Abstract:
A compound cycle engine (10) comprises a compressor and a turbine section (14, 18), and at least one cycle topping device (16) providing an energy input to the turbine section (18). The compressor section (14) compresses the air according to a pressure ratio PRgt. The cycle topping device (16) further compresses the air according to a volumetric compression ratio Rvc, and wherein PRgt×Rvc are selected, according to one aspect of the invention, to provide a cycle which permit a more compact and lighter compound cycle engine to be provided.
Abstract:
The invention provides in a gas turbine engine combustion chamber, an array of elongate louver strips between fuel nozzles of a combustion chamber dome wall, to cool the dome wall and contain combustion gases in the area between nozzles. The elongate louver strips are each disposed symmetrically along the median line on the inner surface dome wall and extend between each nozzle cup of the annular array. Each strip includes an elongate flange extending into the combustion chamber from the inner dome wall. The flange has an inner surface, and lateral side walls, with the inner surface generally parallel to the inner surface of the dome wall. Compressed air outlets are disposed along each flange lateral side wall, for directing a compressed air film along the inner surface of the dome wall in a direction away from the median line. A compressed air inlet extends from the outer surface of the dome wall to the outlets.
Abstract:
A passively cooled blade platform for a gas turbine rotor adapted for rotation about an axis within a stationary coolant fluid. The platform has a radially outer surface defining an annular gas path, a radially inner surface in flow communication with the coolant fluid, a leading edge, and a trailing edge. The inner surface includes at least one cooling flow channel in the inner surface. Each channel has a flow path from a channel inlet to a channel outlet, preferably with a tangential component at the inlet opposite to the direction of rotation and an axial component at the outlet. The flow channels are defined by ribs or pedestals extending radially inwardly from the platform inner surface to direct cooling fluid flow and create turbulence to dissipate heat from the platform on exposure to cooling fluid flow.