High performance robust gas turbine exhaust with variable (adaptive) exhaust diffuser geometry

A gas turbine engine comprising:

• a rotatable shaft provided along an axis of the gas turbine engine;
• a compressor section responsive to a working fluid and being operable to compress the working fluid to produce a compressed working fluid;
• a combustion section in fluid communication with the compressor section that receives the compressed working fluid, said combustion section including a plurality of combustors that mix the compressed working fluid with a fuel and combust the compressed working fluid and fuel mixture to produce a hot working fluid;
• a turbine section in fluid communication with the combustion section, said turbine section including a plurality of rows of blades that rotate about the axis of the gas turbine engine in response to the hot working fluid to produce mechanical power through rotation of the shaft, each blade of the plurality of rows of blades including a tip positioned proximate to a static portion of the gas turbine engine and defining a tip clearance therebetween;
• and
• a diffuser fixed to the static portion of the gas turbine engine and receiving the hot working fluid from the turbine section, said diffuser including an outer liner defining an outer flow boundary of the hot working fluid and increasing in diameter from an upstream end of the outer liner along an axial length, the outer liner having an end portion pivotally coupled to the upstream end of the outer liner and positioned proximate to the tips of the blades in a last row of the plurality of rows of blades in the turbine section to define a gap therebetween, said end portion including
• a plurality of circumferentially disposed actuated sections that are operable to be actuated to move the end portion so as to control an angular orientation between the end portion and the blades in the last row, and
• a plurality of circumferentially disposed non-actuated sections,
• wherein each of the plurality of actuated sections includes a hinge and each of the plurality of non-actuated sections includes a hinge, each hinge of the plurality of actuated sections and the plurality of non-actuated sections being mounted to a circular rod circumferentially disposed at the upstream end of the outer liner,
• wherein the angular orientation of the plurality of actuated sections is selectively controlled based on operating conditions of the gas turbine engine such that when the operating condition causes the tip clearance to change the performance of the diffuser, the angular orientation of the upstream end portion restores the optimal performance of the diffuser, and
• wherein bleed air from the compressor section is provided to the diffuser through a valve and a bleed orifice, wherein pressure provided at the bleed orifice is controlled by a control system, and wherein the control system adjusts the plurality of actuated sections by the pressure to increase or decrease the angular orientation of the plurality of actuated sections.

A gas turbine engine, comprising:

• an outer casing;
• a row of rotating blades rotating about an axis of the gas turbine engine, each rotating blade including a tip and defining an axial flow direction through the rotating blades;
• an exhaust diffuser outer liner fixedly coupled to the outer casing and defining an inlet edge, an outlet edge downstream of the inlet edge in the flow direction, and an outer boundary for an exhaust gas flow therebetween, wherein a diameter of the exhaust diffuser outer liner increases from an inlet edge diameter at the inlet edge along an axial length in the flow direction;
• a plurality of circumferentially disposed actuated sections each comprising a downstream end pivotally coupled to the inlet edge of the exhaust diffuser outer liner and including a movable upstream end positioned proximate to the tips of the rotating blades to define an exhaust diffuser inlet diameter;
• and an actuator coupled to the outer casing and the actuated sections, the actuator operable to pivot the actuated sections to vary the exhaust diffuser inlet diameter based on ambient temperature.