A wind turbine rotor blade is provided, having a root end, a tip end, a leading edge section, a trailing edge section and a serrated extension, wherein the serrated extension is attached to the trailing edge section and has at least a first tooth. Furthermore, the wind turbine rotor blade has at least one patterning element for guiding a wind flow which is flowing from the leading edge section to the trailing edge section such that noise which is generated at the trailing edge section is reduced. The patterning element has the shape of a ridge. Advantageously, the ridge-shaped patterning element is located upstream, compared to the first tooth, and/or is located on a surface of the first tooth. Furthermore, a method is provided to reduce noise which is generated at a trailing edge section of a wind turbine rotor blade.

A method for detuning a rotor-blade cascade of a turbomachine having a plurality of rotor blades includes: a) establishing at least one target natural frequency for at least one vibration mode; b) setting up a value table having discrete mass values and radial center-of-gravity positions, and determining respective natural frequency; c) measuring the mass and radial center-of-gravity position of one of the rotor blades; d) determining an actual natural frequency by interpolating the measured mass and radial center-of-gravity position in the value table; e) if actual natural frequency is outside a tolerance around target natural frequency, selecting a value pair that at least approximates target natural frequency, and removing material from the rotor blade in such a way that mass and radial center-of-gravity position correspond to the value pair; f) repeating steps c) to e) until actual natural frequency is within the tolerance around target natural frequency.

An array of flow-directing elements for a compressor of a gas turbine including at least one first flow-directing element and at least one second flow-directing element different from the first flow-directing element; the flow-directing elements each having a leading edge facing the gas turbine inlet, a trailing edge, a pressure side connecting them and located ahead in the direction of rotation, a suction side located opposite thereof, as well as successive chords along a stacking axis; the flow-directing elements each extending between an airfoil root proximate to the rotor and an airfoil tip remote from the rotor. The trailing edge of the first flow-directing element is, at least in a portion thereof, axially offset from the trailing edge of the second flow-directing element in a direction toward the leading edge at least in a half proximate to the airfoil tip.

Rotary machines including a hybrid rotor with an integrally bladed rotor portion are provided. The integrally bladed rotor portion for the hybrid rotor comprises a rotor disk portion and a blade portion. The rotor disk portion has a peripheral rim configured to mechanically retain an individual rotor blade. The blade portion comprises an integral rotor blade extending outwardly and integrally from the rotor disk portion. The individual rotor blade is configured to extend outwardly from the rotor disk portion in a blade array with the integral rotor blade. The hybrid rotor is also provided and comprises the integrally bladed rotor portion and a plurality of individual rotor blades extending outwardly from the rotor disk portion in a blade array with a plurality of integral rotor blades.

An arrangement for intentionally mistuning a cavity formed adjacent an impeller in a turbomachine, the arrangement including at least two bladed elements defined within a perimeter of a casing wall adjacent the impeller, wherein the bladed elements are configured to mistune cavity acoustic modes to minimize acoustic pulsations in the cavity.

A profiled structure for an aircraft or turbomachine is elongated in a direction in which the structure has a length exposed to an airflow and includes serrations defined by successive teeth and depressions. The serrations may be transverse to a leading edge and/or a trailing edge of the profiled structure and in the direction of elongation. Along the profiled leading edge and/or profiled trailing edge, the successive teeth and depressions may extend only over a part of the length exposed to the flow. The amplitude and/or spacing of the teeth may vary monotonically except for the few teeth nearest each end of the part, with a remaining part of the length being smooth.

A guide vane segment for a turbomachine stage that has an inner ring segment (10) and a plurality of guide vanes (21-25) that are configured on the inner ring segment; at and/or in at least one detuning region (A; B) of the inner ring segment, that extends circumferentially in a portion of the inner ring segment that, from one end face (11; 12) of the inner ring segment to an inner guide vane (22; 24) that is circumferentially adjacent to an outermost guide vane (21; 25) adjacent to the end face and/or extends at most over an outermost third of a length (L) of the inner ring segment bounded by an end face (11; 12) of the inner ring segment, at least one cavity (112) is configured which contains at least one impulse element (100) with clearance of motion for providing impact contacts.

An airfoil includes a base, a tip, a suction side face, and a pressure side face. The pressure side face includes an outer surface, an inner surface located between the outer surface and the suction side face, and a transition surface that extends between and interconnects the outer surface and the inner surface so as to form a pocket in the airfoil.

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 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.