Abstract: An airfoil rotor hub system including a rotor hub, the rotor hub having a variable radius around a circumference of the rotor hub, and a plurality of airfoils connected to the rotor hub, a first airfoil in the plurality of airfoils having a first span connected to a surface of the rotor hub at a first radius, and a second airfoil in the plurality of airfoils having a second span connected to the surface of the rotor hub at a second radius. The first radius is different from the second radius, and the first span of the first airfoil is different from the second span of the second airfoil so as to mistune a frequency of the first airfoil and the second airfoil to reduce or substantially to eliminate flutter in the plurality of airfoils.

Abstract: An airfoil rotor hub system including a rotor hub, the rotor hub having a variable radius around a circumference of the rotor hub, and a plurality of airfoils connected to the rotor hub, a first airfoil in the plurality of airfoils having a first span connected to a surface of the rotor hub at a first radius, and a second airfoil in the plurality of airfoils having a second span connected to the surface of the rotor hub at a second radius. The first radius is different from the second radius, and the first span of the first airfoil is different from the second span of the second airfoil so as to mistune a frequency of the first airfoil and the second airfoil to reduce or substantially to eliminate flutter in the plurality of airfoils.

Abstract: A rotor blade system for a turbine engine having a longitudinal centerline axis. The rotor blade system includes a rotor configured to rotate about the longitudinal centerline axis and a plurality of rotor blades coupled circumferentially around the rotor, each rotor blade having a leading edge, a trailing edge, a suction side, and a pressure side. At least one rotor blade of the plurality of rotor blades has an axial sweep of both the leading edge and the trailing edge as compared to a base blade of the plurality of rotor blades.

Abstract: A rotor blade system for a turbine engine having a longitudinal centerline axis. The rotor blade system includes a rotor configured to rotate about the longitudinal centerline axis and a plurality of rotor blades coupled circumferentially around the rotor, each rotor blade having a leading edge, a trailing edge, a suction side, and a pressure side. At least one rotor blade of the plurality of rotor blades has an axial sweep of both the leading edge and the trailing edge as compared to a base blade of the plurality of rotor blades.

Abstract: An airfoil for a gas turbine engine includes a leading edge, a trailing edge, a tip, a first side wall that extends in radial span between an airfoil root and the tip, wherein the first side wall defines a first side of said airfoil, and a second side wall connected to the first side wall at the leading edge and the trailing edge, wherein the second side wall extends in radial span between the airfoil root and the tip, such that the second side wall defines a second side of the airfoil. The airfoil also includes a rib extending outwardly from at least one of the first side wall and the second side wall, wherein the rib is configured to reduce airflow spillage past the tip.

Abstract: An airfoil for a gas turbine engine includes a leading edge, a trailing edge, a tip, a first side wall that extends in radial span between an airfoil root and the tip, wherein the first side wall defines a first side of said airfoil, and a second side wall connected to the first side wall at the leading edge and the trailing edge, wherein the second side wall extends in radial span between the airfoil root and the tip, such that the second side wall defines a second side of the airfoil. The airfoil also includes a rib that extends outwardly from at least one of the first side wall and the second side wall, such that a natural frequency of chordwise vibration of the airfoil is increased to a frequency that is not present within the gas turbine engine during engine operations.

Abstract: An airfoil for a gas turbine engine includes a leading edge, a trailing edge, a tip, a first side wall that extends in radial span between an airfoil root and the tip, wherein the first side wall defines a first side of said airfoil, and a second side wall connected to the first side wall at the leading edge and the trailing edge, wherein the second side wall extends in radial span between the airfoil root and the tip, such that the second side wall defines a second side of the airfoil. The airfoil also includes a rib extending outwardly from at least one of the first side wall and the second side wall, wherein the rib is configured to reduce airflow spillage past the tip.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.