A variable geometry turbine comprises a turbine wheel and a primary inlet passage of variable axial width. The turbine has a secondary inlet passage provides a flow path for a working fluid which circumnavigates at least part of the primary inlet passage. A seal element and one or more apertures are cooperable to selectively allow or prevent fluid flow through the secondary inlet passage. The ratio of the minimum cross-sectional area of the flow path through the primary inlet passage to that of the secondary inlet passage is between 1.3 and 1.7.

A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The nozzle ring and shroud are relatively rotatable about a rotational axis of the turbine by at least 0.1 degrees. In use, the nozzle ring and shroud are relatively rotated to bring one side of the vane into close contact with one surface of the slot, to inhibit leakage of gas between the vane and the slot surface. For this purpose the respective surfaces of the nozzle and slot can be configured to closely conform to each other. If there is differential thermal expansion of the shroud and nozzle ring, the nozzle ring and shroud can relatively rotate, to withdraw the vane from the edge of the slot to relieve the pressure between them.

A variable exhaust nozzle for use with a gas turbine engine includes an outer shroud and an inner plug that can move relative to the outer shroud. The relative movement of the inner plug and the outer shroud changes the shape of the variable exhaust nozzle from one that converges in area to one that converges and then diverges in area.

A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The nozzle ring and shroud are relatively rotatable about a rotational axis of the turbine by at least 0.1 degrees. In use, the nozzle ring and shroud are relatively rotated to bring one side of the vane into close contact with one surface of the slot, to inhibit leakage of gas between the vane and the slot surface. For this purpose the respective surfaces of the nozzle and slot can be configured to closely conform to each other. If there is differential thermal expansion of the shroud and nozzle ring, the nozzle ring and shroud can relatively rotate, to withdraw the vane from the edge of the slot to relieve the pressure between them.

A turbofan having a nacelle comprising a slider mobile in translation between an advanced and a retracted position to open a window between a duct and the exterior, a plurality of blades, each one mobile in rotation on the slider between a stowed and a deployed position, where the blades are split into groups, where each group comprises a first blade, and a maneuvering system moving each blade and comprising a cam integral with the first blade of one of the groups and having a tooth, a groove receiving the tooth, a first transmission system transmitting the movement of the first blade bearing the cam to a first blade of each other group, and, for each group, a second transmission system transmitting the movement of the blade that bears the cam or is moved by the first transmission system to each of the other blades of the group.

A blade wheel of a turbomachine, which blade wheel has a multiplicity of blades which are suitable and provided for extending radially in a flow path of the turbomachine, wherein the blades form a blade entry angle and a blade exit angle. Provision is made whereby the blade wheel forms N blocks of blades, where N≥2, wherein the blades of a block have in each case the same blade entry angle and the same blade exit angle, and the blades of at least two mutually adjacent blocks have a different blade entry angle and/or a different blade exit angle. According to a further aspect of the invention, partial gaps that the blades form in relation to an adjacent flow path boundary are varied in mutually adjacent blocks.

A variable geometry turbine is disclosed comprising: a housing; a turbine wheel supported in the housing for rotation about an axis; a movable wall member; a cavity provided in the housing; and an inlet passageway extending radially inwards towards the turbine wheel. The movable wall member comprises a generally annular wall and radially inner and outer flanges extending axially from the generally annular wall, inner surfaces of the generally annular wall and radially inner and outer flanges defining an interior surface of the movable wall member. The cavity is suitable for receipt of the radially inner and outer flanges of the moveable member, the movable wall member being axially movable relative to the housing to vary the extent to which the radially inner and outer flanges of the moveable member are received in the cavity.

A variable vane includes a first vane portion and a second vane portion adjacent the first vane portion. The second vane portion includes a trunnion projecting outward from a radial end of the second vane portion. The second vane portion is configured to rotate about a trunnion axis of the trunnion from a first rotational position to a second rotational position.

The invention relates to an air conditioning system for an aircraft comprising a turbine engine comprising at least one radial turbine and a compressor, said radial turbine extending along a central axis (10) and comprising a wheel (20) equipped with vanes (21) mounted so as to be able to rotate about said central axis (10), a nozzle (30) arranged at the periphery of said wheel (20) comprising a plurality of variable-pitch blades (31) arranged around said central axis (10), and a volute (12) comprising an air inlet (12a) and an air outlet (12b) opening onto said plurality of variable-pitch blades (31), characterized in that said variable-pitch blades (31) are arranged around said central axis (10) between two nozzle casing walls (11a, 11b) delimiting an air passage section of said nozzle between them, each variable-pitch blade (31) further comprising means for axial displacement of the blade between the two casing walls (11a, 11b).

A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The vanes are formed with a leading portion which is arranged to contact a leading portion of a corresponding slot, and a trailing portion which is shaped, when the leading portion of the vane and slot are together, to be spaced from a corresponding trailing portion of the slot with a substantially constant spacing at room temperature. The contact may be a point contact, e.g. close to the leading edge of the vane. Alternatively, the vane may include a leading surface portion which conforms closely with the shape of a corresponding leading surface portion of one of the slots.