A variable pitch bladed disc including a plurality of blades, each being of variable pitch about a blade axis of rotation and having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each shaft having a root and a tip, the root of each blade being mounted on the tip of a corresponding rotor connecting shaft via a pivot so as to allow each blade to be rotated about the blade axis of rotation, the first blade having a first rotation axis inclination such that the rotation axis thereof is inclined in a fixed manner with respect to a radial axis passing through the root of the corresponding shaft, and the second blade has a second rotation axis inclination different from the first rotation axis inclination.

A method and system control the thrust of an aircraft turbomachine having a high bypass ratio by direct action on a variable-pitch system. The variable-pitch system varies the pitch of the vanes of a stator of a low-pressure compressor for the open-loop control of the thrust of the turbomachine. The method also provides closed-loop control of the pitch of the blades of a propeller based on a rotational speed of the propeller.

Methods, apparatus, systems and articles of manufacture for compact compressors are disclosed including a gas turbine engine defining an axial direction and a radial direction, the gas turbine engine including an axial flow compressor and a radial flow compressor, wherein the axial flow compressor is located axially forward of the radial flow compressor, a blade assembly including a splitter shroud to divide incoming air into axial air flow for the axial flow compressor and radial air flow for the radial flow compressor, the blade assembly rotating relative to the axial flow compressor and counter-rotating relative to the radial flow compressor, and wherein the blade assembly is located axially aft of the radial flow compressor.

Methods, apparatus, systems and articles of manufacture for compact compressors are disclosed including a gas turbine engine defining an axial direction and a radial direction, the gas turbine engine including an axial flow compressor and a radial flow compressor, wherein the axial flow compressor is located axially forward of the radial flow compressor, a blade assembly including a splitter shroud to divide incoming air into axial air flow for the axial flow compressor and radial air flow for the radial flow compressor, the blade assembly rotating relative to the axial flow compressor and counter-rotating relative to the radial flow compressor, and wherein the blade assembly is located axially aft of the radial flow compressor.

A turbomachine includes a rotatable annular outer drum rotor connected to a first plurality of blades. The rotatable annular outer drum rotor is constructed of, at least, a first drum segment and a second drum segment. The turbomachine further includes a retaining ring arranged and secured between the first and second drum segments of the rotatable annular outer drum rotor for radially retaining each of the first plurality of blades via their respective blade root portions within the rotatable annular outer drum rotor.

Methods, apparatus, systems and articles of manufacture for compact compressors are disclosed including a gas turbine engine defining an axial direction and a radial direction, the gas turbine engine including an axial flow compressor and a radial flow compressor, wherein the axial flow compressor is located axially forward of the radial flow compressor, a blade assembly including a splitter shroud to divide incoming air into axial air flow for the axial flow compressor and radial air flow for the radial flow compressor, the blade assembly rotating relative to the axial flow compressor and counter-rotating relative to the radial flow compressor, and wherein the blade assembly is located axially aft of the radial flow compressor.

A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in.sup.2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in.sup.2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in.sup.2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in.sup.2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in.sup.2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in.sup.2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

A turbofan gas turbine engine includes, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, and a turbine module. The fan assembly includes fan blades defining a corresponding fan area (A.sub.FAN). The heat exchanger module is in fluid communication with the fan assembly by an inlet duct, and includes radially-extending vanes arranged in a circumferential array with at least one vane including a heat transfer element for heat transfer from a first fluid contained within each element to an airflow passing over a surface of each heat transfer element before entering the fan assembly inlet. Each heat transfer element extends axially along the corresponding vane, with a swept heat transfer element area (A.sub.HTE) being the wetted surface area of all heat transfer elements in contact with the airflow. A Fan to Element Area parameter F.sub.EA of A.sub.HTE/A.sub.FAN lies in the range of 47 to 132.