A novel diffuser for a centrifugal turbomachine to reduce or prevent stall. The diffuser includes diffuser vanes arranged around a diffuser axis. Each diffuser vane includes: a leading edge, a trailing edge, a suction side facing radially inwardly, and a pressure side facing radially outwardly. A respective flow passage is defined between the suction side of a first diffuser vane and the pressure side of a second diffuser vane of each pair of adjacently arranged diffuser vanes. The diffuser vanes are arranged with a non-constant pitch around the diffuser axis. The pitch between each pair of adjacently arranged first diffuser vane and second diffuser vane defining a respective flow passage there between is correlated to a chord of one of said first diffuser vane and second diffuser vane.

The leading edge, the trailing edge, or both may be axially offset for a portion of the airfoils in a disk. By offsetting the airfoils, the downstream wake energy to the next stage of airfoils may be decreased. By staggering airfoils which are offset with airfoils that are not offset, the wake shapes from the airfoils may be out of phase and will not excite the downstream airfoils as much as conventional systems. This may decrease vibration and associated vibratory stresses in the system.

A fan blade (1) has a front inflow edge (2) and a rear outflow edge (3). The fan blade (1) has an at least partially wavy inflow edge (4). The wavy inflow edge (4) forms a wave (W) with a specific three-dimensional waveform.

A rotor blade system includes a rotor, a casing radially spaced apart from the rotor, and a plurality of blades coupled to the rotor and positioned between the rotor and the casing. The one or more of the plurality of blades have a radial length different from a remaining one or more of the plurality of blades so as to vary a tip gap between a tip of the one or more of the plurality of blades and the casing to break up a frequency content of a leakage vortex at the tip to modify natural frequencies of the plurality of blades and mode shapes to reduce or substantially eliminate flutter.

The invention relates to a profiled structure elongated in a direction in which the structure has a length exposed to an airflow and transversely to which the structure has a leading edge and/or a trailing edge, at least one of which is profiled and has, along said direction of elongation, geometric serration patterns defined by a succession of peaks and troughs. Along the profiled leading edge and/or trailing edge, the serration patterns have a geometric pattern that is repeated in the direction of elongation, the shape of which is stretched and/or contracted transversely to the direction of elongation and/or in the direction of elongation.

A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.

A variable-pitch bladed disc including a plurality of blades, each at a variable pitch in relation to a rotation axis of the blade and each 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 having a root and a tip, each root being mounted at the tip of a corresponding rotor connecting shaft by way of a pivot so as to allow each blade to rotate about the blade rotation axis, the first blade having a first blade inclination, such that the first blade is inclined in a fixed manner with respect to the blade rotation axis of the first blade, and the second blade having a second blade inclination different from the first blade inclination.

A turbofan engine is provided. The turbofan engine includes a fan comprising a plurality of fan blades; a turbomachine operably coupled to the fan for driving the fan, the turbomachine comprising a compressor section, a combustion section, and a turbine section in serial flow order and together defining a core air flowpath; a nacelle surrounding and at least partially enclosing the fan; an inlet pre-swirl feature located upstream of the plurality of fan blades, the inlet pre-swirl feature attached to or integrated into the nacelle; and a means for reducing ice buildup or ice formation on the inlet pre-swirl feature, the means in communication with the inlet pre-swirl feature.

A return channel for a centrifugal turbo machine. The return channel includes a plurality of return channel vanes, arranged around a return channel axis. Each return channel vane includes: a leading edge at a first distance from the return channel axis, a trailing edge at a second distance from the return channel axis, the second distance being smaller than the first distance. A respective flow passage is defined between each pair of adjacently arranged return channel vanes. The return channel vanes are arranged with a non-constant pitch around the return channel axis.

A turbine includes a shaft configured to rotate about a rotor axis; a pair of rotating blade rows, the pair of rotating blade rows including a pair of disks that extend radially outward from the shaft and are disposed at an interval in a direction of the rotor axis, each one of the pair of rotating blade rows including a plurality of rotating blades arranged in a circumferential direction on an outer peripheral end of the disk; and a pair of stator vane rows disposed in a one-to-one manner on a first side of the pair of rotating blade rows in the direction of the rotor axis, each one of the pair of stator vane rows including a plurality of stator vanes arranged in the circumferential direction, wherein a number of the rotating blades on each one of the pair of rotating blade rows is the same, and a number of the stator vanes on each one of the pair of stator vane rows is the same.