The present application provides a variable frequency Helmholtz damper system for use with a combustor of a gas turbine engine. The variable frequency Helmholtz damper system may include one or more Helmholtz dampers and a purge medium temperature control unit for providing a flow of purge medium to the Helmholtz dampers. The purge medium temperature control unit may be in communication with a temperature control fluid flow such that the purge medium temperature control unit may vary the temperature of the flow of purge medium.

Systems and methods for controlling tip clearance in a gas turbine engine are provided. The system may include a distribution manifold positioned along an outer surface of an engine case of a gas turbine engine. The distribution manifold may include a plurality of outlets defined on the distribution manifold to direct a thermal fluid received by the distribution manifold onto an outer surface of the engine case of the gas turbine engine. The system may further include a variable blower configured to blow the thermal fluid into the distribution manifold at a flow rate controlled by the variable blower. The flow rate through the variable blower may be adjustable over a range of non-zero target flow rates.

A turbine injection system for a gas turbine engine includes a first end operable to receive air from a heat exchanger, a second end operable to distribute mixed cooling air to a turbine stage, an opening downstream of said first end and a mixing plenum downstream of said first end and said opening. The opening provides a direct fluid pathway into said turbine injection system.

A system and method for active draft control through a combined cycle power plant (CCPP) can initiate a CCPP shutdown, activate the recirculated exhaust gas (REG) system for the turbomachine; measure a HRSG airflow through the HRSG; communicate the HRSG airflow to a controller configured to condition a control signal; and adjust a recirculated exhaust gas volume in accordance with the control signal.

A control system for a gas turbine engine comprises a case structure, a clearance control ring mounted for movement relative to the case structure, an outer air seal mounted to the clearance control ring and facing a first engine component, and a control and valve assembly that receives flow from a flow input source. The control and valve assembly is configured to direct flow into a first cavity positioned radially between the case structure and the outer air seal, and wherein the control and valve assembly is configured to direct flow into a second cavity positioned downstream of the first cavity to interact with a second engine component. A method of controlling flow between a compressor section and turbine section is also disclosed.

A clearance control system for a gas turbine engine comprises at least one case support associated with an engine case defining an engine center axis. A clearance control ring is positioned adjacent the at least one case support to form an internal cavity between the engine case and the clearance control ring. The clearance control ring includes a first mount feature. An outer air seal has a second mount feature cooperating with the first mount feature such that the clearance control ring can move independently of the engine case in response to changes in temperature. An injection source inject flow into the internal cavity to control a temperature of the clearance control ring to allow the outer air seal to move in a desired direction to maintain a desired clearance between the outer air seal and an engine component. A gas turbine engine and a method of controlling tip clearance in a gas turbine engine are also disclosed.

A method for controlling a turbomachine including a temporary power-increasing device, the control method including a step wherein the flow rate of the coolant injected is adjusted as a function of the atmospheric pressure and/or of the ambient temperature and/or of at least one parameter such as the speed of rotation of a gas generator, the speed of rotation of a low-pressure turbine or of a power turbine, the gas pressure at the outlet of a compressor stage, the temperature at the inlet of the low-pressure turbine or of the power turbine, the engine torque, and/or the collective pitch of a helicopter rotor or the pitch of a propeller of a turboprop.

A power generation system includes one or more processors and memory storing instructions that cause the one or more processor to execute a series of steps. That is, the one or more processors receive data indicative of a plurality of inputs associated with the power generation system, such that the plurality of inputs include a flow rate of a valve coupled between an inlet of a compressor in the power generation system and an exhaust of the compressor, where the valve fluidly couples a first fluid exiting the exhaust of the compressor to the inlet of the compressor. Furthermore, the one or more processors determine one or more output parameters of the power generation system based on the plurality of inputs, determine whether the one or more output parameters are within one or more respective threshold values, determine one or more fuel schedule adjustments for the power generation system when the one or more output parameters are outside the one or more respective threshold values; and modify a fuel schedule for providing fuel to a combustor of the power generation system based on the one or more fuel schedule adjustments.

A gas turbine engine has a fan nacelle and a core nacelle arranged to provide a bypass flow path. A compressor section is provided within the core nacelle. A heat exchanger is arranged within a duct. The heat exchanger is configured to receive bypass flow from the bypass flow path. The duct is in fluid communication with the compressor section and is configured to pass bleed air through the heat exchanger.

An assembly including a first turbocharger, the first turbocharger including a first turbine and a first compressor, the first turbine arranged in a turbine flowpath to be driven in rotation by an exhaust gas flowing at a variable flow rate through the turbine flowpath. The first compressor arranged in a compressor flowpath to be driven by the first turbine to urge an intake gas to flow through the compressor flowpath. The first turbine and first compressor being supported for rotation in bearings supplied via an oil flowpath at an oil pressure. The assembly further including a seal arranged between the oil flowpath and the compressor flowpath to resist leakage of the oil into the compressor flowpath and a flow control means configured to control a rotational speed of the first turbine and first compressor by controlling the flow of exhaust gas in the turbine flowpath.