Abstract: A mistuned airfoil assembly for a gas turbine engine is disclosed. The mistuned airfoil assembly may comprise a hub and airfoils extending radially from the hub. The airfoils may consist of first airfoils and at least one second airfoil. The first airfoils may be formed from a first titanium alloy and the at least one second airfoil may be formed from a second titanium alloy. The first titanium alloy and the second titanium alloy may have different natural frequencies.

Abstract: A mistuned airfoil assembly for a gas turbine engine is disclosed. The mistuned airfoil assembly may comprise a hub and airfoils extending radially from the hub. The airfoils may consist of first airfoils and at least one second airfoil. The first airfoils may be formed from a first titanium alloy and the at least one second airfoil may be formed from a second titanium alloy. The first titanium alloy and the second titanium alloy may have different natural frequencies.

Abstract: A system and methods are provided for pre-stressing blade elements for a gas turbine engine. In one embodiment, a method includes rotating a blade element relative to an axis. The method may also include controlling rotational speed of the blade element to generate residual stress in the blade element. The method may also include rotating multiple blade elements and fan blade units to generate residual stress. Blade elements may be rotated to exceed a maximum operating speed of the blade element to 120% of the maximum operating speed of the blade element.

Abstract: A lightweight fan blade for use in turbofan gas turbine engines is disclosed. The fan blade includes a metallic body having a pressure side and a suction side. The suction side of the body includes one or more cavities. A cover is then attached to the suction side of the body to cover or enclose the one or more cavities. The cover includes one or more transverse weakened areas, such as a transverse slit so that the cover separates into one or more smaller segments in the event of a foreign object damage (FOD) or fan blade out (FBO) event occurs. The smaller segments of the cover are less likely to do damage to downstream components such as the low and high-pressure compressors. A single smaller segment of the cover may allow for continued operation of the engine because the imbalance created by the event may be tolerated by the engine.

Abstract: A mistuned airfoil assembly for a gas turbine engine is disclosed. The mistuned airfoil assembly may comprise a hub and airfoils extending radially from the hub. The airfoils may consist of first airfoils and at least one second airfoil. The first airfoils may be formed from a first titanium alloy and the at least one second airfoil may be formed from a second titanium alloy. The first titanium alloy and the second titanium alloy may have different natural frequencies.

Abstract: A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side and a cover. The suction side of the body includes an opening and at least one cavity for purposes of reducing the weight of the fan blade. The cover overlays the opening and includes a peripheral edge that is received in a slot defined by the body. The cavities are filled with a sacrificial material.

Abstract: A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side. The body also includes a leading edge, a trailing edge, a distal tip and a base that is coupled to a hub. The suction side of the body includes at least one cavity for purposes of reducing the weight of the fan blade. The at least one body is surrounded by a slot that extends outwardly away from the cavity. A lip that extends inwardly towards the body further defines the slot. A cover is provided that overlays the cavity and includes a peripheral edge that is received in the slot and that is at least partially covered by the lip for a robust connection between the fan blade body and the cavity cover.

Abstract: A lightweight fan blade for use in turbofan gas turbine engines is disclosed. The fan blade includes a metallic airfoil connected to a root. The airfoil has a pressure side and a suction side. The suction side of the airfoil includes one or more cavities for weight reduction purposes. A cover is attached to the suction side of the body to cover or enclose the one or more cavities. In addition to the one or more cavities, through holes are formed from the inner face of the root into one or more of the cavities for further weight reduction. The through holes may be covered by a spacer and one or more through holes may be extended from the inner face of the root into each of the cavities.

Abstract: The leading edge, the trailing edge, or both may be axially offset for a portion of the airfoils in a disk. By offsetting the airfoils, the downstream wake energy to the next stage of airfoils may be decreased. By staggering airfoils which are offset with airfoils that are not offset, the wake shapes from the airfoils may be out of phase and will not excite the downstream airfoils as much as conventional systems. This may decrease vibration and associated vibratory stresses in the system.

Abstract: A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side and a cover. The suction side of the body includes an opening and at least one cavity for purposes of reducing the weight of the fan blade. The cover overlays the opening and includes a peripheral edge that is received in a slot defined by the body. The cavities are filled with a filler material that may form a permanent part of the fan blade.

Abstract: A lightweight fan blade for use in turbofan gas turbine engines is disclosed. The fan blade includes a metallic body having a pressure side and a suction side. The suction side of the body includes one or more cavities. A cover is then attached to the suction side of the body to cover or enclose the one or more cavities. The cover includes one or more transverse weakened areas, such as a transverse slit so that the cover separates into one or more smaller segments in the event of a foreign object damage (FOD) or fan blade out (FBO) event occurs. The smaller segments of the cover are less likely to do damage to downstream components such as the low and high-pressure compressors. A single smaller segment of the cover may allow for continued operation of the engine because the imbalance created by the event may be tolerated by the engine.

Abstract: A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side and a cover. The suction side of the body includes an opening and at least one cavity for purposes of reducing the weight of the fan blade. The cover overlays the opening and includes a peripheral edge that is received in a slot defined by the body. The cavities are filled with a sacrificial material.

Abstract: A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side. The body also includes a leading edge, a trailing edge, a distal tip and a base that is coupled to a hub. The suction side of the body includes at least one cavity for purposes of reducing the weight of the fan blade. The at least one body is surrounded by a slot that extends outwardly away from the cavity. A lip that extends inwardly towards the body further defines the slot. A cover is provided that overlays the cavity and includes a peripheral edge that is received in the slot and that is at least partially covered by the lip for a robust connection between the fan blade body and the cavity cover.

Abstract: A lightweight fan blade for use in turbofan gas turbine engines is disclosed. The fan blade includes a metallic airfoil connected to a root. The airfoil has a pressure side and a suction side. The suction side of the airfoil includes one or more cavities for weight reduction purposes. A cover is attached to the suction side of the body to cover or enclose the one or more cavities. In addition to the one or more cavities, through holes are formed from the inner face of the root into one or more of the cavities for further weight reduction. The through holes may be covered by a spacer and one or more through holes may be extended from the inner face of the root into each of the cavities.

Abstract: A system and methods are provided for pre-stressing blade elements for a gas turbine engine. In one embodiment, a method includes rotating a blade element relative to an axis. The method may also include controlling rotational speed of the blade element to generate residual stress in the blade element. The method may also include rotating multiple blade elements and fan blade units to generate residual stress. Blade elements may be rotated to exceed a maximum operating speed of the blade element to 120% of the maximum operating speed of the blade element.

Abstract: A mistuned airfoil assembly for a gas turbine engine is disclosed. The mistuned airfoil assembly may comprise a hub and airfoils extending radially from the hub. The airfoils may consist of first airfoils and at least one second airfoil. The first airfoils may be formed from a first titanium alloy and the at least one second airfoil may be formed from a second titanium alloy. The first titanium alloy and the second titanium alloy may have different natural frequencies.