An aero-propulsion system includes a drive shaft, a low-pressure compressor, a fan shaft driving a fan, a reduction device that couples the drive shaft and the fan shaft, and an inlet channel which extends between the fan and the low-pressure compressor, the inlet having a predetermined mean radius, a ratio between a mean radius of the inlet channel and the mean radius of the low-pressure compressor, on the one hand, and the reduction ratio of the reduction mechanism, on the other hand, being less than 0.35.

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.

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 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.

The invention relates to a compression system for a gas turbine, in particular for an aircraft gas turbine, wherein the compression system comprises a flow duct. The flow duct includes cross-sectional areas that are aligned perpendicular to the axial direction along the flow duct length and have the respective predetermined sizes, where the inlet cross-sectional area has a size that is 15.3 to 16.1 times a size of the outlet cross-sectional area, and/or a cross-sectional area arranged at a distance of 40% of the flow duct length from the inlet cross-sectional area has a size that is 5.0 to 5.2 times the size of the outlet cross-sectional area.

Methods and apparatus are provided for an axi-centrifugal compressor in a gas turbine engine for a business aviation or rotorcraft propulsion unit. The compressor includes an axial compressor section operable to affect a first pressure ratio along the flow path between a compressor inlet and a first section exit, and a centrifugal compressor section operable to affect a second pressure ratio along the flow path between a second section inlet and the compressor exit. The pressure rise across the axial and centrifugal compressor section is configured to have a tuning factor is in a range between 2.8 and 4.5 and a loading factor in a range between 0.6 and 0.8.

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 multi-stage axial compressor with an inner wall including a step portion for each of the compressor stages. Each step portion is defined along a respective stage. Each step portion may extend over at least a majority of an axial length of the stage. Each step portion may optionally include a point aligned with a maximum thickness of the airfoil portions of the rotor blades and a point aligned with a maximum thickness of the stator vanes. Adjacent step portions are connected by a transition portion converging toward a central axis of the compressor from the upstream step to the downstream step. Each transition portion has a steeper slope than that of the adjacent step portions. A method of directing flow through a multi-stage axial flow compressor is also discussed.

The air moving device includes a rotor and a stator. The quantity of the rotor blades is not less than 5 and not greater than 12. The average blade angle of rotor blades is not less than 45 degrees and is not greater than 64 degrees. The ratio of the hub diameter to the rotor diameter is not less than 0.4 and not greater than 0.79. The quantity of the stator blades is not less than 6 and not greater than 23. The average blade angle of stator blades is not less than 45 degrees and not greater than 70 degrees. The ratio of the total thickness of the air moving device to the rotor diameter is not less than 0.76 and not greater than 1.7. The ratio of the stator axial thickness to the rotor axial thickness is not less than 0.28 and not greater than 0.65.

A stator vane 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.