Abstract: A rotor blade comprises an elongated body that has a pressure side and a suction side. The pressure side and suction side intersect at a leading edge and a trailing edge. The elongated body extends outward from a rotor hub. A span is described by a first straight line distance extending outward from the rotor hub along the elongated body. A chord of the elongated body is defined by a second straight-line distance extending between the leading edge and the trailing edge. At least one passageway extends through the elongated body between the pressure side and the suction side allowing a corrective flow of air to move from the pressure side to the suction side. The corrective flow of air interacts with and energizes low momentum airflow occurring along the suction side.

Abstract: The present disclosure is generally related to aircraft having one or more unducted fan propulsors at locations within specific regions relative to an airfoil, such as a wing or horizontal stabilizer. More specifically, the specific regions are located where there is a relatively higher pressure air flow beneath the wings or above a horizontal stabilizer. That higher pressure air flow can be utilized to provide increased thrust from the unducted fan propulsor.

Abstract: The present disclosure is generally related to aircraft having one or more unducted fan propulsors at locations within specific regions relative to an airfoil, such as a wing or horizontal stabilizer. More specifically, the specific regions are located where there is a relatively higher pressure air flow beneath the wings or above a horizontal stabilizer. That higher pressure air flow can be utilized to provide increased thrust from the unducted fan propulsor.

Abstract: The present disclosure is generally related to aircraft having one or more unducted fan propulsors at locations within specific regions relative to an airfoil, such as a wing or horizontal stabilizer. More specifically, the specific regions are located where there is a relatively higher pressure air flow beneath the wings or above a horizontal stabilizer. That higher pressure air flow can be utilized to provide increased thrust from the unducted fan propulsor.

Abstract: A shroud assembly for a turbine engine having a centerline axis. The shroud assembly having a shroud hanger, at least one shroud segment, and at least one biasing element extending between the two. The biasing element configured to radially bias the at least one shroud segment between an outboard position and an inboard position radially outward from the outboard position with respect to the centerline axis.

Abstract: An unducted thrust producing system, includes a rotating element, a stationary element. An inlet may be located forward or aft of the rotating element and the stationary element. An exhaust may be located forward, aft, or between the rotating element and the stationary element.

Abstract: An aircraft defines a vertical direction and includes a fuselage and a propulsion system comprising a power source and a plurality of vertical thrust electric fans driven by the power source. A wing extends from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing along a lengthwise direction of the wing. The wing comprises a diffusion assembly along the lengthwise direction of the wing and includes a first diffusion member positioned downstream of at least one of the plurality of vertical thrust electric fans. The first diffusion member defines a curved shape relative to a longitudinal direction of the aircraft. The longitudinal direction is generally perpendicular to the lengthwise direction of the wing.

Abstract: An aircraft defines a vertical direction and includes a fuselage and a propulsion system comprising a power source and a plurality of vertical thrust electric fans driven by the power source. A wing extends from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing along a lengthwise direction of the wing. The wing comprises a diffusion assembly along the lengthwise direction of the wing and includes a first diffusion member positioned downstream of at least one of the plurality of vertical thrust electric fans. The first diffusion member defines a curved shape relative to a longitudinal direction of the aircraft. The longitudinal direction is generally perpendicular to the lengthwise direction of the wing.

Abstract: An unducted thrust producing system, includes a rotating element, a stationary element. An inlet may be located forward or aft of the rotating element and the stationary element. An exhaust may be located forward, aft, or between the rotating element and the stationary element.

Abstract: An aircraft equipped with a distributed fan propulsion system and methods of operating such aircraft are provided. In one aspect, an aircraft includes a wing having a top surface and a bottom surface. The aircraft also has a distributed propulsion system that includes a suction fan array having one or more fans mounted to the wing and a pressure fan array having one or more fans mounted to the wing. The fans of the suction fan array are each positioned primarily above the top surface of the wing and the fans of the pressure fan array are each positioned primarily below the bottom surface of the wing. The fans of the suction fan array are controllable independent of the fans of the pressure fan array so that the air pressure above and/or below the wing can be locally controlled, allowing for adjustment of lift on the wing.

Abstract: There is provided apparatuses and methods for a gas turbine engine. The embodiments include a core section with a flow path. The flow path includes a stator vane array having outlet vanes. Each outlet vane has a trailing edge. A strut has a leading edge that is upstream of the trailing edges. Alternatively, the flow path includes a stator vane array having inlet vanes. Each inlet vane has a leading edge. The strut has a trailing edge that is downstream of the leading edges. There also is increased spacing between adjacent vanes and rotor blades.

