Abstract: A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is within a range of 0.10 to 0.40 and is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is within a range of 1-30 lbf/in2 and is defined as the bearing spanwise force divided by the fan area. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.

Abstract: An unducted single fan engine includes a housing having one or more fan blades coupled to the housing and configured to rotate circumferentially. The engine has one or more outlet guide vanes coupled to the housing. Each of the one or more guide vanes has a leading edge portion having a variable leading edge. The engine has one or more actuation devices coupled to each of the one or more outlet guide vanes. The one or more actuation devices are configured to control the variable leading edge of the respective outlet guide vane. The variable leading edge is controllable to vary the pitch, camber, lean angle, or sweep of the respective outlet guide vane.

Abstract: An unducted single fan engine includes a housing having one or more fan blades coupled to the housing and configured to rotate circumferentially. The engine has one or more outlet guide vanes coupled to the housing. Each of the one or more guide vanes has a leading edge portion having a variable leading edge. The engine has one or more actuation devices coupled to each of the one or more outlet guide vanes. The one or more actuation devices are configured to control the variable leading edge of the respective outlet guide vane. The variable leading edge is controllable to vary the pitch, camber, lean angle, or sweep of the respective outlet guide vane.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to adjust a pitch axis of a blade of an engine. An example blade apparatus includes: a hub to facilitate movement of blades in an engine, the engine having a radial center line; and a trunnion connected to the hub. The example trunnion includes a slot to accommodate a first blade, and at least one of the trunnion or the first blade is positioned with at least one of a tilt or a lean with respect to the radial center line to form a pitch axis offset from the radial center line such that the pitch axis is not parallel to or co-linear with the radial center line. The example hub is to rotate the first blade about the pitch axis.

Abstract: A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is within a range of 0.10 to 0.40 and is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is within a range of 1-30 lbf/in2 and is defined as the bearing spanwise force divided by the fan area. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

Abstract: A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

Abstract: A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example apparatus includes: a socket to receive an end of a blade; and a retaining device to interact with the socket and the blade for retention of the end of the blade in the socket. The example retaining device includes: a spacer to be positioned in the socket with the end of the blade; a wedge positioned inside the spacer; and a spring to tighten to pull the wedge to expand the spacer.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example apparatus includes: a socket to receive an end of a blade; and a retaining device to interact with the socket and the blade for retention of the end of the blade in the socket. The example retaining device includes: a spacer to be positioned in the socket with the end of the blade; a wedge positioned inside the spacer; and a spring to tighten to pull the wedge to expand the spacer.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to adjust a pitch axis of a blade of an engine. An example blade apparatus includes: a hub to facilitate movement of blades in an engine, the engine having a radial center line; and a trunnion connected to the hub. The example trunnion includes a slot to accommodate a first blade, and at least one of the trunnion or the first blade is positioned with at least one of a tilt or a lean with respect to the radial center line to form a pitch axis offset from the radial center line such that the pitch axis is not parallel to or co-linear with the radial center line. The example hub is to rotate the first blade about the pitch axis.

Abstract: A gas turbine engine fan blade includes a main body having a radially spaced apart root and tip, and axially spaced apart leading and trailing edges. A front shell is fixedly joined to a portion of the body leading edge to collectively define with the body an airfoil having first and second opposite sides extending between the root, tip, shell, and trailing edge for pressurizing air flowing thereover. The shell is hollow to offset toward the trailing edge a collective center of gravity of the airfoil to reduce steady stress at the airfoil leading edge.

Abstract: A fan blade includes a spar having first and second opposite sides. The spar sides include a fatigue-life enhanced surface layer, with the spar first side having a cavity bounded in part by the surface layer. A skin closes the cavity and is bonded to the spar for maintaining the enhanced surface layer inside the cavity.

Abstract: A blade retaining sub-assembly for use in a gas turbine engine which includes at least one radially extending blade mounted in a dovetail slot of a rotatable annular disk. The sub-assembly prevents the blade from migrating from the dovetail slot in an axially forward direction and includes a pair of circumferentially spaced lugs extending from a pair of adjacent disk posts such that each of the lugs are disposed axially forward of, and circumferentially adjacent to, respective ones of the lateral surfaces of the blade dovetail. The sub-assembly further includes a retainer plate disposed in each of the lugs and the plate restrained. The plate includes a body section and a contoured platform which is disposed in confronting relationship with the blade dovetail, wherein the contoured platform includes a periphery which is predeterminedly shaped and positioned so as to enhance a load carrying capability of the plate and lugs.