Disclosed is a lubricant supply system for a plurality of bearing dampers in a plurality of engine bearing compartments of a gas turbine engine, including a lubricant supply conduit, a first lubricant delivery conduit fluidly coupled to the supply conduit, the first delivery conduit including one or more lubricant delivery flow paths and delivering lubrication to engine components, a second lubricant delivery conduit fluidly coupled to the supply conduit, the second delivery conduit delivering lubricant to one or more of the plurality of bearing dampers, and an active oil flow management valve, selectively restricting lubricant flow in the first delivery conduit, increasing pressure in the second delivery conduit, based on an engine shaft rotational speed.

A wave guide assembly for a control and diagnostic system for a machine, the wave guide assembly includes a housing defining an exterior surface and an internal cavity extending between distal ends. A wave guide is defined within the internal cavity. At least one open conduit is defined within the internal cavity providing a space for routing conductors through the housing. A fluid passage is defined within the internal cavity separate from the wave guide. A control and diagnostic system for a machine and a gas turbine engine are also disclosed.

According to an aspect, a gas turbine engine includes a turbine section with a turbine case and a plurality of turbine blades within the turbine case. The gas turbine engine also includes an active clearance control system with an active clearance control cooling air supply, a valve pneumatically coupled to the active clearance control cooling air supply, and a controller. The controller is configured to determine an active cooling control schedule adjustment based on a condition of the gas turbine engine, operate the active clearance control system according to an active cooling control schedule as modified by the active cooling control schedule adjustment, apply a decay function to the active cooling control schedule adjustment to reduce an effect on the active cooling control schedule adjustment, and resume operating the active clearance control system according to the active cooling control schedule based on an active cooling control condition being met.

A system includes a gas turbine system including a compressor, a combustor, a turbine, and an exhaust section. The system also includes multiple sensors coupled to components of the gas turbine system. The system further includes a controller communicatively coupled to the gas turbine system and the multiple sensors and configured to control operations of the gas turbine system, wherein the controller is configured to calculate a surrogate value for turbine exit Mach number based on the feedback from the multiple sensors and to utilize the surrogate value to derive a control action for the gas turbine system.

A wave guide assembly for a control and diagnostic system for a machine, the wave guide assembly includes a housing defining an exterior surface and an internal cavity extending between distal ends. A wave guide is defined within the internal cavity. At least one open conduit is defined within the internal cavity providing a space for routing conductors through the housing. A fluid passage is defined within the internal cavity separate from the wave guide. A control and diagnostic system for a machine and a gas turbine engine are also disclosed.

A gas turbine engine has a fan rotor delivering air into a bypass duct defined between an outer fan case and an outer interior housing. The fan rotor also delivers air into a compressor section, a combustor, a turbine section. A chamber is defined between the outer interior housing and an inner housing. The inner housing contains the compressor section, the combustor and the turbine section. A first conduit taps hot compressed air to be cooled and passes the air to at least one heat exchanger. The air is cooled in the heat exchanger and returned to a return conduit. The return conduit passes the cooled air to at least one of the turbine section and the compressor section. The heat exchanger has a core exhaust plane. The turbine section has at least a first and a downstream second rotor blade row, with the core exhaust plane located downstream of a center plane of the second blade row.

A method of starting a turbomachine, performed by an electronic unit, the turbomachine including a gas turbine engine including at least one rotor and a starter to drive the rotor in rotation, the method including: receiving an order to start the turbomachine, and executing in response to receiving the order to start: a primary acceleration during which the starter is operated to increase speed of rotation of the rotor; a thermal homogenization during which the starter is operated to keep the speed of rotation of the rotor constant or to decrease it until a predetermined condition is satisfied; after the predetermined condition is true, a secondary acceleration in which the starter is operated to increase the speed of rotation of the rotor; and an ignition in which ignition of the engine is ordered.

Disclosed is a lubricant supply system for a plurality of bearing dampers in a plurality of engine bearing compartments of a gas turbine engine, including a lubricant supply conduit, a first lubricant delivery conduit fluidly coupled to the supply conduit, the first delivery conduit including one or more lubricant delivery flow paths and delivering lubrication to engine components, a second lubricant delivery conduit fluidly coupled to the supply conduit, the second delivery conduit delivering lubricant to one or more of the plurality of bearing dampers, and an active oil flow management valve, selectively restricting lubricant flow in the first delivery conduit, increasing pressure in the second delivery conduit, based on an engine shaft rotational speed.

An active clearance control system of a gas turbine engine includes an actuation cylinder, a puller engaged with an air seal segment and damped with respect to the actuation cylinder, and a full-hoop thermal control ring that at least partially supports the air seal segment. The puller may move the air seal segment between an extended radially contracted BOAS position and a retracted radially expanded BOAS position.

A propulsion system includes at least two propulsors. The at least two propulsors each include a fan and a controller having one or more processors configured to implement controller logic. The controller logic includes a phase angle control scheme and a speed control scheme. In implementing the controller logic, the one or more processors are configured to: determine an actual pairwise phase difference between a pair of propulsors of the at least two propulsors; generate a reference phase angle for the pair of propulsors; compare the actual pairwise phase difference to the reference phase angle to generate a phase error; provide the phase error to a phase controller module to generate an output based on the phase error; and adjust a speed of at least one propulsor of the at least two propulsors based on the output to drive the phase error towards zero.