Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for passive fan blade tip clearance control. A fan blade for a gas turbine engine, the fan blade comprising a fan blade body including a tip region at a blade tip of the fan blade body and a blade tip insert disposed within the tip region of the fan blade body, the blade tip insert is formed from a material that passively adjusts a shape of the blade tip insert to maintain a blade tip clearance between the blade tip and an engine casing or nacelle by at least one of expanding or contracting based on temperature.

Abstract: An engine for an aircraft. The engine includes a rotating airfoil assembly, at least one actuator, a torque producing system, and a controller. The rotating airfoil assembly includes a rotation axis and a plurality of rotating airfoils configured to rotate about the rotation axis in a plane of rotation. The at least one actuator is operable to change the plane of rotation of the plurality of rotating airfoils. The torque producing system is coupled to the rotating airfoil assembly and configured to rotate the rotating airfoil assembly about the rotation axis of the rotating airfoil assembly. The controller is configured to determine that the aircraft has an angle of attack and to operate the at least one actuator to change the plane of rotation of the plurality of rotating airfoils based on the angle of attack.

Abstract: An airfoil structure including an airfoil and a spring and damper system. The airfoil including a longitudinal axis. The spring and damper system is connected to the airfoil to rotate the airfoil about the longitudinal axis to change airfoil pitch in response to a load applied to the airfoil.

Abstract: Clearance control systems with electromagnetic actuators are disclosed. An example electromagnetically-actuated clearance control system for a gas turbine engine comprises an electromagnetic coil coupled to a first end of a facesheet, the electromagnetic coil to generate a magnetic field in response to a connection of a power supply, a ferromagnetic sheet coupled to a second end of the facesheet, the ferromagnetic sheet drawn radially-inward toward the electromagnetic coil when the magnetic field is generated, a first end of the ferromagnetic sheet coupled to a first compression spring and a second end of the ferromagnetic sheet coupled to a second compression spring, the first and second compression springs to compress in response to the ferromagnetic sheet being drawn radially-inward.

Abstract: Clearance control systems with electromagnetic actuators are disclosed. An example electromagnetically-actuated clearance control system for a gas turbine engine comprises an electromagnetic coil coupled to a first end of a facesheet, the electromagnetic coil to generate a magnetic field in response to a connection of a power supply, a ferromagnetic sheet coupled to a second end of the facesheet, the ferromagnetic sheet drawn radially-inward toward the electromagnetic coil when the magnetic field is generated, a first end of the ferromagnetic sheet coupled to a first compression spring and a second end of the ferromagnetic sheet coupled to a second compression spring, the first and second compression springs to compress in response to the ferromagnetic sheet being drawn radially-inward.

Abstract: An airfoil for a turbomachinery rotor includes: a body having a first density, the body defining a pressure side and a suction side, the pressure side and suction side intersecting at a leading edge and a trailing edge; and a mass positioned within the body and having a second density, wherein the second density is greater than the first density, wherein the mass is offset from a center of gravity of the body in at least one axis.

Abstract: An airfoil for a turbomachinery rotor includes: a body having a first density, the body defining a pressure side and a suction side, the pressure side and suction side intersecting at a leading edge and a trailing edge; and a mass positioned within the body and having a second density, wherein the second density is greater than the first density, wherein the mass is offset from a center of gravity of the body in at least one axis.