Abstract: An airfoil section of a propeller for a propulsion device includes a pressure surface and a suction surface, the pressure surface and suction surface intersecting at a leading edge and a trailing edge. The airfoil section has a meanline defined midway between the pressure surface and the suction surface and a meanline angle is defined as an angle between a tangent to the meanline and a centerline of the propeller. The blade has a meanline curvature defined as the slope of a meanline angle with respect to chord fraction along the meanline, and at least a portion of the meanline has a meanline curvature that increases from between approximately 0.1 chord fraction progressing toward the leading edge and at least a portion of the meanline has a meanline curvature that decreases from between approximately 0.1 chord fraction progressing toward the leading edge.

Abstract: An airfoil section of a propeller for a propulsion device includes a pressure surface and a suction surface, the pressure surface and suction surface intersecting at a leading edge and a trailing edge. The airfoil section has a meanline defined midway between the pressure surface and the suction surface and a meanline angle is defined as an angle between a tangent to the meanline and a centerline of the propeller. The blade has a meanline curvature defined as the slope of a meanline angle with respect to chord fraction along the meanline, and at least a portion of the meanline has a meanline curvature that increases from between approximately 0.1 chord fraction progressing toward the leading edge and at least a portion of the meanline has a meanline curvature that decreases from between approximately 0.1 chord fraction progressing toward the leading edge.

Abstract: A front fan gas turbine engine subassembly which acts as a particle separator. The subassembly includes an aft-most row of full-size fan blades, a flow splitter, and a row of stator vanes. The flow splitter separates the fan exit air into a core engine airflow and a surrounding bypass airflow. The stator vanes each have a first portion disposed radially inward of, and longitudinally forward of, the leading edge of the flow splitter. The subassembly, in essence, has moved the leading edge of a conventional flow splitter aft without also moving the forward-most row of stator vanes aft. This means that particles which would strike a conventionally-positioned flow splitter and be reflected radially into the core engine airflow will instead miss the aft-moved leading edge of the flow splitter to radially outwardly bypass the core engine airflow.

Abstract: The invention concerns reduction of tip vortices in aircraft propellers, wherein a fence having anhedral or dihedral is attached to the blades of the propeller. Another form of the invention is applicable to counterrotating propeller systems, wherein a fence is attached to the blades of the forward propeller of the system, and no fences are attached to the aft propeller.

Abstract: A variable angle vane stator arrangement of relatively simple design is pided enabling widely variable angular stator vane positioning with little aerodynamic loss. This is accomplished by positioning the leading nose portion of each variable second row vane axially ahead of, and adjacent, the trailing edge of an associated fixed vane of a first row of vanes to produce a slot between the adjacent vanes through which air can flow. The axis of rotation of each variable vane is located off of the variable vane itself in a manner to maintain good slot geometry over a wide range of vane stagger angles. The variation of the rear vane stagger angle creates a variation in the direction of the exit air vector, which in turn enhances the performance of the following rotor blade row.

Abstract: A gas turbofan engine including a variable pitch fan is provided with flow straightening means which are adapted to reduce fan exit swirl in the forward thrust mode. The flow straightening means are so arranged to produce low losses in the fluid entering a core engine during reverse thrust operation while allowing large supercharging of the core engine during forward thrust operation.