Abstract: A method is provided of operating a single unducted rotor engine, the single unducted rotor engine comprising a single stage of unducted rotor blades. The method includes operating the single unducted rotor engine to define a flight speed, V0, in a length unit per second and an angular speed, n, in revolutions per second, the single stage of unducted rotor blades defining a diameter, D, in the length unit; wherein operating the single unducted rotor engine comprises operating the single unducted rotor engine to define an advance ratio greater than 3.8 while operating the single unducted rotor engine at a net efficiency of at least 0.8, the advance ratio defined by the equation V0/(n×D).

Abstract: An aircraft equipped with a distributed fan propulsion system and methods of operating such aircraft are provided. In one aspect, an aircraft includes a wing having a top surface and a bottom surface. The aircraft also has a distributed propulsion system that includes a suction fan array having one or more fans mounted to the wing and a pressure fan array having one or more fans mounted to the wing. The fans of the suction fan array are each positioned primarily above the top surface of the wing and the fans of the pressure fan array are each positioned primarily below the bottom surface of the wing. The fans of the suction fan array are controllable independent of the fans of the pressure fan array so that the air pressure above and/or below the wing can be locally controlled, allowing for adjustment of lift on the wing.

Abstract: A flow conditioning structure is disposed about a central axis of an unducted thrust producing apparatus. The unducted thrust producing apparatus has a propeller that generates thrust in a working fluid by rotating about the central axis. The propeller is comprised of blades each with a free end. Each blade also has a leading edge where the working fluid enters during forward thrust operation. The flow conditioning structure comprises a structure forming a passage and the structure forming the passage controls a speed and a direction of the working fluid drawn into the unducted thrust producing apparatus so as to approximate operational speeds and operational directions of the working fluid entering the unducted thrust producing apparatus during operations of a vehicle.

Abstract: A gas turbine engine is provided including a turbine section including a turbine having a plurality of first speed turbine rotor blades; a compressor section including a compressor having a plurality of first speed compressor rotor blades and a plurality of second speed compressor rotor blades; a gearbox; and a first spool rotatable by the plurality of first speed turbine rotor blades, the first spool coupled to the plurality of first speed compressor rotor blades for driving the plurality of first speed compressor rotor blades in a first direction and to the plurality of second speed compressor rotor blades across the gearbox for driving the plurality of second speed compressor rotor blades in a second direction, opposite the first direction.

Abstract: There is provided apparatuses and methods for a gas turbine engine. The embodiments include a core section with a flow path. The flow path includes a stator vane array having outlet vanes. Each outlet vane has a trailing edge. A strut has a leading edge that is upstream of the trailing edges. Alternatively, the flow path includes a stator vane array having inlet vanes. Each inlet vane has a leading edge. The strut has a trailing edge that is downstream of the leading edges. There also is increased spacing between adjacent vanes and rotor blades.

Abstract: A single unducted rotor engine includes a power source; a casing surrounding the power source; an unducted rotor assembly driven by the power source having a single row of rotor blades; and an outlet guide vane assembly having a plurality of pairs of outlet guide vanes, each pair of the plurality of pairs of outlet guide vanes including a first outlet guide vane extending from the casing at a location downstream from the single row of rotor blades of the unducted rotor assembly and a second outlet guide vane also positioned downstream from the single row of rotor blades of the unducted rotor assembly. The first outlet guide vane of each pair of outlet guide vanes defines a first geometry. The second outlet guide vane of each pair of outlet guide vanes defines a second geometry. The first geometry is not equal to the second geometry.

Abstract: A turbo machine, a computer-implemented method, and a computer system for operating a compressor assembly are provided. The method includes comparing a first data set and a second data set to determine a first correlation factor, comparing the first correlation factor to a first threshold that at least partially determines whether a stall precursor exists, removing mean values from the first data set and the second data set, comparing the first data set and the second data set each removed of mean values to determine a second correlation factor, and comparing the second correlation factor to the first threshold, and classifying the stall precursor as either a spike stall precursor, a modal stall precursor, or a combination stall precursor.

Abstract: A lift fan apparatus includes: a rotor having at least one rotatable hub carrying at least one row of blades; a duct surrounding the rotor, the duct including spaced-apart peripheral walls extending between an inlet and an exit, the peripheral walls collectively defining a flow channel which includes a diffuser disposed downstream of the rotor, in which a flow area at the exit is greater than a flow area at the rotor; and a plurality of spaced-apart splitters disposed in the diffuser, each of the splitters having opposed side walls extending between an upstream leading edge and a downstream trailing edge, wherein the splitters divide the diffuser into a plurality of side-by-side flow passages.

Abstract: An unducted thrust producing system has a rotating element with an axis of rotation and a stationary element. The rotating element includes a plurality of blades, each having a blade root proximal to the axis, a blade tip remote from the axis, and a blade span measured between the blade root and the blade tip. The rotating element has a load distribution such that at any location between the blade root and 30% span the value of ?RCu in the air stream is greater than or equal to 60% of the peak ?RCu in the air stream.