream portion of the outer casing and an axially extending downstream portion of the inner casing; a plurality of struts having a gas path surface extending across the gas path between the outer casing and the inner casing; and a plurality of flow separators extending from the adjacent radial inlets. The flow separators have trailing edges disposed upstream of the annular outlet and include a plurality of full length flow separators and a plurality of truncated flow separators.

Abstract: A gas turbine engine for an aircraft having a centrifugal compressor including an impeller with impeller blades extending from a hub, the impeller mounted for rotation about a central longitudinal axis within an outer shroud. A main flow passage wall is located on a shroud side near the impeller exit, the main flow passage wall separating a cavity disposed on the shroud side from the main flow passage. One or more apertures are defined through the main flow passage wall and extending along a respective aperture axis between the cavity and the main flow passage. The apertures have a main flow passage side opening located radially outward from the impeller exit. The aperture axis is disposed at a radial angle relative to the central longitudinal axis.

Abstract: A compressor rotor airfoil in a gas turbine engine is presented. Opposed pressure and suction sides are joined together at chordally opposite leading and trailing edges. The pressure and suction sides extend in a span direction from a root to a tip. A leading edge dihedral angle is defined at a point on the leading edge between a tangent to the airfoil and a vertical. The leading edge dihedral angle has a span-wise distribution. The distribution has at least one inflection point. A method of reducing a rub angle between a compressor rotor blade and a casing surrounding the blade is also presented.

Abstract: A rotor for a gas turbine engine includes a plurality of radially extending blades, each having a remote blade tip defining an outer tip surface, and a leading edge defined between opposed pressure and suction side airfoil surfaces. A shroud circumferentially surrounds the rotor, and a radial distance between an inner surface of the shroud and the outer tip surface of the blades defines a radial tip clearance gap therebetween. The tip of each of the blades has a pressure side edge formed at the intersection between the outer tip surface and the pressure side airfoil surface, and a suction side edge formed at the intersection between the outer tip surface and the pressure side airfoil surface. The suction side edge has a larger radius of curvature than the pressure side edge, thereby reducing the amount of tip leakage flow through the radial tip clearance gap.