An electric propulsion system for an aircraft includes a nacelle and an electric machine. The electric machine includes a stator positioned in the nacelle, and a rotor and fan assembly positioned in a primary flow path through the nacelle. The rotor and fan assembly includes a cylindrical fan shroud, a plurality of rotor magnets positioned on an outer surface of the fan shroud, and a fan hub mounted on a central support shaft via one or more bearings. A plurality of fan blades extend between an inner surface of the fan shroud and an outer surface of the fan hub. The rotor magnets may be loaded in compression in a radial direction when the rotor and fan assembly is at rest. The fan blades may be pre-stressed in a radial direction when the rotor and fan assembly is at rest.

A method of assembling a gas turbine engine is disclosed herein. The method comprises providing a set of standard turbine stages. Each turbine stage included in the set of standard turbine stages includes a single turbine rotor having a plurality of blades configured to rotate about an axis and a subset of standard turbine vane rings associated with the single turbine rotor.

A surge control system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The surge control system also includes sensors configured to collect sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to detect surge event from the sensor data, determine an amount of power to apply to the rotor system, and increase the amount of power provided to the rotor system to recover from the surge event.

A gas turbine engine includes a compressor section arranged in serial flow order with a turbine section, and an electric motor assembly. The electric motor assembly has a rotor assembly that is coupled to, or integrated within, a stage of compressor rotor blades of the compressor section and a stator assembly. The stator assembly is operable with the rotor assembly to rotate the rotor assembly relative to the stator assembly and drive the stage of compressor rotor blades about the axial direction.

A surge control system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The surge control system also includes sensors configured to collect sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to detect surge event from the sensor data, determine an amount of power to apply to the rotor system, and increase the amount of power provided to the rotor system to recover from the surge event.

A fluid processing machine that includes a stator capable of generating an electromagnetic field and a first rotor section having at least one impeller and at least one permanent magnet. The stator is configured to electromagnetically engage with the first rotor section so as to rotate the first rotor section about a central axis in a first rotational direction. Further rotor sections can also be included that are induced to rotate in the first rotational direction. Other rotator sections with impellers and permanent magnets can also be included that are driven in a second, contra-rotating, direction by a second stator. Several of the fluid processing machine can be distributed within a surface system or subsea system that transports produced fluid from wells to a surface facility.

A fan system includes a rotor having plurality of blades and a ring airfoil, the plurality of blades being rotatably joined to a hub and the ring airfoil. The fan system may include a second contra-rotationally disposed rotor having a plurality of blades and a ring airfoil. The first and second ring airfoils having a cambered shape and an angle of attack between about 5 degrees and about 45 degrees, more preferably between about 5 degrees and about 30 degrees. Optionally, an outlet guide vane may be mounted rearward of the one or more rotors having a ring airfoil.

A method of assembling a gas turbine engine is disclosed herein. The method comprises providing a set of standard turbine stages. Each turbine stage included in the set of standard turbine stages includes a single turbine rotor having a plurality of blades configured to rotate about an axis and a subset of standard turbine vane rings associated with the single turbine rotor.

A gas turbine engine includes a fan, compressor, combustor, and turbine coupled to the compressor through a shaft. The compressor includes first, second, and third stages with respective rotor blades and stator vanes. The rotor blades and stator vanes are arranged such that a sum of mid-span axial gaps between the trailing edge of the first rotor blades and the leading edge of the first stator vanes, the trailing edge of the first stator vanes and the leading edge of the second rotor blades, the trailing edge of the second rotor blades and the leading edge of the second stator vanes, and the trailing edge of the second stator vanes and the leading edge of the third rotor blades is equal to $a\sqrt{\frac{\mathrm{inlet}\mathrm{flow}\mathrm{function}}{10}}.a75\mathrm{mm}\mathrm{and}\mathrm{the}\mathrm{inlet}\mathrm{flow}\mathrm{function}=\frac{m\sqrt{T}}{P}.$

The present invention discloses a compressor or pump stage at least comprising a central shaft (8) and one rotor (3), where the axis of rotation of the rotor (3) is the central shaft (8) and where the rotor comprises a number, n, of rows of impellers (5) arranged at an outer perimeter of the rotor with an axial distance between neighbouring rows of impellers (5), where n={2, 3, 4 . . . }.