Abstract: A turbomachine for a gas turbine engine, comprising: a rotor disc arranged to rotate about a fixed central axis. A plurality of rotor blades connected to the rotor disc, wherein the rotor blades extend within a gas flow path. A rotating annulus is arranged to rotate in a fixed rotational alignment relative to the rotor disc. An outer surface of the rotating annulus is arranged to define part of the boundary of the gas flow path. A gas turbine engine for an aircraft and a method of defining the boundary of a gas flow path within a turbomachine is also disclosed.

Abstract: A turbomachine for a gas turbine engine, comprising: a rotor disc arranged to rotate about a fixed central axis. A plurality of rotor blades connected to the rotor disc, wherein the rotor blades extend within a gas flow path. A rotating annulus is arranged to rotate in a fixed rotational alignment relative to the rotor disc. An outer surface of the rotating annulus is arranged to define part of the boundary of the gas flow path. A gas turbine engine for an aircraft and a method of defining the boundary of a gas flow path within a turbomachine is also disclosed.

Abstract: An assembly for receiving in a radially extending bucket groove (31) of a turbine disc (22), the assembly including a turbine blade having an elongate body (26) of aerofoil cross-section, a root portion (24) at one end of the elongate body (26) and a tip at the other. The root portion (24) configured to be retained in the bucket groove (31). A heat shield (27) configured to be received between an end of the root portion (24) and a radially inner surface of the bucket groove (31) and to interlock with the root portion (24) in a manner which deters separation in a radial direction.

Abstract: A waveguide for a sensor system for mounting in a casing structure to measure the clearance between the casing structure and a rotary blade. The casing structure, which may be a turbine casing structure, includes a radially outer casing portion and a radially inner casing portion (e.g. a segment seal). The waveguide includes a radially outer portion for mounting in the radially outer casing portion and a radially inner portion for mounting in the radially inner casing portion. The two portions are sealed together and bridged by a sealing portion having a deformable portion.

Abstract: An assembly for receiving in a radially extending bucket groove (31) of a turbine disc (22), the assembly including a turbine blade having an elongate body (26) of aerofoil cross-section, a root portion (24) at one end of the elongate body (26) and a tip at the other. The root portion (24) configured to be retained in the bucket groove (31). A heat shield (27) configured to be received between an end of the root portion (24) and a radially inner surface of the bucket groove (31) and to interlock with the root portion (24) in a manner which deters separation in a radial direction.

Abstract: A waveguide for a sensor system for mounting in a casing structure to measure the clearance between the casing structure and a rotary blade. The casing structure, which may be a turbine casing structure, includes a radially outer casing portion and a radially inner casing portion (e.g. a segment seal). The waveguide includes a radially outer portion for mounting in the radially outer casing portion and a radially inner portion for mounting in the radially inner casing portion. The two portions are sealed together and bridged by a sealing portion having a deformable portion.