Abstract: A gas turbine including a rotor shaft, a plurality of rotor blades that extend generally radially outwardly from the rotor shaft, each rotor blade including a shroud radially outward of an aerofoil, and a plurality of guide vanes located adjacent to the plurality of rotor blades, the plurality of guide vanes also extending generally radially outwardly is provided. The guide vanes operate to direct gas flowing through the turbine onto the rotor blades. A guide vane accommodates a flow of cooling fluid to an aperture in the guide vane that is located in a region that is adjacent both the radially outer end of the guide vane and the trailing edge of the guide vane. The flow of cooling fluid emanating from the aperture travels to impinge upon the shroud thereby cooling the shroud. The aperture is located in the high or low pressure side of the guide vane.

Abstract: A diffuser for diffusing the exhaust gas produced by an engine is provided. The diffuser includes a wall or walls defining sections of the diffuser, the diffuser including a first section and a second section following the first section, wherein the rate of increase of the cross-sectional area of the diffuser, which includes using an outer annular wall as an outer boundary and the inner annular wall as an inner boundary, in a direction of fluid flow is greater in the first section than it is in the second section. An upstream end of the inner annular wall or an upstream end of the outer annular is bent.

Abstract: A diffuser for diffusing the exhaust gas produced by an engine, said diffuser comprising a wall or walls defining sections of the diffuser, said diffuser comprising: an initial section which extends for substantially one third the length of the diffuser, at the entry to said initial section the shape factor of the boundary layer flow at the or each wall of the section being in the range 1.3 to 1.6, said initial section being configured so as to substantially linearly increase said shape factor so that at the exit of said initial section said shape factor is in the range 1.6 to 2.2; and a main section following the initial section and extending for the remaining length of the diffuser, said main section being configured so as to maintain said shape factor in the range 1.6 to 2.2 over the length of the main section.

Abstract: A gas turbine including a rotor shaft, a plurality of rotor blades that extend generally radially outwardly from the rotor shaft, each rotor blade including a shroud radially outward of an aerofoil, and a plurality of guide vanes located adjacent to the plurality of rotor blades, the plurality of guide vanes also extending generally radially outwardly is provided. The guide vanes operate to direct gas flowing through the turbine onto the rotor blades. A guide vane accommodates a flow of cooling fluid to an aperture in the guide vane that is located in a region that is adjacent both the radially outer end of the guide vane and the trailing edge of the guide vane. The flow of cooling fluid emanating from the aperture travels to impinge upon the shroud thereby cooling the shroud. The aperture is located in the high or low pressure side of the guide vane.

Abstract: A diffuser for diffusing the exhaust gas produced by an engine, said diffuser comprising a wall or walls defining sections of the diffuser, said diffuser comprising: an initial section which extends for substantially one third the length of the diffuser, at the entry to said initial section the shape factor of the boundary layer flow at the or each wall of the section being in the range 1.3 to 1.6, said initial section being configured so as to substantially linearly increase said shape factor so that at the exit of said initial section said shape factor is in the range 1.6 to 2.2; and a main section following the initial section and extending for the remaining length of the diffuser, said main section being configured so as to maintain said shape factor in the range 1.6 to 2.2 over the length of the main section.