A method for controlling a combustion process in a gas turbine wherein a combustion chamber, a control device storing a calculation model of the combustion process, and an exhaust air measurement device are used. A permissible limit value for nitrogen oxides and for carbon monoxide as pollutants is set. The actual value of at least one of the two pollutants is measured continuously in the exhaust air. When a signal to reduce the power of the gas turbine to a lowest possible value is given, then a minimum fuel supply at which the limit values are complied with is calculated. The fuel supply is then reduced either until the calculated minimum fuel supply is reached or until the continuously measured proportion of the pollutant reaches the permissible limit value.

An aircraft engine nacelle comprising an icing protection system and an icing protection method for such an aircraft engine nacelle. The aircraft engine nacelle comprises an air inlet comprising a lip, a tubular air inlet piece and an icing protection system. The icing protection system comprises an icing prevention means powered continuously by a first electrical energy source and wholly or partly covering the lip, a de-icing means powered by a second electrical energy source covering the tubular air inlet piece and a controller configured to acquire a current total air temperature value, and control the second electrical energy source as a function of the current total air temperature value.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.

There is provided a system and a method for controlling a tip clearance between a turbine casing and turbine blade tips of an aircraft engine. At least one operational parameter of the aircraft engine is obtained. Based on the at least one operational parameter, a current value of the tip clearance and a target value of the tip clearance are determined. A limiting factor to be applied to the target value of the tip clearance is computed. The limiting factor is applied to the target value of the tip clearance to obtain a tip clearance demand for the aircraft engine. A tip clearance control apparatus of the aircraft engine is controlled based on a difference between the current value of the tip clearance and the tip clearance demand.

A gas turbine engine includes a compressor, an annular casing surrounding the compressor, and a bleed flow adapter mounted to an exterior side of the annular casing. The annular casing includes the exterior side and an interior side. The interior side surrounds a compressor bleed cavity located downstream of at least a portion of the compressor. The bleed flow adapter is in fluid communication with the bleed cavity. The bleed flow adapter includes an inlet end, an outlet end, and an inner diameter surface extending between the inlet end and the outlet end. The inner diameter surface defines a bleed passage. The bleed flow adapter further includes a fluid port formed through the inner diameter surface. The gas turbine engine further includes a bleed flow measurement system including a first pressure sensor in fluid communication with the bleed passage of the bleed flow adapter via the fluid port.

A method of mitigating contrails produced by an aircraft having a set of gas turbine engines, comprises the steps of (i) for each engine in a first subset of the engines, reducing the operating efficiency of the engine to produce a reduction in thrust provided by that engine and (ii) for each engine in a second subset, increasing the fuel flow to the engine to increase the thrust provided by that engine, the set of at least two gas turbine engines consisting of the first and second subsets. The method provides for contrail mitigation action by means of engine operating efficiency reduction to be directed to a first subset of engines for which contrail mitigation per unit engine operating efficiency reduction is greatest, the resulting reduction in thrust provided by such engines being at least partially compensated by increasing fuel flow to engines of the second subset.

An acquisition unit is configured to acquire measurement values of a target device. The measurement values that are acquired include at least a temperature and a flow rate of an input fluid to be input to the target device, and a temperature and a flow rate of an output fluid to be output from the target device. A correction unit is configured to obtain a correction measurement value by which the measurement values are corrected through thermal equilibrium calculations based on the measurement values. A distance calculation unit is configured to calculate a Mahalanobis distance with a factor of the correction measurement value.

Methods and systems for starting an engine are provided. A cold-start request to start the engine in a first operating condition associated with a predetermined engine temperature range is obtained. In response to obtaining the cold-start request, an amount of boost fuel to provide to the engine is determined, based on at least one second operating condition of the engine. The engine is started by supplementing a baseline fuel flow to the engine with the amount of boost fuel.

An aircraft power plant comprising: a high-pressure spool including a high-pressure compressor, a high-pressure turbine, and a high-pressure shaft drivingly engaging the high-pressure turbine to the high-pressure compressor; a low-pressure spool including a low-pressure compressor, a low-pressure turbine, and a low-pressure shaft drivingly engaging the low-pressure turbine to the low-pressure compressor; an electrical machine operable as a generator; and a transmission having a first input drivingly engaged by the high-pressure shaft, a second input drivingly engaged by the low-pressure shaft, and an output drivingly engaging the electrical machine, the transmission having a coupling system selectively interconnecting the output with one of: the first input, with the second input disconnected from the output; the second input, with the first input disconnected from the output; and both of the first input and the second input.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.