Abstract: An impeller rotatable about a rotation axis, has a hub, blades extending from the hub to tips circumferentially distributed around the rotation axis, the blades having pressure sides and suction sides, the blades including splitter blades interspersed between full blades, a chord length of the splitter blades less than a chord length of the full blades, first flow channels defined between pressure sides of the splitter blades and suction sides of the full blades, second flow channels defined between suction sides of the splitter blades and pressure sides of the full blades, respective widths of the first and second flow channels at a given rotor location defined between adjacent splitter and full blades at the given rotor location, a width of the first flow channels increasing from the hub to the tips of the splitter blades along at least a portion of the chord length of the splitter blades.

Abstract: An airfoil for a gas turbine engine comprises at least three successive sections defined between a root and a tip. A first decrease of maximum thickness-to-chord ratios defined by a difference between a maximum thickness-to-chord ratio at the root and a maximum thickness-to-chord ratio at a first spanwise position, a second decrease of the maximum thickness-to-chord ratios defined by a difference between the maximum thickness-to-chord ratio at the first spanwise position and a maximum thickness-to-chord ratio at a second spanwise position, a third decrease of the maximum thickness-to-chord ratios defined by a difference between the maximum thickness-to-chord ratio at the second spanwise position and a maximum thickness-to-chord ratio at the tip, the second decrease being greater than the corresponding first and third decreases.

Abstract: An impeller comprises a hub and blades extending therefrom. The blades include splitter blades interspersed between full blades. First flow channels are defined between pressure sides of the splitter blades and suction sides of the full blades. Second flow channels are defined between suction sides of the splitter blades and pressure sides of the full blades. A width of the first flow channels at leading edges of the splitter blades and at the hub is less than a width of the second flow channels at the leading edges of the splitter blades and at the hub. The width of the first flow channels at the leading edges of the splitter blades and at the tips is more than the width of the second flow channels at the leading edges of the splitter blades and at the tips.

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 the vanes of the fan stator and an outlet upstream of the vanes. A recirculation rotor has a plurality of airfoils circumferentially distributed around the axis and located in the flow recirculation circuit. The recirculation rotor is rotatable about the axis within the recirculation circuit. A method of operating the fan assembly is also disclosed.

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: 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 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 fan assembly for a gas turbine engine includes a fan rotor having a hub and fan blades protruding from the hub. A fan stator is located downstream of the fan rotor and has vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet located downstream of the vanes of the fan stator and adjacent the radially inner ends thereof. The flow recirculation circuit has an outlet located upstream of the inlet. The outlet is located at the hub of the fan rotor and upstream of trailing edges of the fan blades.

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 compressor of a gas turbine engine is described which includes a rotor and a stator located immediately downstream of the rotor. The stator comprises a plurality of stator vanes each having an airfoil extending along a generally radial span between a root and a tip of the airfoil. The radially inner portion has aerodynamic forward sweep at the leading edge, the forward sweep having a maximum forward sweep that is more forward than a sweep at the leading edge in the intermediate portion.

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.

Abstract: A diffuser for a centrifugal compressor includes a diffuser pipe having an internal flow passage extending therethrough between an inlet and an outlet, a bend in the internal flow passage disposed between the inlet and the outlet, and a throat defined in the internal flow passage downstream of the inlet and upstream of the bend. One or more vortex generators project into the internal flow passage, and the vortex generators are disposed downstream of the throat and upstream of the bend. A method for diffusing fluid flow in a diffuser of a compressor is also described. In operation, the vortex generators engage fluid flow in the internal flow passage to generate downstream vortices.

Abstract: A rotor casing having an inner casing wall surrounding an annular gas path, a plurality of rotor blades radially extending into such annular gas path. The inner casing wall has an annular recess positioned radially outwardly of the gas path outer line and axially downstream of the rotor blades. A plurality of circumferentially spaced-apart vanes are positioned within the annular recess. The vanes may be profiled and circumferentially spaced from one another to accelerate air flowing between circumferentially adjacent vanes. The vanes may include an airflow partition extending between the top edges of at least 2 circumferentially adjacent vanes, from each such vanes' leading edge to each such vanes' trailing edge.

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 rotary airfoil in a gas turbine engine is provided. The airfoil includes opposed pressure and suction sides 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. An axial component of a center of gravity of a cross-section taken chordally toward the tip of the airfoil being upstream relative to an axial component of a center of gravity of a cross-section taken chordally toward the root of the airfoil. A method for forming such blade is also presented.

Abstract: Assemblies and methods for providing injection air to influence flow in a flow passage defined by a fan of a gas turbine engine are disclosed. In one embodiment, the method comprises: receiving air into an interior of a nose cone; increasing the pressure of the air in the interior of the nose cone and directing the pressurized air; and discharging the air into the flow passage defined by the fan.

Abstract: An impeller comprises a hub and blades extending therefrom. The blades include splitter blades interspersed between full blades. First flow channels are defined between pressure sides of the splitter blades and suction sides of the full blades. Second flow channels are defined between suction sides of the splitter blades and pressure sides of the full blades. A width of the first flow channels at leading edges of the splitter blades and at the hub is less than a width of the second flow channels at the leading edges of the splitter blades and at the hub. The width of the first flow channels at the leading edges of the splitter blades and at the tips is more than the width of the second flow channels at the leading edges of the splitter blades and at the tips.

Abstract: A rotor casing having an inner casing wall surrounding an annular gas path, a plurality of rotor blades radially extending into such annular gas path. The inner casing wall has an annular recess positioned radially outwardly of the gas path outer line and axially downstream of the rotor blades. A plurality of circumferentially spaced-apart vanes are positioned within the annular recess. The vanes may be profiled and circumferentially spaced from one another to accelerate air flowing between circumferentially adjacent vanes. The vanes may include an airflow partition extending between the top edges of at least 2 circumferentially adjacent vanes, from each such vanes' leading edge to each such vanes' trailing edge.

Abstract: A diffuser for a centrifugal compressor includes a diffuser pipe having an internal flow passage extending therethrough between an inlet and an outlet, a bend in the internal flow passage disposed between the inlet and the outlet, and a throat defined in the internal flow passage downstream of the inlet and upstream of the bend. One or more vortex generators project into the internal flow passage, and the vortex generators are disposed downstream of the throat and upstream of the bend. A method for diffusing fluid flow in a diffuser of a compressor is also described. In operation, the vortex generators engage fluid flow in the internal flow passage to generate downstream vortices.

Abstract: A gas turbine engine that comprises an engine core having a compressor, a turbine, a combustor, and a rotation axis. The engine further comprising a fan case wall having a radially-inner surface, a by-pass duct between the fan case wall and around the engine core, a plurality of struts circumferentially distributed and extending across the by-pass duct, a surface cooler adjacent to the radially-inner surface of the fan case and configured to be exposed to a by-pass air flow through the by-pass duct during operation of the gas turbine engine, the surface cooler fluidly communicating with a fluid circuit of the engine requiring cooling for of a fluid, and a recirculation conduit extending between an inlet in the radially-inner surface of the fan case disposed downstream of the surface cooler and an outlet in the radially-inner surface of the fan case wall disposed upstream of the surface cooler.