Abstract: A combustor for a gas turbine has a combustor liner including an upstream liner portion, and a downstream liner portion. The upstream liner portion includes an outer shell and a heat shield panel, with a baffle cavity therebetween. The outer shell includes an outer shell cooling opening for providing a flow of compressed air to the baffle cavity, and the heat shield panel includes a heat shield panel cooling opening at a downstream end of the heat shield panel. A fence is arranged at a downstream side of the heat shield panel cooling opening and extends beyond a hot side surface of the heat shield panel into a combustion chamber. The heat shield panel cooling opening provides a flow of the compressed air therethrough from the baffle cavity for cooling of the heat shield panel and for providing at least partial dilution of combustion gases within the combustion chamber.

Abstract: This disclosure is directed to seal assemblies for a turbomachine. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. In some examples, seal assembly includes an oleophilic coating disposed between the stationary and rotating components. The seal assembly may include a surface texture to enhance the oleophilicity of the surface coating disposed between the stationary and rotating components. In other examples, the seal assembly includes an oleophobic coating disposed between the stationary and rotating components. The seal assembly may include a surface texture to enhance the oleophobicity of the surface coating. During operation, the oleophilic seal assembly features retain lubricant between the stationary and rotating components and the oleophobic seal assembly features inhibit the escape of lubricant from the contact regions between the stationary and rotating components.

Abstract: A gas turbine engine includes a compressor rotor shaft assembly, an accessory gearbox, and a bowed-rotor mitigation drive device drivingly coupled with the accessory gearbox. The bowed-rotor mitigation drive device is driven during an engine startup phase so as to induce a mechanical load (mechanical energy) to the bowed-rotor mitigation drive device. The mechanical load (mechanical energy) is retained within the bowed-rotor mitigation drive device during operation of the gas turbine engine. The mechanical load (mechanical energy) retained within the bowed-rotor mitigation drive device is periodically released by the bowed-rotor mitigation drive device in a plurality of periods so as to provide, in each period, a driving force to the accessory gearbox, which provides the driving force to the compressor rotor shaft assembly to periodically rotate the compressor rotor shaft assembly.

Abstract: A combustor including a skeleton structure. The combustor further includes at least one liner operably coupled to the skeleton structure to at least partially define a combustion chamber, and a plurality of first planks mounted to a first side of the at least one liner and a plurality of second planks mounted to a second side of the at least one liner. The combustor also includes at least one dilution hole structure provided with a portion of the skeleton structure, and including at least one dilution hole configured to allow fluid to pass therethrough into the combustion chamber.

Abstract: A combustor includes a skeleton mesh structure having a plurality of structural elements configured to mesh together to form the skeleton mesh structure, each of the plurality of structural elements including a frame and, a plurality of louvers connected to the frame. The combustor also includes an inner liner mounted to the skeleton mesh structure to define a combustion chamber. The inner liner includes a plurality of inner planks mounted to the skeleton mesh structure, each of the plurality of inner planks being mounted to a corresponding one of the plurality of structural elements.

Abstract: A hollow plank of a combustor liner defining a combustion chamber including an inner wall having a plurality of inner openings and one or more inner holes, an outer wall having one or more outer openings and a plurality of outer holes, a plurality of lateral walls coupled to the inner wall and the outer wall to define a cavity, and a partition wall connected to the plurality of lateral walls and dividing the cavity into a first sub-cavity and a second sub-cavity. The one or more outer openings communicate with the first sub-cavity and communicate through a plurality of tubes with the second sub-cavity. The plurality of inner openings communicate with the second sub-cavity and communicate with the first sub-cavity through one or more bypass tubes. The first sub-cavity or the second sub-cavity, or both, are frequency tuned to reduce combustion dynamic frequencies.

Abstract: A combustor includes a skeleton mesh structure having a plurality of structural elements configured to mesh together to form the skeleton mesh structure. The combustor also includes an inner liner and an outer liner mounted to the skeleton mesh structure to define a combustion chamber. The inner liner includes a plurality of inner planks mounted to an inner side of the inner liner and a plurality of outer planks mounted to an outer side of the inner liner. The outer liner includes a plurality of inner planks mounted to an inner side of the outer liner and a plurality of outer planks mounted to the outer side of the outer liner.

Abstract: A combustor includes an inner liner and an outer liner defining a combustion chamber. The inner liner includes an inner mesh structure, a plurality of hot side planks mounted to a hot side of the inner mesh structure, and a plurality of cold side planks mounted to a cold side of the inner mesh structure. The outer liner includes an outer mesh structure, a plurality of hot side planks mounted to a hot side of the outer mesh structure, and a plurality of cold side planks mounted to a cold side of the outer mesh structure. The combustor further includes a plurality of clips configured to couple the plurality of hot side planks and the plurality of cold side planks to a plurality of structural elements of the inner mesh structure and the outer mesh structure.

Abstract: A combustor includes an inner liner and an outer liner defining a combustion chamber. The inner liner includes an inner mesh structure, and a plurality of inner planks mounted to the inner mesh structure. The outer liner includes an outer mesh structure, and a plurality of outer planks mounted to the outer mesh structure. Each of the plurality of inner planks and outer planks includes an inner wall, an outer wall, and lateral walls defining a cavity to allow circulation of airflow within the cavity to cool down the inner wall.

