Methods and apparatus for controlling liquid flow to a turbine fogging array. Some implementations are generally directed toward adjusting the output of a variable output pump that supplies water to the turbine fogging array. In some of those implementations, the output is adjusted based on a determined target pump output value that is indicative of a pump output required to change the moisture content of intake air of a combustion turbine to meet a target humidity value. Some implementations are generally directed toward actuating at least one control valve of a plurality of control valves that control liquid throughput to one or more fogging nozzles of a fogging array.

A method for cooling down a gas turbine, wherein the gas turbine is run down from the power operation thereof to cool-down operation, and wherein a liquid is sprayed into air sucked in by a compressor of the gas turbine during the cool-down operation, and wherein the liquid is sprayed into the sucked-in air in dependence on a humidity of the sucked-in air, a flow velocity of cooling air flowing in the gas turbine in the region of at least one flow-guiding component of the gas turbine, which component is to be cooled, and a temperature difference between a temperature of the sucked-in air and a temperature of the at least one flow-guiding component of the gas turbine.

An intake-air cooling device is disposed on a rear-stage side of a pre-filter disposed on an intake-air inlet side of an intake-air duct for guiding intake air taken in from an intake-air inlet to a compressor, for cooling the intake air by spraying water to the intake air. The intake-air cooling device includes a plurality of nozzles configured to spray the water to the intake air, a plurality of water conduit pipes including the plurality of nozzles arranged in an axial direction of the plurality of water conduit pipes, and a plurality of supply pumps configured to supply the water to a corresponding one of the plurality of water conduit pipes. Each of the plurality of water conduit pipes is an endless member which has a different perimeter.

The invention concerns an aircraft propulsion control system in which a gas turbine engine has an actuable flow opening for control of flow to or from a portion of the engine. One or more sensor is arranged to sense a condition indicative of vapor trail formation by the exhaust flow from the engine. A controller is arranged to control actuation of the flow opening so as to reduce the efficiency of the engine upon sensing of said condition by the one or more sensor. In one example, the flow opening is a variable area fan nozzle.

A system includes an engine configured to generate power to drive a load. The system also includes a power augmentation system configured to augment a power output of the engine when the power augmentation system is activated. Additionally, the system includes a controller operatively coupled to the power augmentation system. The controller is configured to estimate a potential change in the power output of the engine caused by activation of the power augmentation system using a power augmentation model and an engine performance model.

An aircraft including lean-burn gas turbine engines operating in pilot-plus-mains mode with a given initial fuel flow W.sub.0, a method of controlling the optical depth of contrails produced by a first group of engines includes the steps of (i) reducing fuel flow to each engine in the first group to change the operation of each engine from pilot-plus-mains mode to pilot-only mode, and (ii) adjusting fuel flow to one or more engines in a second group of engines such that the total fuel flow to engines of the second group is increased, all engines of the second group remaining in pilot-plus-mains mode, and wherein the set of lean-burn engines consists of the first and second groups. Depending on atmospheric conditions, the average optical depth of contrails produced by the engines may be enhanced or reduced compared to when all engines operate in pilot-plus-mains mode with a fuel flow W.sub.0.

An aircraft propulsion system includes a hydrocarbon fuel store, a hydrogen fuel store, an engine system capable of producing thrust by combusting hydrocarbon fuel and/or combusting or oxidising hydrogen fuel, a conveying system to convey hydrocarbon and hydrogen fuel from the fuel stores to the engine system and a control system to control the respective flow rates of the fuel within the conveying system. The control system adapts the fractions of the total fuel energy flow rate to the engine system represented by the hydrocarbon and hydrogen fuel energy flow rates in order to reduce climate warming impact caused by at least one of carbon dioxide, water vapour and condensation trails and/or increase climate cooling impact caused by condensation trails produced by the aircraft propulsion system compared to a dual-fuel propulsion system in which a reserve of hydrocarbon fuel is entirely combusted before any of a reserve of hydrogen fuel.

The present disclosure relates to the field of air conditioning technology. In particular, it involves an air control method for air handler unit.

In an example, a method for on-board maintenance of an aircraft is described. The method includes measuring, by a pressure sensor, a pressure in a tube associated with an engine of an aircraft. The method also includes determining, by a control system and based on the pressure measured by the pressure sensor, that the tube is at least partially blocked by moisture. Additionally, the method includes, responsive to determining that the tube is at least partially blocked by the moisture, providing an alert signal from the control system to a flight deck of the aircraft. The method also includes, responsive to the alert signal, operating an actuation switch at the flight deck to actuate a valve to an open state. The method further includes, responsive to actuating the valve to the open state, supplying an inert gas from an inert gas supply to the tube to expel the moisture.

A method is provided during which an aircraft powerplant is provided. The aircraft powerplant includes a combustor and a water recovery system. The water recovery system includes a condenser and a reservoir. Fuel is combusted within the combustor to provide combustion products. Water is extracted from the combustion products using the condenser. The water recovery system is operated in one of a plurality of modes based on likelihood of contrail formation. The modes include a first mode and a second mode, where the water is collected within the reservoir during the first mode, and where the water passes through the water recovery system during the second mode.