Abstract: A gas turbine engine of a fan bypass type includes an exhaust shroud having a perforated tubular wall extending between a forward end and an aft end. The exhaust shroud is adapted to be affixed to a gas turbine engine exhaust for discharging engine exhaust gases without substantial blockage thereto. The perforations formed in the shroud wall communicate the regions at both sides of the shroud wall to pass fluid flow across the perforated shroud wall so that the mixing of the engine exhaust gases with a surrounding fluid flow is enhanced. The mixing of the engine exhaust gases with the surrounding fluid flow is further enhanced by a trailing edge of the exhaust shroud. The trailing edge is deviated from a straight line in a circumferential direction of the tubular wall to effectively increase the peripheral length of the mixing boundary. Thus, the jet noise contribution volume of the engine exhaust gases is effectively reduced, thereby significantly reducing the aero-engine jet noise.

Abstract: A method of combustor cycle air flow adjustment for a gas turbine engine according to the present invention solves the problem of a higher flame temperature in the combustor, thereby affecting the emission levels when a heat-recuperated air flow cycle is used to increase the compressed air temperature. In low emission combustors this impact is severe because emission levels are significantly dependent on the primary combustion zone flame temperature. The method of the present invention includes a step of changing a geometry of an air flow passage and thereby changing distribution of a total air mass flow between an air mass flow for combustion and an air mass flow for cooling in order to ensure that flame temperature in a primary combustion zone of a combustor are maintained substantially the same whether the gas turbine engine is manufactured to operate as a simple air flow cycle engine or as a heat-recuperated air flow cycle engine.

Abstract: A multi-stage compressor rotor for a gas turbine engine comprises an axial-flow rotor followed by a centrifugal rotor. The axial-flow rotor and the centrifugal rotor are diffusion bonded together to form a unitary dual flow impeller having blades with continues axial-flow and centrifugal stage sections. By eliminating the gap between the axial flow and centrifugal stages, unsynchronized air deflection between the successive arrays of blades is prevented, thereby improving the aerodynamic performance of the compressor rotor.