Abstract: A combustor liner for a gas turbine has a cold side liner segment, and a hot side liner segment, with a baffle cavity between the cold side liner segment and the hot side liner segment. At least one cooling airflow dispersing member is arranged within the baffle cavity. The at least one cooling airflow dispersing member includes a main cavity portion, and at least one peripheral cavity portion surrounding the main cavity portion. The main cavity portion includes a main cavity inlet side having a cooling airflow opening, a main cavity outlet side having plurality of hot side cooling airflow openings, and at least one peripheral cavity outlet flow passage providing fluid communication between the main cavity portion and the at least one peripheral cavity portion. The at least one peripheral cavity portion includes a peripheral cavity outlet side having a plurality of hot side cooling airflow openings.

Abstract: Oil lubricated supercritical fluid pumps with oil separators are disclosed herein. An example pump system to pressurize a fluid within a closed loop thermal transport bus disclosed herein includes a pump housing, a duct fluidly coupled to the pump housing, a first portion of the duct to include a mixture of an oil and the supercritical fluid, a second portion of the duct to include the supercritical fluid, and a separator positioned in a third portion of the duct between the first portion of the duct and the second portion of the duct, the separator to separate the oil in the mixture from the supercritical fluid.

Abstract: A pump system to pressurize a fluid within a closed loop transport bus is disclosed herein. The example of the pump system disclosed herein includes a pump, including an impeller, to increase kinetic energy of a fluid flowing through the impeller; an electric motor, including a rotor shaft connected to the impeller, to provide torque to the rotor shaft; a first bearing to support the rotor shaft at a first operational speed range, the first bearing coupled to an inner race; a second bearing to support the rotor shaft at a second operational speed range, the rotor shaft coupled to an outer race; and one or more sprag elements configured to: engage the inner race with the outer race at the first operational speed range; and disengage the inner race from the outer race at the second operational speed range.

Abstract: A pump system for pressurizing a fluid within a closed loop supercritical transport bus is disclosed herein. The examples of the pump system disclosed herein include an impeller coupled to an impeller shaft; an axial flux electric motor including rotors and a stator; a rotor shaft connected to the rotors, wherein the rotor shaft is coupled to the impeller shaft; a seal to prevent the fluid from contacting the axial flux electric motor; a first housing to frame the impeller shaft; and a second housing to frame the axial flux electric motor, wherein the second housing is separate from the first housing.

Abstract: Aero-acoustically damped bleed valves are disclosed. An example variable bleed valve apparatus comprises a variable bleed valve door to actuate the variable bleed valve apparatus, and a variable bleed valve port including an upstream edge and a downstream edge, the VBV port to define a secondary flowpath, the VBV door to cover the VBV port in a closed position, and a vortex device at the upstream edge of the variable bleed valve port, the vortex device including a vorticity generating feature along the upstream edge of the variable bleed valve port.

Abstract: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes an annular substrate extending along an axial direction, the annular substrate defining a cavity at a radially inward surface of the annular substrate, and a smart structure coupled to the annular substrate, the smart structure including a support structure; an actuator structure to at least one of expand or contract in response to a change in temperature of the actuator structure, and a variable surface coupled to the support structure, the support structure to move the variable surface in a radial direction.

Abstract: A mounting assembly for a gearbox assembly of a gas turbine engine includes at least one mounting member configured to mount a gear of the gearbox assembly to a component of the gas turbine engine, the at least one mounting member characterized by a lateral impedance parameter, a bending impedance parameter, and a torsional impedance parameter. A gas turbine engine includes the mounting assembly. The at least one mounting member may be a flex mount, a fan frame, or a flex coupling.

Abstract: Clearance control systems with electromagnetic actuators are disclosed. An example electromagnetically-actuated clearance control system for a gas turbine engine comprises an electromagnetic coil coupled to a first end of a facesheet, the electromagnetic coil to generate a magnetic field in response to a connection of a power supply, a ferromagnetic sheet coupled to a second end of the facesheet, the ferromagnetic sheet drawn radially-inward toward the electromagnetic coil when the magnetic field is generated, a first end of the ferromagnetic sheet coupled to a first compression spring and a second end of the ferromagnetic sheet coupled to a second compression spring, the first and second compression springs to compress in response to the ferromagnetic sheet being drawn radially-inward.

Abstract: A combustor liner for a gas turbine includes a liner at least partially defining a combustion chamber. The liner includes a plurality of dilution openings therethrough, at least one dilution opening of the plurality of dilution openings defined by (a) a main dilution opening portion defining a main dilution opening perimeter, and (b) a plurality of secondary dilution opening portions arranged about the main dilution opening perimeter and extending outward from the main dilution opening portion.

Abstract: A combustor liner has an outer liner and an inner liner that define a combustion chamber therebetween, the combustion chamber having a dilution zone. The outer liner and the inner liner each have a converging-diverging section extending into the dilution zone of the combustion chamber and form a throat between them. A bridge member extends across the converging-diverging sections to form a damper cavity therebetween. Each of the converging-diverging sections includes at least one dilution opening defined through the respective converging-diverging section at the throat, and includes a damper inlet feed member on a downstream portion of the converging-diverging section, so that an acoustic damper is defined by the converting-diverging section, the bridge, and the damper inlet feed. The acoustic damper dampens acoustic characteristics of the combustor.

Abstract: A gas turbine engine includes a casing, a rotor assembly rotatably mounted within the casing, the rotor assembly comprising a forward rotor portion defining a forward rotor cavity and an aft rotor portion defining an aft rotor cavity, the aft rotor cavity being fluidly isolated from the forward rotor cavity, and a cooling system. The cooling system includes a forward cooling fluid supply, a forward supply line providing fluid communication between the forward cooling fluid supply and the forward rotor cavity, an aft cooling fluid supply, an aft supply line providing fluid communication between the aft cooling fluid supply and the aft rotor cavity, and a flow control system fluidly coupled to the forward supply line and the aft supply line for regulating a flow of forward cooling fluid and a flow of aft cooling fluid.