A compressor section for a gas turbine engine according to an example of the present disclosure includes, among other things, a low pressure compressor including a plurality of rotor blades arranged about an axis, a high pressure compressor, and a core flowpath passing through the low pressure compressor. The core flowpath at the low pressure compressor defines an inner diameter and an outer diameter relative to the axis. The outer diameter has a slope angle relative to the axis.

A propulsion system includes a drive shaft movable in rotation about an axis of rotation, a low-pressure compressor driven in rotation by the drive shaft, the low-pressure compressor having a mean radius, a fan shaft, a fan driven in rotation by the fan shaft, a reduction mechanism coupling the drive shaft and the fan shaft, having a reduction ratio, and an inlet channel which extends between the fan and the low-pressure compressor, the inlet channel having an inlet adjacent to the fan and an outlet opposite the inlet and adjacent to the low-pressure compressor, the inlet having a mean radius. A first ratio between a ratio of a mean radius of the inlet channel and the mean radius of the low-pressure compressor, and the reduction ratio of the reduction mechanism, is strictly less than 0.35.

A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor that delivers flow to a core flowpath and a compressor section including first and second compressors. The core flowpath passes through the first compressor. The core flowpath in the first compressor has an outer diameter relative to the engine longitudinal axis. The outer diameter has a slope angle relative to the axis.

A pumping system includes a motor and a drive shaft configured for rotation by the motor. The pumping system includes an upper pump positioned above the motor, an upper pump shaft and an upper directional coupling connected between the drive shaft and the upper pump shaft. The upper directional coupling is configured to lock the upper pump shaft to the drive shaft when the drive shaft is rotated in a first direction. The pumping system further includes a lower pump positioned below the motor, a lower pump shaft, and a lower directional coupling connected between the drive shaft and the lower pump shaft. The lower directional coupling is configured to lock the lower pump shaft to the drive shaft when the drive shaft is rotated in a second direction.

A rotor blade includes an airfoil having an airfoil shape. The airfoil shape has a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in one of Table I, Table II, Table III, Table IV, Table V, Table VI, Table VII, Table VIII, or Table IX. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances expressed in a unit of distance by multiplying the Cartesian coordinate values of X, Y and Z by a scaling factor of the airfoil in the unit of distance. The X and Y values, when connected by smooth continuing arcs, define airfoil profile sections at each Z value. The airfoil profile sections at Z values are joined smoothly with one another to form a complete airfoil shape.

A rotor blade includes an airfoil having an airfoil shape. The airfoil shape has a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in one of Table I, Table II, Table III, Table IV, Table V, Table VI, Table VII, Table VIII, Table IX, Table X, Table XI, or Table XII. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances expressed in a unit of distance by multiplying the Cartesian coordinate values of X, Y and Z by a scaling factor of the airfoil in the unit of distance. The X and Y values, when connected by smooth continuing arcs, define airfoil profile sections at each Z value. The airfoil profile sections at Z values are joined smoothly with one another to form a complete airfoil shape.

The invention concerns a transition duct for a multi-stage compressor of a gas turbine engine. Regions of the inner surface of the duct are provided with a predetermined and dissimilar surface roughness to optimise gas flow efficiency within the duct.

The invention relates to a vacuum system, comprising a vacuum pump, preferably turbomolecular pump, and at least one vacuum chamber, wherein the vacuum pump comprises: at least a first and a second inlet and a common outlet; at least a first and a second pumping stage, each pumping stage comprising at least one rotor element being arranged on a common rotor shaft, wherein the first inlet is connected to an upstream end of the first pumping stage and the second inlet is connected to an upstream end of the second pumping stage; a direction element for preventing a gas flow from a downstream end of the first pumping stage to the second inlet; a conduit having a conduit inlet and a conduit outlet, wherein the conduit inlet is connected to the downstream end of the first pumping stage and the conduit outlet is connected to a location downstream of the second pumping stage; wherein the first inlet and the second inlet of the pump are connected to the same vacuum chamber.

A fan assembly and associated methods are disclosed. In one example, the fan assembly includes an electric motor and motor controller with a heat exchanger coupled between the motor controller and an airflow pathway of the fan assembly. In selected examples, a method of operating a fan assembly includes cooling a motor controller that is located external to an airflow pathway by conducting heat from the motor controller into the airflow pathway using a heat exchanger.

A compressor section for a gas turbine engine according to an example of the present disclosure includes, among other things, a low pressure compressor including a plurality of rotor blades arranged about an axis, a high pressure compressor, and a core flowpath passing through the low pressure compressor. The core flowpath at the low pressure compressor defines an inner diameter and an outer diameter relative to the axis. The outer diameter has a slope angle relative to the axis.